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TABLE OF CONTENTS
Allos Therapeutics, Inc. Index to Financial Statements

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

Commission File Number 00029815

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Allos Therapeutics, Inc.
(Exact name of Registrant as specified in its charter)

11080 CirclePoint Road, Suite 200
Westminster, Colorado 80020
(303) 426-6262
(Address, including zip code, and telephone number, including area code, of principal executive offices)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

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          Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o    No ý

          Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o    No ý

          Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý    No o

          Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405) of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes o    No o

          Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ý

          Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

          Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o    No ý

          The aggregate market value of common stock held by nonaffiliates of the registrant (based upon the closing sale price of such shares on the NASDAQ Global Market on June 30, 2010) was $482,335,587. Shares of the registrant's common stock held by each current executive officer and director and by each stockholder who is known by the registrant to own 10% or more of the outstanding common stock have been excluded from this computation in that such persons may be deemed to be affiliates of the registrant. Share ownership information of certain persons known by the registrant to own greater than 10% of the outstanding common stock for purposes of the preceding calculation is based solely on information on Schedules 13D and 13G, if any, filed with the Commission. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

          As of February 25, 2011, there were 105,580,200 shares of the registrant's common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

          Portions of the registrant's definitive Proxy Statement for the 2011 Annual Meeting of Stockholders to be filed within 120 days after the end of the Registrant's fiscal year ended December 31, 2010 are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated therein.

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PART I

        Allos Therapeutics, Inc., the Allos Therapeutics, Inc. logo, FOLOTYN, the FOLOTYN logo and all other Allos names are trademarks of Allos Therapeutics, Inc. in the United States and in other selected countries. All other brand names or trademarks appearing in this report are the property of their respective holders. Unless the context requires otherwise, references in this report to "Allos," the "Company," "we," "us," and "our" refer to Allos Therapeutics, Inc.

        This report contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements include, but are not limited to, statements regarding our commercialization of FOLOTYN for patients with relapsed or refractory peripheral T-cell lymphoma; statements regarding our Marketing Authorisation Application, or MAA, for FOLOTYN in Europe; our projected operating costs and expenses for fiscal year 2011; other statements regarding our future product development and regulatory strategies, including our intent to develop or seek regulatory approval for FOLOTYN for additional indications; the ability of our third-party manufacturers to support our requirements for drug supply; any statements regarding our future financial performance, results of operations or sufficiency of capital resources to fund our operating requirements; and any other statements that are other than statements of historical fact. In some cases, these statements may be identified by terminology such as "may," "will," "should," "expects," "plans," "anticipates," "believes," "estimates," "predicts," "potential" or "continue," or the negative of such terms and other comparable terminology. Although we believe that the expectations reflected in the forward-looking statements contained herein are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. These statements involve known and unknown risks and uncertainties that may cause our, or our industry's results, levels of activity, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. Factors that may cause or contribute to such differences include, among other things, those discussed under the captions "Business," "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations." Forward-looking statements not specifically described above also may be found in these and other sections of this report. All forward-looking statements included in this report are based on information available to us as of the date hereof and we undertake no obligation to revise any forward-looking statements in order to reflect any subsequent events or circumstances. You are advised, however, to consult any further disclosures we make on related subjects in our Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and our website.

ITEM 1.    BUSINESS

        We incorporated in the Commonwealth of Virginia on September 1, 1992 as HemoTech Sciences, Inc. and filed amended Articles of Incorporation to change our name to Allos Therapeutics, Inc. on October 19, 1994. We reincorporated in Delaware on October 28, 1996. We completed our initial public offering in 2000 and our shares are listed on the NASDAQ Global Market, where our symbol is ALTH. Our corporate headquarters are located in Westminster, Colorado, a suburb of Denver. Our mailing address is 11080 CirclePoint Road, Suite 200, Westminster, Colorado 80020. Our website address is www.allos.com; however, information found on our website is not incorporated by reference into this report. We operate as a single business segment.

Corporate Overview and Business Strategy

        We are a biopharmaceutical company committed to the development and commercialization of innovative anti-cancer therapeutics. Our goal is to build a profitable company by generating income from products we develop and commercialize, either alone or with one or more potential strategic partners. We strive to develop proprietary products that have the potential to improve the standard of care in cancer therapy.

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        We are currently focused on the development and commercialization of FOLOTYN® (pralatrexate injection). FOLOTYN is a targeted folate inhibitor designed to accumulate preferentially in cancer cells. FOLOTYN targets the inhibition of dihydrofolate reductase, or DHFR, an enzyme critical in the folate pathway, thereby interfering with DNA and RNA synthesis and triggering cancer cell death. FOLOTYN can be delivered as a single agent, for which we currently have approval for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma, or PTCL, and has the potential to be used in combination therapy regimens. We believe that FOLOTYN's unique mechanism of action offers us the ability to target the drug for development in a variety of hematological malignancies and solid tumor indications. We currently retain exclusive worldwide commercial rights to FOLOTYN for all indications. We may also seek to grow our product portfolio through product acquisition and in-licensing efforts.

        On September 24, 2009, the U.S. Food and Drug Administration, or FDA, granted accelerated approval of FOLOTYN for use as a single agent for the treatment of patients with relapsed or refractory PTCL. This approval was based on overall response rate from our pivotal Phase 2 trial known as PROPEL (Pralatrexate in patients with Relapsed Or refractory PEripheral T-cell Lymphoma). Clinical benefit such as improvement in progression-free survival or overall survival has not been demonstrated. FOLOTYN represents our first drug approved for marketing in the United States. FOLOTYN is the first and only drug approved by the FDA for this indication. In connection with the accelerated approval, we are required to conduct post-approval studies that are intended to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphoma and to determine whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment.

        We began making FOLOTYN available for commercial sale in the United States in October 2009 and commenced our commercial launch of FOLOTYN in January 2010. We have established a commercial organization, including sales, marketing, supply chain management and reimbursement capabilities, to commercialize FOLOTYN in the United States. We believe the market for relapsed or refractory PTCL is addressable with a targeted U.S. sales and marketing organization, and we intend to continue promoting FOLOTYN ourselves in the United States.

        We are also seeking regulatory approval to market FOLOTYN in Europe for the treatment of patients with relapsed or refractory PTCL. In December 2010, our Marketing Authorisation Application, or MAA, was accepted by the European Medicines Agency, or EMA. Acceptance of the MAA by the EMA indicates that the application is complete and initiates the EMA's regulatory review process. The MAA is based on clinical data from our pivotal PROPEL trial. We may also seek regulatory approval to market FOLOTYN for the treatment of patients with relapsed or refractory PTCL in Japan and other countries. We intend to secure a strategic partner for the potential co-development of FOLOTYN globally and commercialization outside the United States.

        We are currently prioritizing our resources on the development and commercialization of FOLOTYN for the treatment of PTCL, cutaneous T-cell lymphoma and other hematologic malignancies. We also intend to complete our ongoing Phase 2 studies in bladder and breast cancer, and investigators are evaluating FOLOTYN in solid tumor indications through our collaboration with the National Comprehensive Cancer Network, or NCCN, Oncology Research Program.

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        The following table summarizes the target indications and clinical development status of the FOLOTYN development program, including our planned post-approval studies:

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        Our goal is to build a profitable company by generating income from products we develop and commercialize, either alone or with one or more potential strategic partners. The key elements of our strategy are to:

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Increase sales of FOLOTYN in the United States.  We commenced the U.S. commercial launch of FOLOTYN in January 2010 and reported net product sales of $35.2 million for the year ended December 31, 2010. We have identified approximately 2,000 accounts and 3,000 physicians as priority targets for our sales and marketing efforts. Our commercial organization is currently focused on increasing account penetration, improving brand and disease state awareness among physicians, and optimizing the duration of treatment with FOLOTYN. Our goal is to position FOLOTYN as the second-line standard of care for PTCL.



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Obtain regulatory approval to market FOLOTYN in foreign jurisdictions.  We are currently seeking regulatory approval to market FOLOTYN in Europe for the treatment of patients with relapsed or refractory PTCL. Our MAA was accepted for review by the EMA in December 2010. We may also seek regulatory approval to market FOLOTYN in Japan and other countries.



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Secure a strategic partner for the co-development of FOLOTYN globally and commercialization outside the United States.  We currently retain exclusive worldwide rights to develop and commercialize FOLOTYN for all indications. We intend to secure a strategic partner for the potential co-development of FOLOTYN globally and commercialization outside the United States.



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Advance our FOLOTYN development program in hematologic malignancies and pursue new indications.  We are currently prioritizing our resources on the development and commercialization of FOLOTYN in hematologic malignancies. FOLOTYN can be delivered as a single agent, for which we currently have approval for the treatment of patients with relapsed or refractory PTCL, and has the potential to be used in combination therapy regimens. We plan to complete our ongoing clinical trials and initiate new clinical trials to pursue additional indications for FOLOTYN.



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Explore the activity of FOLOTYN in solid tumor indications through targeted investments.  We intend to complete our ongoing Phase 2 studies in bladder and breast cancer, and investigators are evaluating FOLOTYN in solid tumor indications through our collaboration with the NCCN Oncology Research Program.



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Expand our product portfolio.  We may pursue opportunities from time to time to expand our product portfolio by identifying and evaluating new compounds that have demonstrated potential in preclinical or clinical studies and are strategically aligned with our existing oncology portfolio. Our intent is to build a portfolio of proprietary product candidates that have the potential to improve the standard of care in cancer therapy and provide commercial, regulatory or geographic exclusivity.

FOLOTYN (pralatrexate injection)

        FOLOTYN is a targeted folate inhibitor designed to accumulate preferentially in cancer cells. Based on preclinical studies, we believe that FOLOTYN selectively enters cells expressing RFC-1, a protein that is frequently over expressed on cancer cells compared to normal cells. Once inside cancer cells, FOLOTYN is efficiently polyglutamylated, which makes it less susceptible to efflux-based drug resistance and leads to high intracellular drug retention compared to other antifolates. Inside the cell, FOLOTYN targets the inhibition of DHFR, an enzyme critical in the folate pathway, thereby interfering with DNA and RNA synthesis and triggering cancer cell death.

        The antimetabolites, including antifolates such as FOLOTYN, are a group of low-molecular weight compounds that exert their effect by virtue of their structural or functional similarity to naturally occurring molecules involved in DNA synthesis. Because the cell mistakes them for a normal

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metabolite, the antimetabolites either inhibit critical enzymes involved in DNA synthesis or become incorporated into the nucleic acid, producing incorrect codes. Both mechanisms result in inhibition of DNA synthesis and ultimately, cell death. Because of their primary effect on DNA synthesis, the antimetabolites are most effective against actively dividing cells and are largely cell-cycle phase specific. There are three classes of antimetabolites; purine analogs, pyrimidine analogs and folic acid analogs, also termed antifolates. FOLOTYN is a folic acid analog.

        The selectivity of antifolates for tumor cells involves their conversion to a polyglutamylated form by the enzyme folypolyglutamyl synthetase. Polyglutamylation is a time- and concentration-dependent process that occurs in tumor cells, and to a lesser extent, normal tissue. The selective activity of the folic acid analogs in malignant cells versus normal cells likely is due to the relative difference in polyglutamylate formation. Polyglutamylated metabolites have prolonged intracellular half-life, increased duration of drug action and are potent inhibitors of several folate-dependent enzymes, including DHFR.

        We believe that the resistance of malignant cells to the effects of the folic acid analogs may, in part, be due to impaired polyglutamylation. We believe the improved antitumor effects of FOLOTYN in comparison to methotrexate, as observed in preclinical studies, is likely due to the more effective uptake and transport of FOLOTYN into the cell followed by the greater accumulation of FOLOTYN and its metabolites within the tumor cell through the formation of the polyglutamylated derivatives.

FOLOTYN for the Treatment of Patients with Relapsed or Refractory PTCL

United States

        On September 24, 2009, the FDA granted accelerated approval of FOLOTYN for use as a single agent for the treatment of patients with relapsed or refractory PTCL. FOLOTYN is the first and only drug approved by the FDA for this indication. We began making FOLOTYN available for commercial sale in the United States on October 5, 2009 and commenced our commercial launch of FOLOTYN in January 2010.

        T-cell lymphomas comprise a biologically diverse group of blood cancers that account for approximately 10% to 15% of all cases of non-Hodgkin lymphoma, or NHL, in the United States. The American Cancer Society estimated that approximately 66,000 new cases of NHL were expected to be diagnosed in the U.S. in 2010. We estimate the current annual incidence of PTCL to be approximately 5,900 patients in the United States. There are currently no pharmaceutical agents approved for use in the treatment of first-line PTCL and, prior to the September 2009 approval of FOLOTYN, there were no pharmaceutical agents approved for use in the treatment of patients with relapsed or refractory PTCL. The outcome of patients with PTCL is poor and the majority of patients ultimately have relapsed or refractory disease to a variety of agents, including multi-agent chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) or CHOP-like regimens. The five-year overall survival rate in these patients is approximately 25% to 40%, depending on sub-type.

        We have established a commercial organization, including sales, marketing, supply chain management and reimbursement capabilities, to commercialize FOLOTYN in the United States. We believe the U. S. market for relapsed or refractory PTCL is addressable with a targeted sales and marketing organization, and we intend to continue promoting FOLOTYN ourselves in the United States.

        We have also established the Allos Support for Assisting Patients, or ASAP program, to facilitate access to FOLOTYN by providing reimbursement resources to uninsured, underinsured and insured patients, and reimbursement support to healthcare providers. In addition, through the ASAP program, indigent patients who are not eligible for reimbursement may obtain free drug.

        In October 2009, the NCCN updated its Clinical Practice Guidelines in Oncology™ for Non-Hodgkin Lymphomas to include FOLOTYN as a suggested treatment regimen for all patients with

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second-line PTCL. NCCN is recognized by the Centers for Medicare and Medicaid Services and private payers as a mandated reference for oncology coverage policies. Managed care, medical directors, pharmacy benefit directors and other healthcare professionals also reference NCCN compendia when making treatment and reimbursement decisions.

        FOLOTYN was approved by the FDA based on the results from PROPEL, an open-label, single-arm, multi-center, international clinical trial that enrolled 115 patients with relapsed or refractory PTCL, 109 of whom were considered evaluable for efficacy according to the trial protocol. Patients were considered evaluable if they received at least one dose of FOLOTYN, their diagnosis of PTCL was confirmed by independent pathology review, and they had relapsed or refractory disease after at least one prior treatment. Patients were treated with FOLOTYN at 30 mg/m² once weekly by intravenous push over 3-5 minutes for 6 weeks in 7-week cycles until disease progression or unacceptable toxicity. In addition, patients received 1 mg of vitamin B₁₂ intramuscularly every 8-10 weeks and 1.0-1.25 mg of folic acid orally on a daily basis.

        The primary efficacy endpoint of the trial was overall response rate (complete response, complete response unconfirmed and partial response) as assessed by International Workshop Criteria, or IWC. The key secondary efficacy endpoint was duration of response. Response assessments were scheduled at the end of cycle 1 and then every other cycle (every 14 weeks). Duration of response was measured from the first day of documented response to disease progression or death. Response and disease progression were evaluated by independent central review using the IWC. The results of the trial demonstrated that 29 of 109 evaluable patients, or 27%, responded to FOLOTYN. The median duration of response was 287 days, or 9.4 months (range 1-503 days). Thirteen of 109 evaluable patients had a duration of response greater-than or equal to 14 weeks (range 98-503 days). The most common grade 3/4 adverse events were thrombocytopenia, which was observed in 33% of patients; mucositis in 21% of patients; neutropenia in 20% of patients; and anemia in 17% of patients.

        In December 2009, updated results from the PROPEL trial were presented at the 51^st Annual Meeting of the American Society of Hematology, or ASH. The updated results demonstrated that patients treated with FOLOTYN achieved an overall response rate of 29% (32 of 109 evaluable patients) with 63% of patients responding within the first cycle of therapy. The median duration of response was 10.1 months and median overall survival was 14.5 months.

        The FDA has awarded orphan drug status to FOLOTYN for the treatment of patients with T-cell lymphoma, which includes patients with relapsed or refractory PTCL. Orphan drug designation is granted by the FDA to drugs intended to treat a rare disease or condition, which for this program is defined as having a prevalence of less than 200,000 individuals in the United States. Under the U.S. Orphan Drug Act, the first company to receive FDA approval for an orphan drug for a designated indication obtains seven years of marketing exclusivity during which the FDA may not approve another company's application for the same orphan drug for the same orphan indication. Because the FDA approved pralatrexate (which we market as FOLOTYN) for the treatment of patients with relapsed or refractory PTCL, a subset of T-cell lymphoma, we expect to receive seven years of marketing exclusivity for that indication. However, if a competitive product that is the same as FOLOTYN, as defined under the applicable regulations, is shown to be clinically superior to our product in the treatment of patients with relapsed or refractory PTCL, or if a competitive product is different from FOLOTYN, as defined under the applicable regulations, the orphan drug exclusivity we have obtained may not block the approval of such competitive product.

Europe and Other Countries

        We are currently seeking regulatory approval to market FOLOTYN in Europe for the treatment of patients with relapsed or refractory PTCL. In December 2010, our MAA was accepted for review by the EMA. Acceptance of the MAA indicates that the application is complete and initiates the EMA's regulatory review process. The EMA has granted orphan medicinal product designation to FOLOTYN

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for the treatment of nodal, other extranodal, and leukaemic/disseminated PTCL. We may also seek regulatory approval to market FOLOTYN for the treatment of patients with relapsed or refractory PTCL in Japan and other countries.

        There is a high unmet medical need with no approved agents in either Europe or Japan for the treatment of patients with relapsed or refractory PTCL. We estimate the annual incidence of PTCL in the top five European markets (Germany, France, Italy, Spain and the United Kingdom) in 2010 to be approximately 6,000 to 7,000 patients, with an estimated 4,500 to 6,000 second-line PTCL patients. Likewise, based on our internal research, we estimate the incidence of PTCL in Japan in 2010 to be approximately 3,700 to 4,100 patients, with an estimated 2,800 to 3,500 second-line PTCL patients.

        We currently retain exclusive worldwide rights to develop and commercialize FOLOTYN for all indications. One of our key objectives for 2011 is to secure a strategic partner for the potential co-development of FOLOTYN globally and commercialization outside the United States.

        We currently provide healthcare professionals outside of the United States with access to FOLOTYN through a named patient program, which is a mechanism through which physicians can prescribe investigational drugs under individual country-specific guidelines for patients prior to marketing approval.

FOLOTYN Post-approval Clinical Studies

        FOLOTYN was approved for the treatment of patients with relapsed or refractory PTCL in the United States under the FDA's accelerated approval program, which allows the FDA to approve products for cancer or other life-threatening diseases based on initial positive clinical data. As a condition of approval, we are required to conduct the following post-approval studies that are intended to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphomas and assess whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment:

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A Phase 3, multi-center, randomized clinical study of sequential FOLOTYN versus observation in patients with newly diagnosed aggressive PTCL who have responded following initial treatment with chemotherapy based on CHOP. Patients responding (either a complete response or a partial response) after CHOP-based treatment will be randomized 2:1 to FOLOTYN versus observation. In the first quarter of 2011, we reached agreement with the FDA under its Special Protocol Assessment process (SPA) on the design of this trial. The SPA process provides an agreement that the study design, including trial size, clinical endpoints and/or data analyses are acceptable to the FDA. The SPA agreement is not a guarantee of approval, and we cannot assure you that the design of, or data collected from, this trial will be adequate to demonstrate the safety and efficacy of FOLOTYN in this patient population, or otherwise be sufficient to support FDA or any foreign regulatory approval. We plan to initiate this study in 2011. We have agreed to submit the results of this study to the FDA by June 30, 2017.



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A Phase 3, multi-center, randomized clinical study comparing FOLOTYN in combination with systemic bexarotene versus systemic bexarotene alone in patients with cutaneous T-cell lymphoma, or CTCL, who are refractory to at least one prior systemic therapy. Prior to initiation of the Phase 3 study, we will conduct a Phase 1 study to determine the maximum tolerated dose, or MTD of the combination. We initiated the Phase 1 study in 2010 and patient enrollment is ongoing. We have agreed to complete the Phase 1 study by August 31, 2011. The final design of the Phase 3 study, including number of patients, clinical endpoints and other study details, remains subject to review by the FDA. We have agreed to submit the results of the Phase 3 study to the FDA by September 30, 2015.

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A Phase 1 clinical study to evaluate the pharmacokinetics of FOLOTYN in relapsed or refractory advanced solid tumor or advanced lymphoma patients (B-cell, T-cell and Hodgkin lymphoma) with mild to severe renal impairment. The trial will have four cohorts of six patients for a total of 24 patients. Cohorts will be based on the severity of renal impairment: severely impaired, moderately impaired, mildly impaired and normal. We plan to initiate this study in 2011. We have agreed to submit the results of this study to the FDA by January 31, 2013.



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Completion of an ongoing Phase 1 mass balance clinical study to evaluate the excretion and metabolic profile of FOLOTYN.

        Failure to complete these post-approval studies or adhere to the timelines set by the FDA could result in penalties, including fines or withdrawal of FOLOTYN from the market, unless we are able to demonstrate good cause for not completing the studies or adhering to the timelines. The FDA may also initiate proceedings to withdraw approval if our Phase 3 post-approval studies fail to verify the clinical benefit of FOLOTYN. Further, the FDA may require us to strengthen the warnings and precautions section of the FOLOTYN package insert based on the results of the Phase 1 studies.

FOLOTYN Clinical Development Program

        We are developing FOLOTYN both as a single agent and in combination therapy regimens in a variety of hematologic malignancies and solid tumor indications. In addition to the post-approval clinical studies discussed above, the following is a summary of the target indications and clinical development status of the FOLOTYN development program.

Cutaneous T-Cell Lymphoma

        Cutaneous T-cell lymphoma, or CTCL, is comprised of a number of indolent non-Hodgkin T-cell lymphomas, including mycosis fungoides and Sézary syndrome. In its early stages, CTCL primarily affects the skin, causing patches, plaques, and tumors, as well as redness and itching; however, as it progresses, CTCL can spread to the blood, lymph nodes and internal organs. For some patients, their disease will progress despite treatment with topical and skin directed therapies and will require systemic treatments, including chemotherapies. Even when CTCL is found in an early stage, it can be difficult to treat and usually returns after initial treatment. According to the Lymphoma Research Foundation, CTCL accounts for approximately 2% to 3% of the estimated 66,000 new cases of NHL diagnosed each year in the United States. According to the Cutaneous Lymphoma Foundation, the prevalence of CTCL in the United States is estimated between 16,000 and 20,000 cases.

        In August 2007, we initiated patient enrollment in a Phase 1, open-label, multi-center study of FOLOTYN with vitamin B₁₂ and folic acid supplementation in patients with relapsed or refractory CTCL. In this study, patients with either relapsed or refractory CTCL receive FOLOTYN as part of a weekly schedule for two or three weeks followed by one week of rest. In the Phase 1 dose de-escalation portion, patients received a starting dose of FOLOTYN at 30 mg/m², with dose reduction in subsequent cohorts to identify an optimal dose for patients with CTCL based on tolerability and efficacy. The dosing regimen of 15 mg/m² weekly for three weeks out of a four-week cycle was determined to be the optimal starting dose and schedule that provided activity with tolerability.

        In December 2010, data from this Phase 1 study were presented at the 52^nd Annual ASH Meeting. Of the total 54 patients enrolled in the trial (which includes patients who received lower than the optimal dose), objective responses were observed in 22 patients (41%), including three complete responses and 19 partial responses. In total, 41 of the 54 patients were treated at the optimal dose of FOLOTYN or higher; of these 41 patients, responses were observed in 21 patients (51%). Responses to FOLOTYN were observed in patients whose disease failed to respond to key prior systemic therapies, including 46% of patients whose disease failed to respond to oral bexarotene, 46% whose disease failed to respond to methotrexate, 41% whose disease failed to respond to HDAC inhibitors, and 36% whose

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disease failed to respond to interferon. Patients in the study were heavily pretreated, having received a median of 6.5 prior therapies (range 1-25) and 4.0 prior systemic therapies (range 1-11). For the 29 patients treated at the optimal starting dose and schedule:

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overall response rate was 45% (13 out of 29 patients);



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responses were durable, with a Kaplan-Meier estimate for duration of response of 73% at six months; and



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median progression-free survival had not been reached at the time of this analysis. Progression-free survival ranged from 1-429 days.

        In the 29 patients treated at the optimal dose and schedule, Grade 3-4 adverse events observed were mucositis (17%), thrombocytopenia (3%) and fatigue (3%); and the most common Grade 1-2 adverse events observed were fatigue (34%), mucositis (31%), nausea (31%), epistaxis/nose bleeds (24%), edema (14%) and vomiting (14%). There was no neutropenia reported in patients at the optimal dose or higher.

        As part of our post-approval clinical studies discussed above, we plan to initiate a Phase 3, multi-center, randomized clinical study comparing FOLOTYN in combination with systemic bexarotene versus systemic bexarotene alone in patients with CTCL who are refractory to at least one prior systemic therapy. Prior to initiation of the Phase 3 study, we will conduct a Phase 1 study to determine the maximum tolerated dose of the combination. We initiated the Phase 1 study in 2010 and patient enrollment is ongoing. We have agreed to complete the Phase 1 study by August 31, 2011. The final design of the Phase 3 Study, including number of patients, clinical endpoints and other study details remains subject to review by the FDA. We have agreed to submit the results of the Phase 3 study to the FDA by September 30, 2015.

        In June 2010, the European Commission, or EC, granted orphan medicinal product designation for pralatrexate for the treatment of CTCL. The EMA orphan medicinal product designation is intended to promote the development of drugs that may provide significant benefit to patients suffering from rare diseases identified as life-threatening or very serious. Under EMA guidelines, orphan medicinal product designation provides ten years of potential market exclusivity once the product is approved for marketing for the designated indication in the European Union.

Non-Hodgkin Lymphoma and Hodgkin Lymphoma

        According to the American Cancer Society, an estimated 66,000 new cases of NHL were expected to be diagnosed in the United States in 2010. Approximately 85% of NHL patients represent patients with B-cell lymphoma. Patients with indolent or low-grade NHL may have survival rates as long as 10 years, yet the disease is usually not curable in advanced stages. Aggressive lymphomas generally result in shorter median survival times although patients with these malignancies can be cured in 30% to 60% of cases.

        In May 2007, we initiated patient enrollment in a Phase 1/2a, open-label, multi-center study of FOLOTYN and gemcitabine with vitamin B₁₂ and folic acid supplementation in patients with relapsed or refractory NHL or Hodgkin's lymphoma. In the Phase 1 portion of this study, patients with either relapsed or refractory NHL or Hodgkin's lymphoma received FOLOTYN either concurrently on the same day with or followed on sequential days by gemcitabine as part of a weekly schedule for three or four weeks or every two weeks with concurrent vitamin B₁₂ and folic acid supplementation. We enrolled 35 evaluable patients in the Phase 1 portion of the study with the objective of determining the maximum tolerated dose, or MTD, safety, tolerability, and pharmacokinetic profile of escalating doses of sequential or same day administration of FOLOTYN and gemcitabine. The MTD for the sequential dosing regimen was determined to be 10 mg/m² of FOLOTYN followed on sequential days by 400 mg/m² of gemcitabine in an every two week schedule. The MTD for the same-day regimen was

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determined to be 15 mg/m² of FOLOTYN and 600 mg/m² of gemcitabine in an every two week schedule. The Phase 2a portion of the trial is closed to enrollment, and we expect to report a final analysis of the data for this trial by the first half of 2012.

        In September 2009, we initiated patient enrollment in a Phase 2, open-label, single-arm, multi-center trial of FOLOTYN in patients with relapsed or refractory B-cell NHL. This trial will seek to enroll approximately 27 evaluable patients in up to 10 investigative sites worldwide. The primary endpoint of the study is objective response rate (complete and partial response) as assessed by IWC. Secondary endpoints include duration of response, progression-free survival, overall survival, and the safety and tolerability of FOLOTYN.

        In October 2008, the FDA granted orphan drug designation to FOLOTYN for the treatment of patients with follicular lymphoma and for the treatment of patients with diffuse large B-cell lymphoma. In October 2010, the EC granted orphan medicinal product designation for pralatrexate for the treatment of Hodgkin Lymphoma.

Non-Small Cell Lung Cancer

        Lung cancer is the most common cause of cancer death in the United States. According to the American Cancer Society, an estimated 222,520 new cases of lung cancer were expected to be diagnosed in the United States in 2010. Non-small cell lung cancer, or NSCLC, accounts for the majority of lung cancers, or approximately 85%. The three most common subtypes of NSCLC are squamous cell carcinoma, which accounts for 25% to 30% of all lung cancers; adenocarcinoma, which is the most common type of lung cancer and accounts for about 40% of lung cancers; and large-cell undifferentiated carcinoma, which accounts for 10% to 15% of lung cancers. The majority of people are diagnosed with advanced stage disease and only one to five percent of people with advanced stage (IIIB/IV) NSCLC survive to five years. The most widely used therapies to date remain surgery, chemotherapy and radiation therapy.

        In January 2008, we initiated patient enrollment in a Phase 2b, randomized, international, multi-center study comparing FOLOTYN and erlotinib in second or third line patients with Stage IIIB/IV NSCLC who are, or have been, cigarette smokers who have failed treatment with at least one prior platinum-based chemotherapy regimen. We completed enrollment of this study in July 2009 with 201 patients. The objectives of this Phase 2b study were to estimate the efficacy of FOLOTYN relative to that of erlotinib as assessed by overall survival, or OS, the primary endpoint of the trial, and to determine the treatment effect of both drugs in predefined patient cohorts, including light vs. heavy smokers; current vs. former smokers; squamous vs. non-squamous histology; and patients who received prior pemetrexed vs. those who have not. In the fourth quarter of 2010, we announced the presentation of favorable survival data from this trial. The results demonstrated that patients receiving FOLOTYN had a 16% lower risk of death than those treated with erlotinib in the overall (intent-to-treat) population (n=201; hazard ratio (HR)=0.84) and a 13% lower risk of death in the primary efficacy analysis population (n=166; HR=0.87). At six months, 56% of patients treated with FOLOTYN were alive and 51% of patients treated with erlotinib were alive; at one year, 28% of patients treated with FOLOTYN were alive and 18% of patients treated with erlotinib were alive. The median overall survival (OS) time was 6.7 months for patients who received FOLOTYN and 7.0 months for patients who received erlotinib.

        Secondary endpoints included progression-free survival (PFS) (HR=0.91; median PFS=3.4 months and 2.8 months for FOLOTYN and erlotinib, respectively) and objective response rate (2% and 7%, respectively). Analyses were also performed according to the statistical analysis plan to assess the activity of FOLOTYN and erlotinib in predefined patient cohorts. These analyses indicated that the majority of cohorts responded favorably to FOLOTYN relative to erlotinib. The most favorable data were observed in patients with non-squamous cell carcinoma (n=107), which demonstrated that

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patients who received FOLOTYN showed a 35% lower risk of death (OS HR=0.65) and 42% reduction in the risk of disease progression (PFS HR=0.58) relative to erlotinib. In patients with squamous cell carcinoma, a HR for OS of 1.06 was observed, which suggests activity of FOLOTYN given that erlotinib has historically shown a survival benefit in these patients. In the small subset of patients who received prior pemetrexed (n=30), a HR for OS of 1.15 was observed.

        The safety profile of FOLOTYN was consistent with that observed and reported in previous FOLOTYN solid tumor studies. The most common Grade 3-4 adverse event observed in patients treated with FOLOTYN was mucositis (23%). Other Grade 3-4 adverse events occurring in more than 5% of patients were fatigue (9%), dyspnea (6%), neutropenia (6%), thrombocytopenia (5%) and anemia (5%) in patients treated with FOLOTYN, and rash (8%), dyspnea (8%), anemia (8%) and fatigue (5%) in patients treated with erlotinib. Of those patients treated with FOLOTYN (n=97) in the trial, 32 patients (33%) discontinued treatment due to adverse events.

        In January 2011, we announced that we will not pursue Phase 3 studies for NSCLC at this time based on our assessment of the costs of future development and the potential clinical, regulatory and commercial opportunities in this indication.

Bladder Cancer

        According to the American Cancer Society, an estimated 70,530 new cases of bladder cancer were expected to be diagnosed in the United States in 2010. Transitional cell carcinoma, or TCC, is the most common form of bladder cancer, accounting for more than 97% of all bladder cancers. There are currently no agents approved in the United States for the treatment of advanced or metastatic relapsed TCC of the urinary bladder.

        In July 2008, we initiated patient enrollment in a Phase 2, open-label, single-arm, multi-center study of FOLOTYN in patients with advanced or metastatic relapsed TCC of the urinary bladder. The primary endpoint of the study is objective response rate (complete and partial response). Secondary endpoints include duration of response, clinical benefit rate, progression-free survival, overall survival and the safety and tolerability of FOLOTYN. Patients received FOLOTYN as an IV push administered on days 1 and 15 of a 4-week/28 day cycle. The initial dose of FOLOTYN is 190 mg/m², which may be adjusted based on criteria defined in the protocol. Patients received concurrent vitamin therapy of B₁₂ and folic acid. This Phase 2 study is closed to enrollment and we expect to report top line data for this trial in the second half of 2011.

        In March 2009, the EC granted orphan medicinal product designation to pralatrexate for the treatment of patients with non-papillary TCC of the urinary bladder. In May 2010, the FDA granted orphan drug designation to FOLOTYN for the treatment of patients with advanced or metastatic TCC of the urinary bladder.

Breast Cancer

        Breast cancer is the second most common cancer among American women. According to the American Cancer Society, an estimated 207,090 new cases of invasive breast cancer were expected to be diagnosed in women in the United States in 2010.

        In the second quarter of 2010, we initiated patient enrollment in a Phase 2, open-label, single-arm, multi-center international study of FOLOTYN in female patients with advanced or metastatic breast cancer who have failed prior chemotherapy. The primary endpoint is objective response. Secondary endpoints include duration of response, overall survival, safety and pharmacokinetic parameters. Patients will be dosed at 190 mg/m² every two weeks of a four-week cycle. The study will seek to enroll approximately 30 patients. Patient enrollment is ongoing and we expect to report top line data for this trial in the second half of 2011.

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NCCN Program

        In addition to our ongoing company-sponsored clinical studies, investigators are evaluating FOLOTYN in a variety of solid tumor indications and multiple myeloma through our collaboration with the NCCN Oncology Research Program. We have agreed to provide the NCCN with a research grant of approximately $2.3 million for the study of FOLOTYN as a single agent and in combination therapy regimens, of which approximately $860,000 was paid as of the end of 2010. The current investigator-sponsored studies include a:

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Phase 1/2 study of Carboplatin and FOLOTYN in patients with recurrent platinum sensitive ovarian, fallopian or primary peritoneal cancer,



•

Phase 1 study of Bortezomib in combination with FOLOTYN in relapsed or refractory multiple myeloma,



•

Phase 1 study of sequential FOLOTYN followed by a 48-hour infusion of 5-Fluorouracil given every other week in adult patients with solid tumors,



•

Phase 2, multi-center, study of FOLOTYN with vitamin B₁₂ and folic acid supplementation for previously treated recurrent or metastatic head and neck squamous cell cancer,



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Phase 2 study of FOLOTYN in combination with Oxaliplatin in advanced esophago-gastric cancer, and



•

Phase 2 study of FOLOTYN and Docetaxel in patients with advanced esophageal and gastroesophageal carcinoma who have failed prior platinum-based therapy.

        There can be no assurances that we will pursue the development of FOLOTYN for one or more of these indications or that such development efforts will be ultimately successful.

Manufacturing

        The production of FOLOTYN employs small molecule organic chemistry procedures standard for the pharmaceutical industry. We have arrangements with two third-party manufacturers to produce FOLOTYN bulk drug substance and two third-party manufacturers to produce FOLOTYN formulated drug product. We believe these third-party manufacturers have the capability to meet our projected worldwide clinical trial and commercial requirements for FOLOTYN although we cannot assure you of this. Prior to receiving FDA approval of FOLOTYN, all costs related to purchases of the active pharmaceutical ingredient and the manufacturing of FOLOTYN were recorded as research and development expense. As such, we have established supplies of FOLOTYN bulk drug substance and formulated drug product that are not recorded on our balance sheet as inventory.

        We plan to continue to outsource manufacturing responsibilities for FOLOTYN and any additional future product candidates. We believe this manufacturing strategy allows us to direct our financial and managerial resources to the development and commercialization of products rather than to the establishment of a manufacturing infrastructure. We believe it also enables us to minimize fixed costs and capital expenditures, while gaining access to advanced manufacturing process capabilities and expertise. However, if our third party suppliers become unable or unwilling to provide sufficient future drug supply or meet regulatory requirements relating to the manufacture of pharmaceutical agents, we would be forced to incur additional expenses to secure alternative third party manufacturing arrangements and may suffer delays in our ability to conduct clinical trials or commercialize FOLOTYN or future products.

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Sales and Marketing

        We have established a commercial organization, including sales, marketing, supply chain management and reimbursement capabilities, to commercialize FOLOTYN in the United States. We believe the U. S. market for relapsed or refractory PTCL is addressable with a targeted sales and marketing organization, and we intend to continue promoting FOLOTYN ourselves in the United States for this and any additional indications we may obtain in the future. We intend to secure a strategic partner for the co-development of FOLOTYN globally and commercialization outside the United States.

Intellectual Property

        We believe that patent protection and trade secret protection are important to our business and that our future success will depend, in part, on our ability to maintain our technology licenses, maintain trade secret protection, obtain and maintain patents and operate without infringing the proprietary rights of others both in the United States and abroad. We believe that obtaining identical patents and protection periods for a given technology throughout all markets of the world will be difficult because of differences in patent laws. In addition, the protection provided by non-U.S. patents, if any, may be weaker than that provided by U.S. patents.

        In order to protect the confidentiality of our technology, including trade secrets and know-how and other proprietary technical and business information, we require all of our employees, consultants, advisors and collaborators to enter into confidentiality agreements that prohibit the use or disclosure of confidential information. The agreements also oblige our employees, consultants, advisors and collaborators to assign or license to us ideas, developments, discoveries and inventions made by such persons in connection with their work with us. We cannot be sure that these agreements will maintain confidentiality, will prevent disclosure, or will protect our proprietary information or intellectual property, or that others will not independently develop substantially equivalent proprietary information or intellectual property.

        The pharmaceutical industry is highly competitive and patents have been applied for by, and issued to, other parties relating to products or new technologies that may be competitive with those being developed by us. Therefore, FOLOTYN may give rise to claims that it infringes the patents or proprietary rights of other parties now or in the future. Furthermore, to the extent that we, our consultants, or manufacturing and research collaborators, use intellectual property owned by others in work performed for us, disputes may also arise as to the rights to such intellectual property or in related or resulting know-how and inventions. An adverse claim could subject us to significant liabilities to such other parties and/or require disputed rights to be licensed from such other parties. A license required under any such patents or proprietary rights may not be available to us, or may not be available on acceptable terms. If we do not obtain such licenses, we may encounter delays in product market introductions, or may find that we are prevented from the development, manufacture or sale of products requiring such licenses. In addition, we could incur substantial costs in defending ourselves in legal proceedings instituted before patent and trademark offices in the United States, the European Union, or other ex-U.S. territories, or in a suit brought against us by a private party based on such patents or proprietary rights, or in a suit by us asserting our patent or proprietary rights against another party, even if the outcome is not adverse to us.

FOLOTYN License Agreement

        In December 2002, we entered into a license agreement with Memorial Sloan-Kettering Cancer Center, SRI International and Southern Research Institute, as amended, under which we obtained exclusive worldwide rights to a portfolio of patents and patent applications related to FOLOTYN and its uses. The portfolio currently consists of three issued patents in the United States, two granted

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patents in Europe, a single granted patent in each of Mexico, New Zealand, Singapore and South Africa, and pending patent applications in the United States, Canada, Europe, Australia, Japan, China, Brazil, Indonesia, India, South Korea, Mexico, Norway, New Zealand and the Philippines. The licensed patents and applications, which expire at various times between July 2017 and May 2025, contain claims covering FOLOTYN substantially free of 10-deazaaminopterin, methods to treat tumors with FOLOTYN substantially free of 10-deazaaminopterin, treatment of breast, lung, and prostate cancer and leukemia with a combination of FOLOTYN and a taxane, treatment of T-cell lymphoma with FOLOTYN, treatment of lymphoma with a combination of FOLOTYN and gemcitabine, methods of assessing sensitivity of a tumor to FOLOTYN, and other methods and compositions.

        Under the terms of the agreement, we paid an up-front license fee of $2.0 million upon execution of the agreement and have made aggregate milestone payments of $2.5 million based on the passage of time. Additionally, in May and September 2009, we made milestone payments of $1.5 million based on the FDA accepting our New Drug Application for review and $5.8 million based on the FDA approval to market FOLOTYN, respectively. The up-front license fee and all milestone payments under the agreement prior to FDA approval to market FOLOTYN were recorded to research and development expense as incurred. The $5.8 million milestone payment based on the FDA approval was capitalized as an intangible asset and is being amortized over the expected useful life of the composition of matter patent for FOLOTYN, which we expect to last until July 16, 2022. The only remaining potential milestone payment under the license agreement is for $3.5 million upon regulatory approval to market FOLOTYN in Europe, which, if made would be capitalized and amortized over the expected useful life. In addition, we will pay the licensors royalties based on graduated annual levels of net sales of FOLOTYN to our distributors, net of actual rebates and chargebacks, or distributor sales, which may be different than our net product revenue recognized in accordance with U.S. generally accepted accounting principles, or GAAP, or sublicense revenues arising from sublicensing the product, if and when such sales or sublicenses occur. Royalties are 8% of annual distributor sales up to $150.0 million; 9% of annual distributor sales of $150.0 million through $300.0 million; and 11% of annual distributor sales in excess of $300.0 million. In 2010 and 2009, our royalties were 8% of our net distributor sales.

Customers

        We sell FOLOTYN to a limited number of pharmaceutical wholesale distributors, or distributors, who then resell FOLOTYN to patients' respective health care providers. We had $35.2 million and $3.6 million of net product sales for the years ended December 31, 2010 and 2009, respectively. Three distributors affiliated with AmerisourceBergen Corporation accounted for approximately 99% and 100% of our net product sales for the years ended December 31, 2010 and 2009, respectively. We anticipate that affiliates of AmerisourceBergen Corporation will continue to account for substantially all of our net product sales in 2011. We had less than 1% of sales outside of the United States during the year ended December 31, 2010 and none outside the United States during the year ended December 31, 2009.

Competition

        There are currently no FDA-approved drugs other than FOLOTYN for the treatment of patients with relapsed or refractory PTCL. However, we are aware of multiple investigational agents that are currently being studied in clinical trials for peripheral T-cell lymphoma, including romidepsin, belinostat and brentuximab vedotin, which, if successful, may compete with FOLOTYN in the United States in 2011. In addition, there are many existing approaches used in the treatment of relapsed or refractory PTCL, including combination chemotherapy and single agent regimens, which represent competition for FOLOTYN.

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        Many companies of all sizes, including a number of large pharmaceutical companies and several biotechnology companies, are developing product candidates that have disease targets similar to those we are pursuing. Some of these competitive product candidates are in clinical trials and others are approved. There are products and technologies currently on the market that will compete directly with FOLOTYN. Universities, governmental agencies and other public and private research organizations also conduct research and may market commercial products on their own or through joint ventures. These companies and institutions also compete with us in recruiting qualified scientific personnel. Many of these entities may have:

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substantially greater financial and other resources;



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larger research and development staffs;



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lower labor costs; and/or



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more extensive sales, marketing and manufacturing organizations.

        Many of these companies and organizations have significant experience in preclinical testing, human clinical trials, product manufacturing, marketing, sales and distribution and other regulatory approval and commercial procedures. They may also have a greater number of significant patents and greater legal resources to seek remedies for cases of alleged infringement of their patents by us to block, delay, or compromise our own drug development process.

        We expect technology developments in our industry to continue to occur at a rapid pace. Commercial developments by our competitors may render FOLOTYN obsolete or non-competitive, which would have a material adverse effect on our business and financial condition.

Government Regulation

        We operate in a highly regulated industry, which is subject to significant federal, state, local and foreign regulation. Our present and future business has been, and will continue to be, subject to a variety of laws and regulations, including the Federal Food, Drug, and Cosmetic Act, or FDC Act, the Medicaid rebate program, the Veterans Health Care Act of 1992, and the Occupational Safety and Health Act, among others.

        As a result of these laws and regulations, product development and product approval processes are very expensive and time consuming.

FDA Approval Process

        In the U.S., pharmaceutical products are subject to extensive regulation by the FDA. The FDC Act and other federal and state statutes and regulations govern, among other things, the research, development, testing, manufacture, storage, recordkeeping, approval, labeling, marketing and promotion, distribution, post-approval monitoring and reporting, sampling, and import and export of pharmaceutical products. Failure to comply with applicable U.S. requirements may subject a company to a variety of administrative or judicial sanctions, such as FDA refusal to approve pending new drug applications or NDAs, warning letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties, and criminal prosecution.

        Pharmaceutical product development in the U.S. typically involves preclinical laboratory and animal tests, the submission to the FDA of a notice of claimed investigational exemption or an investigational new drug application or IND, which must become effective before clinical testing may commence, and adequate and well-controlled clinical trials to establish the safety and effectiveness of the drug for each indication for which FDA approval is sought. Satisfaction of FDA pre-market approval requirements typically takes many years and the actual time required may vary substantially based upon the type, complexity and novelty of the product or disease.

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        Preclinical tests include laboratory evaluation, as well as animal trials to assess the characteristics and potential pharmacology and toxicity of the product. The conduct of the preclinical tests must comply with federal regulations and requirements including good laboratory practices. The results of preclinical testing are submitted to the FDA as part of an IND along with other information including information about product chemistry, manufacturing and controls and a proposed clinical trial protocol. Long term preclinical tests, such as animal tests of reproductive toxicity and carcinogenicity, may continue after the IND is submitted.

        A 30-day waiting period after the submission of each IND is required prior to the commencement of clinical testing in humans. If the FDA has not objected to the IND within this 30-day period, the clinical trial proposed in the IND may begin.

        Clinical trials involve the administration of the investigational new drug to healthy volunteers or patients under the supervision of a qualified investigator. Clinical trials must be conducted in compliance with federal regulations, good clinical practices or GCP, as well as under protocols detailing the objectives of the trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. Each protocol involving testing on U.S. patients and subsequent protocol amendments must be submitted to the FDA as part of the IND.

        The FDA may order the temporary or permanent discontinuation of a clinical trial at any time or impose other sanctions if it believes that the clinical trial is not being conducted in accordance with FDA requirements or presents an unacceptable risk to the clinical trial patients. The study protocol and informed consent information for patients in clinical trials must also be submitted to an institutional review board, or IRB, for approval. An IRB may also require the clinical trial at the site to be halted, either temporarily or permanently, for failure to comply with the IRB's requirements, or may impose other conditions.

        Clinical trials to support NDAs for marketing approval are typically conducted in three sequential phases, but the phases may overlap. In Phase 1, the initial introduction of the drug into healthy human subjects or patients, the drug is tested to assess metabolism, pharmacokinetics, pharmacological actions, side effects associated with increasing doses and, if possible, early evidence on effectiveness. In the case of product candidates for severe or life-threatening diseases such as cancer, the initial human testing is often conducted in patients rather than in healthy volunteers. Since these patients already have the target disease, these studies may provide initial evidence of efficacy traditionally obtained in Phase 2 trials and thus these trials are frequently referred to as Phase 1b trials. Additionally, when product candidates can do damage to normal cells, it is not ethical to administer such drugs to healthy patients in a Phase 1 trial. Phase 2 usually involves trials in a limited patient population to determine the effectiveness of the drug for a particular indication or indications, dosage tolerance and optimum dosage, and identify common adverse effects and safety risks. If a compound demonstrates evidence of effectiveness and an acceptable safety profile in Phase 2 evaluations, Phase 3 trials are undertaken to obtain additional information about clinical efficacy and safety in a larger number of patients, typically at geographically dispersed clinical trial sites, to permit the FDA to evaluate the overall benefit-risk relationship of the drug and to provide adequate information for the labeling of the drug. After completion of the required clinical testing, an NDA is prepared and submitted to the FDA. FDA approval of the NDA is required before marketing of the product may begin in the U.S. The NDA must include the results of all preclinical, clinical and other testing and a compilation of data relating to the product's pharmacology, chemistry, manufacture, and controls.

        The FDA has 60 days from its receipt of an NDA to determine whether the application will be accepted for filing based on the agency's threshold determination that it is sufficiently complete to permit substantive review. Once the submission is accepted for filing, the FDA begins an in-depth review. The FDA has agreed to certain performance goals in the review of NDAs. Most such applications for non-priority drug products are reviewed within ten months. The review process may be

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extended by the FDA for three additional months to consider new information submitted during the review or clarification regarding information already provided in the submission. The FDA may also refer applications for novel drug products or drug products which present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations. Before approving an NDA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP. Additionally, the FDA will inspect the facility or the facilities at which the drug is manufactured. The FDA will not approve the product unless compliance with current good manufacturing practices or cGMPs, is satisfactory and the NDA contains data that provide substantial evidence that the drug is safe and effective in the indication studied.

        After the FDA evaluates the NDA and the manufacturing facilities, it issues an approval letter or a complete response letter. An approval letter authorizes commercial marketing of the drug with specific prescribing information for specific indications. As a condition of NDA approval, the FDA may require substantial post-approval testing and surveillance to monitor the drug's safety or efficacy and may impose other conditions, including labeling restrictions which can materially affect the potential market and profitability of the drug. Once granted, product approvals may be withdrawn if compliance with regulatory standards is not maintained or problems are identified following initial marketing.

        A complete response letter outlines the deficiencies in an NDA submission and may require substantial additional testing or information in order for the FDA to reconsider the application. If and when those deficiencies have been addressed in a resubmission of the NDA, FDA will re-initiate review. If it is satisfied that the deficiencies have been addressed, the FDA will issue an approval letter. The FDA has committed to reviewing such resubmissions in two or six months depending on the type of information included. It is not unusual for the FDA to issue a complete response letter because it believes that the drug is not safe enough or effective enough or because it does not believe that the data submitted are reliable or conclusive.

Accelerated Approval

        Under the FDA's accelerated approval regulations, the FDA may approve a drug for a serious or life-threatening illness that provides meaningful therapeutic benefit to patients over existing treatments based upon a surrogate endpoint that is reasonably likely to predict clinical benefit. In clinical trials, a surrogate endpoint is a measurement of laboratory or clinical signs of a disease or condition that substitutes for a direct measurement of how a patient feels, functions or survives. Surrogate endpoints can often be measured more easily or more rapidly than clinical endpoints. A drug candidate approved on this basis is subject to rigorous post-marketing compliance requirements, including the completion of post-approval clinical trials to confirm the effect on the clinical endpoint. Failure to conduct required post-approval studies, or confirm a clinical benefit during post-approval studies, will allow the FDA to withdraw the drug from the market on an expedited basis. In addition, all promotional materials for drug candidates approved under accelerated regulations are subject to prior review by the FDA.

        FOLOTYN was approved for the treatment of patients with relapsed or refractory PTCL under the FDA's accelerated approval regulations. The approval was based on overall response rate from our PROPEL trial. In connection with the accelerated approval, we are required to conduct several post-approval studies that are intended to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphoma and assess whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment.

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Other Regulatory Requirements

        Once an NDA is approved, a product is subject to certain post-approval requirements. For instance, the FDA closely regulates the post-approval marketing and promotion of drugs, including standards and regulations for direct-to-consumer advertising, off-label promotion, industry-sponsored scientific and educational activities and promotional activities involving the internet.

        Drugs may be marketed only for the approved indications and in accordance with the provisions of the approved labeling. Changes to some of the conditions established in an approved application, including changes in indications, labeling, or manufacturing processes or facilities, require submission and FDA approval of a new NDA or NDA supplement before the change can be implemented. An NDA supplement for a new indication typically requires clinical data similar to that in the original application, and the FDA uses the same procedures and actions in reviewing NDA supplements as it does in reviewing NDAs. We cannot be certain that the FDA or any other regulatory agency will grant approval for FOLOTYN for any additional indications or any other product candidate for any indication on a timely basis, if at all.

        Adverse event reporting and submission of periodic reports is required following FDA approval of an NDA. The FDA also may require post-marketing testing, known as Phase 4 testing, risk evaluation and mitigation strategies, and surveillance to monitor the effects of an approved product or place conditions on an approval that could restrict the distribution or use of the product. In addition, quality control as well as drug manufacture, packaging, and labeling procedures must continue to conform to current good manufacturing practices, or cGMPs, after approval. Drug manufacturers and certain of their subcontractors are required to register their establishments with FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA during which the agency inspects manufacturing facilities to access compliance with cGMPs. Accordingly, manufacturers must continue to expend time, money and effort in the areas of production and quality control to maintain compliance with cGMPs. Regulatory authorities may withdraw product approvals or request product recalls if a company fails to comply with regulatory standards, if it encounters problems following initial marketing, or if previously unrecognized problems are subsequently discovered.

Orphan Drug Designation

        Orphan drug designation is granted by the FDA to drugs intended to treat a rare disease or condition, which for this program is defined as having a prevalence of less than 200,000 individuals in the U.S. Orphan drug designation must be requested before submitting a marketing application. After the FDA grants orphan drug designation, the generic identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA.

        Orphan drug designation does not shorten the regulatory review and approval process for an orphan drug, nor does it give that drug any advantage in the regulatory review and approval process. However, if an orphan drug later receives the first approval for the indication for which it has orphan drug designation, the FDA may not approve any other applications to market the same drug for the same indication, except in very limited circumstances, for seven years in the U.S. Orphan drug exclusivity may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the drug. The FDA has granted orphan drug designation to FOLOTYN for the treatment of patients with T-cell lymphoma, follicular lymphoma, diffuse large B-cell lymphoma and advanced or metastatic TCC of the urinary bladder. Upon FDA approval of FOLOTYN for the treatment of relapsed or refractory PTCL, FOLOTYN received seven years of orphan drug exclusivity for this indication until September 24, 2016.

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        Although obtaining approval to market a product with orphan drug exclusivity may be advantageous, we cannot be certain:

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that we will be the first to obtain approval for any other drugs or indications for which we obtain orphan drug designation;



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that orphan drug designation will result in any commercial advantage or reduce competition; or



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that the limited exceptions to this exclusivity will not be invoked by the FDA.

The Hatch-Waxman Act

        In seeking approval for a drug through an NDA, applicants are required to list with the FDA each patent with claims that cover the applicant's product or FDA approved method of using this product. Upon approval of a drug, each of the patents listed in the application for the drug is then published in the FDA's Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Drugs listed in the Orange Book can, in turn, be cited by potential competitors in support of approval of an abbreviated new drug application, or ANDA. An ANDA provides for marketing of a drug product that has the same active ingredients in the same strengths and dosage form as the listed drug and has been shown through bioequivalence testing to be therapeutically equivalent to the listed drug. ANDA applicants are not required to conduct or submit results of pre-clinical or clinical tests to prove the safety or effectiveness of their drug product, other than the requirement for bioequivalence testing. Drugs approved in this way are commonly referred to as "generic equivalents" to the listed drug, and can often be substituted by pharmacists under prescriptions written for the original listed drug.

        The ANDA applicant is required to certify to the FDA concerning any patents listed for the approved product in the FDA's Orange Book. Specifically, the applicant must certify that: (i) the required patent information has not been filed; (ii) the listed patent has expired; (iii) the listed patent has not expired, but will expire on a particular date and approval is sought after patent expiration; or (iv) the listed patent is invalid or will not be infringed by the new product. A certification that the new product will not infringe the already approved product's listed patents or that such patents are invalid is called a Paragraph IV certification. If the applicant does not challenge the listed patents, the ANDA application will not be approved until all the listed patents claiming the referenced product have expired.

        If the ANDA applicant has provided a Paragraph IV certification to the FDA, the applicant must also send notice of the Paragraph IV certification to the NDA and patent holders once the ANDA has been accepted for filing by the FDA. The NDA and patent holders may then initiate a patent infringement lawsuit in response to the notice of the Paragraph IV certification. The filing of a patent infringement lawsuit within 45 days of the receipt of a Paragraph IV certification notification automatically prevents the FDA from approving the ANDA until the earlier of 30 months, expiration of the patent, settlement of the lawsuit or a decision in the infringement case that is favorable to the ANDA applicant. The ANDA application also will not be approved until any non-patent exclusivity, such as exclusivity for obtaining approval of a new chemical entity, listed in the Orange Book for the referenced product has expired. Federal law provides a period of five years of exclusivity following approval of a drug containing no previously approved active moiety, during which ANDAs for generic versions of those drugs cannot be submitted unless the submission contains a Paragraph IV challenge to a listed patent, in which case the submission may be made four years following the original product approval. Federal law also provides for a period of three years of exclusivity following approval of a listed drug that contains previously approved active ingredients that is approved in a new dosage form, route of administration or combination, or for a new use, the approval of which was required to be supported by new clinical trials conducted by or for the sponsor, during which the FDA cannot grant effective approval of an ANDA based on that listed drug.

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U.S. Foreign Corrupt Practices Act

        The U.S. Foreign Corrupt Practices Act, to which we are subject, prohibits corporations and individuals from engaging in certain activities to obtain or retain business or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in an official capacity.

Federal and State Fraud and Abuse Laws

        In addition to FDA restrictions on marketing of pharmaceutical products, several other types of state and federal laws have been applied to restrict certain marketing practices in the pharmaceutical and medical device industries in recent years. These laws include anti-kickback statutes and false claims statutes.

        The federal health care program anti-kickback statute prohibits, among other things, knowingly and willfully offering, paying, soliciting, or receiving remuneration to induce or in return for purchasing, leasing, ordering, or arranging for the purchase, lease, or order of any health care item or service reimbursable under Medicare, Medicaid, or other federally financed healthcare programs. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, and formulary managers on the other. Although there are a number of statutory exemptions and regulatory safe harbors protecting certain common activities from prosecution, the exemptions and safe harbors are drawn narrowly, and practices that involve remuneration intended to induce prescribing, purchases, or recommendations may be subject to scrutiny if they do not qualify for an exemption or safe harbor. Our practices may not in all cases meet all of the criteria for safe harbor protection from anti-kickback liability.

        Federal false claims laws prohibit any person from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, or knowingly making, or causing to be made, a false statement to get a false claim paid. Recently, several pharmaceutical and other health care companies have been prosecuted under these laws for allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product. Other companies have been prosecuted for causing false claims to be submitted because of the company's marketing of the product for unapproved, and thus non-reimbursable, uses. The majority of states also have statutes or regulations similar to the federal anti-kickback law and false claims laws, which apply to items and services reimbursed under Medicaid and other state programs, or, in several states, apply regardless of the payer. Sanctions under these federal and state laws may include civil monetary penalties, exclusion of a manufacturer's products from reimbursement under government programs, criminal fines, and imprisonment.

        Because of the breadth of these laws and the narrowness of the safe harbors, it is possible that some of our business activities could be subject to challenge under one or more of such laws. Such a challenge could have a material adverse effect on our business, financial condition and results of operations.

        In addition, as part of the sales and marketing process, pharmaceutical companies frequently provide samples of approved drugs to physicians. This practice is regulated by the FDA and other governmental authorities, including, in particular, requirements concerning record keeping and control procedures. Any failure to comply with the regulations may result in significant criminal and civil penalties as well as damage to our credibility in the marketplace.

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Foreign Regulation and Product Approval

        Outside the United States, our ability to market FOLOTYN is contingent upon receiving marketing authorization from the appropriate regulatory authorities. The requirements governing the conduct of clinical trials, marketing authorization, pricing and reimbursement vary widely from country to country. At present, foreign marketing authorizations are applied for at a national level, although within the European Union centralized registration procedures are available to companies wishing to market a product in more than one European Union member state. If the regulatory authority is satisfied that adequate evidence of safety, quality and efficacy has been presented, a marketing authorization will be granted. In some countries in the European Union, pricing of prescription drugs is subject to government control and agreements must be reached on a national level before marketing may begin in that country. If we are unable to reach agreement on an acceptable price for our products, we may choose not to pursue marketing of FOLOTYN in that country. The foreign regulatory approval process involves all of the risks associated with FDA approval discussed above.

        Similar to the United States, a system for orphan drug designation exists in the European Union. FOLOTYN received orphan medicinal product designation by the European Committee for Orphan Medicinal Products for patients with nodal, other extranodal, and leukaemic/disseminated PTCL, CTCL, Hodgkin lymphoma and non-papillary TCC of the urinary bladder. Orphan designation does not shorten the regulatory review and approval process for an orphan drug, nor does it give that drug any advantage in the regulatory review and approval process. However, if an orphan drug later receives approval for the indication for which it has designation, the relevant regulatory authority may not approve any other applications to market the same drug for the same indication, except in very limited circumstances, for 10 years in the European Union.

Other Regulations

        We are also subject to numerous federal, state and local laws relating to such matters as safe working conditions, manufacturing practices, environmental protection, fire hazard control, and disposal of hazardous or potentially hazardous substances. We may incur significant costs to comply with such laws and regulations now or in the future.

Results of Operations

        Please see financial statements and "Management's Discussion and Analysis of Financial Condition and Results of Operations," included in this report for a discussion of financial information about our business segment and our expenses on research and development.

Employees

        As of February 25, 2011, we had a total of 156 full-time employees. No employee is represented by a labor union.

Other Information

        Our annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K, as well as any amendments to those reports, are available free of charge through our website as soon as reasonably practicable after we file them with, or furnish them to, the Securities and Exchange Commission, or SEC. Once at www.allos.com, go to Investors/Financial Reports to locate copies of such reports. You may also read and copy materials that we file with SEC at the SEC's Public Reference Room at 100 F Street, NE, Washington, DC 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC also maintains a website at www.sec.gov that contains reports, proxy and information statements and other information regarding us and other issuers that file electronically with the SEC.

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ITEM 1A.    RISK FACTORS

        Our business faces significant risks. These risks include those described below and may include additional risks of which we are not currently aware or that we currently do not believe are material. If any of the events or circumstances described in the following risk factors actually occurs, they may materially harm our business, financial condition, operating results and cash flow. As a result, the market price of our common stock could decline. Additional risks and uncertainties that are not yet identified or that we think are immaterial may also materially harm our business, operating results and financial condition. The following risks should be read in conjunction with the other information set forth in this report.

We have a history of net losses and an accumulated deficit, and we may never generate sufficient revenue to achieve or maintain profitability in the future.

        We have incurred significant net losses and negative cash flows from operations. To date, we have financed our operations primarily through the public and private sale of securities and net product sales. For the years ended December 31, 2010, 2009 and 2008, we had net losses of $77.4 million, $73.6 million and $51.7 million, respectively. As of December 31, 2010, we an accumulated deficit of $450.6 million. We have incurred these losses principally from costs incurred in our research and development programs and from our selling, general and administrative expenses.

        On September 24, 2009, we obtained accelerated approval from the FDA for FOLOTYN for use as a single agent for the treatment of patients with relapsed or refractory PTCL. Our ability to achieve profitability is dependent on our ability, alone or with partners, to significantly increase sales of FOLOTYN for the treatment of patients with relapsed or refractory PTCL. We are also developing FOLOTYN for use as a single agent and in combination therapy regimens in a range of hematologic malignancies and solid tumor indications, which may or may not lead to obtaining the necessary regulatory approvals to market FOLOTYN for additional indications. We expect to continue to spend substantial amounts on research and development, including amounts spent on conducting clinical trials and seeking additional regulatory approvals for FOLOTYN, and commercializing FOLOTYN for the treatment of patients with relapsed or refractory PTCL. As a result, we may never generate sufficient revenue from product sales to become profitable or generate positive cash flows.

Our near-term prospects are dependent on FOLOTYN. If we are unable to significantly increase sales of FOLOTYN for the treatment of patients with relapsed or refractory PTCL our ability to achieve profitability will be adversely affected.

        FOLOTYN is our only product approved for marketing by the FDA and our ability to generate revenue in the near term is entirely dependent upon sales of FOLOTYN. We may not be able to significantly increase sales of FOLOTYN for a number of reasons, including:

•

we may not be able to establish or demonstrate in the medical community the safety and efficacy of FOLOTYN and any potential advantages over existing therapeutics and products currently in clinical development;



•

doctors may be hesitant to prescribe FOLOTYN until results from our post-approval studies are available or other long term data regarding efficacy and safety exists;



•

results from our Phase 3 post-approval studies may fail to verify the clinical benefit of FOLOTYN for the treatment of T-cell lymphoma;



•

we may not be able to establish FOLOTYN as the second-line standard of care for PTCL;



•

our limited experience in marketing, selling and distributing FOLOTYN;



•

reimbursement and coverage policies of government and private payers such as Medicare, Medicaid, insurance companies, health maintenance organizations and other plan administrators;

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•

the relative price of FOLOTYN as compared to alternative treatment options;



•

the relatively low incidence and prevalence rates of relapsed or refractory PTCL, including the reliability of our estimates;



•

we may not have adequate financial or other resources to significantly increase sales of FOLOTYN; and



•

we may not be able to continue to manufacture FOLOTYN in commercial quantities or at acceptable costs.

        If we are unable to significantly increase sales of FOLOTYN for the treatment of patients with relapsed or refractory PTCL, our ability to achieve profitability will be adversely affected and our stock price would likely decline.

Our operating results are unpredictable and may fluctuate. If our operating results are below the expectations of securities analysts or investors, the trading price of our stock could decline.

        Our operating results to date have fluctuated from quarter to quarter and year to year. We believe that our quarterly and annual results of operations may continue to fluctuate and will be difficult to predict due to a variety of factors, including:

•

the timing and amount of revenue generated from sales of FOLOTYN;



•

the timing and costs associated with our sales and marketing activities for promoting FOLOTYN;



•

the timing and costs associated with manufacturing clinical and commercial supplies of FOLOTYN;



•

the timing and costs associated with conducting preclinical and clinical development of FOLOTYN, including the post-approval clinical studies required by the FDA;



•

the timing and costs associated with our evaluation of, and decisions with respect to, the potential development of FOLOTYN for additional therapeutic indications;



•

the timing, costs and potential revenue associated with a potential strategic partnership for the co-development of FOLOTYN globally and commercialization outside the United States; and



•

our evaluation of, and decisions with respect to, potential in-licensing or product acquisition opportunities or other strategic alternatives.

        In addition, we measure compensation cost for stock-based awards made to employees at the grant date of the award, based on the fair value of the award, and recognize the cost as an expense over the employee's requisite service period. As the variables that we use as a basis for valuing these awards change over time, including our underlying stock price, the magnitude of the expense that we must recognize may vary significantly. Any such variance from one period to the next could cause a significant fluctuation in our operating results.

        For these reasons, it is difficult for us to accurately forecast future profits or losses. As a result, it is possible that in some quarters our operating results could be below the expectations of securities analysts or investors, which could cause the trading price of our common stock to decline, perhaps substantially.

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If we are unable to maintain adequate sales, marketing or distribution capabilities or enter into agreements with third parties to perform some of these functions, we will not be able to commercialize FOLOTYN effectively.

        The approval of FOLOTYN for the treatment of patients with relapsed or refractory PTCL is our first U.S. approval. Accordingly, we have limited experience in sales, marketing and distribution of pharmaceutical products. We may not be able to adequately maintain the necessary sales, marketing, supply chain management and reimbursement capabilities on our own or enter into arrangements with third parties to perform these functions in a timely manner or on acceptable terms. Additionally, maintaining sales, marketing and distribution capabilities may be more expensive than we anticipate, requiring us to divert capital from other intended purposes or preventing us from building our sales, marketing and distribution capabilities to the desired levels. To be successful we must:

•

recruit and retain adequate numbers of effective sales personnel;



•

effectively train our sales personnel in the benefits of FOLOTYN;



•

establish and maintain successful sales and marketing and education programs that encourage physicians to recommend FOLOTYN to their patients; and



•

manage geographically dispersed sales and marketing operations.

        The commercialization of FOLOTYN requires us to manage relationships with an increasing number of collaborative partners, suppliers and third-party contractors. If we are unable to successfully establish and maintain the required infrastructure, either internally or through third parties, and successfully manage an increasing number of relationships, we will have difficulty growing our business. In addition, we intend to enter into co-promotion or out-licensing arrangements with other pharmaceutical or biotechnology partners where necessary to reach foreign market segments and when deemed strategically and economically advisable. To the extent that we enter into co-promotion or other licensing arrangements, our product revenues are likely to be lower than if we directly marketed and sold FOLOTYN, and some or all of the revenues we receive will depend upon the efforts of third parties, which may not be successful. If we are unable to develop and maintain adequate sales, marketing and distribution capabilities, independently or with others, we may not be able to significantly increase sales of FOLOTYN or become profitable.

Even though we have obtained accelerated approval to market FOLOTYN for the treatment of patients with relapsed or refractory PTCL, we are subject to ongoing regulatory obligations and review, including post-approval requirements.

        FOLOTYN was approved for the treatment of patients with relapsed or refractory PTCL under the FDA's accelerated approval regulations, which allow the FDA to approve products for cancer or other life threatening diseases based on initial positive data from clinical trials. Under these provisions, we are subject to certain post-approval requirements pursuant to which we are required to conduct two randomized Phase 3 trials to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphoma. The FDA has also required that we conduct two Phase 1 trials to assess whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment. Failure to complete the studies or adhere to the timelines established by the FDA could result in penalties, including fines or withdrawal of FOLOTYN from the market. The FDA may also initiate proceedings to withdraw approval if our Phase 3 studies fail to verify clinical benefit. Further, the FDA may require us to strengthen the warnings and precautions section of the FOLOTYN package insert or institute a Risk Evaluation and Mitigation Strategy based on the results of these studies or clinical experience. We are also subject to additional, continuing post-approval regulatory obligations, including the possibility of additional clinical studies required by the FDA, safety reporting requirements and regulatory oversight of the promotion and marketing of FOLOTYN.

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        In addition, we or our third-party manufacturers are required to adhere to regulations setting forth the FDA's current Good Manufacturing Practices, or cGMP. These regulations cover all aspects of the manufacturing, storage, testing, quality control and record keeping relating to FOLOTYN. Furthermore, we or our third-party manufacturers are subject to periodic inspection by the FDA and foreign regulatory authorities to ensure compliance with cGMP or other applicable government regulations and corresponding foreign standards. We have limited control over a third-party manufacturer's compliance with these regulations and standards. If we or our third-party manufacturers fail to comply with applicable regulatory requirements, we may be subject to fines, suspension, modification or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

The status of coverage and reimbursement from third-party payers for newly approved health care drugs is uncertain and failure to obtain adequate coverage and reimbursement could limit our ability to generate revenue.

        Our ability to successfully commercialize FOLOTYN for the treatment of patients with relapsed or refractory PTCL or for other future indications will depend, in part, on the extent to which coverage and reimbursement for FOLOTYN is available from government and health administration authorities, private health insurers, managed care programs and other third-party payers. Significant uncertainty exists as to the coverage and reimbursement of newly approved health care products. In addition, in March 2010, the U.S. Congress enacted legislation to reform the health care system that includes cost containment measures that may adversely affect the amount of reimbursement for pharmaceutical products, including FOLOTYN. These measures include increasing the minimum rebates for products covered by Medicaid programs and extending such rebates to drugs dispensed to Medicaid beneficiaries enrolled in Medicaid managed care organizations as well as expansion of the 340B Public Health Services drug discount program.

        Healthcare providers and third-party payers use coding systems to identify diagnoses, procedures, services, drugs, pharmaceutical devices, equipment and other health-related items and services. Proper coding is an integral component to receiving appropriate reimbursement for the administration of FOLOTYN and related services. The majority of payers use nationally recognized code sets to report medical conditions, services and drugs. We obtained transitional pass-through status that enables FOLOTYN to be reimbursed under the hospital outpatient prospective payment system. In addition, in January 2011 we received a permanent reimbursement J-Code for FOLOTYN, although healthcare providers prescribing FOLOTYN were recently required to submit claims for reimbursement using a temporary J-Code, which may result in payment delays or incorrect payment levels. We cannot predict at this time whether our customers will receive adequate reimbursement for FOLOTYN.

        Third-party payers, including Medicare, are challenging the prices charged for medical products and services. Government and other third-party payers increasingly are attempting to contain health care costs by limiting both coverage and the level of reimbursement for new drugs and by refusing, in some cases, to provide coverage for uses of approved products for disease conditions for which the FDA has not granted labeling approval. Third-party insurance coverage may not be available to patients for FOLOTYN. If government and other third-party payers do not provide adequate coverage and reimbursement levels for FOLOTYN, FOLOTYN's market acceptance may be adversely affected.

We are dependent upon a small number of customers for a significant portion of our revenue, and the loss of, or significant reduction or cancellation in sales to, any one of these customers could adversely affect our results of operations and financial condition.

        In the United States, we sell FOLOTYN to a small number of distributors who in turn sell-through to patient health care providers. These distributors also provide multiple logistics services relating to the distribution of FOLOTYN, including transportation, warehousing, cross-docking,

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inventory management, packaging and freight-forwarding. We do not promote FOLOTYN to these distributors and they do not set or determine demand for FOLOTYN. For the years ended December 31, 2010 and 2009, three companies affiliated with AmerisourceBergen Corporation accounted for substantially all of our FOLOTYN sales. We expect significant customer concentration to continue for the foreseeable future. Our ability to generate sales of FOLOTYN will depend, in part, on the extent to which these distributors are able to provide adequate distribution of FOLOTYN to patient health care providers. Although we believe we can find alternative distributors on a relatively short notice, our revenue during that period of time may suffer and we may incur additional costs to replace a distributor. The loss of any large customer, a significant reduction in sales we make to them, any cancellation of orders they have made with us or any failure to pay for the products we have shipped to them could materially and adversely affect our results of operations and financial condition.

If the distributors that we rely upon to sell FOLOTYN fail to perform, our business may be adversely affected.

        Our success depends on the continued customer support efforts of our network of distributors. The use of distributors involves certain risks, including, but not limited to, risks that these distributors will:

•

not provide us with accurate or timely information regarding their inventories, the number of patients who are using FOLOTYN or complaints about FOLOTYN;



•

not effectively distribute or support FOLOTYN;



•

reduce or discontinue their efforts to sell or support FOLOTYN;



•

be unable to satisfy financial obligations to us or others; and



•

cease operations.

        Any such failure may result in decreased sales of FOLOTYN, which would harm our business.

If we fail to comply with healthcare fraud and abuse laws, we could face substantial penalties and our business, operations and financial condition could be adversely affected.

        As a biopharmaceutical company, even though we do not and will not control referrals of health care services or bill directly to Medicare, Medicaid or other third-party payers, certain federal and state healthcare laws and regulations pertaining to fraud and abuse are applicable to our business. These laws and regulations, include, among others:

•

the federal Anti-Kickback statute, which prohibits, among other things, persons from soliciting, receiving or providing remuneration, directly or indirectly, to induce either the referral of an individual for an item or service or the purchasing or ordering of a good or service, for which payment may be made under federal health care programs such as the Medicare and Medicaid programs;



•

federal false claims laws that prohibit, among other things, individuals or entities from knowingly presenting, or causing to be presented, claims for payment from Medicare, Medicaid, or other third-party payers that are false or fraudulent;



•

the federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which prohibits executing a scheme to defraud any healthcare benefit program or making false statements relating to healthcare matters and which also imposes certain requirements relating to the privacy, security and transmission of individually identifiable health information;



•

federal self-referral laws, such as STARK, which prohibit a physician from making a referral to a provider of certain health services with which the physician or the physician's family member has a financial interest; and

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•

state law equivalents of each of the above federal laws, such as anti-kickback and false claims laws that may apply to items or services reimbursed by any third-party payer, including commercial insurers, and state laws governing the privacy of health information in certain circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA.

        Although there are a number of statutory exemptions and regulatory safe harbors protecting certain common activities from prosecution under the federal Anti-Kickback statute, the exemptions and safe harbors are drawn narrowly, and practices that involve remuneration intended to induce prescriptions, purchases or recommendations may be subject to scrutiny if they do not qualify for an exemption or safe harbor. Further, the recently enacted health care reform law known as the Patient Protection and Affordable Care Act, as modified by the Health Care and Education Affordability Reconciliation Act of 2010, or PPACA, amends the intent requirement of the federal anti-kickback and criminal health care fraud statutes. A person or entity no longer needs to have actual knowledge of this statute or specific intent to violate it. In addition, the government may assert that a claim including items or services resulting from a violation of the federal anti-kickback statute constitutes a false or fraudulent claim for purposes of the false claims laws. Our practices may not in all cases meet all of the criteria for safe harbor protection from anti-kickback liability.

        Although physicians are permitted to, based on their medical judgment, prescribe products for indications other than those cleared or approved by the FDA, manufacturers are prohibited from promoting their products for such off-label uses. We market FOLOTYN for the treatment of patients with relapsed or refractory PTCL and provide promotional materials and training programs to physicians regarding the use of FOLOTYN for the treatment of patients with relapsed or refractory PTCL. Although we believe our marketing, promotional materials and training programs for physicians do not constitute off-label promotion of FOLOTYN, the FDA may disagree. If the FDA determines that our promotional materials, training or other activities constitute off-label promotion of FOLOTYN, the FDA could request that we modify our training or promotional materials or other activities or subject us to regulatory enforcement actions, including the issuance of a warning letter, injunction, seizure, civil fine and criminal penalties. It is also possible that other federal, state or foreign enforcement authorities might take action if they believe that the alleged improper promotion led to the submission and payment of claims for an unapproved use, which could result in significant fines or penalties under other statutory authorities, such as laws prohibiting false claims for reimbursement. Even if it is later determined we are not in violation of these laws, we may be faced with negative publicity, incur significant expenses defending our position and have to divert significant management resources from other matters.

        The PPACA imposes new reporting and disclosure requirements for pharmaceutical and device manufacturers with regard to payments or other transfers of value made to physicians and teaching hospitals, effective March 30, 2013. Such information will be made publicly available in a searchable format beginning September 30, 2013. In addition, pharmaceutical and device manufacturers will also be required to report and disclose investment interests held by physicians and their immediate family members during the preceding calendar year. Failure to submit required information may result in civil monetary penalties of up to $150,000 per year (and up to $1 million per year for "knowing failures"), for all payments, transfers of value or ownership or investment interests not reported in an annual submission.

        In recent years, several states and localities, including California, the District of Columbia, Maine, Massachusetts, Minnesota, Nevada, Vermont, and West Virginia, have enacted legislation requiring pharmaceutical companies to establish marketing compliance programs, and file periodic reports with the state or make periodic public disclosures on sales, marketing, pricing, clinical trials, and other activities. Similar legislation is being considered in other states. Many of these requirements are new and uncertain, and the penalties for failure to comply with these requirements are unclear. Nonetheless, if we are found not to be in full compliance with these laws, we could face enforcement action and fines and other penalties, and could receive adverse publicity.

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        If our operations are found to be in violation of any of the healthcare fraud and abuse laws described above or any other governmental regulations that apply to us, we may be subject to penalties, including civil and criminal penalties, damages, fines and the curtailment or restructuring of our operations. Any penalties, damages, fines, curtailment or restructuring of our operations could adversely affect our ability to operate our business and our financial results. Although compliance programs can mitigate the risk of investigation and prosecution for violations of these laws, the risks cannot be entirely eliminated. Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management's attention from the operation of our business. Moreover, achieving and sustaining compliance with all applicable federal and state fraud and abuse laws may be costly.

If our competitors develop and market products that are more effective than FOLOTYN, our commercial opportunity will be reduced or eliminated.

        Even though we have obtained approval to market FOLOTYN for the treatment of patients with relapsed or refractory PTCL, our commercial opportunity will be reduced or eliminated if our competitors develop and market products that are more effective, have fewer side effects or are less expensive than FOLOTYN for this or any other potential indication. Our potential competitors include large, fully-integrated pharmaceutical companies and more established biotechnology companies, each of which have significant resources and expertise in research and development, manufacturing, testing, obtaining regulatory approvals and marketing. Academic institutions, government agencies, and other public and private research organizations conduct research, seek patent protection and establish collaborative arrangements for research, development, manufacturing and marketing. It is possible that competitors will succeed in developing technologies that are more effective than those being developed by us or that would render our technologies obsolete or noncompetitive.

We cannot predict when or if we will obtain regulatory approval to market FOLOTYN in the United States for any additional indications or in any other countries.

        We are subject to stringent regulations with respect to product safety and efficacy by various international, federal, state and local authorities. FOLOTYN has not been approved for marketing in the United States for any indication other than the treatment of patients with relapsed or refractory PTCL. In addition, FOLOTYN has not been approved for marketing for this or any other indication in any other country. A pharmaceutical product cannot be marketed in the United States or most other countries until it has completed a rigorous and extensive regulatory review and approval process. Satisfaction of regulatory requirements typically takes many years, is dependent upon the type, complexity and novelty of the product and requires the expenditure of substantial resources. Of particular significance are the requirements covering research and development, preclinical and clinical testing, manufacturing, quality control, labeling and promotion of drugs for human use. We may not obtain the necessary regulatory approvals to market FOLOTYN in the United States for any additional indications or in any other countries. If we fail to obtain or maintain regulatory approvals to market FOLOTYN in the United States for any additional indications or in any other countries, our ability to generate significant revenue or achieve profitability may be adversely affected.

Reports of adverse events or safety concerns involving FOLOTYN or similar small molecule chemotherapeutic agents could delay or prevent us from obtaining or maintaining regulatory approval or negatively impact sales of FOLOTYN.

        FOLOTYN may cause serious adverse events. These adverse events could interrupt, delay or halt clinical trials of FOLOTYN, including the FDA-required post-approval studies, and could result in the FDA or other regulatory authorities denying or withdrawing approval of FOLOTYN for any or all indications, including for the treatment of patients with relapsed or refractory PTCL. Adverse events

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may also negatively impact the sales of FOLOTYN. The FDA, other regulatory authorities or we may suspend or terminate clinical trials at any time. We may also be required to update the warnings and precautions section of the FOLOTYN package insert based on reports of adverse events or safety concerns or implement a Risk Evaluation and Mitigation Strategy, which could adversely affect FOLOTYN's acceptance in the market. We cannot assure you that FOLOTYN will be safe for human use.

        At present, there are a number of clinical trials being conducted by other pharmaceutical companies involving small molecule chemotherapeutic agents. If other pharmaceutical companies announce that they observed frequent adverse events or unknown safety issues in their trials involving compounds similar to, or competitive with, FOLOTYN, we could encounter delays in the timing of our clinical trials or difficulties in obtaining or maintaining the necessary regulatory approvals for FOLOTYN. In addition, the public perception of FOLOTYN might be adversely affected, which could harm our business and results of operations and cause the market price of our common stock to decline, even if the concern relates to another company's product or product candidate.

If FOLOTYN fails to meet safety or efficacy endpoints in clinical trials for additional indications, it will not receive regulatory approval and we will be unable to market FOLOTYN for those indications studied.

        We have ongoing clinical trials involving FOLOTYN and plan to initiate additional trials to evaluate FOLOTYN's potential clinical utility in other hematologic malignancies. FOLOTYN may not prove to be safe and efficacious in clinical trials for other indications and may not meet all of the applicable regulatory requirements needed to receive regulatory approval for those indications. The clinical development and regulatory approval process is expensive and takes many years. Failure can occur at any stage of development, and the timing of any regulatory approval cannot be accurately predicted. In addition, failure to comply with the FDA and other applicable U.S. and foreign regulatory requirements applicable to clinical trials may subject us to administrative or judicially imposed sanctions.

        As part of the regulatory approval process, we must conduct clinical trials for FOLOTYN and any other product candidate to demonstrate safety and efficacy to the satisfaction of the FDA and other regulatory authorities abroad. The number and design of clinical trials that will be required varies depending on the product candidate, the condition being evaluated, the trial results and regulations applicable to any particular product candidate. The designs of our clinical trials for FOLOTYN are based on many assumptions about the expected effect of FOLOTYN, and if those assumptions prove incorrect, the clinical trials may not demonstrate the safety or efficacy of FOLOTYN. Preliminary results may not be confirmed upon full analysis of the detailed results of a trial, and prior clinical trial program designs and results may not be predictive of future clinical trial designs or results. Product candidates in later stage clinical trials may fail to show the desired safety and efficacy despite having progressed through initial clinical trials with acceptable endpoints. For example, we terminated the development of EFAPROXYN, one of our former product candidates, when it failed to demonstrate statistically significant improvement in overall survival in the targeted patients in a Phase 3 clinical trial. If FOLOTYN fails to show clinically significant benefits in any clinical trial or for any particular indication, it may not be approved for marketing for such indication. Additionally, if FOLOTYN is demonstrated to be unsafe in clinical trials for other indications, such demonstration could negatively impact FOLOTYN's existing approval for the treatment of patients with relapsed or refractory PTCL.

        Even if we achieve positive interim results in clinical trials, these results do not necessarily predict final results, and acceptable results in early trials may not be repeated in later trials. Data obtained from preclinical and clinical activities are susceptible to varying interpretations that could delay, limit or prevent regulatory clearances, and the FDA can request that we conduct additional clinical trials. A number of companies in the pharmaceutical industry have suffered significant setbacks in advanced clinical trials, even after promising results in earlier trials. In addition, negative or inconclusive results

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or adverse safety events during a clinical trial could cause a clinical trial to be repeated or terminated. Also, failure to construct clinical trial protocols to screen patients for risk profile factors relevant to the trial for purposes of segregating patients into the patient populations treated with the drug being tested and the control group could result in either group experiencing a disproportionate number of adverse events and could cause a clinical trial to be repeated or terminated. If we have to conduct additional clinical trials for FOLOTYN for any particular indication, it will significantly increase our expenses and may delay marketing of FOLOTYN for such indication.

Even if FOLOTYN meets safety and efficacy endpoints in clinical trials for additional indications, regulatory authorities may not approve FOLOTYN, or we may face post-approval problems that require withdrawal of FOLOTYN from the market.

        We will not be able to market FOLOTYN in the United States for any additional indications or in any other countries for any indications until we have obtained the necessary regulatory approvals. Our receipt of approval of FOLOTYN in the United States for the treatment of patients with relapsed or refractory PTCL does not guarantee that we will obtain regulatory approval to market FOLOTYN in the United States for any additional indications or in any other countries. We have limited experience in filing and pursuing applications necessary to gain regulatory approvals, which may place us at risk of delays, overspending and human resources inefficiencies.

        FOLOTYN may not be approved for any additional indications even if it achieves its endpoints in clinical trials. Regulatory agencies, including the FDA, or their advisors, may disagree with our interpretations of data from preclinical studies and clinical trials. The FDA has substantial discretion in the approval process, and when or whether regulatory approval will be obtained for any drug we develop. Regulatory agencies also may approve a product candidate for fewer conditions than requested or may grant approval subject to the performance of post-approval studies or Risk Evaluation and Mitigation Strategies for a product candidate. In addition, regulatory agencies may not approve the labeling claims that are necessary or desirable for the successful commercialization of FOLOTYN.

        Following regulatory approval for any additional indication, FOLOTYN may later produce adverse events that limit or prevent its widespread use or that force us to withdraw FOLOTYN from the market for that indication or other indications. In addition, a marketed product continues to be subject to strict regulation after approval and may be required to undergo post-approval studies. For example, we are required to conduct two randomized Phase 3 trials to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphoma as well as two Phase 1 trials to assess whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment. Any unforeseen problems with an approved product, any failure to meet the post-approval study requirements or any violation of regulations could result in restrictions on the product, including its withdrawal from the market. Any delay in or failure to obtain or maintain regulatory approvals for FOLOTYN in the United States for any additional indication or in any other countries could harm our business and prevent us from ever generating significant revenues or achieving profitability.

When we seek approval for FOLOTYN in other countries, we are subject to numerous complex regulatory requirements and if approval is denied or limited in another country, or if another country imposes post-marketing requirements, that decision could affect our ability to market FOLOTYN in other countries.

        We have filed an MAA with the EMA for FOLOTYN for the treatment of patients with relapsed or refractory PTCL, using the centralized procedure. If major objections are raised during the review procedure, we may not receive marketing approval and would be unable to commercialize FOLOTYN in the European Union. Alternatively, the marketing authorization may be subject to conditions for approval or post authorization obligations. Such conditions or obligations may be costly and time consuming to fulfill and may affect our operations. For example, additional clinical data may be required to confirm the safety or efficacy profile of FOLOTYN in the target patient population. In

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addition, marketing authorizations are subject to periodic reviews, which, if negative, could affect our ability to commercialize FOLOTYN in the European Union.

        Additionally, failure to comply with, or changes to, the regulatory requirements that are applicable to FOLOTYN may result in a variety of consequences, including the following:

•

restrictions on FOLOTYN or our manufacturing processes;



•

warning letters;



•

withdrawal of FOLOTYN from the market;



•

voluntary or mandatory recall of FOLOTYN;



•

fines against us;



•

suspension or withdrawal of regulatory approvals for FOLOTYN;



•

suspension or termination of any of our ongoing clinical trials of FOLOTYN;



•

refusal to permit import or export of FOLOTYN;



•

refusal to approve pending applications or supplements to approved applications that we submit;



•

denial of permission to file an application or supplement in a jurisdiction;



•

product seizure; and



•

injunctions, consent decrees, or the imposition of civil or criminal penalties against us.

We may experience delays in our clinical trials that could adversely affect our financial position and our commercial prospects.

        We do not know when our current clinical trials will be completed, if at all. We also cannot accurately predict when other planned clinical trials will begin or be completed. Many factors affect patient enrollment, including the size of the patient population, the proximity of patients to clinical sites, the eligibility criteria for the trial, competing clinical trials and new drugs approved for the conditions we are investigating. Other companies are conducting clinical trials and have announced plans for future trials that are seeking or likely to seek patients with the same diseases as those we are studying. Competition for patients in some cancer trials is particularly intense because of the limited number of leading specialist physicians and the geographic concentration of major clinical centers.

        As a result of the numerous factors that can affect the pace of progress of clinical trials, our trials may take longer to enroll patients than we anticipate, if they can be completed at all. Delays in patient enrollment in the trials may increase our costs and slow our product development and approval process. Our product development costs will also increase if we need to perform more or larger clinical trials than planned. If other companies' product candidates show favorable results, we may be required to conduct additional clinical trials to address changes in treatment regimens or for our products to be commercially competitive. Any delays in completing our clinical trials will delay our ability to obtain regulatory approval to market FOLOTYN in the United States for any additional indications or in any other countries, which may adversely affect our ability to generate significant revenues or achieve profitability.

We may be required to suspend, repeat or terminate our clinical trials if they are not conducted in accordance with regulatory requirements, the results are negative or inconclusive or the trials are not well designed.

        Clinical trials must be conducted in accordance with current Good Clinical Practices, or cGCP, or other applicable foreign government guidelines and are subject to oversight by the FDA, foreign governmental agencies and Institutional Review Boards at the medical institutions where the clinical

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trials are conducted. In addition, clinical trials must be conducted with product candidates produced under cGMP and may require large numbers of test subjects. Clinical trials may be suspended by the FDA, foreign governmental agencies, or us for various reasons, including:

•

deficiencies in the conduct of the clinical trials, including failure to conduct the clinical trial in accordance with regulatory requirements or clinical protocols;



•

deficiencies in the clinical trial operations or trial sites;



•

the product candidate may have unforeseen adverse side effects;



•

the time required to determine whether the product candidate is effective may be longer than expected;



•

fatalities or other adverse events arising during a clinical trial due to medical problems that may not be related to clinical trial treatments;



•

the product candidate may appear to be less effective than current therapies;



•

the quality or stability of the product candidate may fall below acceptable standards; or



•

insufficient quantities of the product candidate to complete the trials.

        In addition, changes in regulatory requirements and guidance may occur and we may need to amend clinical trial protocols to reflect these changes. Amendments may require us to resubmit our clinical trial protocols to Institutional Review Boards for reexamination, which may impact the costs, timing or successful completion of a clinical trial. Due to these and other factors, FOLOTYN could take a significantly longer time to gain regulatory approval for any additional indications than we expect or we may never gain approval for additional indications, which could reduce our revenue by delaying or terminating the commercialization of FOLOTYN for additional indications.

Due to our reliance on contract research organizations and other third parties to conduct our clinical trials, we are unable to directly control the timing, conduct and expense of our clinical trials.

        We rely primarily on third parties to conduct our clinical trials. As a result, we have had and will continue to have less control over the conduct of our clinical trials, the timing and completion of the trials, the required reporting of adverse events and the management of data developed through the trial than would be the case if we were relying entirely upon our own staff. Communicating with outside parties can also be challenging, potentially leading to mistakes as well as difficulties in coordinating activities. Outside parties may have staffing difficulties, may undergo changes in priorities or may become financially distressed, any of which may adversely affect their willingness or ability to conduct our trials. We may experience unexpected cost increases that are beyond our control. Problems with the timeliness or quality of the work of a contract research organization may lead us to seek to terminate the relationship and use an alternative service provider. However, making this change may be costly and may delay our trials, and contractual restrictions may make such a change difficult or impossible. Additionally, it may be impossible to find a replacement organization that can conduct our trials in an acceptable manner and at an acceptable cost.

We may need to raise additional capital to support our future operations. If we fail to obtain the capital necessary to fund our operations, we will be unable to successfully develop or commercialize FOLOTYN.

        Based upon the current status of our product development and commercialization plans, we believe that our cash, cash equivalents, and investments as of December 31, 2010, should be adequate to support our operations through at least the next 12 months, although there can be no assurance that this can, in fact, be accomplished. We anticipate continuing our current development programs and beginning other long-term development projects involving FOLOTYN, including the post-approval

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clinical studies required for FOLOTYN. These projects may require many years and substantial expenditures to complete and may ultimately be unsuccessful. In addition, we expect to incur significant costs relating to the commercialization of FOLOTYN, including costs related to our sales and marketing, medical affairs and manufacturing operations. Therefore, we may need to raise additional capital to support our future operations. Our actual capital requirements will depend on many factors, including:

•

the timing and amount of revenue generated from sales of FOLOTYN;



•

the timing and costs associated with our sales and marketing activities for promoting FOLOTYN;



•

the timing and costs associated with manufacturing clinical and commercial supplies of FOLOTYN;



•

the timing and costs associated with conducting preclinical and clinical development of FOLOTYN, including the post-approval clinical studies required by the FDA;



•

the timing and costs associated with our evaluation of, and decisions with respect to, the potential development of FOLOTYN for additional therapeutic indications;



•

the timing, costs and potential revenue associated with a potential strategic partnership for the co-development of FOLOTYN globally and commercialization outside the United States; and



•

our evaluation of, and decisions with respect to, potential in-licensing or product acquisition opportunities or other strategic alternatives.

        We may seek to obtain this additional capital through equity or debt financings, arrangements with corporate partners, or from other sources. Such financings or arrangements, if successfully consummated, may be dilutive to our existing stockholders. However, there is no assurance that additional financing will be available when needed, or that, if available, we will obtain such financing on terms that are favorable to our stockholders or us. In the event that additional funds are obtained through arrangements with collaborative partners or other sources, such arrangements may require us to relinquish rights to some of our technologies, product candidates or products under development, which we might otherwise seek to develop or commercialize ourselves, on terms that are less favorable than might otherwise be available. If we are unable to significantly increase sales of FOLOTYN or cannot otherwise raise sufficient additional funds to support our operations, we may be required to delay, reduce the scope of or eliminate one or more of our development programs and our business and future prospects for profitability may be harmed.

Budget constraints may force us to delay our efforts to develop FOLOTYN for additional indications while we complete the post-approval clinical studies required by the FDA, which may prevent us from commercializing FOLOTYN for all desired indications as quickly as possible.

        Because we have limited resources, and because research and development is an expensive process, we must regularly assess the most efficient allocation of our research and development budget. In particular, our approval of FOLOTYN in patients with relapsed or refractory PTCL is conditioned upon us undertaking two additional Phase 3 studies and two additional Phase 1 studies which will result in significant additional expense. As a result of our limited resources, we may have to prioritize the development of FOLOTYN for additional indications and may not be able to fully realize the value of FOLOTYN for other indications in a timely manner, if at all.

        For example, in January 2011, we announced that we will not pursue Phase 3 studies for NSCLC at this time in order to prioritize our resources on the development and commercialization of FOLOTYN for the treatment of hematologic malignancies, and to manage our operating costs and expenses.

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We do not have manufacturing facilities or capabilities and are dependent on third parties to fulfill our manufacturing needs, which could result in the delay of clinical trials, regulatory approvals, product introductions and commercial sales.

        We are dependent on third parties for the manufacture and storage of FOLOTYN for clinical trials and for commercial sale. If we are unable to contract for a sufficient supply of FOLOTYN on acceptable terms, or if we encounter delays or difficulties in the manufacturing process or our relationships with our manufacturers, we may not have sufficient product to conduct or complete our clinical trials or support commercial requirements for FOLOTYN.

        FOLOTYN is cytotoxic, which requires the manufacturers of FOLOTYN to have specialized equipment and safety systems to handle such a substance. In addition, the starting materials for FOLOTYN require custom preparations, which require us to manage an additional set of suppliers to obtain the needed supplies of FOLOTYN.

        We have arrangements with two third-party manufacturers to produce FOLOTYN bulk drug substance and two third-party manufacturers to produce FOLOTYN formulated drug product. We believe these third-party manufacturers have the capability to meet our projected worldwide clinical trial and commercial requirements for FOLOTYN although we cannot assure you of this. In particular, our third party manufacturers may not be able to fulfill our potential commercial needs or meet our deadlines, or the components they supply to us may not meet our specifications and quality policies and procedures. If we need to find additional alternative suppliers of FOLOTYN or its components, we may not be able to contract for those components on acceptable terms, if at all. Any such failure to supply or delay caused by such suppliers would have an adverse effect on our ability to continue clinical development of FOLOTYN or commercialize FOLOTYN.

        Our current or future manufacturers may be unable to accurately and reliably manufacture commercial quantities of FOLOTYN at reasonable costs, on a timely basis and in compliance with the FDA's cGMP. If our current or future contract manufacturers fail in any of these respects, our ability to timely complete our clinical trials, obtain or maintain required regulatory approvals and successfully commercialize FOLOTYN may be materially and adversely affected. This risk may be heightened with respect to FOLOTYN as there are a limited number of manufacturers with the ability to handle cytotoxic products such as FOLOTYN. Our reliance on contract manufacturers exposes us to additional risks, including:

•

our current and future manufacturers are subject to ongoing, periodic, unannounced inspections by the FDA and corresponding state and international regulatory authorities for compliance with strictly enforced cGMP regulations and similar state and foreign standards, and we do not have control over our contract manufacturers' compliance with these regulations and standards;



•

our manufacturers may not be able to comply with applicable regulatory requirements, which would prohibit them from manufacturing products for us;



•

our manufacturers may have staffing difficulties, may undergo changes in control or may become financially distressed, adversely affecting their willingness or ability to manufacture products for us;



•

our manufacturers might not be able to fulfill our commercial needs, which would require us to seek new manufacturing arrangements and may result in substantial delays in meeting market demands;



•

if we need to change to other commercial manufacturing contractors, the FDA and comparable foreign regulators must approve our use of any new manufacturer, which would require additional testing, regulatory filings and compliance inspections, and the new manufacturers

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would have to be educated in, or themselves develop substantially equivalent processes necessary for, the production of our products; and

•

we may not have intellectual property rights, or may have to share intellectual property rights, to any improvements in the manufacturing processes or new manufacturing processes for our products.

        Any of these factors could result in the delay of clinical trials, regulatory submissions, required approvals or commercialization of FOLOTYN. They could also entail higher costs and result in our being unable to effectively commercialize FOLOTYN.

If we are unable to effectively protect our intellectual property, we will be unable to prevent third parties from using our technology, which would impair our competitiveness and ability to commercialize FOLOTYN. In addition, enforcing our proprietary rights may be expensive and result in increased losses.

        Our success will depend in part on our ability to obtain and maintain meaningful patent protection for FOLOTYN, both in the United States and in other countries. We rely on patents to protect a large part of our intellectual property and our competitive position. Any patents issued to or licensed by us could be challenged, invalidated, infringed, circumvented or held unenforceable, based on, among other things, obviousness, inequitable conduct, anticipation or enablement. In addition, it is possible that no patents will issue on any of our licensed patent applications. It is possible that the claims in patents that have been issued or licensed to us or that may be issued or licensed to us in the future will not be sufficiently broad to protect our intellectual property or that the patents will not provide protection against competitive products or otherwise be commercially valuable. Failure to obtain and maintain adequate patent protection for our intellectual property would impair our ability to be commercially competitive.

        Our commercial success will also depend in part on our ability to commercialize FOLOTYN without infringing patents or other proprietary rights of others or breaching the licenses granted to us. We may not be able to obtain a license to third-party technology that we may require to conduct our business or, if obtainable, we may not be able to license such technology at a reasonable cost. If we fail to obtain a license to any technology that we may require to commercialize FOLOTYN, or fail to obtain a license at a reasonable cost, we will be unable to commercialize FOLOTYN or to commercialize at a price that will allow us to become profitable.

        In addition to patent protection, we also rely upon trade secrets, proprietary know-how and technological advances that we seek to protect through confidentiality agreements with our collaborators, employees, advisors and consultants. Our employees and consultants are required to enter into confidentiality agreements with us. We also enter into non-disclosure agreements with our collaborators and vendors, which agreements are intended to protect our confidential information delivered to third parties for research and other purposes. However, these agreements could be breached and we may not have adequate remedies for any breach, or our trade secrets and proprietary know-how could otherwise become known or be independently discovered by others.

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        Furthermore, as with any pharmaceutical company, our patent and other proprietary rights are subject to uncertainty. Our patent rights related to FOLOTYN might conflict with current or future patents and other proprietary rights of others. For the same reasons, the products of others could infringe our patents or other proprietary rights. Litigation or patent interference proceedings, either of which could result in substantial costs to us, may be necessary to enforce any of our patents or other proprietary rights, or to determine the scope and validity or enforceability of other parties' proprietary rights. We may be dependent on third parties, including our licensors, for cooperation and information that may be required in connection with the defense and prosecution of our patents and other proprietary rights. The defense and prosecution of patent and intellectual property infringement claims are both costly and time consuming, even if the outcome is favorable to us. Any adverse outcome could subject us to significant liabilities to third parties, require disputed rights to be licensed from third parties, or require us to cease selling our future products. We are not currently a party to any patent or other intellectual property infringement claims.

We may explore strategic partnerships that may never materialize or may fail.

        We may, in the future, periodically explore a variety of possible strategic partnerships in an effort to gain access to additional product candidates or resources. For example, we are currently seeking a strategic partnership for the potential co-development of FOLOTYN globally and commercialization outside the United States. At the current time, we cannot predict what form such a strategic partnership might take. We are likely to face significant competition in seeking appropriate strategic partners, and these strategic partnerships can be complicated and time consuming to negotiate and document. We may not be able to negotiate strategic partnerships on acceptable terms, or at all. We are unable to predict when, if ever, we will enter into any additional strategic partnerships because of the numerous risks and uncertainties associated with establishing strategic partnerships.

If we enter into one or more strategic partnerships, we may be required to relinquish important rights to and control over the development of FOLOTYN or otherwise be subject to unfavorable terms.

        Any future strategic partnerships we enter into could subject us to a number of risks, including:

•

we may be required to undertake the expenditure of substantial operational, financial and management resources in integrating new businesses, technologies and products;



•

we may be required to issue equity securities that would dilute our existing stockholders' percentage ownership;



•

we may be required to assume substantial actual or contingent liabilities;



•

we may not be able to control the amount and timing of resources that our strategic partners devote to the development or commercialization of FOLOTYN;



•

strategic partners may delay clinical trials, provide insufficient funding, terminate a clinical trial or abandon a product candidate, repeat or conduct new clinical trials or require a new version of a product candidate for clinical testing;



•

strategic partners may not pursue further development and commercialization of products resulting from the strategic partnering arrangement or may elect to discontinue research and development programs;



•

strategic partners may not commit adequate resources to the marketing and distribution of FOLOTYN or any other products, limiting our potential revenues from these products;



•

disputes may arise between us and our strategic partners that result in the delay or termination of the research, development or commercialization of FOLOTYN or any other product

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candidate or that result in costly litigation or arbitration that diverts management's attention and consumes resources;

•

strategic partners may experience financial difficulties;



•

strategic partners may not properly maintain or defend our intellectual property rights or may use our proprietary information in a manner that could jeopardize or invalidate our proprietary information or expose us to potential litigation;



•

business combinations or significant changes in a strategic partner's business strategy may also adversely affect a strategic partner's willingness or ability to complete its obligations under any arrangement;



•

strategic partners could independently move forward with a competing product candidate developed either independently or in collaboration with others, including our competitors; and



•

strategic partners could terminate the arrangement or allow it to expire, which would delay the development and may increase the cost of developing FOLOTYN or any other product candidate.

Health care reform measures could adversely affect our business.

        The business and financial condition of pharmaceutical and biotechnology companies are affected by the efforts of governmental and third-party payers to contain or reduce the costs of health care. The U.S. Congress recently enacted legislation to reform the health care system. While we anticipate that this legislation may, over time, increase the number of patients who have insurance coverage for pharmaceutical products, it also imposes cost containment measures that may adversely affect the amount of reimbursement for pharmaceutical products, including FOLOTYN. These measures include increasing the minimum rebates for products covered by Medicaid programs and extending such rebates to drugs dispensed to Medicaid beneficiaries enrolled in Medicaid managed care organizations as well as expansion of the 340B Public Health Services drug discount program. In foreign jurisdictions there have been, and we expect that there will continue to be, a number of legislative and regulatory proposals aimed at changing the health care system. For example, in some countries other than the United States, pricing of prescription drugs is subject to government control and we expect to see continued efforts to reduce healthcare costs in international markets.

        Some states are also considering legislation that would control the prices of drugs, and state Medicaid programs are increasingly requesting manufacturers to pay supplemental rebates and requiring prior authorization by the state program for use of any drug for which supplemental rebates are not being paid. Managed care organizations continue to seek price discounts and, in some cases, to impose restrictions on the coverage of particular drugs. Government efforts to reduce Medicaid expenses may lead to increased use of managed care organizations by Medicaid programs. This may result in managed care organizations influencing prescription decisions for a larger segment of the population and a corresponding constraint on prices and reimbursement for drugs, including FOLOTYN. It is likely that federal and state legislatures and health agencies will continue to focus on additional health care reform in the future although we are unable to predict what additional legislation or regulation, if any, relating to the health care industry or third-party coverage and reimbursement may be enacted in the future or what effect such legislation or regulation would have on our business. The pendency or approval of such proposals or reforms could result in a decrease in our stock price or limit our ability to raise capital or to obtain strategic partnerships or licenses.

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We may not obtain orphan drug exclusivity or we may not receive the full benefit of orphan drug exclusivity even if we obtain such exclusivity.

        The FDA has awarded orphan drug status to pralatrexate, which we market under the tradename FOLOTYN, for the treatment of patients with relapsed or refractory PTCL. In addition, the FDA has awarded orphan drug designation to pralatrexate for the treatment of patients with follicular lymphoma and diffuse large B-cell lymphoma and advanced or metastatic TCC of the urinary bladder, for which we do not have approval. Under the Orphan Drug Act, the first company to receive FDA approval for pralatrexate for a designated orphan drug indication will obtain seven years of marketing exclusivity during which the FDA may not approve another company's application for pralatrexate for the same orphan indication. Because the FDA approved FOLOTYN for the treatment of patients with relapsed or refractory PTCL, we have received seven years of marketing exclusivity for that indication. Orphan drug exclusivity does not prevent FDA approval of a different drug for the orphan indication or the same drug for a different indication. In addition, the FDA may void orphan drug exclusivity under certain circumstances.

If product liability lawsuits are successfully brought against us, we may incur substantial liabilities and may be required to limit commercialization of FOLOTYN.

        The testing and marketing of pharmaceutical products entail an inherent risk of product liability. Product liability claims might be brought against us by consumers or health care providers or by pharmaceutical companies or others selling FOLOTYN or any future products. If we cannot successfully defend ourselves against such claims, we may incur substantial liabilities or be required to limit the commercialization of FOLOTYN. We have obtained limited product liability insurance coverage for our human clinical trials and commercial sales of FOLOTYN. However, product liability insurance coverage is becoming increasingly expensive, and we may be unable to maintain such insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to product liability. A successful product liability claim in excess of our insurance coverage could have a material adverse effect on our business, financial condition and results of operations.

Our success depends on the retention of our President and Chief Executive Officer and other key personnel.

        We are highly dependent on our President and Chief Executive Officer, Paul L. Berns, and other members of our management team. We are named as the beneficiary on a term life insurance policy covering Mr. Berns in the amount of $10.0 million. We also depend on key employees and academic collaborators for each of our research and development programs. The loss of any of our key employees or academic collaborators could delay the development and commercialization of FOLOTYN or result in the termination of our FOLOTYN development program in its entirety. Mr. Berns and others on our executive management team have employment agreements with us, but the agreements provide for "at-will" employment with no specified term. Our future success also will depend in large part on our continued ability to attract and retain other highly qualified scientific, technical and management personnel, as well as personnel with expertise in clinical testing, governmental regulation and commercialization of pharmaceutical products. We face competition for personnel from other companies, universities, public and private research institutions, government entities and other organizations. Additionally, we have recently implemented a strategic reduction in workforce and we may have a more difficult time in attracting and retaining the employees we need as a result of a perceived risk of future workforce and expense reductions. If we are unsuccessful in our recruitment and retention efforts, our business will be harmed.

        We also rely on consultants, collaborators and advisors to assist us in formulating and conducting our research and development programs. All of our consultants, collaborators and advisors are employed by other employers or are self-employed and may have commitments to or consulting contracts with other entities that may limit their ability to contribute to our company.

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We cannot guarantee that we will be in compliance with all potentially applicable regulations.

        The development, manufacturing, pricing, marketing, sale and reimbursement of FOLOTYN, together with our general operations, are subject to extensive regulation by federal, state and other authorities within the United States and numerous entities outside of the United States. We have fewer employees than many other companies that have one or more product candidates that are approved for marketing and we rely heavily on third parties to conduct many important functions.

        As a publicly-traded company, we are subject to significant regulations including the Sarbanes Oxley Act of 2002 and the Dodd-Frank Wall Street Reform and Consumer Protection Act, or the Dodd-Frank Act. The Dodd-Frank Act contains significant corporate governance and executive compensation-related provisions, some of which the Securities and Exchange Commission, or SEC, has recently implemented by adopting additional rules and regulations in areas such as the compensation of executives ("say-on-pay"). We cannot assure you that we are or will be in compliance with all potentially applicable regulations. If we fail to comply with the Sarbanes Oxley Act of 2002, the Dodd-Frank Act and associated SEC rules, or any other regulations, we could be subject to a range of consequences, including restrictions on our ability to sell equity securities or otherwise raise capital funds, the de-listing of our common stock from The NASDAQ Global Market, or NASDAQ, suspension or termination of our clinical trials, failure to obtain approval to market FOLOTYN, restrictions on future products or our manufacturing processes, significant fines, or other sanctions or litigation. Our efforts to comply with these requirements have resulted in, and are likely to continue to result in, an increase in expenses and a diversion of management's time from other business activities.

If our internal controls over financial reporting are not considered effective, our business and stock price could be adversely affected.

        Section 404 of the Sarbanes-Oxley Act of 2002 requires us to evaluate the effectiveness of our internal controls over financial reporting as of the end of each fiscal year, and to include a management report assessing the effectiveness of our internal controls over financial reporting in our annual report on Form 10-K for that fiscal year. Section 404 also requires our independent registered public accounting firm to attest to, and report on, management's assessment of our internal controls over financial reporting.

        Our management, including our chief executive officer and principal financial officer, does not expect that our internal controls over financial reporting will prevent all error and all fraud. A control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system's objectives will be met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud involving a company have been, or will be, detected. The design of any system of controls is based in part on certain assumptions about the likelihood of future events, and we cannot assure you that any design will succeed in achieving its stated goals under all potential future conditions. Over time, controls may become ineffective because of changes in conditions or deterioration in the degree of compliance with policies or procedures. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected. We cannot assure you that we or our independent registered public accounting firm will not identify a material weakness in our internal controls in the future. A material weakness in our internal controls over financial reporting would require management and our independent registered public accounting firm to consider our internal controls as ineffective. If our internal controls over financial reporting are not considered effective, we may experience a loss of public confidence, which could have an adverse effect on our business and on the market price of our common stock.

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Our reserves and estimates depend upon the accuracy and consistency of third party data as well as dependence upon key finance and accounting personnel to maintain and implement the surrounding controls.

        We have reserves and estimates that incorporate a significant amount of third party data from our wholesalers. To effectively maintain the reserves and estimates, we depend to a considerable degree upon the timely and accurate reporting to us of such data from these third parties and our key accounting and finance personnel to accurately interpolate such data into the reserves and estimates. If the third party data is not calculated on a consistent basis and reported to us on an accurate or timely basis or we lose any of our key accounting and finance personnel, the accuracy of our consolidated financial statements could be materially affected. This could cause future delays in our earnings announcements, regulatory filings with the SEC and delisting with NASDAQ.

If we do not progress in our programs as anticipated, our stock price could decrease.

        For planning purposes, we estimate the timing of a variety of clinical, regulatory and other milestones, such as when a certain product candidate will enter clinical development, when a clinical trial will be initiated or completed, or when an application for regulatory approval will be filed. Some of our estimates are included in this report. Our estimates are based on information available to us as of the date of this report and a variety of assumptions. Many of the underlying assumptions are outside of our control. If milestones are not achieved when we estimated that they would be, investors could be disappointed and our stock price may decrease.

Warburg Pincus Private Equity VIII, L.P. controls a substantial percentage of the voting power of our outstanding common stock.

        On March 2, 2005, we entered into a Securities Purchase Agreement with Warburg Pincus Private Equity VIII, L.P., or Warburg, and certain other investors in connection with an equity financing. In connection with this financing, Warburg and certain of its affiliates entered into a standstill agreement pursuant to which they agreed not to pursue, for so long as they continue to own a specified number of shares of our common stock, certain activities the purpose or effect of which may be to change or influence the control of our company.

        As of February 25, 2011, we had 105,580,200 shares of common stock outstanding, of which Warburg owned 26,124,430 shares, or approximately 25% of the voting power of our outstanding common stock. Although Warburg has entered into a standstill agreement with us, Warburg is, and will continue to be, able to exercise substantial influence over any actions requiring stockholder approval.

Anti-takeover provisions in our charter documents and under Delaware law could discourage, delay or prevent an acquisition of us, even if an acquisition would be beneficial to our stockholders, and may prevent attempts by our stockholders to replace or remove our current management.

        Provisions of our amended and restated certificate of incorporation and bylaws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us, even if doing so would benefit our stockholders. In addition, these provisions may make it more difficult for stockholders to replace members of our board of directors. Because our board of directors is responsible for appointing the members of our management team, these provisions could in turn affect any attempt by our stockholders to replace current members of our management team. These provisions include:

•

authorizing the issuance of "blank check" preferred stock that could be issued by our board of directors to increase the number of outstanding shares or change the balance of voting control and thwart a takeover attempt;

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•

prohibiting cumulative voting in the election of directors, which would otherwise allow for less than a majority of stockholders to elect director candidates;



•

prohibiting stockholder action by written consent, thereby requiring all stockholder actions to be taken at a meeting of our stockholders;



•

eliminating the ability of stockholders to call a special meeting of stockholders; and



•

establishing advance notice requirements for nominations for election to the board of directors or for proposing matters that can be acted upon at stockholder meetings.

        In addition, we are subject to Section 203 of the Delaware General Corporation Law, which generally prohibits a Delaware corporation from engaging in any of a broad range of business combinations with an interested stockholder for a period of three years following the date on which the stockholder became an interested stockholder. This provision could have the effect of delaying or preventing a change of control, whether or not it is desired by or beneficial to our stockholders. Notwithstanding the foregoing, the three-year moratorium imposed on business combinations by Section 203 will not apply to Warburg because, prior to the date on which Warburg became an interested stockholder, our board of directors approved the transactions that resulted in Warburg becoming an interested stockholder. However, in connection with Warburg's participation in an equity financing we completed in March 2005, Warburg and certain of its affiliates entered into a standstill agreement pursuant to which they agreed not to pursue, for so long as they continue to own a specified number of shares of our common stock, certain activities the purpose or effect of which may be to change or influence the control of our company.

We have adopted a stockholder rights plan that may discourage, delay or prevent a merger or acquisition that is beneficial to our stockholders.

        In May 2003, our board of directors adopted a stockholder rights plan that may have the effect of discouraging, delaying or preventing a merger or acquisition of us that our stockholders may consider beneficial by diluting the ability of a potential acquirer to acquire us. Pursuant to the terms of the stockholder rights plan, when a person or group, except under certain circumstances, acquires 15% or more of our outstanding common stock or 10 business days after announcement of a tender or exchange offer for 15% or more of our outstanding common stock, the rights (except those rights held by the person or group who has acquired or announced an offer to acquire 15% or more of our outstanding common stock) would generally become exercisable for shares of our common stock at a discount. Because the potential acquirer's rights would not become exercisable for our shares of common stock at a discount, the potential acquirer would suffer substantial dilution and may lose its ability to acquire us. In addition, the existence of the plan itself may deter a potential acquirer from acquiring or making an offer to acquire us. As a result, either by operation of the plan or by its potential deterrent effect, mergers and acquisitions of our company that our stockholders may consider in their best interests may not occur.

        Because Warburg owns a substantial percentage of our outstanding common stock, we amended the stockholder rights plan in connection with Warburg's participation in an equity financing we completed in March 2005 to provide that Warburg and its affiliates will be exempt from the stockholder rights plan, unless Warburg and its affiliates become, without the prior consent of our board of directors, the beneficial owner of more than 44% of our common stock.

Unstable market conditions may have serious adverse consequences on our business.

        Market instability has made the business climate more volatile and more costly. Our general business strategy may be adversely affected by unpredictable and unstable market conditions. If the current equity and credit markets deteriorate further, or do not improve, it may make any necessary

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equity or debt financing more difficult, more costly, and more dilutive. While we believe we have adequate capital resources to meet our expected working capital and capital expenditure requirements for at least the next 12 months, a radical economic downturn or increase in our expenses could require additional financing on less than attractive rates or on terms that are excessively dilutive to existing stockholders. Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay or abandon clinical development plans. There is a risk that one or more of our current service providers, manufacturers or other partners may encounter difficulties during challenging economic times, which could have an adverse effect on our business, results of operations and financial condition.

The market price for our common stock has been and may continue to be highly volatile, and an active trading market for our common stock may never exist.

        We cannot assure you that an active trading market for our common stock will exist at any time. Holders of our common stock may not be able to sell shares quickly or at the market price if trading in our common stock is not active. The trading price of our common stock has been and is likely to continue to be highly volatile and could be subject to wide fluctuations in price in response to various factors, many of which are beyond our control, including:

•

the timing and amount of revenues generated from sales of FOLOTYN;



•

actual or anticipated variations in quarterly operating results;



•

actual or anticipated regulatory approvals or non-approvals of FOLOTYN or of competing product candidates;



•

the loss of regulatory approval for FOLOTYN in patients with relapsed or refractory PTCL;



•

actual or anticipated results of our clinical trials involving FOLOTYN;



•

changes in laws or regulations applicable to FOLOTYN;



•

changes in the expected or actual timing of our development programs;



•

announcements of technological innovations by us or our competitors;



•

changes in financial estimates or recommendations by securities analysts;



•

conditions or trends in the biotechnology and pharmaceutical industries;



•

changes in the market valuations of similar companies;



•

announcements by us of significant acquisitions, strategic partnerships, joint ventures or capital commitments;



•

additions or departures of key personnel;



•

disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to obtain patent protection for our technologies;



•

developments concerning any of our research and development, manufacturing and marketing collaborations;



•

sales of large blocks of our common stock;



•

sales of our common stock by our executive officers, directors and five percent stockholders; and



•

economic and other external factors, including disasters or crises.

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        Public companies in general and companies included on NASDAQ in particular have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of those companies. There has been particular volatility in the market prices of securities of biotechnology and other life sciences companies, and the market prices of these companies have often fluctuated because of problems or successes in a given market segment or because investor interest has shifted to other segments. These broad market and industry factors may cause the market price of our common stock to decline, regardless of our operating performance. We have no control over this volatility and can only focus our efforts on our own operations, and even these may be affected due to the state of the capital markets. In the past, following large price declines in the public market price of a company's securities, securities class action litigation has often been initiated against that company, including in 2004 against us. Litigation of this type could result in substantial costs and diversion of management's attention and resources, which would hurt our business. Any adverse determination in litigation could also subject us to significant liabilities.

Substantial sales of shares may impact the market price of our common stock.

        If our stockholders sell substantial amounts of our common stock, the market price of our common stock may decline. These sales also might make it more difficult for us to sell equity or equity-related securities in the future at a time and price that we consider appropriate. We are unable to predict the effect that sales may have on the then prevailing market price of our common stock. We have entered into a Registration Rights Agreement with Warburg pursuant to which Warburg is entitled to certain registration rights with respect to shares of our common stock. On July 20, 2009, we filed a Registration Statement on Form S-3 with the SEC providing for the registration for resale by Warburg of up to 26,124,430 shares of our common stock, which registration statement was declared effective on August 28, 2009.

ITEM 1B.    UNRESOLVED STAFF COMMENTS

        Not Applicable.

ITEM 2.    PROPERTIES

        Our corporate headquarters facility consists of approximately 34,536 square feet in Westminster, Colorado. We lease our corporate headquarters facility pursuant to a lease agreement that expires on January 31, 2012. We also lease an office in Princeton, New Jersey which consists of approximately 9,458 square feet. The lease for this office expires on September 30, 2011. We believe that our leased facilities are adequate to meet our needs at this time.

ITEM 3.    LEGAL PROCEEDINGS

        None.

ITEM 4.    RESERVED

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PART II

ITEM 5.    MARKET FOR REGISTRANT'S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Market Information and Holders

        Our common stock is traded on the NASDAQ Global Market under the symbol "ALTH." The following table sets forth, for the periods indicated, the high and low sales prices for our common stock as reported on the NASDAQ Global Market:

 

        On February 25, 2011, we had approximately 53 holders of record of our common stock.

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Stock Performance Measurement Comparison(1)

        The following graph shows the total stockholder return of an investment of $100 in cash on December 31, 2005 for (i) the Company's common stock, (ii) the NASDAQ Composite Index and (iii) the NASDAQ Biotechnology Index. All values assume reinvestment of the full amount of all dividends and are calculated as of December 31 of each year:

Comparison of 5 year Cumulative Total Return on Investment

Dividends

        We have never paid dividends to holders of our common stock, and we do not anticipate paying any cash dividends in the foreseeable future as we intend to retain any earnings for use in our business. Any future determination to pay dividends will be at the discretion of our board of directors and will depend upon our results of operations, financial condition, contractual restrictions, restrictions imposed by applicable law and other factors our board of directors deems relevant.

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ITEM 6.    SELECTED FINANCIAL DATA

        The selected financial data set forth below should be read in conjunction with our financial statements and the related notes and "Management's Discussion and Analysis of Financial Condition and Results of Operations," included in this report. The statement of operations data for the years ended December 31, 2010, 2009 and 2008, and the balance sheet data as of December 31, 2010 and 2009, are derived from, and should be read in conjunction with, our audited financial statements and related notes included elsewhere in this report. The statement of operations data for the years ended December 31, 2007 and 2006, and the balance sheet data as of December 31, 2008, 2007 and 2006, are derived from our audited financial statements that do not appear in this report. The historical results are not necessarily indicative of the operating results to be expected in the future.

 

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ITEM 7.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Overview

        We are a biopharmaceutical company committed to the development and commercialization of innovative anti-cancer therapeutics. Our goal is to build a profitable company by generating income from products we develop and commercialize, either alone or with one or more potential strategic partners. We strive to develop proprietary products that have the potential to improve the standard of care in cancer therapy.

        We are currently focused on the development and commercialization of FOLOTYN® (pralatrexate injection). FOLOTYN is a targeted folate inhibitor designed to accumulate preferentially in cancer cells. FOLOTYN targets the inhibition of dihydrofolate reductase, or DHFR, an enzyme critical in the folate pathway, thereby interfering with DNA and RNA synthesis and triggering cancer cell death. FOLOTYN can be delivered as a single agent, for which we currently have approval for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma, or PTCL, and has the potential to be used in combination therapy regimens. We believe that FOLOTYN's unique mechanism of action offers us the ability to target the drug for development in a variety of hematological malignancies and solid tumor indications. We currently retain exclusive worldwide commercial rights to FOLOTYN for all indications. We may also seek to grow our product portfolio through product acquisition and in-licensing efforts.

        On September 24, 2009, the U.S. Food and Drug Administration, or FDA, granted accelerated approval of FOLOTYN for use as a single agent for the treatment of patients with relapsed or refractory PTCL. This approval was based on overall response rate from our pivotal Phase 2 trial known as PROPEL (Pralatrexate in patients with Relapsed Or refractory PEripheral T-cell Lymphoma). Clinical benefit such as improvement in progression-free survival or overall survival has not been demonstrated. FOLOTYN represents our first drug approved for marketing in the United States. FOLOTYN is the first and only drug approved by the FDA for this indication. In connection with the accelerated approval, we are required to conduct post-approval studies that are intended to verify and describe FOLOTYN's clinical benefit in patients with T-cell lymphoma and to determine whether FOLOTYN poses a serious risk of altered drug levels resulting from organ impairment.

        We began making FOLOTYN available for commercial sale in the United States in October 2009 and commenced our commercial launch of FOLOTYN in January 2010. We have established a commercial organization, including sales, marketing, supply chain management and reimbursement capabilities, to commercialize FOLOTYN in the United States. We believe the market for relapsed or refractory PTCL is addressable with a targeted U.S. sales and marketing organization, and we intend to continue promoting FOLOTYN ourselves in the United States.

        We are also seeking regulatory approval to market FOLOTYN in Europe for the treatment of patients with relapsed or refractory PTCL. In December 2010, our Marketing Authorisation Application, or MAA, was accepted by the European Medicines Agency, or EMA. Acceptance of the MAA by the EMA indicates that the application is complete and initiates the EMA's regulatory review process. The MAA is based on clinical data from our pivotal PROPEL trial. We may also seek regulatory approval to market FOLOTYN for the treatment of patients with relapsed or refractory PTCL in Japan and other countries. We intend to secure a strategic partner for the potential co-development of FOLOTYN globally and commercialization outside the United States.

        We are currently prioritizing our resources on the development and commercialization of FOLOTYN for the treatment of PTCL, cutaneous T-cell lymphoma and other hematologic malignancies. We are committed to evaluating FOLOTYN for oncology use as a single agent and in combination with other therapies. We also intend to complete our ongoing Phase 2 studies in bladder

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and breast cancer, and investigators are evaluating FOLOTYN in solid tumor indications through our collaboration with the National Comprehensive Cancer Network, or NCCN, Oncology Research Program.

Results of Operations

        We have incurred significant net losses and negative cash flows from operations. We have incurred these losses principally from costs incurred in our research and development programs and from our selling, general and administrative expenses. Our primary business activities have been focused on the development of FOLOTYN for the three year period ended December 31, 2010. For the years ended December 31, 2010, 2009 and 2008, we had net losses of $77.4 million, $73.6 million and $51.7 million, respectively. Research and development expenses for the years ended December 31, 2010, 2009 and 2008 were $31.4 million, $32.6 million and $30.6 million, respectively. As of December 31, 2010, we had accumulated a deficit of $450.6 million.

        Our ability to achieve profitability is dependent on our ability, alone or with partners, to significantly increase sales of FOLOTYN for the treatment of patients with relapsed or refractory PTCL in the United States. The amount of our future product sales are subject to significant uncertainty. We may never generate sufficient revenue from product sales to become profitable.

        We expect to continue to spend substantial amounts on research and development, including amounts spent on conducting clinical trials and seeking additional regulatory approvals for FOLOTYN. We also expect to continue to spend substantial amounts on selling, general and administrative expenses to promote FOLOTYN for the treatment of patients with relapsed or refractory PTCL in the United States. Therefore, we may need to raise additional capital to support our future operations. Our actual capital requirements will depend on many factors, including those discussed under the "Liquidity and Capital Resources" section below.

        If we are unable to significantly increase sales of FOLOTYN or cannot otherwise raise sufficient additional funds to support our operations, we may be required to delay, reduce the scope of or eliminate one or more of our development programs and our future prospects for profitability may be harmed.

Comparison of Years Ended December 31, 2010, 2009 and 2008

        Net product sales.    Net product sales represent total revenue less distributor fees and estimated allowances for product returns, government rebates and chargebacks to be incurred on the selling price of FOLOTYN related to the respective revenue, as further described in the "Critical Accounting Policies" section below. We began making FOLOTYN available for commercial sale in the United States in October 5, 2009 and commenced our commercial launch of FOLOTYN in January 2010.

        We sell FOLOTYN to a limited number of pharmaceutical wholesale distributors, or distributors, the three largest of which are affiliates under common control of an unrelated party. Title to the product passes upon delivery to our distributors, when the risks and rewards of ownership are assumed by the distributor (freight on board destination). These distributors then resell FOLOTYN to the patients' respective health care providers. Prior to the fourth quarter of 2010, product sales to distributors were recorded as deferred revenue until the product was sold through from our distributors to health care providers because we did not have sufficient history to be able to reasonably estimate returns. Beginning in the fourth quarter of 2010, we began recognizing revenue as product is sold to distributors as we established a sufficient history in order to reasonably estimate returns from our distributors. Consequently, for the year ended December 31, 2010, we recognized a one time increase of $604,000 in net product sales of FOLOTYN, or $0.01 per common share, representing product sales previously deferred as of December 31, 2009, net of distributor fees and estimated product returns, government rebates and chargebacks. Through December 31, 2010, product returns have been

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negligible. Our distributors' contractual return rights are limited to defective product or product that was shipped in error. Returns are not allowed for expired product. Given these limited contractual return rights, the price of FOLOTYN and the limited number of patients in the United States, FOLOTYN distributors and their customers generally carry limited inventory.

        Balances and activity in the deferred revenue account and a reconciliation of gross to net product sales for the years ended December 31, 2010, 2009 and 2008 are as follows:

        The $35.2 million of net product sales in 2010 represents the first full calendar year of sales of FOLOTYN. The $3.6 million of net product sales in 2009 relates to sales of FOLOTYN commencing in the fourth quarter of 2009. There were no corresponding net product sales in 2008.

        Balances and activity for the components of our gross to net sales adjustments for the years ended December 31, 2010 and 2009 are as follows:

        During the first quarter of 2010, we obtained additional market research and were able to refine our estimated Medicaid utilization, which resulted in a reversal of Medicaid rebate allowances related to 2009 sales totaling $208,000. In March 2010, the Patient Protection and Affordable Care Act, as modified by the Health Care and Education Affordability Reconciliation Act of 2010, or PPACA, was enacted, which increased the Medicaid rebate percentage from 15.1% to 23.1%, retroactive to January 1, 2010.

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        Product returns, government rebates and chargebacks reflect management estimates which are further discussed in the "Critical Accounting Policies" section below.

        Cost of sales, excluding amortization expense.    Cost of sales, excluding amortization expense, includes royalties, inventory packaging and labeling, warehousing and shipping costs associated with FOLOTYN product revenue.

        Prior to receiving FDA approval of FOLOTYN on September 24, 2009, all costs related to purchases of the active pharmaceutical ingredient and manufacturing of the product were recorded as research and development expense. Until we sell the inventory for which the costs were previously expensed, our cost of sales will reflect only royalties and other incremental costs incurred subsequent to the FDA approval date. Accordingly, our cost of sales of FOLOTYN will be lower with respect to product that was manufactured prior to FDA approval. This occurred with respect to all sales of FOLOTYN in the fourth quarter of 2009 and a significant amount of sales of FOLOTYN in 2010.

        The $3.6 million and $408,000 of cost of sales, excluding amortization expense in 2010 and 2009, respectively, was primarily due to an 8% royalty on our product sales payable to the licensors of FOLOTYN under the terms of our license agreement. There were no corresponding cost of sales in 2008.

        Cost of sales for 2011 is expected to approximate 10% of gross product sales to distributors, which includes the current 8% royalty on FOLOTYN sales.

        Research and development.    Research and development expenses include the costs of certain personnel, preclinical studies, clinical trials, regulatory affairs, biostatistical data analysis, third-party manufacturing costs for development of drug materials for use in preclinical studies and clinical trials, and manufacturing costs and licensing fees incurred for FOLOTYN prior to receipt of FDA approval.

        The $1.3 million decrease in research and development expenses in 2010 as compared to 2009 was primarily due to the following:

•

a $2.6 million decrease in third-party manufacturing costs for clinical trial material and manufacturing pre-commercial product in preparation for the approval and commercial availability of FOLOTYN in 2009;



•

a $2.5 million decrease in costs related to clinical trials involving FOLOTYN that have closed enrollment, including decreased costs for our Phase 2b non-small cell lung cancer, or NSCLC, study, which completed patient enrollment in July 2009;



•

a $1.5 million decrease in licensing costs resulting from the milestone payment made under the license agreement for FOLOTYN upon FDA acceptance of our New Drug Application, or NDA, for review in May 2009, with no corresponding amount in 2010; and

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•

a $709,000 decrease in consulting, professional fees and grants, primarily resulting from regulatory affairs and preparations related to the filing of our NDA and the FDA's Oncologic Drugs Advisory Committee, or ODAC, meeting for FOLOTYN in September 2009, with no corresponding amounts in 2010.

This decrease was partially offset by:

•

a $3.8 million increase in costs related to clinical trials involving FOLOTYN, including start-up costs for the post-approval studies required by the FDA and other trials with ongoing enrollment;



•

a $1.2 million increase in personnel and related travel costs, mainly attributable to additional headcount and increases in compensation costs year-over-year; and



•

a $919,000 increase in non-cash stock-based compensation expense, primarily resulting from a one-time $0.9 million reversal of stock-based compensation expense in connection with the resignation of our former Chief Medical Officer, or CMO, in September 2009, as discussed in more detail in the Stock-based Compensation Expense section below.

        The $2.0 million increase in research and development expenses in 2009 as compared to 2008 was primarily due to the following:

•

a $1.6 million increase in personnel and related travel costs, mainly attributable to additional headcount and increases in compensation costs year-over-year;



•

a $1.6 million increase in consulting and professional fees, primarily related to regulatory affairs, including preparations related to the filing of our NDA for FOLOTYN and the FDA's ODAC meeting in September 2009;



•

a $1.4 million increase in third-party manufacturing costs for clinical trial material and pre-commercial scale-up activities for FOLOTYN; and



•

a $1.0 million increase in licensing costs for FOLOTYN, as $1.5 million of milestone payments under the license agreement for FOLOTYN became due upon FDA acceptance of our NDA for review in May 2009, with a corresponding amount of $500,000 in the same period in 2008.

        These increases were partially offset by:

•

a $2.1 million decrease in clinical trial costs involving FOLOTYN, including decreased costs for PROPEL, which completed patient enrollment in April 2008;



•

a $724,000 decrease in stock-based compensation, primarily related to the resignation of our former CMO, as discussed in more detail in the Stock-based Compensation Expense section below; and



•

a $617,000 decrease in preclinical study costs involving FOLOTYN.

        We expect research and development expenses for 2011, excluding non-cash stock-based compensation expense, to be fairly consistent with the 2010 amount of $28.0 million. Our guidance for 2011 research and development expenses includes our ongoing and planned studies, including the planned initiation in 2011 of our post-marketing Phase 3 study in PTCL.

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        We expect the non-cash stock-based compensation portion of research and development expense to increase in 2011 as compared to 2010, as discussed in more detail in the Stock-based Compensation Expense section below.

        In January 2011, we implemented a strategic reduction of our workforce by approximately 13%, or 25 employees. Personnel reductions were primarily focused in research and development and general and administrative functions. The restructuring was a result of our decision to prioritize our resources on the development and commercialization of FOLOTYN for the treatment of PTCL, cutaneous T-cell lymphoma and other hematologic malignancies, and to manage our operating costs and expenses accordingly. We expect to incur total restructuring charges of approximately $0.7 million in connection with the restructuring, all in the form of one-time termination benefits, including approximately $0.3 million of research and development expenses. We expect to record substantially all of these charges in the first quarter of 2011.

        We charge direct internal and external research and development expenses to the respective development programs. In December 2002, we entered into a license agreement with Memorial Sloan-Kettering Cancer Center, SRI International and Southern Research Institute, as amended, under which we obtained exclusive worldwide rights to a portfolio of patents and patent applications related to FOLOTYN and its uses. From December 2002 through December 31, 2010, we have incurred direct costs of approximately $71.3 million associated with the development of FOLOTYN, including $65.5 million related to research and development expenses for FOLOTYN and an additional $5.8 million related to a milestone payment as a result of the FDA's approval to market FOLOTYN on September 24, 2009, which was capitalized as an intangible asset on our balance sheet. In addition, we incur indirect costs related to FOLOTYN, which consist primarily of salaries and benefits for all clinical, regulatory affairs, biostatistical analysis and manufacturing personnel, consulting and professional fees, including costs associated with filing our NDA and MAA for FOLOTYN, facilities costs and other internal-shared resources related to the development and maintenance of infrastructure, systems and processes. The research and development expenses of $31.4 million, $32.6 million and $30.6 million for the years ended December 31, 2010, 2009 and 2008 primarily relate to FOLOTYN development including all direct and indirect costs incurred in each of those years.

        The timing and costs to complete the successful clinical development of FOLOTYN for additional indications is highly uncertain, and therefore difficult to estimate. The lengthy process of seeking regulatory approvals for additional indications, and the subsequent compliance with applicable regulations, require the expenditure of substantial resources. Clinical development timelines, likelihood of success and total costs vary widely and are impacted by a variety of factors, including those discussed in the "Risk Factors" section of Part I, Item 1A above. Because of these risks and uncertainties, we cannot predict whether or when we will successfully complete the development of FOLOTYN for any additional indications or the ultimate costs of such efforts.

        Selling, general and administrative.    Selling, general and administrative expenses include costs for sales and marketing activities, corporate development, medical affairs, executive administration, corporate offices and related infrastructure.

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(1)

Weighted-average exercise price of outstanding options and rights excludes restricted stock unit awards, as they have no exercise price.

(2)

Includes 11,191,603 shares of common stock available for future issuance under our 2008 Equity Incentive Plan. All stock awards granted under our 2008 Equity Incentive Plan after the June 24, 2008 effective date thereof, other than stock options and stock appreciation rights granted with an exercise price of at least 100% of such stock award's fair market value on the date of grant, reduce the number of shares available for issuance under our 2008 Equity Incentive Plan by 1.35 shares per share granted pursuant to the stock award. Shares of common stock that revert to and again become available for issuance under our 2008 Equity Incentive Plan and that prior to such reversion were granted pursuant to a stock award that reduced the number of shares available under our 2008 Equity Incentive Plan by 1.35 shares per share granted pursuant to such stock award, will cause the number of shares of our common stock available for issuance under our 2008 Equity Incentive Plan to increase by 1.35 shares upon such reversion.

(3)

Includes 2,101,917 shares of common stock available for future issuance under our 2001 Employee Stock Purchase Plan.