Exhibit 99.1

		501 Elliott Ave. W. #400 Seattle, WA 98119		T 206.312.7100 F 206.272.4010

Cell Therapeutics Provides Monthly Information

at Request of CONSOB

August 31, 2011 Seattle — Cell Therapeutics, Inc. (the “Company” or “CTI”) (NASDAQ: CTIC and MTA: CTIC) is providing the information herein pursuant to a request from the Italian securities regulatory authority, CONSOB, pursuant to Article 114, Section 5 of the Unified Financial Act, that the Company issue at the end of each month a press release providing a monthly update of certain information relating to the Company’s management and financial situation. However, the Company also directs its Italian shareholders to the Italian language section of its website at www.celltherapeutics.com/italiano, where more complete information about the Company and its products and operations, including press releases issued by the Company, as well as the Company’s U.S. Securities and Exchange (“SEC”) filings and the Registration Document authorized to be published by CONSOB, can be found. The information provided below is qualified in its entirety by reference to such information. Please note that all the information disclosed in this press release primarily refers to the period July 1, 2011 through July 31, 2011 except as otherwise expressly noted.

Provisional (unaudited) financial information and EBITDA as of July 31, 2011

The following information concerns the Company’s provisional (unaudited) results for the month ended July 31, 2011.

Such financial information represents estimates that are based on assumptions the occurrence of which depends on circumstances relating to the Company and the macroeconomic situation, and which assumptions might or might not occur.

The following table reports the estimated indication of a few relevant items referring to the unaudited statements of operations for the month ended July 31, 2011:

Estimated financial data of the Company for the month ended July 31, 2011

The estimated and unaudited financial data of the Company as of July 31, 2011 compared with those for the previous month are shown below (amounts in thousands of U.S. dollars):

Estimated research and development expenses were $3.9 million for the month June 2011 and $2.1 million for the month July 2011.

Estimated Net Financial Standing

The following table reports the estimated and unaudited net financial standing of the Company as of June 30, 2011 and July 31, 2011, including the separate indication of the total estimated financial needs, regarding debts expiring less than 12 months ahead (current portion). The relevant estimated financial data are compared with those for the previous month (amounts in thousands of U.S. dollars).

The total estimated and unaudited net financial position of the Company as of July 31, 2011 was approximately $36,931 (in thousands of U.S. dollars).

The Company’s 5.75% Convertible Senior Notes with a maturity date of December 15, 2011 come due within the next 12 months.

The Company had no debt that matured during the month of July 2011.

Outstanding notes

The following tables disclose information about the Company’s outstanding Convertible Senior Notes as of July 31, 2011, compared with the same information as of June 30, 2011:

Convertible Notes–July 31, 2011

Debt Restructuring Program

In July 2011, the Company neither issued any new debt instruments nor bought any debt instruments already issued by the Company. The Company believes it is in compliance with the covenants on its outstanding convertible notes.

Regulatory Matters and Products in Development

Pixantrone

On March 3, 2011, the Company announced that it met with officials of the U.S. Food and Drug Administration’s (“FDA”) Office of New Drugs (“OND”) and presented its arguments supporting the Company’s belief that the data contained in its New Drug Application (“NDA”) 22-481 for pixantrone support the conclusion that pixantrone is effective for its planned

use. On May 3, 2011 the Company announced that the Company would resubmit the NDA in consideration for accelerated approval in accordance with guidance from FDA’s OND following receipt of the FDA’s OND response to the Company’s appeal to the FDA, which provided the Company with the opportunity to resubmit the NDA to the FDA with additional information for consideration of accelerated approval of the NDA based on the PIX 301 trial. In the FDA’s response to the Company’s appeal, the FDA requested that the Company submit two items—an additional review of radiographs by an independent panel and additional information regarding circumstances of stopping the clinical trial prior to achieving the planned accrual to assure reviewers that efficacy assessments were not involved in the decision to stop accrual early. As announced on June 14, 2011, the Company met with the FDA’s Division of Oncology Drug Products (the “DODP”). The meeting provided guidance for re-submitting the Company’s NDA for pixantrone for relapsed or refractory aggressive non-Hodgkin’s lymphoma (“NHL”) including the potential for accelerated approval of the NDA based on the PIX301 study result. The Company plans to submit the requested information, as well as the other relevant data requested in the FDA’s Complete Response Letter received by the Company. The DODP confirmed that the NDA would be reviewed within six months from the resubmission of the NDA. The Company anticipates filing the additional information later this year, and could obtain FDA approval in the first half of 2012.

On August 18, 2011, the Company announced that enrollment has opened for a randomized phase II clinical study comparing the combination of OPAXIO (paclitaxel poliglumex, PPX) and radiation (“RT”) to the combination of temozolomide and RT for patients with newly diagnosed glioblastoma, a high-grade malignant brain tumor. For further information, please refer to the relevant press release disseminated on August 18, 2011.

On August 23, 2011, the Company announced that it submitted to the European Medicines Agency’s (the “EMA”) Committee for Medicinal Products for Human Use (“CHMP”) its response to the Day 120 List of Outstanding Issues in regards to the Company’s Marketing Authorization Application for pixantrone (the “MAA”) in Europe to treat relapsed or refractory aggressive NHL.

Corporate Transactions and Assignment of Assets

With respect to the period from July 1, 2011 through July 31, 2011, the Company has no additional information to disclose to the market.

Exchange Listing Matters

With respect to the period from July 1, 2011 through July 31, 2011, the Company has no additional information to disclose to the market.

Update on Outstanding Shares of Common Stock

The number of shares outstanding of the Company’s common stock, no par value (the “Common Stock”), issued and outstanding as of June 30, 2011 and July 31, 2011 was 175,229,878 and 192,876,765, respectively.

During the month of July 2011, the following transactions contributed to the change in the number of shares of the Company’s outstanding Common Stock:

The Company is not aware of any agreement for the resale of its shares of Common Stock on the MTA nor of the modalities by means of which shares of Common Stock were or will be resold.

Information about the capacity of the Company to sustain its financial needs

As disclosed in this press release, the Company had approximately $54.3 million in cash and cash equivalents as of July 31, 2011.

This amount includes the proceeds from a registered offering announced on June 30, 2011, which closed on July 5, 2011 pursuant to which the Company entered into an agreement to sell approximately $30 million of shares of its Series 13 Preferred Stock and warrants to purchase shares of its Common Stock in a registered offering to institutional investors (the “Investors”). Each share of Series 13 Preferred Stock was convertible at the option of the holder, at any time during its existence, into approximately 588 shares of Common Stock at a conversion price of $1.70 per share of Common Stock, for a total of 17,647,057 shares of Common Stock. As of July 6, 2011, all 30,000 shares of Series 13 Preferred Stock were converted and the investors received all 17,647,057 shares of the Common Stock issuable upon conversion. The Company received approximately $27.9 million in net proceeds from the offering, after deducting placement agent fees and estimated offering expenses. In connection with the offering, the Investors received warrants to purchase up to 8,820,000 shares of Common Stock. The warrants have an exercise price of $2.15 per warrant share, for total potential additional proceeds to the Company of approximately $19.0 million upon exercise of the warrants. The warrants are exercisable beginning six months and one day from the date of issuance and terminate five years and one day after the date of issuance. For further information about this registered offering please refer to the press releases disseminated on June 30, 2011 and July 6, 2011.

About Cell Therapeutics, Inc.

Headquartered in Seattle, the Company is a biopharmaceutical company committed to developing an integrated portfolio of oncology products aimed at making cancer more treatable. For additional information, please visit www.CellTherapeutics.com.

This press release includes forward-looking statements that involve a number of risks and uncertainties, the outcome of which could materially and/or adversely affect future results and the trading price of the Company’s securities. Specifically, the risks and uncertainties that could affect the development of pixantrone include risks associated with preclinical and clinical developments in the biopharmaceutical industry in general, and with pixantrone in particular, including, without limitation, the potential failure of pixantrone to prove safe and effective for the treatment of relapsed or refractory aggressive NHL, relapsed/refractory diffuse large B-cell lymphoma and/or other tumors as determined by the FDA and/or the EMA, that the Company cannot predict or guarantee the pace or geography of enrollment of its clinical trials or the total number of patients enrolled, that the FDA may request additional clinical trials, that the EMA may not approve the MAA after review, that accelerated approval by the FDA of pixantrone may not be possible or occur, that the Company may not be able to address satisfactorily the two key matters raised by the OND or other matters raised by the FDA, the OND, and/or the DODP, that the Company’s interpretation of the guidance provided by the OND and/or the DODP may be different than the intent of the OND and/or the DODP, that the OND and/or the DODP may change its guidance, that the PIX301 study may not be deemed successful, that upon a re-review of the NDA that the FDA may find pixantrone to not be safe and/or effective, that the PIX301 study may still be deemed to be a failed study, that if the Company conducts an additional clinical trial, it may not demonstrate the safety and effectiveness of pixantrone, that the Company may not be able to provide satisfactory information in response to the FDA’s Complete Response Letter, that the Company may not be able to re-submit the pixantrone NDA quickly, that the Company may not be able to file the additional information for the NDA later this year, that the Company may not obtain approval of the NDA from the FDA in the first half of 2012, that the Company cannot guarantee that it will maintain compliance with the NASDAQ listing standards, the risk that the Company may not be able to continue to raise capital as needed to fund its operations, competitive factors, technological developments, and costs of developing, producing and selling pixantrone. Further risks and uncertainties include that the Company continues to have a substantial amount of debt outstanding and the quarterly interest expense associated with the debt is significant, the Company’s operating expenses continue to exceed its net revenues, that the Company may not be able to further reduce its operating expenses, that the Company will continue to need to raise capital to fund its operating expenses and may not be able to raise sufficient amounts to fund its continued operation, and that the information presented herein with respect to the Company’s convertible notes and non-convertible

preferred stock may differ materially from the information presented by the Company with respect to its convertible notes and non-convertible preferred stock prepared in accordance with U.S. GAAP in its periodic reports on Form 10-K and Form 10-Q, as well as other risks listed or described from time to time in the Company’s most recent filings with the SEC on Forms 10-K, 10-Q and 8-K. Except as required by law, the Company does not intend to update any of the statements in this press release upon further developments.

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Media Contact:

Cell Therapeutics, Inc.

Dan Eramian

T: 206.272.4343

C: 206.854.1200

E: deramian@ctiseattle.com

www.CellTherapeutics.com/press_room

Investors Contact:

Cell Therapeutics, Inc.

Ed Bell

T: 206.272.4345

F: 206.272.4434

Lindsey Jesch Logan

T : 206.272.4347

F : 206.272.4434

E: invest@ctiseattle.com

www.CellTherapeutics.com/investors