Exhibit 99.1

COMPANY CONTACTS

Shiv Kapoor

Vice President, Strategic Planning & Investor Relations

702-835-6300

InvestorRelations@sppirx.com

Spectrum Pharmaceuticals Announces Authorization Of Stock Repurchase

Program up to $100 Million

HENDERSON, Nevada – August 10, 2012 – Spectrum Pharmaceuticals (NasdaqGS: SPPI), a biotechnology company with fully integrated commercial and drug development operations with a primary focus in hematology and oncology, today announced that the Company’s Board of Directors has approved an increase in its stock repurchase program authorizing the repurchase of up to a total of $100 million of the Company’s common stock. The Company was previously authorized to repurchase up to $25 million of its stock.

“Spectrum’s Board of Directors and senior management have confidence in our Company’s prospects and believe repurchases of Spectrum stock represent an attractive opportunity to enhance long-term shareholder value,” stated Rajesh C. Shrotriya, M.D., Chairman, President and Chief Executive Officer of Spectrum Pharmaceuticals, Inc. “This program gives us the opportunity to invest in our stock as we need to. We believe that the current share price represents a significant discount to the intrinsic value of the Company. We will be starting to purchase stock today.”

Stock will be purchased from time to time, in the open market, through block trades, through 10b5-1 plans, or through privately negotiated transactions in compliance with Securities and Exchange Commission guidelines.

About Spectrum Pharmaceuticals, Inc.

Spectrum Pharmaceuticals is a leading biotechnology company focused on acquiring, developing, and commercializing drug products, with a primary focus in oncology and hematology. Spectrum currently markets two oncology drugs – FUSILEV^® (levoleucovorin) for Injection in the U.S. and ZEVALIN^® (ibritumomab tiuxetan) Injection for intravenous use, for which the Company has worldwide marketing rights. Spectrum’s strong track record in in-licensing and acquiring differentiated drugs, and expertise in clinical development have generated a robust, diversified, and growing pipeline of product candidates in advanced-stage Phase 2 and Phase 3 studies. More information on Spectrum is available at www.sppirx.com.

11500 S. Eastern Ave., Ste. 240 Ÿ Henderson, Nevada 89052 Ÿ Tel: 702-835-6300 Ÿ  Fax: 702-260-7405 Ÿ www.sppirx.com  Ÿ NASDAQ: SPPI

Forward-looking statement — This press release may contain forward-looking statements regarding future events and the future performance of Spectrum Pharmaceuticals that involve risks and uncertainties that could cause actual results to differ materially. These statements are based on management’s current beliefs and expectations. These statements include but are not limited to statements that relate to our business and its future, including certain company milestones, Spectrum’s ability to identify, acquire, develop and commercialize a broad and diverse pipeline of late-stage clinical and commercial products, leveraging the expertise of partners and employees around the world to assist us in the execution of our strategy, and any statements that relate to the intent, belief, plans or expectations of Spectrum or its management, or that are not a statement of historical fact. Risks that could cause actual results to differ include the possibility that our existing and new drug candidates may not prove safe or effective, the possibility that our existing and new applications to the FDA and other regulatory agencies may not receive approval in a timely manner or at all, the possibility that our existing and new drug candidates, if approved, may not be more effective, safer or more cost-efficient than competing drugs, the possibility that our efforts to acquire or in-license and develop additional drug candidates may fail, our lack of sustained revenue history, our limited marketing experience, our dependence on third parties for clinical trials, manufacturing, distribution and quality control and other risks that are described in further detail in the Company’s reports filed with the Securities and Exchange Commission. We do not plan to update any such forward-looking statements and expressly disclaim any duty to update the information contained in this press release except as required by law.

SPECTRUM PHARMACEUTICALS, INC.^® is a registered trademark of Spectrum Pharmaceuticals, Inc. REDEFINING CANCER CARE^™ and the Spectrum Pharmaceutical logos are trademarks owned by Spectrum Pharmaceuticals, Inc.

^© 2012 Spectrum Pharmaceuticals, Inc. All Rights Reserved.

11500 S. Eastern Ave., Ste. 240 Ÿ Henderson, Nevada 89052 Ÿ Tel: 702-835-6300 Ÿ  Fax: 702-260-7405 Ÿ www.sppirx.com  Ÿ NASDAQ: SPPI