Spectrum Pharmaceuticals Announces Impressive Responses in Difficult to Treat Carcinomas with SPI-1620 in a Phase I Study

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 top-line data from part one of a two-part Phase 1 study of SPI-1620 in combination with docetaxel was presented in an oral presentation at the 12^th International Conference on Endothelin, held in Cambridge, United Kingdom, from September 11-14, 2011. Part one of the study has been completed, while part two is ongoing.

The primary objective of this Phase 1 study was to assess the safety and tolerability of SPI-1620 administered to patients with recurrent or progressive carcinoma who have failed all standard therapy. Secondary objectives of the study include assessing the pharmacokinetic and pharmacodynamic profiles of SPI-1620 and identifying the optimum dose of SPI-1620 to be used in future Phase 2 studies.

A total of 30 patients were enrolled in this study. Patients ranged in age from 41 to 77 years (median 61), and had prostate cancer (9/30), breast cancer (3/30), female reproductive malignancies (4/30), gastrointestinal cancer (3/30), and pancreatic cancer (2/30), among other types.

Anthony W. Tolcher, M.D., FRCP, Director of Clinical Research at South Texas Accelerated Research Therapy, and the principal investigator of the Phase 1 study, said, "SPI-1620, a novel anti-tumor endothelin-B agonist agent, when combined with docetaxel, has had impressive responses in difficult to treat carcinomas. These preliminary observations deserve confirmation in a Phase 2 study, which is under development. In addition, lung cavitation suggesting necrosis at previous tumor sites was noted in responding patients.”

Among the 30 patients, all of whom were treated with SPI-1620 and docetaxel, 5 partial responses (PR) were seen. Of the 5 partial responses, two were in prostate cancer, and those patients experienced a prolonged duration of response of approximately 12 and 18 months. Encouraging antitumor activity was also seen in patients with cholangiocarcinoma, transitional cell urothelial carcinoma, and ovarian cancer.

"We are very pleased with the promising top-line data from the SPI-1620 study and believe that it could be an effective drug in the treatment of solid tumors,” said Rajesh C. Shrotriya, MD, Chairman, Chief Executive Officer, and President of Spectrum Pharmaceuticals. "Spectrum is committed to bringing safe and effective treatment options to cancer patients. We look forward to continuing the development of SPI-1620, and we currently expect to initiate a Phase 2 study for SPI-1620 in 2012.”

About the Phase 1 Study

In part one of this two-part, open-label, single-arm, dose-escalation study, eligible patients received SPI-1620 delivered intravenously over one minute on days 1, 8, and 15. On day 8, patients underwent a series of four H₂¹⁵O PET Blood Flow scans to assess alterations in blood flow induced by SPI-1620 in tumor and non-tumor regions. Fifteen minutes after receiving SPI-1620 on day 15, patients received docetaxel, 60mg/m², administered by infusion over 1 hour.

SPI-1620 was well tolerated, both as a single agent as well as with docetaxel. Encouraging anti-tumor activity was seen in docetaxel pretreated patients.

Part two of this Phase 1 study will further focus on safety and tolerability of SPI-1620. CT or MRI scans will be used to assess the patient’s tumor size. A series of dynamic contrast enhancer pattern MRI scans will be used to measure the effects of SPI-1620.

About SPI-1620

According to the American Cancer Society’s Cancer Facts & Figures 2011 estimates, there will be approximately 1.6 million new cases of cancer in the U.S. in 2011 and almost 572 thousand cancer related deaths. Cancer is the second most common cause of death in the US, exceeded only by heart disease. In the US, cancer accounts for nearly 1 of every 4 deaths. Chemotherapy is one of the mainstays of therapy for solid tumors. However, chemotherapy often fails because adequate tissue levels of the cytotoxic agents are not achieved in the tumor, and serious side effects result from toxicity to normal cells. Consequently, any means to increase the delivery of a cytotoxic agent selectively to tumors, while minimizing its concentration in normal tissues would be beneficial.

SPI-1620 is believed to be a highly selective endothelin-B agonist that causes a selective and transient increase in blood flow to tumors, thereby increasing the delivery of anticancer agents to the tumor, and as a result increasing the efficacy of these drugs. In pre-clinical studies, when anti-cancer drugs, such as paclitaxel, doxorubicin, cisplatin, 5-FU, cyclophoshamide and others were administered shortly after SPI-1620, the anti-cancer drug concentration in the tumor increased several fold. This resulted in increased anti-tumor efficacy at a given dose of a cytotoxic agent. This might allow physicians to maximize efficacy with reduced doses of cytotoxic agents with resultant decreased toxicity to the normal organs. Proof of principle studies have been successfully conducted in a wide variety of indications such as breast, ovarian, melanoma, and prostate cancer.

Spectrum has proprietary worldwide rights to SPI-1620.

About Spectrum Pharmaceuticals, Inc.

Spectrum Pharmaceuticals is a biotechnology company with fully integrated commercial and drug development operations with a primary focus in oncology. The Company’s strategy is comprised of acquiring, developing and commercializing a broad and diverse pipeline of late-stage clinical and commercial products. The Company markets two oncology drugs, FUSILEV and ZEVALIN, and has two drugs, apaziquone and belinostat, in late stage development along with a diversified pipeline of novel drug candidates. The Company has assembled an integrated in-house scientific team, including clinical development, medical research, regulatory affairs, biostatistics and data management, formulation development, and has established a commercial infrastructure for the marketing of its drug products. The Company also leverages the expertise of its worldwide partners to assist in the execution of its strategy. For more information, please visit the Company’s website at www.sppirx.com.

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 drug candidates may not receive approval from the FDA, and other regulatory agencies 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 revenues, 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.

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