Encouraging Overall Survival Data Show Consistent Trend With Earlier Tumor Response Rate and PFS Data; Data Further Support Ongoing Randomized Phase II Trial Evaluating Bavituximab With Docetaxel for Lung Cancer

TUSTIN, CA, USA | August 25, 2011 | Peregrine Pharmaceuticals, Inc. (NASDAQ: PPHM), a clinical-stage biopharmaceutical company developing first-in-class monoclonal antibodies for the treatment of cancer and viral infections, today announced 20.7 month median overall survival (OS) from a prior single-arm Phase II trial evaluating bavituximab in combination with docetaxel in patients with locally advanced or metastatic breast cancer. In a separate published study(1) included in the docetaxel package insert, median OS was 11.7 months for metastatic breast cancer patients treated with docetaxel alone. Currently, Peregrine’s bavituximab is being evaluated in randomized Phase II trials in non-small cell lung cancer (NSCLC), pancreatic cancer, and hepatitis C virus (HCV), as well as in four investigator-sponsored trials (ISTs) in additional oncology indications, including HER2-negative metastatic breast cancer.

"This newest data point from our prior Phase II signal-seeking trials is encouraging, and shows adding bavituximab to the standard chemotherapy docetaxel offers meaningful survival benefits to breast cancer patients," said Kerstin B. Menander, M.D. Ph.D., head of medical oncology at Peregrine Pharmaceuticals. "We are eager to complete patient enrollment in our two randomized Phase II trials in non-small cell lung cancer to assess further bavituximab’s potential in combination with chemotherapy for advanced cancer patients."

In Peregrine’s prior single-arm, multi-center Phase II trial, 46 patients with locally advanced or metastatic breast cancer who had received one prior chemotherapy regimen were treated with weekly bavituximab and docetaxel. The primary endpoint, objective response rate (ORR), was 61%, with 11% of the patients achieving a clinical complete response in accordance with RECIST criteria, compared to ORR of 41% of patients in a separate trial used as a historical control using weekly docetaxel alone. Neither of these earlier studies selected patients based on hormone receptor status.

About Bavituximab
Bavituximab is a first-in-class phosphatidylserine (PS)-targeting monoclonal antibody that represents a new approach to treating cancer. PS is a highly immunosuppressive molecule usually located inside the membrane of healthy cells, but "flips" and becomes exposed on the outside of cells that line tumor blood vessels, creating a specific target for anti-cancer treatments. PS-targeting antibodies target and bind to PS and block this immunosuppressive signal, thereby enabling the immune system to recognize and fight the tumor.

For further information about bavituximab trials conducted by Peregrine and its investigators, please visit http://www.peregrinetrials.com or http://www.clinicaltrials.gov/ct2/results?term=bavituximab.

About Breast Cancer
The World Health Organization reports that breast cancer is the most commonly diagnosed cancer in women and is second only to lung cancer as a leading cause of female cancer deaths. The National Cancer Institute estimates that approximately 230,480 U.S. women will be diagnosed with breast cancer and 39,520 will die from this disease in 2011. HER2-negative accounts for approximately 75% of metastatic breast cancers.

About Peregrine Pharmaceuticals
Peregrine Pharmaceuticals, Inc. is a biopharmaceutical company with a portfolio of innovative monoclonal antibodies in clinical trials for the treatment of cancer and serious viral infections. The company is pursuing multiple clinical programs in cancer and hepatitis C virus infection with its lead product candidate bavituximab and novel brain cancer agent Cotara®. Peregrine also has in-house cGMP manufacturing capabilities through its wholly-owned subsidiary Avid Bioservices, Inc. (www.avidbio.com), which provides development and biomanufacturing services for both Peregrine and outside customers. Additional information about Peregrine can be found at www.peregrineinc.com.

(1) Nabholtz, J. et al (1999). Journal of Clinical Oncology.

SOURCE: Peregrine Pharmaceuticals