Updated Data from Initial Cohort Shows 11 of 17 Evaluable Patients Receiving Bavituximab in Combination with Carboplatin + Paclitaxel Achieved an Objective Tumor Response
Patient Dosing Initiated in Expansion Stage of Trial with Target of Enrolling 49 Patients Overall

TUSTIN, CA, USA | April 20, 2009 | Peregrine Pharmaceuticals, Inc. (Nasdaq: PPHM – News), today announced that updated preliminary data from the initial cohort of 21 patients in its Phase II trial evaluating bavituximab in combination with carboplatin and paclitaxel showed that 11 of 17 evaluable patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) achieved an objective tumor response according to RECIST criteria, after completing the maximum six treatment cycles. The company also reported that patient dosing is underway in the expansion stage of the trial, which will enroll an additional 28 patients for a total of 49 patients overall.

"We are very pleased to see these additional objective tumor responses in this difficult-to-treat cancer following the full regimen of six treatment cycles of bavituximab and chemotherapy," said Steven W. King, president and CEO of Peregrine. "These updated results build on the impressive data we reported after only four treatment cycles, which had already exceeded the pre-defined number of objective tumor responses needed to expand the trial to the larger cohort."

Mr. King added, "The tumor response data to date from this trial compares favorably to published studies with current standard-of-care lung cancer treatments, and we are looking forward to seeing results from the entire study. With dosing now underway in the expanded patient cohort, we expect to resume the brisk pace of enrollment achieved in the first cohort, with the goal of completing patient enrollment around mid-year. We intend to provide further updates as patient treatment and follow-up continue in the coming months."

The primary objective of the multi-center, open-label Phase II study is to assess the overall response rate to bavituximab with carboplatin and paclitaxel. In the trial’s Simon two-stage design, 21 patients with previously untreated locally advanced or metastatic NSCLC were initially enrolled and 17 of these patients were deemed evaluable. In this initial cohort, 11 of the 17 evaluable patients achieved an objective tumor response by the time that treatment with the combination of bavituximab, carboplatin and paclitaxel was completed. Eight of the 11 objective tumor responses were confirmed by at least one repeat scan no less than four weeks after the criteria for response were first met.

Secondary objectives of the study include measuring time to tumor progression, duration of response, overall patient survival and safety parameters. Patients in the study are evaluated regularly for tumor response according to RECIST criteria. Patients may continue to receive bavituximab as monotherapy after completion of chemotherapy as long as the cancer does not progress and side effects are acceptable. The trial is being conducted in India according to International Conference on Harmonization (ICH) and Good Clinical Practices (GCP) guidelines.

Lung cancer is a major cause of cancer deaths worldwide. According to the American Cancer Society, lung cancer is the second most commonly diagnosed cancer in men and women in the U.S. and is the leading cause of cancer deaths. It estimates that in 2008, there were approximately 215,020 new cases of lung cancer in the U.S. and an estimated 161,840 lung cancer deaths. NSCLC is the most common type of lung cancer, accounting for approximately 85-90% of lung cancer cases.

Bavituximab is a monoclonal antibody that binds to the cellular membrane component phosphatidylserine (PS) that is usually located inside cells, but which becomes exposed on the outside of the cells that line the blood vessels of tumors, creating a specific target for anti-cancer treatments. By binding to PS, bavituximab is believed to help mobilize the body’s immune system to destroy the tumor and the tumor blood vessels. Bavituximab currently is in two separate Phase II combination therapy trials for the treatment of advanced breast cancer and a Phase II combination therapy trial for the treatment of non-small cell lung cancer. A Phase I bavituximab monotherapy trial in advanced solid cancers is also continuing.

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 three separate clinical programs in cancer and hepatitis C virus infection with its lead product candidates bavituximab and Cotara®. Peregrine also has in-house 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.

SOURCE: Peregrine Pharmaceuticals, Inc.