Peregrine Pharmaceuticals, Inc., a biopharmaceutical company with a portfolio of innovative monoclonal antibodies in clinical trials for the treatment of cancer and serious viral infections,  has completed enrollment and randomization of 70 patients in a phase II trial evaluating bavituximab in combination with gemcitabine versus gemcitabine alone in patients with previously untreated stage IV pancreatic cancer.

Peregrine's lead clinical candidate, bavituximab, is a phosphatidylserine (PS)-targeting monoclonal antibody that has demonstrated promising tumor response and survival trends in randomized phase II trials in front-line and second-line non small-cell lung cancer (NSCLC). The compound is also being assessed in four investigator-sponsored trials in additional oncology indications.

“Completion of patient enrollment in this trial represents another important milestone for our bavituximab oncology program. With standard chemotherapeutic treatment yielding only minor improvements in patient survival and newer combination regimens demonstrating significant toxicities, there is an urgent need for more effective treatment options,” said Steven W King, president and chief executive officer of Peregrine. “We look forward to reporting interim survival data from this trial before year end, as well as reporting median overall survival data from both of our randomized phase II NSCLC trials, making the remainder of 2012 an exciting period in the clinical development of this novel candidate with such broad therapeutic potential.”

This multicentre trial enrolled 70 patients in the United States and internationally with previously untreated stage IV pancreatic cancer. Patients were randomly assigned to one of two treatment arms to receive gemcitabine alone or gemcitabine plus bavituximab. Patients treated with bavituximab received 3mg/kg weekly until disease progression. Gemcitabine was administered on days 1, 8, and 15 of 28-day cycles until disease progression or toxicities. The primary endpoint of the trial is median overall survival (OS) of patients. Secondary endpoints include overall response rate (ORR), duration of response (DR), and median progression-free survival (PFS).

According to the National Cancer Institute, pancreatic cancer is the fourth leading cause of cancer-related death in the United States in both men and women. Because it is usually diagnosed at an advanced stage, the survival rate is poor compared with that of other types of cancer. Unfortunately, overall pancreatic cancer incidence and mortality rates have changed very little throughout the past three decades.

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 tumour 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 tumour.

Bavituximab is currently being tested in seven clinical trials in oncology including three randomized phase II trials in front-line and second-line non-small cell lung cancer, front-line pancreatic cancer and four investigator-sponsored trials (ISTs) in additional oncology indications.