Peregrine reports positive data from second Phase II breast cancer trial

Peregrine Pharmaceuticals, a biopharmaceutical company, has reported that updated preliminary data from its Phase II trial evaluating bavituximab in combination with carboplatin and paclitaxel in advanced breast cancer showed that nine of 14 evaluable patients in the initial cohort achieved an objective tumor response after a maximum of six treatment cycles according to RECIST criteria.

The company has also reported that patient dosing is underway in the expansion stage of the trial, which will enroll an additional 31 patients for a total of 46 advanced breast cancer patients overall.

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, 15 patients with locally advanced or metastatic breast cancer were initially enrolled and 14 of these patients were deemed evaluable. In this initial cohort, nine of the 14 evaluable patients achieved an objective tumor response by the time that treatment with the combination of bavituximab, carboplatin and paclitaxel was completed, said Peregrine.

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 response evaluation criteria in solid tumors (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.

Bavituximab currently is in a separate Phase II trial in combination with docetaxel 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.

Steven King, president and CEO of Peregrine, said: These updated results further strengthen the positive data we reported in February 2009 after two treatment cycles, which had already exceeded the pre-defined number of objective tumor responses needed to expand the trial to the larger cohort.