Peregrine Pharmaceuticals, Inc, a clinical stage biopharmaceutical company developing monoclonal antibodies for the treatment of cancer and hepatitis C virus infection (HCV), has completed enrolment in the first stage of its phase II trial of bavituximab in combination with chemotherapy in patients with advanced breast cancer.
The main objective of the safety and efficacy study is to assess the overall response rate to the combination of bavituximab with docetaxel, a chemotherapy drug commonly used to treat breast cancer, the company said in a press statement.
"We are very pleased that patient enrolment in this trial has proceeded quickly, reflecting the enthusiasm and efficiency of our clinical colleagues in Europe and the level of patient interest in a potential new therapy for this difficult disease," said Steven W. King, president and CEO, Peregrine. "We look forward to providing an update on the trial as patients continue to be dosed in the study and tumour response data is generated."
As part of this trial's two-stage design, 15 patients with locally advanced or metastatic breast cancer have been enrolled initially. The primary objective of the multi-centre, open-label study is to assess overall tumour response rate to the combination of bavituximab with docetaxel. The study may be expanded to include up to an additional 31 subjects if promising results are seen in the first 15 patients. Patients enrolled in the trial will remain in the study until disease progression.
Secondary objectives of the phase II study include measuring time to tumour progression, duration of response, overall patient survival and safety parameters. Patients may continue to receive bavituximab alone after completion of chemotherapy as long as the cancer does not progress and side effects are acceptable.
Tumour response in this study will be evaluated using Response Evaluation Criteria in Solid Tumours (RECIST) parameters. The trial is being conducted in the Republic of Georgia according to International Conference on Harmonization (ICH) and Good Clinical Practices (GCP) standards.
The National Cancer Institute estimates that approximately 178,480 U.S. women were diagnosed with cancer of the breast in 2007 and about 40,460 women died of the disease. According to the World Health Organisation, 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.
Bavituximab is a monoclonal antibody that binds to a phospholipid called phosphatidylserine that is usually located inside normal cells, but which becomes exposed on the outside of the cells that line the blood vessels of tumours, creating a specific target for anti-cancer treatments. Bavituximab is believed to help mobilize the body's immune system to destroy the blood vessels needed for tumour growth and spread. In a phase Ib pilot trial in advanced cancer patients, bavituximab plus chemotherapy appeared to have a safety profile consistent with chemotherapy alone and showed positive signs of clinical activity, achieving objective response or disease stabilization in 50 per cent of the evaluable patients. Peregrine has received regulatory approval to conduct three phase II trials to study the anti-tumour effects of bavituximab in combination with chemotherapy. These include two breast cancer protocols and a non-small cell lung cancer protocol. Bavituximab is in clinical trials in the US in patients with advanced solid tumours and in patients co-infected with HCV and HIV.