Genentech Inc. halted enrollment in a multicenter, single-arm Phase II study of Avastin (bevacizumab) in platinum-refractory ovarian cancer due to a high rate of gastrointestinal perforations.
The decision was made by the South San Francisco-based company in consultation with the FDA.
While GI perforations are a known possible side effect of Avastin, there was a higher rate of them in this patient population than in previous Avastin studies. Of the 44 patients enrolled in the proposed 53-patient study, five experienced GI perforations.
Those enrolled in the trial will be informed of the new safety information, and may continue to receive treatment with Avastin or elect to discontinue it. Patients in the study had more advanced disease, which typically involves the bowel, and had received more prior chemotherapy than in previous clinical trials of Avastin in ovarian cancer, which could explain the higher rate of GI perforations.
Genentech expects to continue studying Avastin in earlier-stage ovarian cancer and other tumor types. The therapeutic antibody is designed to inhibit vascular endothelial growth factor, a protein that plays a role in tumor angiogenesis and maintenance of existing tumor vessels.
FDA-approved in February 2004, Avastin is indicated as a first-line treatment for metastatic colorectal cancer in combination with intravenous 5-FU-based chemotherapy. It had sales of $246 million in the second quarter.
The company's stock (NYSE:DNA) dipped $2.17 on Friday, to close at $85.83.