Sanofi-Aventis does not appear to be too downcast about the news that its investigational drug aflibercept missed its primary endpoint in a mid-stage trial of the compound as a treatment for advanced ovarian cancer.

Sanofi and partner Regeneron Pharmaceuticals reported results of a Phase II study of 215 women with the disease who were treated with aflibercept, a fusion protein targeting vascular endothelial growth factor, at a dose of 2 mg/kg or 4 mg/kg every two weeks. As assessed by an independent review committee, patients achieved a response rate of 4.6% in the 4 mg/kg arm and 0.9% in the 2 mg/kg arm, less than the 5% mark which was the primary endpoint.

However when the response to treatment was assessed both by the clinical investigators the rates were 7.3% with the 4 mg/kg dose and 3.8% in the 2 mg/kg arm. Marc Cluzel, head of R&D at Sanofi, said that "we are encouraged by the results reported with the use of single-agent aflibercept in this advanced ovarian cancer patient population for whom few therapeutic options are available".

The companies also announced that six abstracts describing the results of clinical trials with aflibercept will be presented at the American Society of Clinical Oncology meeting. Sanofi and Regeneron currently are enrolling some 4,000 patients in four Phase III studies that combine the drug with chemotherapy to treat colorectal, pancreatic, prostate and non-small cell lung cancer.