Sanofi-Aventis and Regeneron discontinue one Ph III study of aflibercept

French drug major Sanofi-Aventis and the USA's Regeneron Pharmaceuticals, say they have discontinued the Phase III trial that evaluated aflibercept (VEGF Trap) plus gemcitabine versus placebo plus gemcitabine (Eli Lilly's Gemzar) for the first-line treatment of metastatic pancreatic cancer (VANILLA), based on the recommendations by an Independent Data Monitoring Committee (IDMC).

Shares of Regeneron fell 3% to $21.23 in after-hours trading. Sanofi-Aventis' American depositary shares closed at $35.05, up 0.4%, on September 11 when the announcement was made, and were inactive in after-hours trading.

As part of a planned interim efficacy analysis, the IDMC determined that the addition of aflibercept to gemcitabine would be unable to demonstrate a statistically-significant improvement in the primary endpoint of overall survival compared to placebo plus gemcitabine in this study. The types and frequencies of adverse events reported on the combination arm with aflibercept were generally as anticipated.

With the closure of the study, a detailed analysis of the efficacy and safety results will be conducted by the companies and results will be presented at a future medical meeting. Sanofi-Aventis and Regeneron have notified the study investigators and appropriate regulatory authorities of the decision to discontinue the study. Patients in the study will continue to be provided access to aflibercept at the determination of the study investigators in consultation with the patients.

Metastatic pancreatic cancer is among the most intractable cancers. Clinical development of new therapies, including anti-VEGF agents, has been generally characterized by a failure to achieve significant incremental clinical benefit over existing treatments.

"We are disappointed with the result of this study and we will continue our efforts to bring new and effective treatments for these patients," said Marc Cluzel, senior vice president, R&D at Sanofi-Aventis. "We remain committed to the other ongoing Phase III trials of aflibercept in colorectal cancer, non-small cell lung cancer, and hormone-refractory metastatic prostate cancer."

Three Phase III studies continue, each of which is currently over 7% enrolled:
 VELOUR study: 2nd-line metastatic colorectal cancer in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI)
 VITAL study: 2nd-line non-small cell lung cancer in combination with docetaxel
 VENICE study: 1st-line hormone-refractory metastatic prostate cancer in combination with docetaxel and prednisone.