Sanofi-aventis (Euronext: SAN and NYSE: SNY) and Regeneron Pharmaceuticals, Inc. (Nasdaq: REGN) today announced that advanced ovarian cancer patients with recurrent symptomatic malignant ascites (SMA) receiving aflibercept (VEGF Trap) in a randomized, placebo-controlled Phase 2 study experienced a statistically significant improvement in the primary study endpoint, mean time to first repeat paracentesis (removal of fluid from the abdominal cavity), versus placebo control. Symptomatic malignant ascites is an abnormal build-up of fluid in the abdominal cavity in patients with advanced cancer.

Mean time to first repeat paracentesis following a baseline procedure was 55 days with aflibercept as compared to 23 days for patients receiving placebo (p=0.0019). Time to first repeat paracentesis was defined as the number of days between study randomization and the first post-randomization paracentesis or, in cases where there was no repeat paracentesis, study withdrawal, death, or six months from randomization.

There was a similar incidence of deaths in both treatment groups (no statistically significant difference; hazard ratio 1.02). In this late-stage patient population with advanced ovarian cancer who were heavily pre-treated (median of four prior courses of chemotherapy), four fatal events were assessed by the investigators as aflibercept treatment related, including one case each of intestinal perforation, dyspnea, pneumonia, and cause unknown.

The types and frequencies of adverse events reported with aflibercept in this study were generally consistent with those reported in clinical studies with other anti-VEGF therapies in advanced ovarian cancer patients.

"The results of this Phase 2, placebo-controlled study demonstrate that aflibercept is a clinically active agent in patients with advanced ovarian cancer with symptomatic malignant ascites. However, given the small number of patients enrolled in this study and the fragile health status of these advanced ovarian cancer patients, who had a median survival of only about three to four months, it is difficult to definitively assess the overall clinical benefit that might be derived from treatment in the real-world clinical practice setting,” stated George D. Yancopoulos, M.D., Ph.D., President of Regeneron Research Laboratories. “Therefore, we and sanofi-aventis have decided not to submit these Phase 2 data for accelerated approval in symptomatic malignant ascites. We will focus our efforts on completing the current Phase 3 program which combines aflibercept with standard chemotherapy regimens for the treatment of earlier stage metastatic colorectal, non-small cell lung, pancreatic, and prostate cancers, which should begin delivering data in 2010.”

About the Phase 2 Study

This double-blind, placebo-controlled, multi-center Phase 2 trial enrolled 55 patients with symptomatic malignant ascites, related to advanced ovarian cancer, who had failed a prior platinum-based chemotherapy regimen and who had also received chemotherapy treatment with either liposomal doxorubicin or topotecan. All patients had to have undergone between one and four prior paracenteses in the month prior to randomization in addition to a baseline procedure. Twenty-nine patients were randomized to receive aflibercept administered intravenously as 4 milligrams per kilogram of patient body weight (mg/kg) and 26 patients were randomized to placebo. Patients were dosed every two weeks. In this study the double-blind treatment period was defined as the earliest of the date of death, withdrawal from the study, six months, or entry into open-label treatment. All patients were offered the opportunity to receive open-label aflibercept after 60 days of double-blind treatment provided that at least one post-randomization paracentesis had occurred.

There was a statistically significant 2.4-fold lengthening of time to first repeat paracentesis with aflibercept as compared to placebo. Pre-specified secondary endpoint results were consistent with this primary endpoint finding. The frequency of paracentesis over the first 60 days of the study was reduced, on average, by nearly 50 percent in patients receiving aflibercept versus those receiving placebo (p=0.0035). Patient-reported symptoms of ascites, including abdominal discomfort, pain, and bloating, as well as patients’ ability to move, were recorded daily from the time of randomization to the time of first repeat paracentesis.