Sanofi-aventis announces publication of positive BSI-201 phase II results for breast cancer

Sanofi-aventis and its wholly-owned subsidiary, BiPar Sciences, today announced that The New England Journal of Medicine (NEJM) published the final phase II data for the investigational drug iniparib* (BSI-201) demonstrating significant clinical benefit in women with metastatic triple negative breast cancer (mTNBC) when iniparib was administered in combination with chemotherapy agents gemcitabine/carboplatin. Although not a pre-specified endpoint, overall survival also was significantly increased in women who received iniparib. The study, "Iniparib plus Chemotherapy in Metastatic Triple-Negative Breast Cancer," was published in the January 5, 2011, online version of the NEJM and will be published in the January 20, 2011, print edition.  These findings were presented at the 35th European Society for Medical Oncology (ESMO) Congress in Milan, Italy.

"These published data show that the addition of iniparib to gemcitabine and carboplatin provided a significant improvement in clinical benefit in women with metastatic triple negative breast cancer, an aggressive form of breast cancer with no approved standard treatments that target this particular tumor subtype," said Joyce O'Shaughnessy, M.D., lead investigator of the study and co-chair of the Breast Cancer Research Program, Baylor-Charles A. Sammons Cancer Center, Texas Oncology, US Oncology in Dallas.

According to the study results, 56 percent of patients in the iniparib (BSI-201) group showed a clinical benefit – defined as a complete or partial response or stable disease of at least six months – compared with 34 percent>

In the phase II iniparib (BSI-201) study, the most common any grade adverse events in the iniparib (BSI-201) arm were neutropenia, anemia, thrombocytopenia, fatigue/asthenia, nausea and constipation. The most common grade 3/4 adverse events in the iniparib treatment arm were neutropenia, anemia, thrombocytopenia, leukopenia and fatigue/asthenia. There were two fatal adverse events (3.4%) in the chemotherapy-alone group and three (5.3%) in the iniparib (BSI-201) group, all attributed to disease progression within 30 days of receiving study treatment.  A large phase III study is ongoing and results are expected in 2011.

"The positive iniparib phase II data in this difficult to treat form of breast cancer is encouraging and underscores the innovative science and approach we have taken as we continue to investigate iniparib's potential to address this unmet medical need," said Atul Dhir M.D., CEO, BiPar Sciences, a wholly- owned subsidiary of sanofi-aventis.

Phase II Iniparib Study

This multicenter, open-label, randomized study included 123 women with mTNBC. The primary endpoints were safety and tolerability and clinical benefit rate of iniparib (BSI-201) defined as a complete or partial response or stable disease of at least six months. Secondary endpoints included overall response rate and progression-free survival. Overall survival also was assessed, although it was not a pre-specified endpoint of the trial. Patients received gemcitabine/carboplatin alone (chemotherapy group) or in combination with iniparib (BSI-201) until disease progression or unacceptable toxicity. Patients in the chemotherapy group whose disease progressed were allowed to cross over to the iniparib (BSI-201) plus chemotherapy group. Efficacy analyses were conducted on the intent-to-treat (ITT) population.