Sanofi-aventis and its subsidiary, BiPar Sciences, announced that a randomized phase III trial evaluating BSI-201 (iniparib) in patients with metastatic triple-negative breast cancer (mTNBC) did not meet the pre-specified criteria for significance for co-primary endpoints of overall survival and progression-free survival.

Importantly, the results of a pre-specified analysis in patients treated in the second- and third-line setting demonstrate an improvement in overall survival and progression-free survival, consistent with what was seen in the phase II study. The overall safety analysis indicates that the addition of BSI-201 did not significantly add to the toxicity profile of gemcitabine and carboplatin.

"While this trial did not meet its primary goal, we believe that the improvement in overall survival and progression-free survival in patients in the second- and third-line setting are important findings," said Dr Debasish Roychowdhury, M.D. senior vice president and head of sanofi-aventis oncology. "We are conducting in-depth analysis to gain further insight into these phase III results. Sanofi-aventis remains committed to improving outcomes for patients with triple negative breast cancer where there is high unmet medical need."

Sanofi-aventis plans to discuss these data with United States and European health authorities in the near future. Full study results will be presented at an upcoming major oncology conference. Patients with questions are encouraged to consult with their treating physicians. The current clinical development program for BSI-201 continues in breast, lung and other cancers.

The study enrolled 519 women with mTNBC from 109 sites in the United States. Patients were randomized to receive a standard chemotherapy regimen (gemcitabine and carboplatin) on days one and eight of each 21- day cycle, with or without BSI-201 5.6 mg/kg, which was administered on days one, four, eight and 11 of each 21-day cycle. Patients in the study had received up to two previous lines of chemotherapy in a metastatic setting. The co-primary endpoints were overall survival and progression-free survival.

BSI-201 is a novel investigational anti-tumour agent with poly (ADP-ribose) polymerase (PARP) inhibitory activity in preclinical models. BSI-201 is in phase III trials for patients with squamous non-small cell lung cancer, as well as in phase II trials for patients with breast, lung and other cancers.

When women are diagnosed with breast cancer, their tumours are routinely tested for the presence of estrogen and progesterone receptors and for the over-expression of HER2. However, 15 to 20 per cent of all breast cancers lack over-expression of all three proteins – giving rise to the term “triple-negative breast cancer” or TNBC. Research has shown TNBC continues to be difficult to treat and associated with poorer outcomes than other types of breast cancer. Women with TNBC are not candidates for hormonal therapies such as tamoxifen or therapies targeting the human epidermal growth factor receptor , such as Herceptin, leaving chemotherapy as the standard treatment. Therefore, finding new strategies to enhance the effectiveness of chemotherapy in this population has become an important research focus.

BiPar Sciences is a biopharmaceutical organization dedicated to pioneering novel tumour-selective therapies designed to address urgent unmet needs of cancer patients. Located in South San Francisco, California, BiPar is a subsidiary of sanofi-aventis.

Based in Cambridge, Massachusetts, and Vitry, France, sanofi-aventis Oncology is translating science into effective cancer therapeutics to address unmet medical needs for patients with cancer. Starting with a deep understanding of the mechanisms by which cancer develops, grows and spreads, the company employs innovative approaches in drug discovery, clinical development and partnerships to bring the right medicines to the right patients with the goal of helping cancer patients live healthier and longer lives.