Sanofi breast cancer drug flunks Phase III trial

Sanofi subsidiary BiPar Sciences says its metastatic breast cancer drug iniparib (BSI-201) failed a late-stage trial, missing the co-primary endpoints of overall survival and progression-free survival. The drug was tested in 519 women with triple-negative breast cancer (TNBC)--a form of the disease that doesn't respond to hormonal therapies treatments targeting the human epidermal growth factor receptor 2, like Herceptin. Up to 20 percent of women who develop the disease have TNBC; they tend to have worse outcomes than patients who develop other types of breast cancer.

Sanofi purchased BiPar for $500 million in 2009, shortly after Chris Viehbacher (photo) took over as CEO. Iniparib is part of a new class of drug called PARP inhibitors to stop enzymes in cancer cells from being able to repair DNA damage caused by radiation and chemotherapy. The drug was projected to hits $1 billion in sales in 2012, helping offset revenue lost from major drugs like Lovenox and Plavix going off-patent.

"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, senior VP and head of Sanofi-Aventis Oncology. The company said it would further analyze the findings before reporting full results at an oncology conference later this year. Iniparib is also in Phase III trials for squamous non-small cell lung cancer, and Phase II trials for breast, lung and other cancers.

- here's Sanofi's release
- read the Bloomberg report for more