Sanofi-Aventis / BiPar Sciences, Inc.

Triple-Negative Breast Cancer (TNBC)

48K US cases/yr

Disease Overview

Triple-negative breast cancer lacks estrogen, progesterone, and HER2 receptor expression, making it unresponsive to endocrine and HER2-targeted therapies. It accounts for roughly 15-20% of breast cancers, disproportionately affects younger women and Black women, and historically relied on cytotoxic chemotherapy with poor outcomes in metastatic disease.

Competitive Landscape

In April 2009, the metastatic TNBC standard of care was chemotherapy backbones (taxanes, anthracyclines, gemcitabine/carboplatin) with no targeted therapies approved. AstraZeneca's olaparib and Abbott/Enzon's veliparib were earlier in development; KuDOS/AstraZeneca had not yet reported the BRCA-mutant breast cancer data that later defined the PARP class. BiPar's BSI-201/iniparib, then believed to be a PARP inhibitor, had reported eye-catching Phase 2 data showing median OS extension from 7.7 to 12.2 months when added to gemcitabine/carboplatin in metastatic TNBC, framing it as potential first-in-class. Sanofi paid up to $500M to access this asset just as Roche's Avastin was struggling in breast cancer and the targeted-TNBC space was wide open. The deal collapsed when Phase 3 data in January 2011 missed both OS and PFS, and subsequent mechanistic work in 2012 showed iniparib did not actually inhibit PARP — it nonselectively modified cysteine residues. Sanofi terminated development at ASCO 2013, taking a $285M charge. True PARP inhibitors (olaparib/Lynparza, talazoparib/Talzenna) ultimately validated the class in BRCA-mutated TNBC.