Sanofi-aventis and its fully owned subsidiary, BiPar Sciences, announced that final results from a randomized phase-II clinical trial confirmed that treatment with BSI-201 (iniparib) in combination with gemcitabine/carboplatin results in a significant improvement in overall survival and a high rate of clinical response in women with metastatic triple negative breast cancer (mTNBC). Findings from the study were presented today at an oral presentation at the 35th European Society for Medical Oncology (ESMO) Congress in Milan, Italy.

“These results confirm that more than half of the patients treated with BSI-201 (iniparib) had substantial decrease in their tumor burden, and they lived significantly longer than women getting chemotherapy alone,” said Joyce O’Shaughnessy, lead investigator of the study and co-chair of the Breast Cancer Research Programme Baylor-Charles A. Sammons Cancer Center; Texas Oncology, US Oncology in Dallas.  “Iniparib appears to enhance the ability of chemotherapy to kill cancer cells without increasing the severity of adverse events.”

According to the study results, median overall survival among women who received BSI-201 (iniparib) in combination with the chemotherapy agents gemcitabine and carboplatin was 12.3 months compared with 7.7 months among women who received chemotherapy alone, translating to a 43 percent reduction in the risk of death (HR=0.57). Median progression-free survival in the BSI-201 (iniparib) group was 5.9 months compared to 3.6 months in the chemotherapy group (HR=0.59) . In addition, 55.7 percent of patients in the BSI-201 (iniparib) group showed a clinical benefit, defined as a complete or partial response or stable disease of at least six months, compared with 33.9 percent of patients in the chemotherapy group. There was no significant difference in adverse events between the two groups. The most common severe (grade 3 and 4) adverse events included neutropenia, thrombyocytopenia, anemia, fatigue, leukopenia and increases in the enzyme ALT. The study included 123 women with mTNBC.

“BSI 201 (Iniparib) continues to demonstrate potential as a promising new treatment option for women with metastatic triple negative breast cancer, an aggressive disease that currently has no approved treatments,” said Debasish Roychowdhury, senior vice president, Global Oncology, sanofi-aventis. “The development of BSI 201 (iniparib) is progressing well and we hope iniparib can become the first treatment available specifically for this disease.”

The US Food and Drug Administration (FDA) granted Fast Track designation to iniparib for mTNBC. As described by the FDA, the Fast Track process is designed to expedite the review of drugs being developed for serious diseases with the potential to address an unmet need. The regulatory submissions are planned for Q1 2011 in the U.S. and Q2 2011 in the European Union.

IBSI-201 (Iniparib) is a novel investigational anti-tumor agent with poly (ADP-ribose) polymerase (PARP) inhibitory activity.