Source: BiPar Sciences

BSI-201 Enters Phase 3 in Metastatic Triple Negative Breast Cancer

Recruitment Into Pivotal Phase 3 Study Initiated Just 2 Months After Striking Phase 2 Results

PARIS and SOUTH SAN FRANCISCO, Calif., July 17, 2009 (GLOBE NEWSWIRE) -- Sanofi-aventis (EURONEXT:SAN) (NYSE:SNY) and its wholly owned subsidiary, BiPar Sciences, today announced the initiation of the pivotal Phase 3 trial for BSI-201 in combination with chemotherapy in patients with metastatic triple-negative breast cancer (mTNBC), defined by tumors lacking expression of estrogen, progesterone receptors and without over-expression of HER2. BSI-201 is a novel, investigational, targeted therapy which inhibits poly (ADP-ribose) polymerase (PARP1), an enzyme involved in DNA damage repair.

The Phase 3 trial is a multi-center, randomized trial designed to evaluate the safety and efficacy of BSI-201 when combined with gemcitabine and carboplatin (GC) in women with mTNBC. A total of 420 mTNBC patients, who have received 0-2 prior therapies in the metastatic setting, will be randomized to receive GC with or without BSI-201.

The co-primary objectives of this study are to assess improvement in progression-free survival and overall survival. The secondary objectives are to assess objective response rate and safety. An estimated 60-75 sites will be distributed throughout the United States. Importantly, this trial will have a crossover provision that will ensure that all patients enrolled in the BSI-201 Phase 3 clinical trial have the potential opportunity to receive BSI-201 (patients randomly assigned to the control arm may receive BSI-201 upon disease progression).

The decision to commence with the Phase 3 study was made based on Phase 2 study results presented during the Plenary Session of the American Society of Clinical Oncology (ASCO) annual conference on May 31, 2009. The Phase 2 clinical trial involved 116 women with metastatic TNBC who were randomly assigned to receive GC in combination with the investigational agent BSI-201 or GC alone.

Approximately 62 percent of patients receiving BSI-201 in combination with GC showed clinical benefit, compared with 21 percent in the group receiving chemotherapy alone (p= 0.0002). Tumor response (complete or partial response) was observed in 48 percent of patients who received BSI-201 combined with chemotherapy, whereas patients receiving chemotherapy alone showed a response rate of 16 percent. Women who received BSI-201 had a median progression-free survival of 6.9 months and overall survival of 9.2 months compared with 3.3 and 5.7 months, respectively, for women who received chemotherapy alone. The hazard ratios for progression-free survival and overall survival were 0.342 (p< 0.0001) and 0.348 (p=0.0005), respectively.

The most common severe (grades 3 and 4) side effects included neutropenia [25/57 in patients treated with GC and BSI-201; 31/59 patients treated with GC alone], thrombocytopenia and anemia. No febrile neutropenia was observed in patients receiving BSI-201 combined with chemotherapy. BSI-201 did not add to the frequency or severity of adverse events associated with chemotherapy.

For more information about the BSI-201 Phase 3 clinical trial, please go to: www.clinicaltrials.gov or www.biparsciences.com, or call the BiPar Sciences Call Center at +1 866 668 2232.

About BSI-201

Among other investigational PARP inhibitors in the industry, BSI-201 is the furthest along in clinical development in metastatic TNBC. BSI-201 is currently being evaluated for its potential to enhance the effect of chemotherapy-induced DNA damage.

About TNBC

When patients are diagnosed with breast cancer, their tumors are routinely tested for the presence of estrogen and progesterone receptors and for the over-expression of HER2. Commonly used breast cancer therapies target these receptors; for example, tamoxifen for estrogen receptor and trastuzumab (Herceptin(r)) for HER2. However, 15-20 percent of all breast cancers lack over-expression of all three proteins, thus giving rise to the term "triple-negative breast cancer" or "TNBC."

TNBC can be an aggressive disease, with higher rates of metastases and poorer survival rates than other breast cancer subtypes. No treatment has been approved specifically for TNBC.

About BiPar Sciences

BiPar Sciences is a biopharmaceutical organization pioneering novel tumor-selective therapies designed to address urgent unmet needs of cancer patients. In addition to BSI-201, the company also has two additional compounds in preclinical development. BiPar Sciences, located in South San Francisco, California, is a wholly owned subsidiary of sanofi-aventis, Inc. For more information, please visit www.biparsciences.com.

About sanofi-aventis

Sanofi-aventis is a leading global pharmaceutical company that discovers, develops and distributes therapeutic solutions to help improve the lives of patients. Sanofi-aventis is listed in Paris (EURONEXT:SAN) and in New York (NYSE:SNY).

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