Results from an interim analysis of this study showed that the median progression-free survival was 11 months for patients treated with Avastin (bevacizumab) plus chemotherapy, compared to six months for patients treated with chemotherapy alone.
At this interim analysis, a 49% improvement in the secondary endpoint of overall survival was observed. In patients with measurable disease, the overall response rate was 28% in the Avastin plus chemotherapy arm, a 100% increase over the 14% observed in the chemotherapy alone arm.
However, a preliminary assessment of safety showed that grade 3/4 adverse events that occurred more often in the Avastin arm included neuropathy, hypertension and proteinuria. Neuropathy occurred in 21% of patients in the Avastin plus chemotherapy arm and in 14% of patients in the chemotherapy alone arm. Hypertension occurred in 13% of patients treated with Avastin plus chemotherapy and in no patients who received chemotherapy alone.
“The results from this study are an important advance in the potential treatment of breast cancer,” said Dr Hal Barron, Genentech’s senior vice president of development, and chief medical officer. “The data from this trial showed that Avastin had a clinically important improvement in overall survival, the study’s secondary endpoint, which is exciting given that this improvement was observed at an early interim analysis.”
Genentech is discussing plans for the filing of a supplemental biologics license application (sBLA) for Avastin plus chemotherapy in first-line metastatic breast cancer with the FDA.