Phase III Ixabepilone Study Shows Improvement in Progression-Free Survival in Patients With Advanced Metastatic Breast Cancer

Bristol-Myers Squibb reported results from a large randomized phase III study of the investigational compound ixabepilone in patients with breast cancer whose disease had rapidly progressed through, or did not respond to, prior treatment with chemotherapies (anthracycline and taxane). Results showed that patients treated with ixabepilone in combination with capecitabine (Xeloda), experienced a statistically significant improvement in progression-free survival, the primary endpoint, compared to patients treated with capecitabine alone. The data were presented at the 43rd Annual Meeting of the American Society of Clinical Oncology (ASCO).

"Patients whose disease is no longer responding to currently approved chemotherapies have few proven treatment options available to them," said Renzo Canetta, Vice President, Oncology Global Clinical Research, Bristol-Myers Squibb. "The results of this study provide important information about this investigational compound especially for patients with metastatic breast cancer resistant to anthracyclines and taxanes."

Key Study Findings

In this international open-label phase III trial, 752 patients with metastatic breast cancer whose disease had rapidly progressed through at least two prior therapies (anthracycline and taxane), were randomly assigned to receive ixabepilone in combination with capecitabine or capecitabine alone. Study results showed that ixabepilone in combination with capecitabine:

• Prolonged progression-free survival (5.8 vs 4.2 months), with a statistically significant 25% decrease in the risk of disease progression (hazard ratio = 0.75; P < .0003), and

• Resulted in an objective response rate in more than twice as many patients (35% vs 14%).

Progression-free survival was defined as the time from randomization to progressive disease or death from any cause, as determined by the Independent Radiology Review committee. Secondary endpoints include objective response rate (defined as complete and partial antitumor response), time to response, and duration of overall response, which was assessed independently by investigators at the study site.

For ixabepilone in combination with capecitabine, most treatment-related adverse events were consistent with the safety profile of the individual agents. In addition, capecitabine-associated toxicities (such as hand-foot syndrome) were not exacerbated by ixabepilone.