Ixabepilone addition helpful in metastatic breast cancer

December 11, 2007

NEW YORK (Reuters Health) - Ixabepilone, the first of a new class of antineoplastic agents, in combination with capecitabine is more effective than capecitabine alone in patients with refractory metastatic breast cancer, according to researchers.

Dr. Eva S. Thompson of Oakland Kaiser, California, and colleagues compared the two treatment strategies in anthracycline-pretreated or -resistant and taxane-resistant locally advanced or metastatic breast cancer. Their findings appear in the November 20th issue of the Journal of Clinical Oncology.

The team studied 752 patients who were assigned to an intravenous dose of ixabepilone on day 1 of a 21-day cycle along with oral capecitabine 2000 mg per square meter on days 1 through 14 or oral capecitabine 2500 mg per square meter alone given on the same schedule.

With the combination, median free survival was 5.8 months, compared to 4.2 months for capecitabine alone, and there was a 25% reduction in the estimated risk of disease progression. Objective response was 35% in the combination group versus 14% with monotherapy.

However, in the combination group, 21% had grade 3 and 4 sensory neuropathy versus none of the monotherapy group. There was also a higher rate of neutropenia (68% versus 11%) and fatigue (9% versus 3%).

The rate of death as a result of toxicity was also higher (3% versus 1%) and patients with liver dysfunction were at increased risk. The incidence of capecitabine related-toxicities was similar in both groups.

These results support use of the combination in this population, the researchers conclude, and "also warrant evaluation of the role of ixabepilone in earlier settings of breast cancer."