Eisai has published detailed data from a head-to-head trial which shows that its breast cancer drug Halaven is no more effective than Roche's Xeloda for women with advanced disease.

Results from a Phase III trial (known as study 301) comparing Halaven (eribulin) with Xeloda (capecitabine) in women with earlier-stage metastatic breast cancer (MBC) who had received treatment that included an anthracycline and a taxmen, have been presented at the San Antonio Breast Cancer Symposium. The full data set (top-line results were revealed in July) showed that women treated with the Eisai drug had a median overall survival (OS) of 15.9 months versus 14.5 months with Xeloda, which was not statistically significant.

Also the trial did not meet the pre-specified endpoint for progression-free survival (PFS), with 4.1 and 4.2 months for Halaven and Xeloda, respectively. Nevertheless, despite failing to meet both primary endpoints, Eisai was still upbeat.

Much of that optimism came from an exploratory analysis for the planned subset of HER2 negative women, which showed that OS was 15.9 months for eribulin vs 13.5 months for capecitabine. Furthermore, in triple negative breast cancer patients, a group with "extremely high unmet medical needs" in which the disease is HER2-negative, estrogen receptor-negative and progesterone receptor-negative, the median OS was 14.4 months for Halaven and 9.4 months for Xeloda.

Presenting the data, Peter Kaufman of the Geisel School of Medicine at Dartmouth, noted that "this is the first study demonstrating that eribulin is active in the first-, second- and third-line setting in MBC. He added that "although we didn’t show a statistically significant superiority… numerically the overall survival with eribulin was better than with capecitabine".

Prof Kaufman and his colleagues are still compiling data from the quality-of-life analysis, which he says will help guide their next steps in further studying Halaven in in this patient population. The drug is currently indicated in Europe for the treatment of women with locally advanced or MBC who have previously received at least two chemotherapeutic regimens and Eisai is hoping to get the label extended for earlier use.