Bristol-Myers Squibb has presented promising Phase III data on its new compound ixabelipone which reveals that the drug, combined with a standard chemotherapy, shows significant improvement in progression-free survival in patients with advanced metastatic breast cancer.

The New York-based company presented data at the American Society of Clinical Oncology meeting in Chicago from a Phase III trial of 752 patients with metastatic breast cancer whose disease had rapidly progressed through at least two prior therapies (anthracycline and taxane), who were then randomly assigned to receive ixabepilone in combination with Roche’s Xeloda (capecitabine) or capecitabine alone.

The results showed that patients getting ixabepilone in combination with capecitabine showed prolonged progression-free survival for 5.8 months, compared to 4.2 months with capecitabine alone, with a statistically significant 25% decrease in the risk of disease progression. The study also revealed that 35% of patients receiving the combination experienced reduction in tumour size, compared to 14% receiving capecitabine alone.

The firm noted that for ixabepilone in combination with capecitabine, most treatment-related adverse events were consistent with the safety profile of the individual agents and capecitabine-associated toxicities (such as hand-foot syndrome) were not exacerbated by the B-MS compound. Renzo Canetta, vice president of the company’s oncology clinical research, stated that “patients whose disease is no longer responding to currently approved chemotherapies have few proven treatment options available to them" and ixabepilone may be able to step into the breach.

Ixabepilone belongs to a new class of drugs called epothilones, and a filing of the compound, in combination with Xeloda, is expected in the second half of this year.

Sprycel may be effective as first-line CML treatment

Also at ASCO, B-MS presented data from a Phase II trial of Sprycel (dasatinib) which suggest that the compound may be effective in the first-line treatment of chronic myelogenous leukaemia. It was approved by the US Food and Drug Administration last June for use when treatment fails with Novartis’ blockbuster Gleevec (imatinib).

The ongoing study has enrolled 35 patients (out of a possible 100) with CML who had not previously received treatment with Gleevec and 31 were deemed to be evaluable. Of those, 77% at three months had a complete cytogenetic response, which rose to 92% at six months and 95% at the one-year mark. It is far too early to say whether Sprycel’s benefit is greater than Gleevec but B-MS plans to discuss setting up larger trials of the drug as a first-line CML treatment with EU and US regulators.