Treatment with ruxolitinib reduced the risk of death by 33% compared to a placebo, although this survival benefit -- a secondary endpoint of the study -- was only a trend and did not reach statistical significance.
New safety data include a 34% rate of thrombocytopenia (abnormally low platelet counts) reported by ruxolitinib patients compared to a 9% rate for placebo patients. The discontinuation rate due to thrombocytopenia was 0.6% for ruxolitinib compared to 0.7% for placebo patients.
Incyte and Novartis previously disclosed the primary endpoint of the COMFORT-1 study: Treatment with 24 weeks of ruxolitinib significantly reduced the spleen size of 42% of myelofibrosis patients compared to 0.7% of patients treated with a placebo.
Results from a second, positive phase III study of ruxolitinib in myelofibrosis dubbed COMFORT-II and conducted in Europe will be presented at the ASCO meeting next month. Data from this study remain embargoed and were not released Wednesday. Incyte and Novartis have stated their intention to seek regulatory approval of ruxolitinib later this quarter.
New details also emerged Wednesday from a phase III study of Ariad Pharmaceuticals' sarcoma drug ridaforolimus. While a survival analysis of the study is still ongoing, patients treated with ridaforolimus have to date reported a median overall survival of 88 weeks compared to a median overall survival of 79 weeks for placebo-treated patients. The 8% relative reduction in the risk of death favoring ridaforolimus is not yet statistically significant.
Ariad and its partner
previously announced meeting the study's primary endpoint -- a statistically significant, 28% reduction in the risk of tumor progression that favored ridaforolimus over placebo. Ariad and Merck will be seeking approval for ridaforolimus later this year.
Exelixis's cancer drug cabozantinib will be the subject of three closely watched oral data presentations at this year's ASCO meeting, although the research abstracts released Wednesday yield little new disclosures about the drug's efficacy and safety. Still, cabozantinib is one of the more exciting drugs at this year's conference, prompting ASCO officials to highlight the drug during a preview press conference on Wednesday afternoon.