Bristol-Myers' immunotherapy drug nivolumab takes center stage at ASCO

June 1, 2013 | By John Carroll CHICAGO--Bristol-Myers Squibb ($BMY) arrived at ASCO with one of the most closely watched experimental immunotherapy drugs in the pipeline. And racing against some major league rivals, the biopharma company will leave with its frontrunner reputation for nivolumab intact.Nivolumab's claim to fame as a breakthrough melanoma therapy was enhanced by long-term results from their Phase I study, which show that the PD-1 drug demonstrated durable responses among a significant group of patients with Stage 4 melanoma. Close to a third of the patients in the study experienced tumor shrinkage, compared to a historical trend rate of 5% to 10% for Yervoy, Bristol-Myers' pioneering immunotherapy for this disease.Researcher Mario Sznol spelled out the data on Saturday, highlighting the 33 of 107 patients whose tumors shrank at least 30%. There was a rapid response among 45% of the patients and the median duration of response was two years, says Sznol. The median overall survival for patients was 16.8 months, with the optimal dose being used in subsequent studies hitting an impressive OS rate of 20.3 months. (Yervoy manages about half of that rate.) There was no comparison arm in the Phase I study, but Sznol noted that OS rates clearly exceeded anything seen in newly approved melanoma therapies.