FDA Grants Merck’s Anti-PD1 Antibody Priority Review

Source: Cancer Network, May 2014

The FDA has granted Merck’s anti-PD1 antibody MK-3475 a priority review designation for the treatment of unresectable or metastatic melanoma in patients who have previously been treated with ipilimumab. Priority review status is reserved for drugs considered to offer a significant improvement in the safety or efficacy of the treatment of a serious condition. It will shorten the drug’s FDA review period from 10 months to 6 months.

Data on MK-3475 were first presented at the 2013 ASCO Annual Meeting by Omid Hamid, MD, of the University of California, Los Angeles, and colleagues, and subsequently published in the New England Journal of Medicine. These early results looked at 135 patients with advanced melanoma given MK-3475 every 2 to 3 weeks. Confirmed response to the treatment was found in 38% of patients.

In November, additional data from the large phase I study of patients with melanoma were presented at the 10th International Congress of the Society for Melanoma Research. Results showed that treatment with MK-3475 resulted in an objective response rate of 41%, with a response of 51% for patients treated with a dose of 10 mg/kg every 2 weeks, and a 1-year survival rate of 81%.

MK-3475 is currently being tested in a phase II study that is comparing it with traditional chemotherapy in patients who have progressed after prior therapy. A phase III trial comparing the drug with the anti-CTLA-4 ipilimumab is also ongoing.

According to a Merck statement, there will be six oral abstracts on MK-3475 presented at the 2014 ASCO Annual Meeting.

Bristol-Myers Squibb also has an anti-PD1 therapy, nivolumab, under investigation in patients with myeloma. Early results of studies of nivolumab showed that patients treated with the drug in combination with ipilimumab had an objective response rate of 40%; those patients receiving the highest dose of the drug had a response rate of 53%.