Anti-PD-1 immunotherapy boosts long-term survival in metastatic melanoma

One-third of patients with metastatic melanoma in a phase 1 clinical trial have survived five years after treatment with the immunotherapy drug nivolumab, which blocks the PD-1 immune checkpoint, reports a Dana-Farber Cancer Institute scientist.

The five-year-survival rate seen with nivolumab (Opdivo) is double the rate for similar patients diagnosed between 2005 and 2011, and who were not treated with immunotherapy. The nivolumab phase 1 trial opened in 2008.

“This is the first long-term follow-up analysis of data from a clinical trial testing an anti-PD-1 immunotherapy, and it is very encouraging that a subset of melanoma patients is experiencing a long-term survival benefit,” said F. Stephen Hodi, MD, director of the Melanoma Treatment Center and the Center for Immuno Oncology at Dana-Farber.

Hodi is lead author on an abstract presented at the 2016 Annual Meeting of the American Association for Cancer Research (AACR) being held April 16-20 in New Orleans.

The phase 1 trial enrolled 107 patients, whose median age was 61, with metastatic melanoma who had received up to five prior treatments – but not a different immunotherapy drug, ipilimumab. The patients received one of five doses of nivolumab every two weeks for up to two years. Earlier data from this trial, which were published in the Journal of Clinical Oncology in 2014, showed that some patients had durable responses that persisted even after discontinuation of the treatment.

The investigators followed the 107 patients for up to five years (with a minimum of 45 months of follow-up) from the time a patient received his or her first dose of nivolumab.

“The five-year overall survival in all 107 patients was 34 percent, and those rates appeared to plateau at around four years,” said Hodi, who is also an associate professor of medicine at Harvard Medical School. “This is indicative of long-term benefit in some patients, although more follow-up is needed to fully appreciate the benefit of nivolumab as a single agent,” Hodi said.

For patients who received the optimal dose of 3 milligrams per kilogram of body weight, the overall survival was 64.7 percent at 12 months, 47.1 percent at 24 months, 41.2 percent at 36 months, and 35.3 percent at 48 months. After that, the survival rate plateaued. The median overall survival was 20.3 months for those who received the 3mg/kg dose, versus 17.3 months in all 107 patients. At 30 months after treatment, progression-free survival (PFS) rates were 25.7 percent for those who received 3mg/kg nivolumab and 18.6 percent for all patients.

“These data provide a foundation for establishing anti-PD-1 therapy as another standard for melanoma patients, and hopefully this would translate to other cancer types as well,” Hodi said.

This study was funded by Bristol Myers Squibb.