The first long-term follow-up results from a phase 1b immunotherapy trial combining drugs for advanced melanoma patients has shown encouraging results—long-lasting with high survival rates—researchers report. First author Mario Sznol, M.D., professor of medical oncology at Yale Cancer Center, is presenting the updated data at the 2014 annual conference of the American Society of Clinical Oncology (ASCO) in Chicago.
Sznol, clinical research leader of the melanoma research program at Yale Cancer Center, was the senior author on the original study of combination immunotherapy that was first published in the New England Journal of Medicine and presented at ASCO in 2013. Jedd Wolchok, M.D., of Memorial Sloan Kettering Cancer Center was first author of the earlier study, and senior author of this updated research.
The trial evaluated the safety and activity of the combination regimen of nivolumab (anti-PD-1), an investigational PD-1 immune checkpoint inhibitor, and ipilimumab (anti-CTLA-4; Yervoy), given either concurrently or sequentially, to patients with advanced melanoma whose disease progressed after prior treatment. The one-year overall survival rate was 94% and the two-year rate was 88%.
"The treatment of advanced melanoma has changed dramatically in the last few years, but there continues to be a need to increase the number of patients who experience a long-term survival benefit," Sznol said. "While these are phase 1b data, the duration of response and one- and two-year survival rates observed with the combination regimen of nivolumab and Yervoy are very encouraging and support the rationale for the ongoing, late-stage trials of this combination regimen."
CTLA-4 and PD-1 are targets for cancer immunotherapy because they are shut down the immune system's ability to respond to attack tumors. Antibodies blocking CTLA-4 and PD-1 enable a strong immune response against cancer by removing the brakes from the immune system. Nivolumab targets the PD-1 receptor on the surface of T-cells, and ipilimumab targets CTLA-4 receptors. Both are manufactured by Bristol-Myers Squibb, which sponsored the study with Ono Pharmaceutical Company, Ltd.