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 — according to a presentation at the 2014 annual conference of the American Society of Clinical Oncology (ASCO) in Chicago.
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. Both drugs are manufactured by Bristol-Myers Squibb, which sponsored the study with Ono Pharmaceutical Company, Ltd.
The one-year overall survival rate was 94% and the two-year rate was 88%.
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.
First author Mario Sznol, M.D., professor of medical oncology and clinical research leader of the melanoma research program at Yale Cancer Center, was also the senior author on the original study of combination immunotherapy published in the New England Journal of Medicine last year. "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," he 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."