Five years. In the brutal world of Stage III/IV melanoma — a cancer where the five-year survival rate was below 20 percent just fifteen years ago — five years of sustained, meaningful reduction in the risk of recurrence and death represents an outcome that was not achievable in the recent past. At the American Society of Clinical Oncology Annual Meeting in Chicago on June 3, 2026, and simultaneously published in the Journal of Clinical Oncology, researchers presented the five-year update from the KEYNOTE-942 Phase 2b trial of intismeran autogene (mRNA-4157/V940) combined with Keytruda (pembrolizumab). The results have prompted some of the most effusive responses ever heard at an oncology conference.
After a median 60.3 months of follow-up, patients who received the combination of intismeran autogene and Keytruda had a 49 percent lower risk of melanoma recurrence or death compared to those who received Keytruda alone. This 49 percent reduction is precisely identical to the three-year result reported in 2024 — a finding of remarkable significance. When a treatment effect maintains its magnitude unchanged from year 3 to year 5 in an oncology trial, it suggests that the immune system changes induced by the treatment are durable and potentially permanent, rather than fading as time passes.
