Immunocore Holdings (Nasdaq: IMCR) reported five-year overall survival data from the Phase III CT029 trial at AACR 2026, showing that tebentafusp (Kimmtrak) doubled the likelihood of survival at five years compared to investigator's choice in previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma — the longest prospective OS follow-up reported in a randomized trial in this disease and, according to the company, for any T cell engager studied in a solid tumor.
The CT029 trial is a randomized Phase III study enrolling previously untreated HLA-A*02:01-positive patients with unresectable or metastatic uveal melanoma, comparing tebentafusp against investigator's choice of pembrolizumab, ipilimumab, or dacarbazine in the first-line setting.
The five-year readout extends a survival trajectory that was already visible at the three-year analysis published in the New England Journal of Medicine in 2023 and represents the longest prospective OS follow-up reported in a randomized trial in this disease. Survival benefit was observed across high-risk subgroups, including patients with high tumor burden and elevated lactate dehydrogenase, and in some patients whose best radiographic response was progressive disease, reinforcing prior observations that imaging responses may not fully capture tebentafusp activity.
Exploratory analyses suggest that continued treatment beyond progression and early ctDNA reductions may be associated with improved outcomes, though these findings remain hypothesis-generating.