Intismeran autogene (intismeran; formerly V940 or mRNA-4157) is an mRNA-based individualized neoantigen therapy. We report 5-year outcomes of intismeran plus pembrolizumab from the phase 2b KEYNOTE-942 study (NCT03897881). Eligible patients with resected stage IIIB‒IV cutaneous melanoma were randomized 2:1 to receive 9 doses of intramuscular intismeran 1 mg Q3W plus 18 doses of intravenous pembrolizumab 200 mg Q3W or 18 doses of intravenous pembrolizumab 200 mg Q3W. Primary endpoint was recurrence-free survival (RFS); secondary endpoints included distant metastasis-free survival (DMFS) and safety. Five-year analyses were descriptive. Among 157 randomized patients (intismeran plus pembrolizumab, n=107; pembrolizumab, n=50), median planned follow-up at data cutoff (December 15, 2025) was 60.3 (range, 50.5‒76.4) months. Intismeran plus pembrolizumab continued to prolong RFS (HR, 0.510; 95% CI, 0.294‒0.887) and DMFS (0.411; 0.200‒0.843), with a favorable trend in overall survival (0.471; 0.165‒1.345) versus pembrolizumab. Safety profile continued to be manageable, with no new safety signals. Intismeran plus pembrolizumab was associated with increased T-cell receptor clonality and novel clonotypes versus pembrolizumab; greater novel clone expansion was observed in patients without versus with recurrence in the combination arm. After 5 years' follow-up, intismeran plus pembrolizumab demonstrated sustained, durable treatment benefits versus pembrolizumab alone in resected high-risk melanoma.
Khattak et al. (Mon,) studied this question.