The U.S. FDA has granted Fast Track designation for mRNA-4359 in combination with pembrolizumab for the treatment of checkpoint inhibitor refractory unresectable or metastatic melanoma with PD-L1+ (TPS>1%)

CAMBRIDGE, MA / ACCESS Newswire / April 17, 2026 / Moderna, Inc. (NASDAQ:MRNA) today announced that the Company will present data from a Phase 1/2 study of mRNA-4359, an investigational cancer antigen therapy, at the American Association for Cancer Research (AACR) Annual Meeting in San Diego, CA, on April 17-22, 2026. The presentation reports safety, efficacy and translational data from a Phase 2 dose-expansion cohort of the Phase 1/2 study (NCT05533697), which evaluated mRNA-4359 + pembrolizumab as a first-line therapy in patients with locally advanced or metastatic melanoma.

Among 12 participants, mRNA-4359 + pembrolizumab resulted in an overall response rate (ORR) of 83% (95% CI: 52%-98%), with two patients achieving a complete response and eight achieving a partial response, as well as a disease control rate (DCR) of 92% (95% CI: 62%-100%). The median time to response was six weeks (range, 5.6-24.0). Responses occurred across baseline tumor PD-L1 expression categories, with an ORR of 88% (95%CI: 47%-100%) among patients with PD-L1+ (TPS≥1%) tumors, and 67% (95%CI: 9%-99%) among patients with PD-L1- (TPS<1%) tumors. Consistent with mRNA-4359's mechanistic rationale, antigen-specific T-cell responses and novel expanded T-cell receptor (TCR) clonality was observed in all patients (n=7) with evaluable samples. mRNA-4359 + pembrolizumab demonstrated a manageable safety profile, with no new immune-related adverse events (AEs).