mRNA-4200 in combination with pembrolizumab

July 16, 2026: Moderna, Inc. (NASDAQ: MRNA) announced dosing of the first U.S. participant in a Phase 1 trial of mRNA-4200, an off-the-shelf, tumor-targeted cancer antigen therapy candidate, in adults with advanced or metastatic solid tumors. The open-label, multicenter, dose-escalation study (NCT06880549) will evaluate safety and tolerability of mRNA-4200 administered in combination with checkpoint inhibitor therapy. Moderna stated mRNA-4200 encodes seven antigens shared across patients and tumor types and is designed to induce and expand T-cell responses against selected tumor targets. The first dose was administered at START Mountain Region (The START Center for Cancer Research network) in Salt Lake City, Utah. Moderna noted mRNA-4200 was developed in collaboration with Immatics under the Database Program, using Immatics’ XPRESIDENT target discovery/validation platform and XCUBE bioinformatics/AI platform.