Safety, Tolerability, and Immunogenicity of mRNA-4157 Alone and in Combination in Participants With Solid Tumors

This is a multi-part, dose-escalation study of mRNA-4157 monotherapy in participants with resected solid tumors (Part A), mRNA-4157 monotherapy lead-in and then in combination with standard of care (SoC) adjuvant chemotherapy followed by mRNA-4157 monotherapy in participants with resected pancreatic ductal adenocarcinoma (PDAC) (Part A2), mRNA-4157 in combination with pembrolizumab in participants with both unresectable (locally advanced or metastatic) solid tumors (Parts B and C) and adjuvant resected cutaneous melanoma (Part D), and mRNA-4157 in combination with pembrolizumab and SoC chemotherapy in peri-operative setting in participants with non-squamous non-small cell lung cancer (NSCLC) (Part E1), squamous cell NSCLC (Part E2), and gastric/ gastroesophageal (GEJ) cancer (Part E3). Parts A and B will include a dose escalation phase of the study to identify doses of mRNA-4157 for the expansion phase of the study. Doses of mRNA-4157 will be administered to participants in a dose escalation regimen. Participants in Parts A2, B, C, D, E1, E2 and E3 dose expansion phase will receive mRNA-4157 at a recommended dose for expansion.