A Study of mRNA-4106 Administered Alone and in Combination With Immune Checkpoint Blockade in Participants With Solid Tumors

Inclusion Criteria: * Arm 1, Monotherapy Arm: Histologically confirmed advanced or metastatic cancer (melanoma, non-small cell lung cancer (NSCLC), hepatocellular carcinoma (HCC), esophageal carcinoma, head and neck squamous cell carcinoma (HNSCC), urinary bladder cancer (UBC), colon/rectal adenocarcinomas, gastric, ovarian, cervical, and endometrial carcinomas) with measurable disease as determined by RECIST v1.1 and have completed or refused all standard therapies (no limit to prior lines of therapy). Participants must have a tumor lesion amenable to biopsy, or alternatively archival tumor tissue is acceptable as long as the collection date is within one year of the enrollment date. * Arm 2, Combination with Nivolumab/Relatlimab Arm: Histologically confirmed unresectable or metastatic melanoma, with measurable disease as determined by RECIST v1.1 and have not had any prior therapy for this cancer in this setting (that is, first-line therapy). Note that prior adjuvant, neoadjuvant, or perioperative melanoma therapy (that is, anti-CTLA-4, anti-PD1/L1, BRAF/MEK inhibitors, or interferon) is permitted if disease recurrence did not occur within 3 months from the last treatment date. * Participant has an Eastern Cooperative Oncology Group (ECOG) performance status of ≤1. * Participant has adequate hematological and biological function. * Participants who could become pregnant: negative pregnancy test within 24 hours before the first dose of study treatment. Exclusion Criteria: …