Substudy 02C: Safety and Efficacy of Pembrolizumab in Combination With Investigational Agents or Pembrolizumab Alone in Participants With Stage III Melanoma Who Are Candidates for Neoadjuvant Therapy (MK-3475-02C/KEYMAKER-U02)

Substudy 02C is part of a larger research study that is testing experimental treatments for melanoma, a type of skin cancer. The larger study is the umbrella study. The goal of substudy 02C is to evaluate the safety and efficacy of investigational treatment arms in participants with Stage III melanoma who are candidates for neoadjuvant therapy to identify the investigational agent(s) that, when used in combination, are superior to the current treatment options/historical control available. Arm 1: Pembrolizumab + Vibostolimab, Arm 2: Pembrolizumab + Gebasaxturev, and Arm 3: Pembrolizumab were added in the base protocol on 13-Nov-2019, and enrollment into those arms has been completed. Arm 4: Pembrolizumab + MK-4830 was added in Amendment 04 on 20-Dec-2021, and enrollment into that arm has been completed. Arm 5: Favezelimab + Pembrolizumab and Arm 6: Pembrolizumab + all-trans retinoic acid (ATRA) were added in Amendment 06 on 25-Jun-2022, and enrollment is ongoing.