A Trial to See if the Combination of Fianlimab With Cemiplimab Works Better Than Pembrolizumab for Preventing or Delaying Melanoma From Coming Back After it Has Been Removed With Surgery

Open to people ages 12 years and up

1. All patients must be either stage IIB, IIC, III, or stage IV per American Joint Committee on Cancer (AJCC) 8th edition and have histologically confirmed melanoma that is completely surgically resected in order to be eligible as defined by the protocol
2. Complete surgical resection must be performed within 12 weeks prior to randomization, and enrollment may occur only after satisfactory wound healing from the surgery
3. All patients must have disease-free status documented by a complete physical examination and imaging studies within 4 weeks prior to randomization, as described in the protocol

1. Uveal melanoma
2. Any evidence of residual disease after surgery by imaging, pathology, or cytology.
3. Ongoing or recent (within 2 years) evidence of clinically significant autoimmune disease that required treatment
4. Uncontrolled infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C (HCV) infection; or diagnosis of immunodeficiency that is related to, or results in chronic infection, as described in the protocol
5. Another malignancy that is currently progressing or that required active treatment in the past 5 years, as described in the protocol
6. Participants with a history of myocarditis
7. Adolescent patients (≥12 to <18 years old) with body weight <40 kg

Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply