The purpose of this study is to investigate the pharmacokinetic (PK) similarity and efficacy, safety, and immunogenicity of GME751 compared with Keytruda® (pembrolizumab) in subjects with resected advanced melanoma requiring adjuvant treatment with pembrolizumab.

Eligible subjects will be randomized in a 1:1:1 ratio to receive either GME751, Food and Drug Administration (FDA)-licensed pembrolizumab (Keytruda-US) or European Union (EU)-authorized pembrolizumab (Keytruda-EU). The maximum study duration for a participant will be approximately 28 weeks including screening.

Treatment duration is 24 weeks (4 treatment cycles, each of 6 weeks duration). However, subject should discontinue study participation in case of disease recurrence, unacceptable toxicity or other reasons.

Participants who are benefiting from treatment with pembrolizumab without signs of recurrence or unacceptable toxicity will be eligible for continued pembrolizumab treatment via most suitable option based on the respective country regulations.

Inclusion Criteria:

• At least 18 years of age
• Advanced Melanoma
• Completely removed melanoma by surgery performed within 13 weeks of randomization
• Adequate organ function
• Subject has an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1

Exclusion Criteria:

• Known history or evidence of ocular or uveal melanoma
• Known history of hypersensitivity (grade ≥3) to pembrolizumab or its excipients
• Known History of auto-immune disease
• Received live vaccine ≤30 days before the first study treatment
• Prior treatment with anti-PD-1 agents or agent against another stimulatory or co-inhibitory T cell receptor
• Active autoimmune disease that has necessitated chronic systemic treatment within 2 years before the first study treatment

Other protocol-defined inclusion/exclusion criteria apply