Pharmacokinetics, Safety, and Immunogenicity of Bmab1800 and Keytruda® as Adjuvant Monotherapy in Patients With Melanoma

Inclusion Criteria: * Male or female patients aged ≥18 years (or legal adult age per local regulations) * ECOG Performance Status of 0 or 1 at screening and prior to randomization. * Histologically confirmed melanoma that is completely surgically resected with negative margins (per local standard), classified as: Stage IIB, IIC, or Stage III melanoma per AJCC Cancer Staging Manual, 8th edition. * Patients must have undergone definitive melanoma resection ≥28 days prior to signing informed consent, and randomization must occur within 12 weeks after surgery. * All patients must have disease-free status (ie, no evidence of locoregional recurrence or distant metastasis); no clinical evidence of brain metastases. Exclusion Criteria: * History of ocular/uveal and mucosal melanoma. * Active autoimmune disease that has necessitated chronic systemic treatment within 2 years before the first study treatment * Active, known, or suspected autoimmune disease that has required systemic treatment in past 2 years. * Prior malignancy active within the previous 3 years, except for early-stage cancers (carcinoma in situ or Stage 1) treated with curative intent, basal cell carcinoma of the skin, squamous cell carcinoma of the skin, in situ cervical cancer, in situ prostate cancer, or in situ breast cancer that has undergone potentially curative therapy. * Prior therapy with anti-PD-1 (including pembrolizumab), anti PD-L1, anti PD L2, anti CD137, or anti-CTLA-4 antibody (including ipilimumab o…