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

This is a randomized, double-blind, two-arm, parallel-group, multicenter Phase 1 study conducted in adult patients with Stage IIB, IIC, or Stage III melanoma following complete surgical resection. Approximately 138 patients will be randomized in 1:1 ratio to receive either Bmab1800 or Keytruda. Study treatment will be administered intravenously at a dose of 200 mg every 3 weeks till Week 21. Post which the patient will continue through Week 21, with continuation through Week 24. At Week 24, following completion of all pre dose assessments, patients who were initially randomized to the pembrolizumab arm and who are eligible to continue treatment will transition to the Bmab1800 arm and receive Bmab1800 during an open label treatment period. These patients will continue to receive Bmab1800 through Week 48 (end of treatment for the open label treatment period \[EOT OL TP\]), with end of study at Week 51 (EOS OL TP), ensuring that all patients receive pembrolizumab equivalent therapy in accordance with recommended treatment guidelines. The primary objective is to demonstrate PK equivalence based on AUC0-21 and AUC over a dosage interval at steady-state (AUCτ during Cycle 7; Week 18 to Week 21) PK parameters. Safety and immunogenicity will be evaluated through Week 24. Additional safety follow-up during an open-label treatment period through Week 51.