A Study to Evaluate Sotigalimab (APX005M) in Subjects With Unresectable or Metastatic Melanoma

This is a multicenter, open label, Phase 2 study, with 3 parallel cohorts. The aim of the study is to evaluate the efficacy of Sotigalimab administered at 2 different schedules to adult participants with unresectable or metastatic melanoma who have not received prior immunotherapy. Enrolled participants will be alternately assigned to one of the following 2 cohorts (groups) as long as both cohorts are open. Cohort 1: APX005M administered IV at 0.3 mg/kg every 3 weeks (21-day cycle) Cohort 2: APX005M administered IV at 0.3 mg/kg every 2 weeks (14-day cycle) Sotigalimab in combination with stereotactic body radiation therapy (SBRT) in adults with unresectable or metastatic melanoma who have failed any number of prior lines of therapy will be assigned to Cohort 3: Sotigalimab administered IV at 0.3 mg/kg in combination with radiation therapy every 2 weeks (14 day cycle) up to 16 weeks followed by sotigalimab administered IV at 0.3 mg/kg every 2 weeks (14-day cycle). Primary Objective • Evaluate the overall response rate (ORR) by RECIST 1.1 measurements in each of the cohorts. Secondary Objectives * Evaluate the safety of sotigalimab alone or in combination with radiation therapy in each cohort * Evaluate ORR by modified RECIST 1.1 for immune-based therapeutics (iRECIST) in each cohort * Evaluate median duration of response (DOR) in each cohort