Primary Objective:~• Assess the safety and tolerability of OBX-115 + acetazolamide by CTCAE version 5 criteria to provide a recommended Phase II dose~Secondary Objectives:~Assess preliminary efficacy of OBX-115 + acetazolamide cell therapy in patients with immune checkpoint inhibitor (ICI)-relapsed and/or refractory metastatic melanoma by evaluating overall response rate (ORR; complete response [CR] + partial response [PR]) by RECIST 1.1 criteria~Evaluate feasibility of the manufacturing process~Evaluate duration of response (DOR)~Evaluate progression free survival (PFS)~Characterize in vivo cellular kinetics of OBX-115 cells in tumor and/or in peripheral blood by polymerase chain (PCR) and/or fluorescence-activated cell sorting (FACS) analyses~Characterize the pharmacokinetic profile of acetazolamide when administered in combination with OBX-115~Characterize the incidence and prevalence of OBX-115 therapy immunogenicity~Exploratory Objectives:~Assess relationship of soluble immune factors and pharmacodynamic markers, with cellular kinetics, safety, and efficacy~Describe the composition of OBX-115 subsets (immunophenotyping in peripheral blood mononuclear cells [PBMCs] and in tumor), summarized by clinical response~Explore the correlation of OBX-115 kinetics in tumor and peripheral blood with clinical endpoints~Explore the correlation of immune checkpoints with OBX-115 cellular kinetics and efficacy~Evaluate overall survival (OS)
To find the recommended dose of OBX-115 in combination with acetazolamide that can be given to patients with metastatic melanoma previously treated with immune checkpoint inhibitors.