Neoadjuvant Immune Checkpoint Blockade + a Prebiotic Food-enriched Dietary Intervention to Optimize Immune Response in Melanoma: NEO-PreFED

Primary Objectives: Determine the feasibility, compliance and adherence to PreFED intervention in patients with resectable melanoma initiating neoadjuvant combination ICB therapy. Secondary Objectives: 1. Determine the safety (AEs) and tolerability (GSRS-IBS) of the dietary intervention during the neoadjuvant phase and maintenance phases 2. Assess the rate of immune related adverse events in patients of dietary intervention + ICB during neoadjuvant and maintenance phases. 3. Determine the objective response rate (ORR) to dietary intervention + ICB as determined by RECIST1.1 after 2 cycles of neoadjuvant ICB + diet 4. Determine the pathological response rate (pRR) to neoadjuvant ICB + dietary intervention 5. Determine the Event-free Survival (EFS), Relapse-free Survival (RFS), and Overall Survival (OS) to neoadjuvant ICB + dietary intervention Exploratory Objectives: 1. Assess the effect of dietary intervention + ICB on gut microbiome composition at completion of neoadjuvant phase and maintenance phase 2. Assess the effects of dietary intervention + neoadjuvant ICB on gut metabolic output and systemic metabolism at completion of neoadjuvant phase and maintenance phase 3. Assess the effects of dietary intervention + neoadjuvant ICB on systemic and tumor immunity at time of surgery 4. Assess the effects of dietary intervention + neoadjuvant ICB on quality of life and other patient reported outcomes (PROs) during neoadjuvant and maintenance phases