Fecal transplantation in patient with metastatic melanoma refractory to immunotherapy: A case report

BACKGROUND: Immunotherapy has revolutionized the treatment of metastatic melanoma, but a significant proportion of patients still experience treatment resistance. Fecal microbiota transplantation (FMT) has emerged as a potential strategy to overcome immunotherapy resistance by modulating the gut microbiome. CASE SUMMARY: We present a case report of a 57-year-old male with metastatic melanoma refractory to immunotherapy who received FMT in combination with anti-programmed death-ligand 1 (PD-L1) immunotherapy (pembrolizumab). After failing multiple lines of treatment, the patient underwent a single FMT procedure by colonoscopy using fecal material from a female metastatic melanoma donor who successfully responded to immunotherapy. Following FMT, the patient demonstrated a response with decreased subcutaneous disease and subsequently underwent surgery to remove the residual disease. Despite a subsequent recurrence in the small bowel that was resected, the patient remained on pembrolizumab without evidence of melanoma recurrence at the time of writing. CONCLUSION: The favorable clinical and long-lasting effect we saw in our patient without significant toxicity suggests that this procedure should be considered in similar patients with immunotherapy refractory melanomas.