LND101 for Fecal Microbiota Transplantation in Combination With Immune Checkpoint Blockade in Advanced Melanoma

This study tests whether adding a fecal microbiota transplant (FMT) — transferring gut bacteria from a healthy donor — alongside standard immunotherapy can improve outcomes for people with advanced melanoma (skin cancer) that has spread and cannot be surgically removed. Researchers believe the gut microbiome may affect how well immunotherapy works. **You may be eligible if...** - You have been diagnosed with stage IV or unresectable advanced cutaneous melanoma or melanoma of unknown origin - You have not previously received immunotherapy (immune checkpoint blockers, or ICB) for advanced disease - If you received prior ICB as adjuvant/preventive therapy, your last dose was at least 6 months ago - Prior targeted therapy (BRAF/MEK inhibitors) is allowed if it ended at least 2 weeks before joining the study **You may NOT be eligible if...** - You have already received immunotherapy for advanced or metastatic melanoma - You have serious autoimmune conditions - You recently completed targeted therapy and side effects have not resolved Talk to your doctor to see if this trial is right for you.