This clinical trial is focused on studying a type of skin cancer called melanoma, specifically in patients who have not received prior treatment for advanced stages of the disease. The study is comparing the effectiveness of a new treatment combination of two medications, Fianlimab and Cemiplimab, against another medication called Pembrolizumab. Fianlimab is a solution for injection, while Cemiplimab and Pembrolizumab are concentrates for solution for infusion, which means they are given through a vein. The purpose of the study is to see if the combination of Fianlimab and Cemiplimab is better than Pembrolizumab in helping patients live longer without the cancer getting worse.

Participants in the study will receive either the combination of Fianlimab and Cemiplimab or Pembrolizumab. Some participants may receive a placebo, which looks like the real medication but does not contain any active ingredients. The study will last for up to 24 months, during which time participants will receive regular treatments and check-ups to monitor their health and the progress of the melanoma. The study aims to gather information on how well the treatments work and their safety, including any side effects that may occur.

This trial is important for understanding how these medications can help people with melanoma, especially those who have not been treated before for advanced stages of the disease. By participating, researchers hope to find better ways to manage melanoma and improve the quality of life for patients. The study will also collect data on how the medications affect the body, including the presence of any antibodies, which are proteins made by the immune system in response to the medications.