A Trial to Learn if Fianlimab and Cemiplimab Are Safe and Work Better Than Anti-PD1 Alone in Adult Participants With Resectable Stage 3 or 4 Melanoma

This study is looking for adults aged 18 and over who have a type of skin cancer called melanoma. To be considered, your melanoma must be at stage 3 or 4, and your doctors must believe it can be completely removed through surgery.

Before joining, you'll need a full health check-up, including scans of your body and brain, to make sure you fit the study's requirements. Your general health should also be good enough that you can carry out most everyday activities without much trouble.

You won't be able to join if you have a different type of melanoma (like uveal melanoma in the eye), or if you've had certain autoimmune diseases that needed strong medicine within the last two years. Also, if you've already received other anti-cancer treatments for your current melanoma, you likely won't be eligible.

If you join this study, you will first have a detailed check-up to make sure the study is right for you. This will involve physical exams, blood tests, and imaging scans like CT and MRI. Once enrolled, you will receive either the combined fianlimab and cemiplimab treatment, cemiplimab alone, or a placebo (a dummy treatment, which does not contain active drug) through an infusion, given into a vein.

You will receive a course of this treatment before your planned surgery to remove the melanoma. After your surgery, you will have the option to continue with the study treatment for a further period. You'll need to attend regular clinic visits for more infusions, blood tests to check how the drugs are affecting your body, and to discuss any side effects you might be experiencing. The total duration of your participation will depend on the treatment plan and your individual response.