This study is testing a new drug called fianlimab, used with another drug called cemiplimab. These drugs are tested on people with advanced melanoma, a type of skin cancer. The goal is to find out if this combination is safe and works better than a current treatment called Opdualag™. Researchers want to know about any side effects, how much of the drug is in the blood, and if the body makes any antibodies against the drug.

• **Study Length:** Participants will be in the study for a specific period as detailed in the protocol.
• **Visits Needed:** Participants must attend regular visits for check-ups and tests.
• **Risks:** There may be side effects, and researchers will monitor participants closely.

Eligibility: To join, you must have melanoma that is confirmed as stage III or IV, cannot have had certain prior treatments, and must meet other health criteria. Some conditions, like certain types of melanoma or uncontrolled infections, may exclude you.