This study is researching the long-term effects of a combination of experimental drugs called fianlimab and cemiplimab. The study is being conducted in patients with advanced skin cancer (melanoma) who had previously been treated with fianlimab and cemiplimab in the study called R3767-ONC-1613 (NCT03005782).

The aim of the current study is to see how safe and effective the study drugs are in a long-term follow-up. No study drug will be given during this study. Cancer status will be monitored, in addition to routine care. The study is also collecting information about general health status, and other treatments that may have been received since participation in study R3767-ONC-1613 (NCT03005782).

Key Inclusion Criteria:

1. Participants with melanoma who enrolled in cohorts 6, 15, or 16 of study R3767-ONC- 1613 (NCT03005782)

Key Exclusion Criteria:

None

Note: Other protocol-defined Inclusion/ Exclusion criteria may apply

All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing

When Regeneron has:

• received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development
• made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry)
• the legal authority to share the data, and
• ensured the ability to protect participant privacy

Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf