Study of the Effectiveness and Safety of Acasunlimab Alone and With Pembrolizumab to Treat Advanced Melanoma of the Skin That Has Returned After Treatment With an Approved Checkpoint Inhibitor Therapy (ABBIL1TY MELANOMA-07)

The goal of this clinical trial is to learn about the effectiveness and safety of the bispecific antibody acasunlimab (also known as DuoBody®-PD-L1x4-1BB) when given either alone or together with the cancer drug pembrolizumab in participants with locally advanced or metastatic melanoma of the skin. All participants will receive active drugs; no one will be given a placebo. The trial duration will be approximately 15 months for each participant, including a 28-day screening period and estimated 4-month treatment and 10-month follow-up periods; however, the duration of the treatment and follow-up periods may vary for each participant. Participants will have regular check-ups while on treatment, with visits every week initially, and then every 3 weeks later in the trial.