The CoMpass trial will determine how well an investigational treatment, known as bel-sar, works in adults who have ocular melanoma, the most common type of eye cancer in adults. The trial will specifically look at this cancer in its early stages, which can also be known as small choroidal melanoma or indeterminate lesions (also known as early choroidal melanoma)

There are no drugs approved by the Food and Drug Administration (FDA) for the treatment of ocular melanoma in its early stages.

The investigational treatment is called belzupacap sarotalocan, or bel-sar for short. The trial will test two different doses of the drug compared to an untreated, or "sham" group. Participants will be randomized, which means that they will be put into different groups at random. The trial will also be masked, meaning that participants will not know which group they are in.