Outside of a clinical trial, what is your treatment of choice for metastatic melanoma of soft parts or clear cell sarcoma?

There are two distinct entities - CSS of soft-tissues, an extremity tumor with melanoma-like behavior and some anecdotal evidence of melanoma-specific therapy having some activity, e.g. checkpoint inhibitors. The other one is a CSS-like tumor of the GI tract. Both have EWSR1 rearrangement. The speci...