What treatment options would you consider for a patient with an ECOG PS of 0 with metastatic non-uterine leiomyosarcoma who has progressed on all standard systemic therapies including anthracycline, gemcitabine, taxane, vinorelbine, pazopanib, temozolomide, and trabectidin?

The correct answer is a phase 1 clinical trial, or perhaps compassionate use immunotherapy.

I would agree but add one other options. Though not based on the strict FDA indication, Doxorubicin plus PDGFR antibody OLARATUMAB is approved as first line therapy --since your patient didnt have access to newly approved Olaratumab first line, you could use this regimen. Caveats re: cumulative Dox ...