Study of Nivolumab With or Without Pazopanib in Metastatic or Unresectable Soft Tissue Sarcomas

The investigators hypothesize that the nivolumab alone or nivolumab plus pazopanib will be associated with an improvement in progression free survival (PFS) at 6 months compared to historical controls of placebo and pazopanib alone respectively. This is a randomized, Phase 2 study of nivolumab alone or nivolumab plus pazopanib in adult (≥ 18 years old) male and female subjects with unresectable or metastatic soft tissue sarcoma either ineligible to receive an anthracycline-based first line treatment or after one prior systemic therapy. Up to 33 and 46 subjects will be randomized (1:1) in the nivolumab and nivolumab plus pazopanib cohorts respectively, with a Simon two-stage design. Preliminary endpoint analysis will be performed when at least 18 subjects in the nivolumab cohort and 16 subjects in the nivolumab plus pazopanib cohort, have completed the first 12 cycles of nivolumab (6 months). Accrual duration is expected to be around 2 years.