This is a Phase 2, open-label, non-randomized, two-cohort multi center study with a safety run-in of 6 patients in Cohort 1. It is anticipated that a total of 48 patients will be enrolled.
Durvalumab will be administered with the standard regimen of 1500 mg intravenously (IV) every four weeks. Vactosertib will be administered at a dose of 300 mg PO BID for 5 days per week All treatment will be administered up to two years and the trial is anticipated to be completed over a period of 36 months.