This is a single-institution, open-label, single-arm Phase II study to determine the efficacy and safety of anlotinib in combination with Toripalimab compared with historical controls as first-line treatment in patients with Unresectable or Metastatic Undifferentiated Pleomorphic Sarcoma.~Since the primary endpoint is survival outcome, progression-free survival (PFS) sample size calculation is based on a single-arm survival design. The investigators will employ early stopping rules for lack of efficacy, based on previously reported historical controls progression-free rate at 3 months was 57% in MFH and This study predicts that as the First-Line treatment of Undifferentiated Pleomorphic Sarcoma, progression-free rate at 3 months is expected to reach more than 80%.~Patients will be treated with once a day dosing of anlotinib alone for the first 7 days, followed by concurrent anlotinib administered once a day at 12mg orally (PO), plus intravenous administration of toripalimab every 21 days. Patients will be assessed every six weeks for toxicity. After the first five patients are enrolled, the investigators will assess safety of the combination. If 2 or fewer patients exhibit dose-limiting toxicity (DLT), the investigators will then proceed with intrapatient titration of anlotinib dosing at each cycle based on the presence or absence of predefined toxicities.~Correlative studies characterizing T-cells in tumor tissue and in peripheral blood will be performed at three timepoints: 1. pre-treatment, 2. on-treatment on cycle 3 day 1, and 3. off-study. Additional exploratory imaging investigations, and assessment of circulating tumor cells are included for all patients.~Trial therapy will last until withdrawal of consent, disease progression and/or unacceptable toxicity, whichever occurs first.
The investigators hypothesize that combination anlotinib with toripalimab will improve progression-free survival relative to historical controls in patients with Unresectable or Metastatic Undifferentiated Pleomorphic Sarcoma.