ENVASARC: Envafolimab And Envafolimab With Ipilimumab In Patients With Undifferentiated Pleomorphic Sarcoma Or Myxofibrosarcoma

Inclusion Criteria: * Histologically confirmed locally advanced or metastatic undifferentiated pleomorphic sarcoma (UPS) or grade ≥ 2 myxofibrosarcoma (MFS) * Documented progression following systemic chemotherapy * At least one measurable lesion * Eastern Cooperative Oncology Group performance status of 0 or 1 * Adequate hematologic and organ function Exclusion Criteria: * More than two prior lines of chemotherapy for UPS/MFS * Prior immune checkpoint inhibitor or immunomodulatory therapy * Active autoimmune disease that has required systemic treatment * Major surgery within 4 weeks of dosing of investigational agent * Active additional malignancy * Pericardial effusion, pleural effusion, or ascites * Central nervous system metastases and/or carcinomatous meningitis * Active hepatitis or cirrhosis * Interstitial lung disease * Unwilling to apply highly effective contraception during the study * Other concurrent severe and/or uncontrolled medical conditions that would, in the investigator's judgment, contraindicate patient participation in the clinical study