A Study of Durvalumab in Combination With Doxorubicin for Advanced Soft Tissue Sarcoma

Inclusion Criteria: 1. Histologically confirmed STS(soft tissue sarcoma) 2. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 3. Measurable disease by Response Evaluation Criteria in Solid Tumors Version 1.1 4. Body weight \>30kg 5. Adequate normal organ and marrow function as defined below: 6. Left ventricular ejection fraction (LVEF) ≥ 45% 7. Evidence of post-menopausal status or negative urinary or serum pregnancy test for female pre-menopausal patients. Women will be considered post-menopausal if they have been amenorrheic for 12 months without an alternative medical cause. 8. Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up. 9. Must have a life expectancy of at least 12 weeks 10. Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. Written informed consent and any locally required authorization obtained from the patient/legal representative prior to performing any protocol-related procedures, including screening evaluations Exclusion Criteria: 1. Histologically- or cytologically-confirmed Kaposi's sarcoma or GIST 2. Previous treatment with anthracyclines 3. Participation in another clinical study with an investigational product during the last 2 weeks 4. Receipt of the last dose of anticancer therapy (chemotherapy, immunotherapy, endocrine therapy, targeted therapy, biologic therapy, tumor embolization, monoclonal antibodies, other investigational agent) 14 days prior to the first dose of study drug 5. Any previous treatment with a PD1 or PD-L1 inhibitor (including durvalumab) and/or PDGFR inhibitor 6. Mean QT interval corrected for heart rate (QTc) \> 480 ms calculated from 3 electrocardiograms (ECGs) using Fridericia's Correction 7. Any unresolved toxicity NCI CTCAE Grade ≥2 from previous anticancer therapy with the exception of alopecia, vitiligo, and the laboratory values defined in the inclusion criteria 8. Any concurrent chemotherapy, biologic, or hormonal therapy for cancer treatment within 14 days prior to entering the study. Concurrent use of hormonal therapy for non-cancer-related conditions (e.g., hormone replacement therapy) is acceptable 9. Radiotherapy treatment to more than 30% of the bone marrow or with a wide field of radiation within 14 days of the first dose of study drug 10. Major surgical procedure (as defined by the Investigator) within 28 days prior to the first dose of IP(investigational product). 11. History of allogenic organ transplantation. 12. Active or prior documented autoimmune or inflammatory disorders 13. Uncontrolled intercurrent illness 14. Known active infection 15. History of another primary malignancy 16. History of leptomeningeal carcinomatosis who are neurologically unstable or have required active treatment 17. Receipt of live attenuated vaccine within 30 days prior to the first dose of IP. 18. Female patients who are pregnant or breastfeeding or male or female patients of reproductive potential who are not willing to employ effective birth control from screening to 90 days after the last dose. 19. Known allergy or hypersensitivity to any of the study drugs or any of the study drug excipients.