• Patients must have histologically confirmed leiomyosarcoma that has been clinically determined to be metastatic or unresectable. Pathology must have been reviewed at a National Comprehensive Cancer Network (NCCN) designated cancer center such as Northwestern University's Lurie Cancer Center

• Patients must have undergone \> 2 prior lines of antineoplastic treatment, but no more than 2 lines of treatment can be a tyrosine kinase inhibitor

• Patients must have measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1

• Patients must be aged ≥ 18 years on day of signing any informed consent documents

• Patients must exhibit a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale or \> 70% on the Karnofsky Scale

• Leukocytes (white blood cells \[WBC\]) ≥ 3,000/mcL

• Absolute neutrophil count (ANC) ≥ 1,500/mcL (without granulocyte colony-stimulating factor support within 14 days of screening sample collection)

• Hemoglobin (Hgb) ≥ 9 g/dL without transfusion within 14 days of screening laboratory sample collection

• Platelets (PLT) ≥ 100,000/mm\^3 (\> 100 GI/L) without transfusion within 14 days of screening laboratory sample collection

• International normalized ratio (INR) ≤ 1.5 and activated partial thromboplastin time (aPTT) ≤ 1.2 x upper limit of normal (ULN)

• Total bilirubin ≤ 1.5 x institutional upper limit of normal ULN; for patients with Gilbert's disease, total bilirubin ≤ 3 x ULN

• Alanine aminotransferase (AST) ≤ 3 x institutional ULN

• Aspartate aminotransferase (ALT) ≤ 3 x institutional ULN

• Alkaline phosphatase (ALP) ≤ 3 x institutional ULN; for patients with documented bone metastasis, ALP ≤ 5 x ULN

• Serum creatinine ≤ 1.5 x institutional ULN OR calculated creatinine clearance ≥ 40 mL/min ( ≥ 0.67 mL/sec) using the Cockcroft-Gault equation

• Creatinine clearance ≥ 40mL/min

• Urine protein-to-creatinine ratio (UPCR) ≤ 1 mg/mg ( ≤ 113.12 mg/mmol)

• INR (or prothrombin time \[PT\] or partial thromboplastin time \[PTT\]; one will be used) ≤ 1.5

• aPTT ≤ 1.5 x ULN (unless patient is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants \[within 10 days of treatment initiation\])

• Patient of child-bearing potential (POCBP) and any of their partners with sperm-producing reproductive capability must agree to use a highly effective method of contraception throughout the course of the study and for 186 days after the last dose of treatment. Additional contraceptive method, such as a barrier method (e.g., condom) is also required

• Patients with sperm-producing reproductive capacity (PWSPRC) treated or enrolled on this protocol must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence), with partners of childbearing potential from time of informed consent, for the duration of study participation, and for 120 days following completion of therapy

• Patients must have ejection fraction \> 50% by either MUGA scan or echocardiogram

• Patients must be capable of understanding and complying with the protocol requirements

• Patients must have the ability to understand and the willingness to sign a written informed consent document