Inclusion Criteria:

- Histologically confirmed leiomyosarcoma of the uterus

- Recurrent or persistent disease

- Refractory to curative therapy or established treatments

- Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by
conventional techniques or ≥ 10 mm by spiral CT scan

- Ascites and pleural effusions are not considered measurable disease

- Must have ≥ 1 target lesion to assess response

- Tumors in a previously irradiated field are considered non-target lesions unless
there is documented progression or biopsy-confirmed persistence ≥ 90 days after
completion of radiotherapy

- Received at least 1 but no more than 2 prior cytotoxic regimens

- Initial treatment may have included high-dose chemotherapy, consolidation, or
extended therapy administered after surgery or nonsurgical assessment

- Cytotoxic regimens may have included any agent that targets the genetic and/or
mitotic apparatus of dividing cells, resulting in dose-limiting toxicity to the
bone marrow and/or gastrointestinal mucosa

- Not a candidate for a higher priority GOG protocol

- No known brain metastases

- GOG performance status 0-2 (for patients who have received 1 prior regimen) OR GOG
0-1 (for patients who have received 2 prior regimens)

- Absolute neutrophil count ≥ 1,500/mm³

- Platelet count ≥ 100,000/mm³

- Hemoglobin ≥ 9 g/dL

- Creatinine ≤ 1.5 times upper limit of normal (ULN)

- Bilirubin ≤ 1.5 times ULN

- SGOT ≤ 2.5 times ULN

- Alkaline phosphatase ≤ 1.5 times ULN

- QTc < 500 msec

- LVEF normal by echocardiogram

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for ≥ 1 month after
completion of study treatment

- Patients with a pre-existing thyroid abnormality unable to maintain normal thyroid
function with medication are not eligible

- No significant EKG abnormalities (i.e., no history of serious ventricular arrhythmia
OR EKG with ventricular tachycardia or ventricular fibrillation ≥ 3 beats in a row)

- No sensory or motor neuropathy > grade 1

- No NYHA class III-IV congestive heart failure

- NYHA class II cardiac dysfunction allowed

- History of NYHA class II heart failure that is asymptomatic on treatment allowed

- No active infection requiring antibiotics

- No other invasive malignancies within the past 5 years except for nonmelanoma skin
cancer

- No history of allergic reactions attributed to compounds of similar chemical or
biologic composition to sunitinib malate

- No poorly controlled hypertension (i.e., systolic blood pressure [BP] ≥ 140 mm Hg or
diastolic BP ≥ 90 mm Hg)

- No gastrointestinal tract disease resulting in an inability to take oral medication

- No requirement for IV alimentation

- No active peptic ulcer disease

- No other condition that would impair ability to swallow and retain study drug

- No serious or nonhealing wound, ulcer, or bone fracture

- No abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within
the past 28 days

- No cerebrovascular accident or transient ischemic attack within the past year

- No myocardial infarction, cardiac arrhythmia, stable or unstable angina, or
symptomatic congestive heart failure within the past year

- No pulmonary embolism within the past year

- No uncontrolled illness including, but not limited to, any of the following:

- Ongoing or active infections

- Psychiatric illness or social situations that would preclude study compliance

- Recovered from prior surgery, chemotherapy, or radiotherapy

- Prior anthracycline exposure and central thoracic radiation that included the heart
allowed provided patient has New York Heart Association (NYHA) class II cardiac
function

- At least 1 week since prior hormonal therapy

- At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas and mitomycin C)
or radiotherapy

- At least 4 weeks since prior major surgery

- At least 3 years since prior radiotherapy for localized cancer of the breast, head
and neck, or skin and no recurrent or metastatic disease

- At least 3 years since prior adjuvant chemotherapy for localized cancer of the breast
and no recurrent or metastatic disease

- No prior radiotherapy to any portion of the abdominal cavity or pelvis unless for
treatment of leiomyosarcoma

- No prior chemotherapy to any portion of the abdominal cavity or pelvis unless for
treatment of leiomyosarcoma

- No prior noncytotoxic chemotherapy for recurrent or persistent disease

- No prior surgical procedures affecting absorption

- No coronary or peripheral artery bypass graft or stenting within the past year

- No other prior antiangiogenic agents (e.g., bevacizumab, sorafenib, pazopanib,
AZD2171, vatalanib, or vascular endothelial growth factor [VEGF] Trap)

- No other prior cancer treatment that would preclude study treatment

- At least 7 days since prior and no concurrent CYP3A4 inhibitors, including any of the
following:

- Azole fungals (e.g., ketoconazole or itraconazole)

- Clarithromycin

- Erythromycin

- Diltiazem

- Verapamil

- HIV protease inhibitors (e.g., indinavir, saquinavir, ritonavir, atazanavir, or
nelfinavir)

- Delavirdine

- At least 12 days since prior and no concurrent CYP3A4 inducers, including any of the
following:

- Rifampin

- Rifabutin

- Carbamazepine

- Phenobarbital

- Phenytoin

- Hypericum perforatum (St. John's wort)

- Efavirenz

- Tipranavir

- No concurrent proarrhythmic potential agent, including any of the following:

- Terfenadine

- Quinidine

- Procainamide

- Disopyramide

- Sotalol

- Probucol

- Bepridil

- Haloperidol

- Risperidone

- Indapamide

- Flecainide

- No concurrent therapeutic coumarin-derivative anticoagulants, such as warfarin

- Doses ≤ 2 mg daily allowed for prophylaxis of thrombosis

- Low molecular weight heparin allowed provided PT INR ≤ 1.5

- No concurrent amifostine or other protective agents

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other concurrent investigational agents

- No other concurrent anticancer agents or therapies