Sunitinib in Treating Patients With Myelodysplastic Syndromes or Chronic Myelomonocytic Leukemia

Inclusion Criteria: * MDS syndromes meeting 1 of the following: Intermediate-2 disease, high-risk disease (IPSS score\>=1.5) * CMML: WBC\>12,000/mm\^3, Intermediate-2 disease with WBC=\<12,000/mm\^3, high-risk disease (IPSS score\>=1.5) with WBC=\<12,000/mm\^3 * Patients with insufficient/inadequate metaphases for cytogenetic analysis are eligible if bone marrow blasts are \>10% and/or 2-3 cytopenias are present * No known brain metastases * Life expectancy\>12 weeks * ECOG PS 0-2/Karnofsky PS 60-100% * Calcium=\<3.0 mmol/L * Bilirubin normal * AST and ALT=\<2.5 times upper limit of normal * Creatinine normal/creatinine clearance\>=60 mL/min Exclusion Criteria: * No history of significant ECG abnormalities including but not limited to: ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation\>=3 beats in a row); QTc prolongation (i.e.QTc interval\>=500msec) * No history of allergic reaction to compounds of similar chemical/biological composition to sunitinib malate * No NYHA class III-IV congestive heart failure * Patients with history of NYHA class II congestive heart failure who are asymptomatic on treatment are eligible * No abdominal fistula/G perforation/intraabdominal abscess within past 28 days * No serious cardiovascular disease within past 12 months including: cerebrovascular accident or transient ischemic attack, myocardial infarction, cardiac arrhythmia, stable or unstable angina, symptomatic congestive heart failure, coronary or peripheral artery bypass graft or stenting * No pulmonary embolism within past 12 months * No uncontrolled hypertension (systolic BP\>=140 mmHg/diastolic BP\>=90 mmHg) * No condition impairing ability to swallow/retain sunitinib malate tablets including: GI tract disease resulting in inability to take oral medication, requirement for IV alimentation, prior surgical procedures affecting absorption, active peptic ulcer disease * No serious/nonhealing wound, ulcer, or bone fracture * No uncontrolled pre-existing thyroid abnormality * No concurrent uncontrolled illness including ongoing/active infection * No psychiatric illness/social situation that would preclude study participation * Not pregnant/nursing * Negative pregnancy test * Fertile patients must use effective barrier contraception * 4 weeks since prior major surgery * Prior central thoracic radiotherapy that included heart in radiotherapy port allowed provided NYHA congestive heart failure=\<class II * Prior anthracycline exposure allowed provided NYHA congestive heart failure=\<class II * No other prior therapy for MDS/CMML except epoetin alfa, darbepoetin alfa, filgrastim or sargramostim * At least 2 weeks since prior epoetin alfa * At least 4 weeks since prior darbepoetin alfa * No other prior antiangiogenic agents including but not limited to: bevacizumab, sorafenib tosylate, pazopanib hydrochloride, AZD2171, vatalanib, VEGF Trap * More than 7 days since prior and no concurrent potent CYP3A4 inhibitors * More than 12 days since prior and no concurrent potent CYP3A4 inducers including: Rifampin, Rifabutin, Carbamazepine, Phenobarbital, Phenytoin, Hypericum perforatum, Efavirenz, Tipranavir * No concurrent birth control patch/oral birth control pills/depot/injectable birth control methods * No concurrent therapeutic coumarin-derivative anticoagulants * Low dose(=\<2mg) warfarin for prophylaxis of thrombosis allowed * Low molecular weight heparin allowed if INR=\<1.5 * No concurrent agents with proarrhythmic potential including: Terfenadine, Quinidine, Procainamide, Disopyramide, Sotalol, Probucol, Bepridil, Haloperidol, Risperidone, Indapamide, Flecainide acetate * No concurrent combination antiretroviral therapy for HIV-positive patients * No other concurrent investigational agents