Sunitinib and Gemcitabine in Treating Patients With Pancreatic Cancer or Other Solid Tumors

Criteria: * Histologically or cytologically confirmed pancreatic adenocarcinoma OR other solid tumor: * Not amenable to curative therapy * Previously untreated metastatic pancreatic adenocarcinoma allowed * Measurable or evaluable disease * No history of or known brain metastases, spinal cord compression, carcinomatous meningitis, or new evidence of brain or leptomeningeal disease on screening CT scan or MRI scan * ECOG performance status (PS) 0-2 OR Karnofsky PS 60-100% * Life expectancy \>= 12 weeks * Absolute neutrophil count \>= 1,500/mm3 * Platelet count \>= 100,000/mm3 * Hemoglobin \>= 8.5 g/dL * Bilirubin =\< 1.5 mg/dL * Creatinine normal OR creatinine clearance \>= 60 mL/min * AST and ALT =\< 2.5 times upper limit of normal (ULN) (=\< 5 times ULN if due to underlying disease) * Calcium =\< 12.0 mg/dL * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for at least 6 months after completion of study therapy * LVEF normal by MUGA scan or ECHO at baseline * Deep venous thrombosis or pulmonary embolism allowed provided they are clinically stable and adequately treated * No preexisting thyroid abnormality that results in the inability to maintain thyroid function in the normal range while using medication * No history of allergic reactions attributed to compounds of similar chemical or biological composition to sunitinib malate * No history of any of the following within the past 6 months: * Myocardial infarction * Ventricular arrhythmia (i.e., ventricular tachycardia or ventricular fibrillation \>= 3 beats in a row) * Severe/unstable angina * Severe peripheral vascular disease (i.e., claudication) * Procedure on peripheral vasculature * Coronary/peripheral artery bypass graft * Cerebrovascular accident * No history of any of the following within the past 6 months: * Transient ischemic attack; * Clinically significant bleeding requiring red blood cell transfusion * No NYHA class III or IV heart disease: * Patients with NYHA class II disease who are stable and on medication are eligible * No ongoing cardiac dysrhythmias \>= grade 2, atrial fibrillation of any grade, or any significant EKG abnormalities * No hypertension that cannot be controlled by medications to a systolic blood pressure (BP) of \< 140 mm Hg and diastolic BP of \< 90 mm Hg * No condition that impairs the ability to swallow and retain sunitinib malate tablets, including any of the following: * Gastrointestinal tract disease resulting in an inability to take oral medication * Requirement for IV alimentation * Prior surgical procedures affecting absorption * Active peptic ulcer disease * No gastrointestinal perforation or intra-abdominal abscess within the past 28 days * No serious nonhealing infection or bone fracture * No other severe acute or chronic medical condition, psychiatric condition, or laboratory abnormality that would preclude study therapy * May have received any number of prior systemic therapies * More than 4 weeks since prior radiotherapy or surgery and recovered * More than 4 weeks since other prior therapies and recovered * Prior gemcitabine hydrochloride allowed * No prior sunitinib malate or other therapy directed against VEGF, including any of the following: Sorafenib; Bevacizumab; Vatalanib; AZD2171; VEGF Trap; Investigational antiangiogenic therapy * More than 7 days since prior and no concurrent CYP3A4 inhibitors, including any of the following: * Ketoconazole * Itraconazole * Clarithromycin * Erythromycin * Diltiazem * Verapamil * Indinavir * Ritonavir * Nelfinavir * Saquinavir * Atazanavir * Delavirdine * More than 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 agents with proarrhythmic potential, including any of the following: * Terfenadine * Quinidine * Procainamide * Disopyramide * Sotalol * Probucol * Bepridil * Haloperidol * Risperidone * Indapamide * Flecainide * No concurrent combination antiretroviral therapy for HIV-positive patients * No concurrent treatment on another clinical trial: Participation in non-therapeutic clinical trials allowed * QTc \< 500 msec