Flavopiridol, Gemcitabine, and Irinotecan in Treating Patients With Unresectable or Metastatic Solid Tumors

Inclusion Criteria: * Histologically confirmed solid tumor that is metastatic or unresectable * Standard curative or palliative measures do not exist or are no longer effective * No known brain metastases * Performance status - ECOG 0-2 * Performance status - Karnofsky 60-100% * More than 12 weeks * WBC ≥ 3,000/mm\^3 * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Bilirubin normal * AST and ALT ≤ 2.5 times upper limit of normal * Creatinine normal * Creatinine clearance ≥ 60 mL/min * No venous thrombosis within the past 6 months * No thrombotic cerebrovascular accident within the past 6 months * No myocardial infarction within the past 6 months * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia * No ongoing or active infection * No prior allergic reaction attributed to compounds of similar chemical or biological composition to study agents * No other concurrent uncontrolled medical condition that would preclude study participation * No psychiatric illness or social situation that would preclude study participation * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Prior biologic therapy allowed * More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered * Prior endocrine therapy allowed * More than 4 weeks since prior radiotherapy and recovered * Prior surgery allowed * No other concurrent investigational agents * No concurrent combination antiretroviral therapy for HIV-positive patients