GTI-2040 and Gemcitabine in Treating Patients With Metastatic or Unresectable Solid Tumors

Inclusion Criteria: * Histologically or cytologically confirmed solid tumor * Metastatic or unresectable disease for which standard curative or palliative measures do not exist or are no longer effective * Measurable or evaluable disease * No known active or progressive brain metastases or primary brain tumors * Performance status - ECOG 0-2 * Performance status - Karnofsky 60-100% * More than 12 weeks * Hemoglobin \> 9 g/dL * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Bilirubin ≤ 2 times upper limit of normal (ULN) * AST and ALT ≤ 3 times ULN (5 times ULN if hepatic metastases are present) * Creatinine ≤ 2.0 mg/dL * Creatinine clearance ≥ 50 mL/min * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No prior allergic reaction attributed to compounds of similar chemical or biological composition to study drugs * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No other condition (e.g., dementia or developmental delay) that would preclude giving informed consent * No other concurrent uncontrolled illness that would preclude study participation * Prior biologic therapy allowed * No concurrent biologic therapy * No concurrent immunotherapy * No concurrent routine filgrastim (G-CSF) or sargramostim (GM-CSF) * Prior gemcitabine allowed * Prior investigational chemotherapy allowed * At least 4 weeks since prior chemotherapy (6 weeks for mitomycin, carmustine, or nitrosoureas) and recovered * No other concurrent chemotherapy * Concurrent hormonal therapy (e.g., luteinizing hormone-releasing hormone agonists) for prostate cancer is allowed * At least 4 weeks since prior radiotherapy and recovered * No prior radiotherapy to more than 25% of bone marrow * No concurrent radiotherapy * Recovered from prior surgery * No other concurrent investigational therapy * No other concurrent anticancer therapy * No concurrent combination antiretroviral therapy for HIV-positive patients * No concurrent long-term oral anticoagulation therapy (e.g., warfarin) * Prophylactic warfarin to maintain central venous access patency allowed