Soblidotin and Gemcitabine in Treating Patients With Locally Advanced or Metastatic Solid Tumors

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed locally advanced or metastatic solid tumors * Minimally pretreated * Not refractory to prior gemcitabine therapy * No disease progression during initial treatment with gemcitabine * No symptomatic brain metastases PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * At least 12 weeks Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * SGOT or SGPT no greater than 2.5 times ULN (5 times ULN if liver metastases are present) Renal * Creatinine no greater than 1.5 times ULN Cardiovascular * Ejection fraction at least 40% by MUGA Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No psychiatric disorder that would preclude study consent or compliance * No concurrent severe or uncontrolled underlying medical disease unrelated to the tumor that would compromise patient safety or affect study outcome * No hypersensitivity to gemcitabine * No other malignancy except nonmelanoma skin cancer or carcinoma in situ of the cervix unless in complete remission and off all therapy for that disease for at least 2 years * No serious infection * No grade 2 or greater neuropathy PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent anticancer biologic therapy Chemotherapy * See Disease Characteristics * Recovered from prior chemotherapy * No other concurrent anticancer chemotherapy Endocrine therapy * Not specified Radiotherapy * Recovered from prior radiotherapy * No concurrent anticancer radiotherapy * Concurrent localized palliative radiotherapy to a non-indicator lesion for pain control allowed only if other methods of pain control are ineffective Surgery * At least 4 weeks since prior major surgery and recovered Other * More than 28 days since prior investigational drugs, including analgesics or antiemetics * At least 4 weeks since prior myelosuppressive therapy * No other concurrent anticancer therapy * No other concurrent anticancer cytotoxic therapy