DISEASE CHARACTERISTICS:

• 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

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy

• More than 12 weeks

Hematopoietic

• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal

Renal

• Creatinine normal OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• 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

Other

• 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 CONCURRENT THERAPY:

Biologic therapy

• Prior biologic therapy allowed

Chemotherapy

• More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy

• Prior endocrine therapy allowed

Radiotherapy

• More than 4 weeks since prior radiotherapy and recovered

Surgery

• Prior surgery allowed

Other

• No other concurrent investigational agents
• No concurrent combination antiretroviral therapy for HIV-positive patients