DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor refractory to standard therapy or for which no standard therapy exists

  • Tumors must be accessible for repeated biopsy in patients in the expanded cohort (at the maximum tolerated dose)

• Evaluable disease

  • Pleural effusions, ascites, and bone metastases are evaluable
• No brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Karnofsky 60-100%

Life expectancy

• At least 2 months

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 mg/dL
• SGOT and SGPT no greater than 2.5 times upper limit of normal

Renal

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min

Cardiovascular

• No poorly controlled cardiovascular disease
• No severe cardiovascular disease that would preclude study

Pulmonary

• No poorly controlled pulmonary disease
• No severe pulmonary disease that would preclude study

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No poorly controlled CNS disease
• No severe CNS disease that would preclude study
• No other poorly controlled nonmalignant disease
• No other severe nonmalignant disease that would preclude study
• No active severe infection requiring therapy

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas and 8 weeks for UCN-01) and recovered

Endocrine therapy

• Not specified

Radiotherapy

• Not specified

Surgery

• Recovered from prior major surgery

Other

• No concurrent antiretroviral medications for HIV-positive patients
• No other concurrent investigational drugs
• No other concurrent antineoplastic therapy