Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed nonhematologic malignancy refractory to
available therapies or for which no curative therapy exists Measurable or evaluable
disease No active brain metastases, including evidence of cerebral edema by CT scan or
MRI, progression from a prior imaging study, or any requirement for steroids or clinical
symptoms of/from brain metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At
least 3 months Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count
at least 100,000/mm3 Hepatic: Bilirubin less than 1.5 mg/dL ALT and AST less than 2 times
upper limit of normal (ULN) (unless clearly related to hepatic metastases) Renal:
Creatinine less than 1.5 times ULN Other: No other serious uncontrolled medical disorder
or active infection that would preclude study No dementia or altered mental status that
would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must
use effective contraception during and for 10 weeks after study

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy No
concurrent colony stimulating factors (e.g., filgrastim (G-CSF) or sargramostim (GM-CSF))
Chemotherapy: No prior topoisomerase I inhibitors (e.g., nitrocamptothecin,
aminocamptothecin, irinotecan, or topotecan) At least 4 weeks since prior chemotherapy (at
least 6 weeks since prior nitrosoureas, mitomycin, or carboplatin) No other concurrent
chemotherapy Endocrine therapy: See Disease Characteristics At least 4 weeks since prior
hormonal therapy No concurrent hormonal anticancer therapy Radiotherapy: At least 4 weeks
since prior radiotherapy involving at least 30% of the bone marrow No concurrent
radiotherapy Surgery: Not specified Other: No other concurrent experimental anticancer
medication