PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9.0 g/dL Hepatic: Bilirubin no greater than 2.0 mg/dL (regardless of liver metastases) SGOT/SGPT no greater than 2 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL Calcium no greater than 9.5 mg/dL No nephrocalcinosis Cardiovascular: No congestive heart failure No angina or ischemia Other: Ability to swallow or nasogastric or gastrostomy tube present Adequate organ and immune system function No known hypersensitivity to ILX23-7553 or analogues HIV negative No active uncontrolled infection No other severe disease or psychiatric disorder that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception