R115777 in Treating Patients With Advanced Solid Tumors

DISEASE CHARACTERISTICS: * Histologically confirmed malignant tumors deemed to be incurable or refractory to therapy * Advanced, recurrent, or metastatic disease * Previously treated with at least 1 chemotherapy regimen * Brain metastases allowed if asymptomatic and controlled (e.g., after prior surgical resection or radiotherapy/radiosurgery) and not on steroids or anticonvulsants PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * Not specified Hematopoietic: * WBC at least 3,500/mm3 * Absolute granulocyte count at least 1,500/mm3 * Platelet count at least 75,000/mm3 Hepatic: * Bilirubin no greater than 2.5 times upper limit of normal (ULN) * SGOT no greater than 2.5 times ULN Renal: * Creatinine clearance at least 60 mL/min OR * Creatinine no greater than 1.6 mg/dL Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 3 months after study PRIOR CONCURRENT THERAPY: Biologic therapy: * No concurrent biologic therapy Chemotherapy: * See Disease Characteristics * At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosourea) Endocrine therapy: * See Disease Characteristics * No concurrent hormonal therapy Radiotherapy: * See Disease Characteristics * At least 4 weeks since prior radiotherapy and recovered * No prior radiotherapy to a field containing a measurable target lesion unless there is evidence of progression or a new lesion is present * No concurrent radiotherapy to measurable lesions Surgery: * See Disease Characteristics * At least 3 weeks since prior major surgery and recovered Other: * At least 2 weeks since prior proton pump inhibitors (e.g., omeprazole) * Concurrent H2 blockers (e.g., cimetidine or related drugs) or antacids are allowed if there is an interval of at least 2 hours between H2 blocker/antacid intake and R115777 dosing