DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor

  • Metastatic or unresectable disease
• Standard curative or palliative measures do not exist or are no longer effective

• CNS metastases allowed provided all of the following criteria are met:

  • Received prior treatment (e.g., radiotherapy, stereotactic radiosurgery, or surgical resection) to sites of CNS metastatic disease
  • No requirement for glucocorticoids
  • No concurrent anticonvulsants
  • No overt evidence of neurological deficit
  • Radiologic scans performed within the past 14 days should not show evidence of disease progression or peritumoral edema

PATIENT CHARACTERISTICS:

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
• Hemoglobin ≥ 9.0 g/dL
• No evidence of bleeding diathesis or coagulopathy

Hepatic

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

Renal

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

Cardiovascular

• Fasting serum cholesterol ≤ 350 mg/dL
• Fasting triglycerides ≤ 400 mg/dL
• No uncontrolled hypertension (i.e., systolic blood pressure [BP] > 140 mm Hg or diastolic BP > 90 mm Hg)
• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Gastrointestinal

• Must be able to swallow pills
• No gastrointestinal tract disease requiring IV alimentation
• No active peptic ulcer disease

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No significant traumatic injury within the past 21 days
• No ongoing or active infection
• No history of allergic reactions attributed to compounds of similar chemical or biological composition to study drugs
• No psychiatric illness or social situation that would preclude study compliance
• No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No concurrent prophylactic colony-stimulating factor except epoetin alfa

Chemotherapy

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

Radiotherapy

• More than 4 weeks since prior radiotherapy

Surgery

• More than 21 days since prior major surgery
• No prior surgical procedures affecting absorption

Other

• Recovered from prior therapy
• More than 28 days since prior and no concurrent investigational drug
• Concurrent bisphosphonates allowed
• Concurrent prophylactic anticoagulation therapy (e.g., low-dose warfarin) allowed provided INR < 1.1 times ULN

• Concurrent full-dose anticoagulation therapy (e.g., warfarin) allowed provided all of the following criteria are met:

  • PT/INR > 1.5
  • INR in-range (between 2 and 3) on a stable dose of oral anticoagulant or a stable dose of low molecular weight heparin
  • No active bleeding or pathological condition that carries risk of bleeding (e.g., tumor involving major vessels or known varices)

• No concurrent enzyme-inducing antiepileptic drugs, including any of the following:

  • Phenytoin
  • Carbamazepine
  • Rifampin
  • Hypericum perforatum (St. John's wort)
  • Phenobarbital
  • Cimetidine
  • Ketoconazole
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent anticancer therapy
• No concurrent ingestion of high-fat meals
• No concurrent grapefruit or grapefruit juice