PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent biologic therapy Chemotherapy: No prior chemotherapy No other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to greater than 25% of the bone marrow No concurrent radiotherapy Surgery: No concurrent surgery Other: At least 28 days since prior investigational drugs No other concurrent investigational drugs during or within 28 days after final dose of study drug No concurrent drugs that induce or inhibit CYP3A enzyme