Regimen I (low-dose of RO4929097): Patients receive low-dose RO4929097 orally (PO) once daily on days 1-3, 8-10, and 15-17 and midazolam hydrochloride IV over 1 minute, omeprazole PO, tolbutamide PO, and dextromethorphan hydrobromide PO on days 1 and 10. After completion of course 1, patients are randomized to 1 of 2 treatment arms.