- Courses 1, 3, 5, and 7: Patients receive rituximab IV on day 1 (courses 1, 3, and 5 only); cyclophosphamide IV over 3 hours twice a day on days 2-4; doxorubicin IV over 24 hours on days 5-7; vincristine IV on days 5 and 12; dexamethasone orally or IV four times a day on days 2-5 and 12-15; and filgrastim (G-CSF) subcutaneously (SC) daily beginning on day 8 and continuing until blood counts recover.