- Patients receive 3 courses of the CODOX-M chemotherapy regimen comprising cyclophosphamide IV on days 1-5, vincristine IV on days 1 and 8, doxorubicin IV on day 1, and methotrexate (MTX) IV over 24 hours on day 10. Patients over age 65 receive reduced-dose MTX on day 10. All patients receive leucovorin calcium (CF) IV once at hour 36 after initiation of MTX infusion, once every 3 hours between hours 36-48, and continuing once every 6 hours until blood levels of MTX are safe. Patients also receive filgrastim (G-CSF) subcutaneously (SC) once daily beginning on day 13 and continuing until blood counts recover.