- Maintenance therapy: Patients receive vincristine IV on days 1, 29, and 57; dexamethasone IV or orally twice daily on days 1-5, 29-33, and 57-61; mercaptopurine orally on days 1-84; IT methotrexate on day 1*; and oral methotrexate on days 8, 15, 22, 29**, 36, 43, 50, 57, 64, 71, and 78.