Mylotarg, fludarabine, cytarabine (ara-C), and cyclosporine (MFAC) regimen as post-remission therapy in acute myelogenous leukemia

Purpose: Mylotarg, a humanized anti-CD33 antibody linked to an antitumor antibiotic, is approved for the treatment of patients with relapsed acute myeloid leukemia (AML). Its role as a component of post-remission therapy in AML has not been established. The Mylotarg, fludarabine, cytarabine, and cyclosporine (MFAC) regimen was evaluated in patients in complete remission following Mylotarg-containing regimens. Methods: The MFAC regimen comprised: Mylotarg 4.5 mg/m² intravenously (i.v.) over 2 h after a loading dose of cyclosporine A (CSA) on day 1; fludarabine 15 mg/m² i.v. over 30 min every 12 h for six doses on days 2 through 4; ara-C 0.5 g/m over 2 h every 12 h for six doses on days 2 through 4, 4 h after fludarabine started; CSA 6 mg/kg over 2 h, followed by 16 mg/kg continuous i.v. infusion on days 1 and 2. Patients in complete remission (CR) commenced idarubicin and araC (IA) alternating with MFAC or vice versa for 9 months from the date of CR. Idarubicin was administered at 8 mg/m² on days 1 and 2 and ara-C at 1.5 g/m² on days 1 and 2. Results: A total of 22 patients received 76 courses of MFAC (35 courses) alternating with IA (41 courses) or vice versa. The interval between courses, and degrees of myelosuppression, were equivalent in the alternating regimens. Failure-free and 12-month survival rates of were 32% and 55%, respectively. Grade 3/4 toxicities, including sepsis, neutropenic fever, and nausea/vomiting, were equivalent with MFAC and IA. Conclusions: Post-remission therapy with MFAC is feasible and well tolerated in patients with AML.