Auto-SCT for AML in second remission: CALGB study 9620

We studied the feasibility and efficacy of a two-step approach to Auto-SCT for patients with AML in second remission. Step 1 consisted of consolidation chemotherapy using cytarabine 2000 mg/m(2) i.v. every 12 h for 4 days plus etoposide 40 mg/kg total dose by continuous i.v. infusion over the same 4 days. PBSC were collected after G-CSF stimulation during recovery from this chemotherapy. Step 2, auto-SCT, used a preparative regimen of oral BU 16 mg/kg over 4 days followed by etoposide 60 mg/kg i.v. Of the 50 patients entered on Step 1, two died from treatment complications, and seven failed to proceed to transplantation. A median CD34+ cell dose of 5.9 x 10(6)/kg was collected in a median of three collections. With a median follow-up of 8.2 years, 5-year disease-free survival (DFS) is 28%. The most important prognostic factor was cytogenetics, with acute promyelocytic leukemia (APL) patients having a 5-year DFS of 67% compared with 16% for others. We conclude that this two-step approach to autologous transplantation produces good CD34+ mobilization and that this approach has cured some patients. Results in patients with APL are especially promising.