Intensified chemotherapy inspired by a pediatric regimen combined with allogeneic transplantation in adult patients with acute lymphoblastic leukemia up to the age of 40

Abstract

Event-free survival (EFS) at 5 years in pediatric acute lymphoblastic leukemia (ALL) is >80%. Outcome in adult ALL is still unsatisfactory, which is due to less cumulative dosing of chemotherapy and less strict adherence to timing of successive cycles. In the present phase II trial, we evaluated a pediatric regimen in adult patients with ALL under the age of 40. Treatment was according to the pediatric FRALLE approach for high-risk ALL patients and characterized by increased dosages of asparaginase, steroids, methotrexate and vincristin. However, allogeneic stem cell transplantation was offered to standard risk patients with a sibling donor and to all high-risk patients in contrast to the pediatric protocol. Feasibility was defined by achieving complete remission (CR) and completion of treatment within a strict timeframe in at least 60% of patients. In all, 54 patients were included with a median age of 26. CR was achieved in 49 patients (91%), of whom 33 completed treatment as scheduled (61%). Side effects primarily consisted of infections and occurred in 40% of patients. With a median follow-up of 32 months, EFS estimated 66% at 24 months and overall survival 72%. These data show that a dose-intensive pediatric regimen is feasible in adult ALL patients up to the age of 40.