Amsacrine combined with etoposide and methylprednisolone is a feasible and safe component in first-line intensified treatment of pediatric patients with high-risk acute lymphoblastic leukemia in CoALL-08-09 trial

Background: The prognosis of children with acute lymphoblastic leukemia (ALL) has improved considerably over the past decades. However, to achieve cure in patients with refractory disease or relapse new treatment options are mandatory. Methods In the multicenter-trial CoALL-08-09, an additional treatment element consisting of the rarely used chemotherapeutic agent amsacrine combined with etoposide and methylprednisolone (AEP) (amsacrine 2 x 100 mg/m2, etoposide 2 x 500 mg/m2 and methylprednisolone 4 x 1000 mg/m2) was implemented into the first-line treatment of pediatric patients with a poor treatment response at the end of induction (EOI) measured by minimal residual disease (MRD). These patients were stratified into a high-risk intensified arm (HR-I) including an AEP element at the end of consolidation. Patients with induction failure (IF), i.e. lack of cytomorphological remission EOI, were eligible for hematopoietic stem cell transplantation (HSCT) after remission had been reached later on. These patients received AEP as a part of their MRD-guided bridging-to-transplant treatment. Results A significant improvement in probality of overall survival (pOS) for the CoALL-08-09 HR-I patients was noted compared to MRD-matched patients from the preceding CoALL-07-03 trial in the absence of severe or persistent treatment-related toxicities. Relapse rate and probability of event-free survival (pEFS) did not differ significantly between trials. In patients with IF a stable or improved MRD response after AEP was observed without severe or persistent treatment-related toxicities. Conclusion In conclusion, AEP is well-tolerated as a component of the HR treatment and useful in bridging-to-transplant settings.