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.

Background. The treatment of childhood acute lymphoblastic leukemia (ALL) remains challenging in low-income countries. Here we evaluate the experience with a modified Berlin-Frankfurt-Münster (BFM) treatment protocol ALL-Moscow Berlin (MB)-91 at the Kantha Bopha hospitals, a charity-funded institution providing free pediatric care in Cambodia. Methods. This is a retrospective study including 110 unselected patients aged 9 months to 14 years diagnosed with ALL between 2015 and 2017. Patients were stratified in high- (HR) and standard-risk (SR) groups based on clinical criteria. The cumulative doses of anthracyclines were reduced to 120 mg/m2 for SR patients and consolidation was based on Capizzi methotrexate elements instead of cyclophosphamide, cytarabine and high dose methotrexate. Supportive empiric antibiotic treatment and whole blood transfusions were possible. Results. 63 patients (57 %) were HR, mostly based on high leukemia burden with hyperleukocytosis > 50 G/l, massive lymph node and hepato-splenic involvement, reflecting a high disease burden. 72 patients (65.5%) reached complete remission (CR) on day 36. The estimated 3-year overall survival (OS) was 34.9 %, 50.5 % for SR and 23.4 % for HR patients. Most events were due to severe infections (40 (53.3 %)) and bleeding (15 (20 %)), mostly during induction and consolidation. Relapse was confirmed in 13 cases (11.8 %). No patients abandoned treatment. Conclusion. ALL chemotherapy is feasible in a charity-funded public institution with results comparable to other low-middle income countries, but treatment-related mortality remains limiting. This will justify investments in diagnostics to stratify more patients for reduced intensity treatment and in supportive care.