Treatment of Relapse in Pediatric Patients with Acute Lymphoblastic Leukemia in Argentina: Results from a Clinical Trial and a Prospective Cohort

Abstract

Introduction: since 2002, the Grupo Argentino para el Tratamiento de la Leucemia Aguda (GATLA) has been implementing protocols from the Berlin-Frankfurt-Münster (BFM) group as the standard treatment for relapses of acute lymphoblastic leukemia (ALL). In 2010, BFM developed the IntReALL 10 protocol, implemented in Argentina with the inherent limitations of the region.Population and Methods: we treated a total of 180 patients under 18 years of age between 2010 and 2015 for high-risk relapsed acute lymphoblastic leukemia (ALL) in Argentina following a BFM relapse protocol. This protocol openly compared standard treatment with an innovative (experimental) therapeutic approach that included Clofarabine. Out of these, 171 patients were assessable, with 78 patients being centrally randomized in a clinical trial, and 93 were assigned to one of the arms based on the treating group’s criteria (prospective cohort). The cohort where the treatment assignment had not been randomized, was analyzed with adjustments for gender, age, and the presence or absence of Down Syndrome, Philadelphia Chromosome, and T-cell immunophenotype. Results: patients who received the experimental treatment had worse outcomes (double the five-year mortality) compared to those who received the standard treatment. This difference reached statistical significance in the clinical trial (p=0.001) and the prospective cohort (p=0.0009).Conclusions: our results support the continuation of the standard arm in BFM-type protocols for relapsed ALL treatment and were consistent with the conclusions of the ALLIC-REC group.

Keywords

• acute lymphoblastic leukemia
• relapse
• treatment
• argentina