Frontline Consolidation with Nelarabine for Adults with High-Risk T-Cell Acute Lymphoblastic Leukemia. Results of the Graall-2014/T Atriall Phase 2 Study

Rationale. Acute lymphoblastic leukemia (ALL) with unfavorable biology and/or high minimal residual disease (MRD) levels are at high-risk of disease recurrence. Based on the results of the GRAALL-2005/T study (Trinquand A et al, JCO 2013; Beldjord K et al, Blood 2014), T-ALL patients enrolled in the GRAALL-2014/T trial were classified at high-risk (HR) if presenting an unfavorable 4-gene classifier (absence of NOTCH1/FBXW7 mutations or presence of RAS/PTEN alterations) and/or a post-induction IG/TR MRD1 ≥ 10 -4 (including the need of a salvage course to reach a complete remission [CR]). In the phase 2 ATRIALL sub-study, HR patients were offered to receive nelarabine (NELA) during consolidation and maintenance or as bridge to allogeneic hematopoietic stem cell transplantation (HSCT). The aim of the present report is to compare their outcome to that of similar patients treated in the same GRAALL-2014/T trial but without frontline NELA.