Augmented use of L-asparaginase markedly improves AYA ALL outcomes: FBMTG prospective MRD2014 study

The enhanced utilization of native L-asparaginase (L-Asp) aims to improve treatment outcomes for adult patients with non-Philadelphia chromosome (Ph) acute lymphoblastic leukemia (ALL). In this measurable residual disease 2014 (MRD2014) study, we modified our protocol to include an augmented dose of native L-Asp. Compared with former MRD2008, the total dose of L-Asp was raised from 36 000 U/m² to 232 000 U/m² in patients aged 16 to 35 and from 36 000 U/m² to 132 000 U/m² in patients aged 36 to 65 years. Adult patients with ALL were enrolled between January 2014 and December 2019 based on the following eligibility criteria: non-L3 ALL, age 16 to 65 years, Eastern Cooperative Oncology Group performance status of 0 to 2, and adequate liver and kidney functions (serum bilirubin ≤ 2.0 mg/dL; serum creatinine ≤ 2.0 mg/dL). The median follow-up time was 1128 days (range, 35-2400). A total of 81 patients with non-Ph ALL (40 males and 41 females; median age, 39 years [range, 16-64]) in whom MRD status was assessed were included. Complete remission was achieved in 72 patients (89%). The probability of 3-year event-free survival (EFS) and overall survival (OS) in these patients were 55% and 72%, respectively. The outcomes for patients aged 16 to 35 years demonstrated remarkable improvement. The 3-year EFS of MRD2008 at 45% significantly increased to 71% for MRD2014. Our study unequivocally demonstrated the beneficial effects of augmented use of L-Asp in this adolescent and young adult population. This trial was registered at UMIN Clinical Trials Registry as #UMIN000012382.