OBJECTIVES : Survival rates remain poor for patients with B-precursor ALL, especially for those in whom MRD is not eradicated early in treatment. This study aims to further understand treatment patterns, MRD testing patterns and outcomes in adult patients with B-precursor ALL, to aid real-world decision-making.

METHODS : This descriptive, retrospective medical chart review collected patient-level data in 2018. Patients needed to have ≥1 MRD test during front-line treatment (induction/consolidation) and were followed from diagnosis until death, loss to follow-up or end of observation period. Data were stratified by MRD status at first MRD test.

RESULTS : Eighty-two patients were included (median age 44 years, 23% Philadelphia chromosome+; median follow-up 25.4 months; MRD-positive: n=17, MRD-negative: n=50, MRD result unknown: n=15 [median follow-up: 31.7, 27.2 and 12.0 months, respectively]). Most patients received HyperCVAD (32%) or HOVON (26%) front-line treatment protocols; 22% received allogeneic stem cell transplantation. Overall, 76% of patients were hospitalized (mean 1.07 hospitalization/month). Complete hematological response (CRh) occurred in 77% of patients (77% of MRD-positive, 94% of MRD-negative patients). Median relapse-free survival from CRh was 32.7 months (MRD-positive:11.7 months; MRD-negative: 33.2 months). Median overall survival from diagnosis was 28.9 months (MRD-positive: 15.3 months; MRD-negative: not reached); 71%, 60% and 39% were alive at 1, 2 and 5 years. Most patients (88%) were MRD tested during induction; testing rates considerably decreased thereafter (39% during consolidation) and timepoints varied. Flow cytometry (60%) and PCR (26%) were the most common MRD testing methods.

CONCLUSIONS : ALL represents clinical and economic burden. Our findings suggest MRD-positive patients have worse prognosis than MRD-negative patients and highlight the clinical relevance of MRD testing outside of clinical trials. Given the prognostic impact of MRD status, it is important to ensure MRD is tested throughout treatment, to ensure appropriate patient management.