End-of-induction MRD predicts early survival in high-risk adult B-acute lymphoblastic leukemia: A study from Eastern India.

UNLABELLED: Measurable residual disease (MRD) monitoring has dramatically improved outcomes in pediatric acute lymphoblastic leukemia (ALL) patients while, the prognosis in adult B-ALL remains poor. Biological heterogeneity, therapy-related toxicity, and inconsistent MRD-integration contribute to this disparity. This study evaluates the early prognostic value of MRD by flow cytometry in high-risk adult B-ALL patients.

METHODS

The present study included 47 high-risk adult B-ALL patients stratified by cytogenetic-risk groups (Age range: 18 - 66 years) and treated between January 2020 and December 2024 at Tata Medical Center, Kolkata. MRD was assessed using an 11-color flow cytometry panel at end-of-induction (EOI) and end-of-consolidation (EOC) timepoints. Patient details including demographics, cytogenetic risk profiles, treatment protocols, and survival outcomes were collected. Statistical analysis was performed using univariable, multivariable (MANNOVA) and multivariable cox-regression tests. Kaplan-Meier analysis was performed for survival at 18-months.

RESULTS

At EOI time point, 27 patients were MRD-negative, while 20 had detectable MRD (4 low-level <0.01%, 16 high-level ≥0.01%). MRD positivity at EOI significantly correlated with inferior survival at 18 months (log-rank p = 0.004). On univariable cox regression, EOI MRD positive patients demonstrated an approximately six-fold higher hazard of relapse or death compared with MRD-negative patients (HR = 6.33; 95% CI, 0.39-103.07). Multivariable and cox-regression analysis confirmed EOI MRD positivity as an independent predictor of OS (p = 0.004). Additionally, Day 8 prednisone response showed prognostic significance with survival (cox-regression p-value = 0.003; MANNOVA p ≈ 0.05).

CONCLUSIONS

The EOI MRD positivity, is a robust independent predictor of 18m-survival in high-risk adult B-ALL patients. Additionally, a longitudinal MRD monitoring enhances risk stratification and informs therapeutic decisions. Therefore, incorporating MRD assessment into routine clinical practice is essential for dynamic risk stratification and optimizing outcomes in High-risk adult B-ALL.