IgH-V(D)J NGS-MRD measurement pre- and early post-allotransplant defines very low- and very high-risk ALL patients

Abstract

Positive detection of minimal residual disease (MRD) by multichannel flow cytometry (MFC) prior to hematopoietic cell transplantation (HCT) of patients with acute lymphoblastic leukemia (ALL) identifies patients at high risk for relapse, but many pre-HCT MFC-MRD negative patients also relapse, and the predictive power MFC-MRD early post-HCT is poor. To test whether the increased sensitivity of next-generation sequencing (NGS)-MRD better identifies pre- and post-HCT relapse risk, we performed immunoglobulin heavy chain (IgH) variable, diversity, and joining (V[D]J) DNA sequences J NGS-MRD on 56 patients with B-cell ALL enrolled in Children's Oncology Group trial ASCT0431. NGS-MRD predicted relapse and survival more accurately than MFC-MRD (P < .0001), especially in the MRD negative cohort (relapse, 0% vs 16%; P = .02; 2-year overall survival, 96% vs 77%; P = .003). Post-HCT NGS-MRD detection was better at predicting relapse than MFC-MRD (P < .0001), especially early after HCT (day 30 MFC-MRD positive relapse rate, 35%; NGS-MRD positive relapse rate, 67%; P = .004). Any post-HCT NGS positivity resulted in an increase in relapse risk by multivariate analysis (hazard ratio, 7.7; P = .05). Absence of detectable IgH-V(D)J NGS-MRD pre-HCT defines good-risk patients potentially eligible for less intense treatment approaches. Post-HCT NGS-MRD is highly predictive of relapse and survival, suggesting a role for this technique in defining patients early who would be eligible for post-HCT interventions. The trial was registered at www.clinicaltrials.gov as #NCT00382109.

Figure 1

Estimated relapse and survival probabilities by time from transplant. (A) Relapse risk by NGS-MRD status. (B) Overall survival (OS) by NGS-MRD status. (C) Relapse risk by aGVHD status among NGS-MRD positive patients.

Figure 2

Probability curves of patients who were MRD negative or positive by flow cytometry or deep sequencing. (A) Relapse risk by pre-HCT NGS-MRD compared with MFC-MRD status. (B) OS by pre-HCT NGS-MRD compared with NGS-MRD status.

Figure 3

Landmark curves for relapse probability as a function of time post-HCT for MFC-MRD and NGS-MRD cohorts. (A) Relapse probability by day +30 MFC-MRD status. (B) Relapse probability by day +30 NGS-MRD status. (C) Relapse probability by day +100 MFC-MRD status. (D) Relapse probability by day +100 NGS-MRD status. (E) Relapse probability by 8-month MFC-MRD status. (F) Relapse probability by 8-month NGS-MRD status.