Abstract

Emergence of clones carrying point mutations in the BCR-ABL1 kinase domain (KD) is a common mechanism of resistance to tyrosine kinase inhibitor (TKI)-based therapies in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Sanger sequencing (SS) is the most frequently used method for diagnostic BCR-ABL1 KD mutation screening, but it has some limitations-it is poorly sensitive and cannot robustly identify compound mutations. Next-generation sequencing (NGS) may overcome these problems. NSG is increasingly available and has the potential to become the method of choice for diagnostic BCR-ABL1 KD mutation screening. A group discussion within an ad hoc constituted Panel of Experts has produced a series of consensus-based statements on the potential value of NGS testing before and during first-line TKI-based treatment, in relapsed/refractory cases, before and after allo-stem cell transplantation, and on how NGS results may impact on therapeutic decisions. A set of minimal technical and methodological requirements for the analysis and the reporting of results has also been defined. The proposals herein reported may be used to guide the practical use of NGS for BCR-ABL1 KD mutation testing in Ph+ ALL.

Abstract

B-cell acute lymphoblastic leukemia (B-ALL) with MLL-rearrangements (MLL-r) is rare in pediatric patients (aged >1 year), and optimal treatment strategies remain unclear. This study aimed to retrospectively evaluate the clinical characteristics, outcomes, and effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) of 37 non-infant children with t(v;11q23)/MLL-r B-ALL. Their 4-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 69.8 %, 58.2 %, and 39.1 %, respectively, and differed significantly between patients receiving allo-HSCT (18/19 cases received haploidentical [haplo]-HSCT) at the first complete remission (HSCT at CR1, n = 19; 87.4 %, 89.5 % and 5.3 %) and those continuing consolidation therapy (Non-HSCT at CR1, n = 18; 52.2 %, 25.9 %, and 74.1 %, respectively), and the p values were 0.022, <0.001 and <0.001, respectively. Of the 13 patients experiencing relapse during consolidation chemotherapy, the five continuing with chemotherapy only died within 44 months, and the eight patients opting for allo-HSCT after CR2 had a 4-year OS of 57.1 %. Multivariate analysis revealed HSCT at CR1 as the only independent protective factor for OS, EFS, and CIR. The present results indicate that allo-HSCT (especially haplo-HSCT) at CR1 may decrease the relapse rate and improve the prognosis of non-infant children with t(v;11q23)/MLL-r B-ALL.

Abstract

A multicenter retrospective study was performed to evaluate the prognostic factors in 104 patients with relapsed or refractory acute lymphoblastic leukemia (ALL), who received allogeneic hematopoietic cell transplantation (HCT) between 2005 and 2015. The median age was 38 (range: 17-68), and the median blast fraction in peripheral blood and bone marrow was 1% (range: 0-99) and 52% (range: 0-100), respectively. With a median follow-up period of 47 months (8.3-105), overall survival (OS), non-relapse mortality, and relapse mortality at 1 year were 25%, 44%, and 31%, respectively. Multivariate analysis demonstrated independent predictors for poor OS, including nuclear cell count in the bone marrow ≥ 10x10(4)/muL (HR=2.14, 95% CI: 1.33-3.43, P=0.002), elevated lactate dehydrogenase level (HR=1.66, 95% CI: 1.05-2.62, P=0.031), and no primary induction failure (HR=2.05, 95% CI: 1.11-3.78, P=0.022). A prognostic scoring index was designed based on these survival predictors. At 2 years, OS was 28%, 14%, and 0% for Good (score 0, 1: n=47), Intermediate (score 2: n=40), and Poor (score 3: n=17), respectively (P < 0.001). This scoring may be useful in identifying the patient's population for which allogeneic HCT is least beneficial in advanced stages of ALL.

Abstract

The prognostic value of IL7-receptor pathway (IL7Rp) mutations in T-cell acute lymphoblastic leukemia (T-ALL) remains unclear. We performed a comprehensive study of 200 adult patients with T-ALL included in the GRAALL2003/2005 protocols to address the clinical significance of IL7Rp mutations. Next-generation sequencing of the IL7Rp (IL7R/JAK1/JAK3/STAT5B) revealed that IL7Rp mutations were frequent in adult T-ALL (28%) particularly in immature/early T-cell progenitor (ETP)-ALL. They were associated with mutations of NOTCH-pathway, PHF6, and PRC2 components but not with K/NRAS. IL7Rp mutated (IL7Rp(mut)) T-ALL were slow-responders, with a high rate of M2/M3 day-8 marrow compared with IL7Rp non-mutated (IL7Rp(WT)) T-ALL (p = 0.002) and minimal residual disease positivity at 6-weeks (MRD1) (p = 0.008) but no difference in MRD2 positivity at 12-weeks. Despite this, no adverse prognosis was evidenced when censored for allogeneic hematopoietic stem cell transplantation (HSCT). In time-dependent analysis, HSCT did not benefit IL7Rp(mut) patients whereas it was of marked benefit to IL7Rp(WT) cases. IL7Rp-mutations identify a subgroup of slow-responder T-ALLs which benefit from post-induction chemotherapy regimens but not from HSCT. Our data suggest that prior knowledge of the mutation status of IL7Rp may influence HSCT decision and help to guide therapy reduction.

Abstract

The impacts of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect might differ depending on minimal residual disease (MRD). Therefore, we examined 1,022 recipients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) in first complete remission. MRD status at HSCT was negative in 791 (77.4%) and positive in 231 (22.6%). The impact of GVHD as a time-dependent covariate on transplant outcomes were analyzed while adjusting for other possible variables. Mild acute GVHD [hazard ratio (HR), 0.90; 95% confidence interval (CI), 0.70-1.16; P = 0.901] and chronic GVHD (HR, 0.82, 95% CI, 0.58-1.14; P = 0.238) were not significantly associated with overall mortality, whereas severe acute GVHD (HR, 2.26, 95% CI, 1.64-3.11; P < 0.001) resulted in inferior overall survival due to high non-relapse mortality. Moreover, even in the subgroup analyses stratified according to MRD status, acute and chronic GVHD were not significantly associated with better overall survival. Therefore, less intensive GVHD prophylaxis to achieve a GVL effect is not recommended for Ph-positive ALL.

Abstract

Outcomes after relapse of childhood B-acute lymphoblastic leukemia (B-ALL) are poor, and optimal therapy is unclear. Children's Oncology Group study AALL0433 evaluated a new platform for relapsed ALL. Between March 2007 and October 2013 AALL0433 enrolled 275 participants with late bone marrow or very early isolated central nervous system (iCNS) relapse of childhood B-ALL. Patients were randomized to receive standard versus intensive vincristine dosing; this randomization closed due to excess peripheral neuropathy in 2010. Patients with matched sibling donors received allogeneic hematopoietic cell transplantation (HCT) after the first three blocks of therapy. The prognostic value of minimal residual disease (MRD) was also evaluated in this study. The 3-year event free and overall survival (EFS/OS) for the 271 eligible patients were 63.6% +/- 3.0% and 72.3% +/- 2.8% respectively. MRD at the end of Induction-1 was highly predictive of outcome, with 3-year EFS/OS of 84.9 +/- 4.0% and 93.8 +/- 2.7% for patients with MRD <0.1%, vs. 53.7 +/- 7.8% and 60.6 +/- 7.8% for patients with MRD ≥0.1% (p<0.0001). Patients who received HCT vs. chemotherapy alone had an improved 3-year disease-free survival (77.5 +/- 6.2% vs. 66.9 +/- 4.5%, p=0.03) but not OS (81.5 +/- 5.8% for HCT vs. 85.8 +/- 3.4% for chemotherapy, p=0.46). Patients with early iCNS relapse fared poorly, with a 3-year EFS/OS of 41.4% +/- 9.2% and 51.7% +/- 9.3%, respectively. Infectious toxicities of the chemotherapy platform were significant. The AALL0433 chemotherapy platform is efficacious for late bone marrow relapse of B-ALL, but with significant toxicities. The MRD threshold of 0.1% at the end of Induction-1 was highly predictive of outcome. The optimal role for HCT for this patient population remains uncertain. This trial is registered at clinicaltrials.gov (NCT# 00381680).

Abstract

Background: This study compared the effects of pre-transplantation measurable residual disease (pre-MRD) on outcomes in Philadelphia chromosome (Ph)-positive ALL patients who underwent human leukocyte antigen-matched sibling donor transplantation (MSDT) or who received unmanipulated haploidentical SCT (haplo-SCT). Methods: A retrospective study (n = 202) was performed. MRD was detected by RT-PCR and multiparameter flow cytometry. Results: In the total patient group, patients with positive pre-MRD had a higher 4-year cumulative incidence of relapse (CIR) than that in patients with negative pre-MRD (26.1% vs. 12.1%, P = 0.009); however, the cumulative incidence of non-relapse mortality (NRM) (7.4% vs. 15.9%, P = 0.148), probability of leukemia-free survival (LFS) (66.3% vs. 71.4%, P = 0.480), and overall survival (OS) (68.8% vs. 76.5%, P = 0.322) were comparable. In the MSDT group, patients with positive pre-MRD had increased 4-year CIR (56.4% vs. 13.8%, P < 0.001) and decreased 4-year LFS (35.9% vs. 71.0%, P = 0.024) and OS (35.9% vs. 77.6%, P = 0.011) compared with those with negative pre-MRD. In haplo-SCT settings, the 4-year CIR (14.8% vs. 10.7%, P = 0.297), NRM (7.3% vs. 16.3%, P = 0.187) and the 4-year probability of OS (77.7% vs. 72.3%, P = 0.804) and LFS (80.5% vs. 75.7%, P = 0.660) were comparable between pre-MRD positive and negative groups. In subgroup patients with positive pre-MRD, haplo-SCT had a lower 4-year CIR (14.8% vs. 56.4%, P = 0.021) and a higher 4-year LFS (77.7% vs. 35.9%, P = 0.036) and OS (80.5% vs. 35.9%, P = 0.027) than those of MSDT. Multivariate analysis showed that haplo-SCT was associated with lower CIR (HR, 0.288; P = 0.031), superior LFS (HR, 0.283; P = 0.019) and OS (HR, 0.252; P = 0.013) in cases with a positive pre-MRD subgroup. Conclusions: Our results indicate that the effects of positive pre-MRD on the outcomes of patients with Ph-positive ALL are different according to transplant modality. For Ph-positive cases with positive pre-MRD, haplo-SCT might have strong graft-vs.-leukemia (GVL) effects.

Abstract

INTRODUCTION Our objectives were to design and validate methods to identify relapse and hematopoietic stem cell transplantation (HSCT) in children with acute lymphoblastic leukemia (ALL) using administrative data representing hospitalizations at US pediatric institutions. METHODS We developed daily billing and ICD-9 code definitions to identify relapses and HSCTs within a cohort of children with newly diagnosed ALL between January 1, 2004, and December 31, 2013, previously assembled from the Pediatric Health Information System (PHIS) database. Chart review for children with ALL at the Children's Hospital of Philadelphia (CHOP) and Texas Children's Hospital (TCH) was performed to establish relapse and HSCT gold standards for sensitivity and positive predictive value (PPV) calculations. We estimated incidences of relapse and HSCT in the PHIS ALL cohort. RESULTS We identified 362 CHOP and 314 TCH ALL patients in PHIS and established true positives by chart review. Sensitivity and PPV for identifying both relapse and HSCT in PHIS were > 90% at both hospitals. Five-year relapse incidence in the 10 150-patient PHIS cohort was 10.3% (95% CI 9.8%-10.9%) with 7.1% (6.6%-7.6%) of children underwent HSCTs. Patients in higher-risk demographic groups had higher relapse and HSCT rates. Our analysis also identified differences in incidences of relapse and HSCT by race, ethnicity, and insurance status. CONCLUSIONS Administrative data can be used to identify relapse and HSCT accurately in children with ALL whether they occur on- or off-therapy, in contrast with published approaches. This method has wide potential applicability for estimating these incidences in pediatric ALL, including patients not enrolled on clinical trials.

Abstract

Objective: To compare the efficacy of autologous HSCT (auto-HSCT) with matched sibling donor (MSD) HSCT in Ph(+) ALL and provide a basis for the choice of transplantation method. Methods: We retrospectively investigated the outcomes of 78 adult patients with Ph(+) ALL who underwent auto-HSCT (n=31) and MSD-HSCT (n=47) in Institute of Hematology and Blood Diseases Hospital, CAMS & PUMC, from January 2008 to December 2017. The overall survival (OS) rate, leukemia-free survival (LFS) rate, cumulative incidence of relapse (CIR) rate, nonrelapse mortality (NRM) rate, and the impact of achievement of complete molecular response (CMR) within 3 months and sustaining CMR up to transplantation (s3CMR) on transplantation method were explored. Results: The median time of neutrophil and platelet reconstitution in auto-HSCT and MSD-HSCT groups were 12 (10-29) days vs14 (11-24) days (P=0.006) and 17.5 (10-62) days vs 7 (10-33) days (P=0.794) , respectively. In the MSD-HSCT group, the incidence of - and - acute graft-versus-host disease (GVHD) was 27.7% (13/47) and 8.5% (4/47) , respectively. The incidence of limited and extensive chronic GVHD was 17.0% (8/47) and 12.8% (6/47) , respectively. The estimated CIR, NRM, LFS, and OS at 3 years were not significantly different between auto-HSCT and MSD-HSCT groups (P>0.05) . For 44 patients who achieved s3CMR, 3-year OS[ (84.0+/-8.6) % vs (78.0+/-8.7) %, P=0.612], LFS[ (70.3+/-10.3) % vs (68.2+/-10.1) %, P=0.970], CIR[ (24.9+/-10.0) % vs (14.4+/-8.0) %, P=0.286], and NRM[ (4.7+/-4.7) % vs (17.4+/-8.1) %, P=0.209] of the auto-HSCT and MSD-HSCT groups were not significantly different. However, for 34 patients who did not reach s3CMR, 3-year cumulative relapse rate of patients in the auto-HSCT group was significantly higher than MSD-HSCT group[ (80.0+/-14.7) % vs (39.6+/-10.9) %, P=0.057]. Conclusions: auto-HSCT with maintenance therapy after HSCT appears to be an attractive treatment option for patients with Ph(+) ALL especially for those with s3CMR maintained up to transplantation. For non-s3CMR patients, allogeneic transplantation may be more effective from lower relapse.

Abstract

An updated strategy combining pediatric-based chemotherapy with risk-oriented allogeneic hematopoietic cell transplantation (HCT) was evaluated in Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph- ALL) and compared with a published control series. Following induction-consolidation chemotherapy, responsive patients were assigned to receive maintenance chemotherapy or undergo early HCT according to the risk stratification criteria and minimal residual disease (MRD) status. Of the 203 study patients (median age 41 years, range 17-67), 140/161 with Ph- ALL achieved complete remission (86.9%; 91.6% ≤55 years, P = 0.0002), with complete MRD clearing in 68/109; 55 patients were assigned to maintenance chemotherapy, and 85 to HCT due to very high-risk characteristics (hyperleukocytosis, adverse genetics, early/mature T-precursor ALL, and MRD persistence). The 5-year relapse incidence was 36%, and the treatment-related mortality rate was 18%. Median overall and relapse-free survival were 7.4 and 6.2 years, with rates of 54 and 53% at 5 years, respectively, which were significantly better than those obtained with the historical protocol (P = 0.001 and P = 0.005, respectively), without significant differences between maintenance and HCT cohorts. In prognostic analysis, MRD negativity and age ≤55 years were the most favorable independent prognostic factors. A reduction in treatment toxicity and further improvements in the risk definitions and risk-oriented design are the focuses of this ongoing research.