Measurable Residual Disease Positive Patients Research Articles

Assessment of Measurable Residual Disease on Day 28 of First Induction Chemotherapy in Acute Myeloid Leukaemia Patients

Background: Measurable residual disease (MRD) is an independent, strong, prognostic marker in acute myeloid leukaemia (AML) that is important for risk stratification and treatment planning. This study assessed the MRD on day-28 after first induction chemotherapy in AML patients. Objective: To assess measurable residual disease status on day 28 after the first induction chemotherapy in newly diagnosed acute myeloid leukaemia patients. Methodology: This cross-sectional study was conducted at the Department of Haematology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from April 2021 to March 2022 among a total of 25 newly diagnosed AML patients who were admitted and received induction chemotherapy with DA (7+3). On Day-28, bone marrow aspiration was done with standard procedure and first pull of 2ml bone marrow sample was sent to a laboratory for MRD evaluation by multiparameter flow cytometry. MRD was considered positive when value was ?0.1%. Results: On day 28 of post induction chemotherapy most of the patients (92%) achieved morphological remission and among them more than half (52.2%) were MRD positive. The presence of CD14 myeloid marker and baseline higher serum uric acid level was significant in MRD positive patients and cytarabine dose 150 mg/m2 was found significant in MRD negative patients. Conclusion: More than half of the Acute Myeloid Leukaemia patients, treated with standard induction chemotherapy and achieved morphological remission on day 28 of chemotherapy, had positive measurable residual disease assessed by multiparameter flow cytometry. Positive MRD indicates relatively poorer prognosis and may necessitate more cycles of induction followed by more intensive consolidation which may include haematopoietic stem cell transplantation.

Myelodysplasia-Related Gene Mutations for NGS-Based MRD Assessment in Acute Myeloid Leukemia

Introduction: Measurable residual disease (MRD) plays an increasing role for treatment management of AML patients. While next-generation-sequencing (NGS) based MRD assessment can be well standardized, there is uncertainty about the type of gene mutations that associate with prognosis and are useful for MRD assessment. The 2022 ELN recommendations assign patients with at least one mutation in the genes ASXL1, BCOR, EZH2, RUNX1, SF3B1, SRSF2, STAG2, U2AF1 or ZRSR2 to the subgroup of myelodysplasia-related gene mutations (MRGM), which is associated with poor prognosis. We aimed to define the prognostic effect of MRD after induction chemotherapy in AML patients with MRGM using MRG mutations for MRD assessment by NGS. Methods: We retrospectively collected bone marrow and peripheral blood samples from AML patients in complete remission (CR) or CR with incomplete hematologic recovery (CRi) after one to two cycles of 7+3-based standard induction chemotherapy (IC) with at least one MRGM detected at diagnosis by myeloid panel sequencing covering 48 AML associated genes. Patients treated with one course of IC were included if they proceeded to allogeneic hematopoietic cell transplantation (alloHCT) already after one cycle. Molecular MRD status was assessed using targeted NGS and bioinformatics error-correction with 0.01% sensitivity as described before using only MRGM as MRD markers. Results: MRD was assessed on 104 adult newly-diagnosed AML patients (median age 58.6) with a total of 166 MRGM, resulting in a median of one MRGM per patient (range 1-4). 43 (41.3%) patients had secondary or therapy-related AML and 20 (19.2%) had myelodysplasia-related cytogenetic abnormalities. 68 (65.4%) patients were MRD positive for at least one MRGM after one (18 patients (17.3%)) or two (86 patients (82.7%)) cycles of intensive chemotherapy, while 36 (34.6%) became MRD negative. Measured variant allele frequencies (VAF) of positive samples ranged from 0.02-43.1% (median VAF 1.34%).MRD positive patients were older and more likely to be male compared to MRD negative patients, while cytogenetic risk, WBC count, Hgb, platelet count and ECOG status at diagnosis were similar to MRD negative patients. 53 (77.9%) MRD positive and 23 (63.9%) MRD negative patients underwent alloHCT in first CR/CRi.Median follow-up was 3.35 years. OS (P = 0.92), RFS (P = 0.99) and CIR (P = 0.98) were similar in MRD positive (at least one MRGM detectable) and negative (no MRGM detectable) patients (Figure 1). OS, RFS and CIR were also similar between MRD positive and negative patients, when MRD negativity was defined by conversion of at least one MRGM to negativity (55 (52.9%) MRD positive, 49 (47.1%) MRD negative), and when ASXL1 was excluded from the analysis. As variants with VAF >5% in CR/CRi samples may indicate clonal hematopoiesis, we excluded all variants with VAF >5% and repeated the analysis with the 88 (84.6%) remaining patients. Again, OS, RFS and CIR were similar for MRD positive and negative patients. We next reasoned that reduction of VAF correlates with the sensitivity of leukemic cells and possibly with depth of remission and long-term outcome. The fold-reduction of VAFs from diagnosis to the time of MRD analysis was calculated for all variants. For patients with several MRGMs, the variant with the largest fold-reduction was considered including undetectable variants. Patients with more or less than a 2-log, 3-log or 4-log reduction (log 10) had similar OS, RFS and CIR, respectively. Evaluating each MRGM individually, only RUNX1-MRD associated with RFS and by trend CIR (comparing MRD positive to negative patients for OS, HR 3.41, 95% CI 0.43-26.82, P = 0.24; RFS, HR 4.37, 95% CI 1.07-17.79, P = 0.04; CIR, HR 3.30, 95% CI 0.79-13.82, P = 0.1). Conclusion: 65.4% of AML-MRGM patients in CR/CRi remained MRD positive when MRGMs were used for MRD assessment by NGS. MRD positivity was associated with age above 60 years and male sex.Using all MRG mutations for MRD assessment at a threshold of 0.01% or by various degrees of log-reduction was not predictive of outcome after intensive induction chemotherapy. This limits the number of potential MRD markers for NGS analysis before alloHCT, although individual markers like RUNX1 may be of prognostic value.

Clinical Significance of Measurable Residual Disease (MRD) in Relapsed/Refractory Multiple Myeloma (RRMM) Patients (Pts) Treated with Chimeric Antigen Receptor (CAR) T Cells and T-Cell Engagers (TCE)

Clinical Significance of Measurable Residual Disease (MRD) in Relapsed/Refractory Multiple Myeloma (RRMM) Patients (Pts) Treated with Chimeric Antigen Receptor (CAR) T Cells and T-Cell Engagers (TCE)

Measurable Residual Disease Status By Clonotypic Mass Spectrometry with Easym Assay Predicts Outcomes Following Autologous Hematopoietic Cell Transplant in Multiple Myeloma

Bone marrow (BM)-based measurable residual disease (MRD) has been established as one of the most important dynamic prognostic markers in multiple myeloma (MM). However, the necessity of bone marrow biopsies limits the feasibility of frequent MRD monitoring. Consequently, there is an urgent unmet need for peripheral blood-based MRD testing for serial monitoring of disease response to allow tailored therapy for patients achieving deep remissions. Quantification of myeloma (M)-protein using mass spectrometry (MS) is a promising approach for peripheral blood-based MRD monitoring due to its exceptional analytical sensitivity. Prior studies have examined the use of MALDI-TOF-based methods, which relies on the mass distribution of intact immunoglobulins light chains and is approximately 1-log more sensitive than traditional testing. However, recent advances in MS technology have allowed determination and tracking of a “clonotypic” MS signature in the peripheral blood which is highly sensitive and patient-specific (Liyasova et al, CCR 2021). Prior reports have demonstrated the feasibility of this approach, but data supporting the association of blood-based clonotypic MS MRD with clinical outcomes is currently lacking. Consequently, we performed a large retrospective analysis of patients enrolled in our institutional MM tissue bank to determine the association of clinical outcomes with clonotypic MS-based MRD testing (EasyM, Rapid Novor, Kitchener, ON). We identified patients in our institutional tissue bank who met the following criteria: 1) diagnosis of MM, 2) underwent autologous hematopoietic cell transplant (AHCT), 3) M-protein ≥0.2 g/dL by serum protein electrophoresis (SPEP) or >20 mg/dL (light chain) at diagnosis, 4) had no detectable M-protein by SPEP at day +100 and 5) had adequate samples for analysis collected at day +100 after AHCT. Patients were included regardless of M-protein isotype. Baseline and follow up samples were analyzed by Rapid Novor without access to the clinical outcomes. Percent residual EasyM at day +100, in respect to baseline EasyM, was used as the independent variable to predict Progression-free survival (PFS). 95 patients were included in the analysis. Median age was 63, 88% were White and 61% were male. 64% were IgG, 20% IgA and 16% were with light chain (LC) MM. 26%, 62% and 12% were R-ISS stage I, II and III, respectively. High-risk cytogenetics were present in 32%. 97% had received proteasome inhibitors, 89% received immunodulatory agents and 13% anti-CD38 antibodies prior to AHCT. The median year of transplant was 2018 (range: 2008 - 2022). 93% patients received AHCT as part of frontline therapy. 66% were in CR or better following AHCT. 95% received maintenance after AHCT. 9 patients had non-quantifiable EasyM at follow up and were excluded from derivation of the MRD definition. Of the remaining 86, patients with IgA/LC and IgG disease had significant different percent residual EasyM following AHCT (median: 0.19% vs. 1.00%, p < 0.001). A cutoff of 1.036% residual EasyM was derived for IgG and 0.048% residual EasyM for IgA/LC patients was determined to fit the PFS data best, and based on these cutoffs, 41 patients (47%) were MRD negative by EasyM. The incidence of MRD negativity between IgG and IgA/LC was similar (55% vs. 32%). MRD positivity by EasyM was a strong predictor of PFS following AHCT (Figure 1) (HR: 2.249, p = 0.017). The median PFS in MRD positive patients was 3.4 years versus not reached in MRD negative patients (log rank: p = 0.014) (Figure 1). Our study is the first, to our knowledge, to demonstrate the clinical utility of peripheral blood-based clonotypic mass spectrometry to predict outcomes for patients with MM. Notably, our results suggest that different cutoffs should be employed for IgG and IgA/LC myeloma if drawn at day +100 after transplant. This is possibly due to the differing half-lives of these molecules. Significant additional questions remain, including the utility of ongoing monitoring at multiple time points and the optimal time post-AHCT to assess for MRD, especially in patients with IgG myeloma. Additionally, these findings require prospective validation in an independent cohort of patients to demonstrate wider applicability.

The Benefit of Allogeneic Transplant in 1 st Complete Remission in NPM1 Mutated AML with or without FLT3 ITD Is Restricted to Those Testing MRD Positive after Induction - an Analysis of the UK NCRI AML17 and AML19 Studies

Background While there is accumulating evidence that measurable residual disease (MRD) negative patients with intermediate risk AML may not benefit from allogeneic transplantation in 1 st complete remission (CR1-allo), many consider the presence of a FLT3 Internal Tandem Duplication (ITD) an indication for this procedure. However, the studies supporting this practice were mainly performed before the development of sensitive molecular MRD techniques (Schlenk NEJM 2008).The UK NCRI AML17 and AML19 trials studied, then incorporated, MRD by RT-qPCR into the management of patients with NPM1 mutated AML. Methods NCRI AML17 (April 2009 to December 2014) and AML19 (November 2015 to November 2020) were sequential prospective randomised trials for younger adults (18 - 60 years) with newly diagnosed AML. In AML17, decisions regarding CR1-allo were made using a validated risk score incorporating baseline factors and response to induction. In AML19, for patients with NPM1 mutated AML ( NPM1mut) the protocol recommended CR1-allo only in patients testing MRD positive in the peripheral blood (PB) post cycle 2 (PC2), regardless of other baseline risk factors such as FLT3 ITD, based on findings from AML17 (Ivey et al, NEJM 2016). Both trials were performed prior to the availability of midostaurin and FLT3 ITD MRD assays. Here we compare the outcomes of patients with NPM1mut in these trials and assess the benefit of CR1-allo according to FLT3 ITD and molecular MRD status. Time-to-event variables are analysed using the Kaplan-Meier method, and the impact of alloSCT assessed using time-dependent Cox regression and visualised with Simon-Makuch plots. Molecular relapses were included as relapse events, and alloSCT performed after molecular relapse was not considered as CR1. Results 737 patients with NPM1mutAML who achieved CR/CRi and had a valid PC2 PB MRD result were included in the analysis. 60/348 (17%) patients from AML17 and 83/389 (21%) from AML19 tested PB PC2 MRD positive. Overall, CR1-allo was performed in 20% of patients in AML17 and 25% in AML19. Of the MRD positive patients CR1-allo was performed in 16/60 (27%) in AML17 compared to 50/83 (60%) in AML19 where these patients were recommended for transplant. CR1-allo was performed in 18% and 16% of MRD negative patients in AML17 and AML19 respectively. In AML17, as previously reported (Ivey et al, NEJM 2016), patients who were MRD+ had poor outcomes, with 3-year cumulative incidence of relapse (CIR) of 84% and overall survival (OS) of 25%. These outcomes were improved in AML19, with 3y CIR 50% and 3y OS 51%. Across both trials, CR1-allo was associated with a significant survival benefit in MRD+ patients (3y OS 61% vs 24%, HR 0.42, 95%CI 0.26-0.69, p<0.001, Figure A). Patients who were MRD negative had excellent outcomes in both trials (3y CIR 33% and 24% and 3y OS 75% and 83% for AML17 and AML19 respectively). AlloSCT in CR1 provided no survival advantage for MRD- patients (HR 0.83, 95%CI 0.51-1.34, p=0.4). There were a total of 286 patients with NPM1mutFLT3 ITD mut AML with a PC2 PB MRD result across both trials. 81/286 (28%) were PB PC2 MRD+ of whom 32/81 (40%) received CR1-allo (28% in AML17 and 49% in AML19). Outcomes in these high-risk patients were improved in AML19, with 3y CIR 91% vs 68% and 3y OS 22% and 31% for AML17 and AML19 respectively. Those who received CR1-allo had improved outcomes (3y OS 45% vs 18%, HR 0.52, 95% CI 0.29-0.93, p=0.03) consistent with the overall MRD+ population. In the 70% of NPM1mutFLT3 ITD mut AML patients who achieved PB PC2 MRD-, outcomes were encouraging in both AML17 (3y CIR 37%, 3y OS 75%) and AML19 (3y CIR 27%, 3y OS 80%). CR1-allo was performed in 20% (19% in AML17, 21% in AML19), with no survival benefit for transplant (HR 0.80, 95% CI 0.37-1.72, p=0.6, Figure B). There remained no benefit when restricted to those with high (>0.5) FLT3 ITD allelic ratio (HR 0.63, 95% CI 0.2 - 2.23, p = 0.50) and there was also no evidence of an interaction between allelic ratio and benefit from transplant for MRD negative patients (p=0.86). Conclusion Molecular MRD can be used to stratify decision making concerning post remission therapy in patients with NPM1mut AML. Patients who achieve MRD negativity in the peripheral blood by the end of course 2 are at low risk of relapse and we found no evidence of benefit from allogeneic transplant in CR1, including in the subset with FLT3 ITD. This finding contrasts with MRD+ patients where there was a significant survival benefit for CR1 transplant.

Clinical significance of end of induction measurable residual disease monitoring in B-cell acute lymphoblastic leukemia: A single center experience.

The assessment of measurable residual disease (MRD) has emerged as a powerful prognostic tool for both pediatric and adult acute lymphoblastic leukemia (ALL). This retrospective study aimed to evaluate the prognostic relevance of the end of induction MRD in B-cell acute lymphoblastic leukemia (B ALL) patients. The study included 481 patients who underwent treatment for B ALL between August 2012 and March 2019 and had their MRD at the end of induction assessed by flow cytometry. Baseline demographic characteristics were collected from the patient's clinical records. Event free survival (EFS) and relapse free survival (RFS) were calculated using Kaplan-Meier analysis and survival estimates were compared using the log-rank test. End of induction MRD and baseline karyotype were the strongest predictors of EFS and RFS on multivariate analysis. The EFS was inversely related to the MRD value and the outcomes were similar in patients without morphological remission at the end of induction and patients in remission with MRD ≥1.0%. Even within the subgroups of ALL based on age, karyotype, BCR::ABL1 translocation and the treatment protocol, end of induction MRD positive patients had poor outcomes compared to patients who were MRD negative. The study outcome would help draft end of induction MRD-based treatment guidelines for the management of B ALL patients.

T-cell replete cord transplants give superior outcomes in high-risk and relapsed/refractory pediatric myeloid malignancy.

Stem cell transplant (SCT) outcomes in high-risk and relapsed/refractory (R/R) pediatric acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) have been historically poor. Cord blood (CB) allows T-cell replete CB transplant (TRCB), enabling enhanced graft-versus-leukemia. We consecutively collected data from 367 patients undergoing TRCB (112patients) or other cell source (255 patients) SCT for pediatric AML/MDS in the United Kingdom and Ireland between January 2014 and December 2021. Data were collected about the patient's demographics, disease, and its treatment; including previous transplant, measurable residual disease (MRD) status at transplant, human leukocyte antigen-match, relapse, death, graft versus host disease (GvHD), and transplant-related mortality (TRM). Univariable and multivariable analyses were undertaken. There was a higher incidence of poor prognosis features in the TRCB cohort: 51.4% patients were MRD positive at transplant, 46.4% had refractory disease, and 21.4% had relapsed after a previous SCT, compared with 26.1%, 8.6%, and 5.1%, respectively, in the comparator group. Event free survival was 64.1% within the TRCB cohort, 50% in MRD-positive patients, and 79% in MRD-negative patients. To allow for the imbalance in baseline characteristics, a multivariable analysis was performed where the TRCB cohort had significantly improved event free survival, time to relapse, and reduced chronic GvHD, with some evidence of improved overall survival. The effect appeared similar regardless of the MRD status. CB transplant without serotherapy may be the optimal transplant option for children with myeloid malignancy.

Single-Cell Immune Landscape of Measurable Residual Disease in AML after Allogeneic Hematopoietic Stem Cell Transplantation

Measurable residual disease (MRD) is the most important prognostic marker for relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML). Unfortunately, our understanding of critical immune cell clusters in bone marrow (BM) which contribute to MRD occurrence is limited. Thus, we generated 184,231 single-cell transcriptomes to compare the BM immune cell landscape between MRD positive and negative patients. KLRG1-CD8+ T cell and KLRG1+CD8+ T cell clusters were prevalent in MRD positive and negative patients, respectively, demonstrating significantly different gene expression profiles (particularly cytotoxicity genes). KLRG1+CD8+ T cells showed a stronger cytotoxicity to leukemia cells compared with KLRG1-CD8+ T cells in vitro. Exhausted CD8+ T cell clusters were similar between MRD positive and negative patients. In addition, IGHG1+ B cells, IFITM3+ monocytes, and HSP90AB1+ erythrocytes were associated with MRD occurrence. MRD clearance by immunotherapies was accompanied with the increase of KLRG1+CD8+ T cell clusters and decrease of KLRG1-CD8+ T cell, IGHG1+ B cell, IFITM3+ monocyte, and HSP90AB1+ erythrocyte clusters, and vice versa. An independent cohort showed that the decrease of immune cell clusters which were prevalent in MRD positive patients was associated with MRD achieving negative after allo-HSCT. Macrophage migration inhibitory factor pathway might be the critical pathway among these immune cell populations, and it was weakened in MRD patients who showed response to immunotherapy. We firstly provided a complete landscape on BM immune cells in MRD stage which will facilitate a better understanding of the immune mechanisms for MRD occurrence in AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Prognostic Significance of Measurable Residual Disease for Patients with Acute Lymphoblastic Leukemia Undergoing Allogeneic Stem Cell Transplant in Second Complete Remission and Beyond

Introduction: For patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (HCT) in first complete remission (CR1), measurable residual disease (MRD) prior to HCT is strongly associated with post-HCT relapse rates and overall survival (OS). However, for a growing number of patients with ALL, HCT is deferred until the second remission (CR2) or beyond. It is unclear whether pre-transplant MRD assessment is also prognostic in the setting of HCT beyond CR1. Methods: We performed a single center retrospective study to test the hypothesis that pre-transplant MRD positivity is associated with outcomes in patients receiving HCT in CR2 or beyond for ALL. MRD was measured by 6-color flow cytometry with a sensitivity of 0.01%. Consecutive pediatric and adult patients who underwent first allogeneic HCT between the years 2004-2021 for ALL in CR2 or beyond were included. Results: We identified 162 patients (Table 1), 123 (76%) with B-ALL and the remainder with T-ALL. The majority (80%, n=129) of patients were in CR2 at the time of HCT, the remainder in third CR or beyond (CR3+). One hundred and five (65%) patients were male and median age at transplant was 31 (range 4-69) years. Graft source was either matched unrelated donor (MUD) (43%, n=69), matched sibling donor (MSD) (24%, n=39), haploidentical (18%, n=29) or cord blood transplantation (CBT) (15%, n=25). Pre-HCT MRD status was determined for 150 (93%) of patients and of those was positive in 43 (26%). Subsequent analyses were limited to the subset of patients with known MRD status. There was no statistical difference in characteristics according to MRD status except for higher proportion of CR3+ patients (33% vs. 16%, p=0.02) and comorbidity index >2 (70% vs. 40%, p=0.001) in MRD positive vs. negative patients. The median follow-up in surviving patients was 62 (range 20-104) and 47 (range: 2-171) months in MRD positive and negative patients, respectively. In multivariate analysis (MVA) evaluating transplantation outcomes at 3 years, pre-HCT MRD positivity was associated with a higher rate of disease relapse (HR 1.9, 95% CI 1.1-3.6; p=0.02); but it had no impact on non-relapse mortality (NRM) (HR 0.8, 95% CI 0.4-1.8; p=0.6). Subset analyses showed that these trends were consistent for patients receiving HCT in CR2 or CR3+; however the impact on disease relapse was more pronounced for patients in CR2 at HCT. MRD positivity was also associated with less favorable overall (HR 1.96, 95% CI 1.2-3.3; p=0.01) and progression-free survival (PFS) (HR 2.5, 95% CI 1.5-4.2; p<0.001) for patients receiving HCT in CR2. MRD was not associated with OS (HR 0.9, 95% CI 0.4-2, p=0.8) or PFS (HR 0.8, 95% CI 0.3-1.7, p=0.5) for patients receiving HCT in CR3+. As shown in Figure 1 A-B, OS and PFS were significantly superior for MRD negative patients receiving HCT in CR2. OS and PFS for MRD positive patients in CR2 were comparable to patients receiving HCT in CR3+. Conclusions: Pre-transplant MRD positivity is predictive of disease relapse in patients undergoing HCT for ALL in CR2 or beyond; however, the survival advantage associated with MRD negativity maybe limited to patients undergoing HCT in CR2. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Chemotherapy or Hematopoietic Stem Cell Transplantation in B-Lineage Acute Lymphoblastic Leukemia Patients Based on IKZF1 and MRD Status

Purpose： We aimed to investigate the outcomes of different post-remission treatment choices based on IKZF1 detection by RT-PCR and dynamic measurable residual disease (MRD) by multiparameter flow cytometry in B-ALL. Prospectively confirm the role of MRD and IKZF1 deletion as a significant predictor of post-remission treatment, replacing the definition of clinical risk categories for patients after complete remission (CR). Patients and Methods： There were 202 patients with B-ALL enrolled in this registry-based cohort study including 99 who received chemotherapy (CMT), and 103 allogeneic stem cell transplantation (allo-SCT). The primary endpoint was the 5-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR). Subgroup analyses were performed based on IKZF1deletion and dynamic MRD 14,24,45 days after induction therapy. Results： In subgroups of patients with IKZF1wt and MRD negative patients， the 5-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse(CIR) probabilities for patients assigned to chemotherapy were 67.6%, 55.2%,36.5% and 71.4%,60.7%,28.6%, for those assigned to HSCT respectively. In subgroups of patients with IZKF1 del or MRD positive patients after CR, with OS, EFS, and CIR rates for patients assigned to chemotherapy were 30.1%, 10.3% and76.2%, and 71.8%, 39.8%, and 43.7%for those assigned to HSCT, respectively. Conclusion： The results thus suggest a clear distinction between HSCT and CMT inIKZF1del or MRD positive Patients. While IKZF1wt patients and MRD negative had significant differences. Affected patients should thus be carefully monitored for IKZF1 and minimal residual disease to decide on the post-remission treatment after CR.

Anti CD19 CAR-T Cell Therapy Can Clear Minimal Residual Disease in Bone Marrow of Patients with Relapsed or Refractory B Cell Non-Hodgkin's Lymphomas

Background: Anti CD19 Chimeric Antigen Receptor T (CAR-T) cell therapy is an effective treatment option for patients with relapsed/refractory B-cell lymphomas. There is limited data on the impact of CAR-T cell therapy on measurable residual disease (MRD) in the bone marrow of these patients. We hereby report CAR-T cell therapy's efficacy to treat bone marrow MRD in patient with relapsed/refractory B-cell lymphomas. Methods: In this retrospective review, patients receiving CAR-T cell therapy for relapsed/refractory B-cell lymphomas who had bone marrow MRD evaluation pre-and post-CAR-T infusion at the University of Arizona Cancer Center (UACC) were analyzed. MRD testing was performed via ClonoSEQ (Adaptive Biotechnologies) on bone marrow aspirates prior to CAR-T cell infusion. Patients with MRD+ (10^6) disease had serial MRD evaluations at day+30, +90, +180, +365 post CAR-T cell infusion. Results: Thirty-three patients with B-cell lymphomas received CAR-T cell therapy at UACC from January 2019 to July 2022. Bone marrow MRD pre-and post-CART was evaluated in ten patients. Baseline characteristics of these patients are outlined in Table 1. Seven (70%) were female, five (50%) had diffuse large B cell lymphoma (DLBCL), two (20%) patients had Richter's syndrome, two patients had transformed DLBCL from follicular lymphoma (FL), one patient had FL grade 3A. Nine (90%) patients were treated with Tisagenlecleucel and one (10%) patient received Axicabtagene ciloleucel CAR-T product. Of the ten patients who had MRD testing done pre-and post-CAR-T, seven (70%) had MRD positive disease prior to treatment. Five of the seven patients converted to MRD negative 10^6 post-CAR-T cell infusion. One patient tested MRD positive below the level of detection on day +30 bone marrow aspirate. One patient is still MRD positive 6 months post-CAR-T infusion but the depth of response continues to improve from MRD positive at 10^4 to MRD negative at 10^5, 6 months post-CAR-T infusion. All MRD positive patients achieved complete metabolic response (CMR) based on the positron emission tomography scans. Conclusion: CAR-T cell therapy has the potential to treat minimal residual disease in patients with B-cell lymphoma. Depth of bone marrow response continues to improve over time. All patients continue to be in CMR. Long term follow-up will help determine if persistent MRD can be used as prognostic marker in B cell lymphomas post CAR-T cell therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

First-Line Consolidation Therapy with CD19/CD22 Bispecific CAR-T Cells for MRD Positive B-ALL Maybe Feasible

Measurable residual disease (MRD) persistence after induction or early intensive therapy has proved to be the strongest independent prognostic indicator for B-cell acute lymphoblastic leukemia (B-ALL). Here we presented a phase I study to evaluate the safety and efficacy of CD19/CD22 bispecific targeted chimeric antigen receptor (CAR) T-cells for MRD positive B-ALL, especially as first-line consolidation therapy for primary patients. The primary objective was to assess the safety and the secondary objective was for its efficacy. The most common adverse events (AEs) were hematologic related, including anemia of 93.3%(14/15), leukopenia of 100% (15/15), decreased neutrophil count of 100% (15/15), and decreased lymphocyte count of 100% (15/15).Cytokine release syndrome (CRS) occurred in 4 patients (26.7%) and all of them were grade 1 or 2. One patient (6.7%) developed delayed later neurotoxicity and related symptoms were obviously alleviated after treatments with prednisone. The overall MRD response rate was 100% at day 28. With a median follow-up of 15.5 months (range, 2.5-33), the median RFS and OS were not reached. For all patients, the 2-year RFS and OS were 77% (95% CI, 55-99) and 86% (95% CI, 68-104), respectively, while for patients in first-line consolidation group, the 2-year RFS and OS 77.8% (95% CI, 51-105) and 80.8% (95% CI, 57-105), respectively. The results suggested that CD19/CD22 bispecific CAR-T cells as first-line consolidation therapy might be feasible for MRD positive patients. This trial was registered at clinicaltrials.org (NCT: 03919526).

Measurable Residual Disease Assessment in Multiple Myeloma: How Deep Is Enough?

The introduction of new and more effective therapeutic options for Multiple Myeloma (MM) has significantly deepened and prolonged patients’ remission. As currently used treatment protocols induce high rates of complete responses, Measurable Residual Disease (MRD) assessment has become essential to enhance the evaluation of treatment efficacy. Detection of MRD has improved with the development of highly sensitive and standardized techniques such as Next Generation Flow or Next Generation Sequencing, complemented by functional imaging techniques. These advances offer a valuable opportunity to further optimize criteria of response to treatment. Currently, extensive data demonstrate that MRD status is a valuable prognostic factor of survival. Since MRD represents a real measurement of disease burden, its incorporation in clinical trials to guide treatment decisions will certainly translate into clinical benefits. Sustained MRD negativity can be used to consider optimal candidates for treatment discontinuation, whereas MRD positive high-risk patients may have access to novel immunotherapeutic strategies such as bispecific drugs or CAR T cell therapy. In this review, we describe the available techniques to detect MRD, address the current data regarding MRD as a surrogate endpoint within clinical trials, examine how MRD can be introduced into the clinical management of MM patients, and discuss the future of MRD monitoring.

The Utility of Euroflow MRD Assessment in Real-World Multiple Myeloma Practice.

Measurable residual disease (MRD) is being recognised as an optimal method for assessing depth of response, identifying higher risk of relapse, and guiding response-based treatment paradigms for multiple myeloma (MM). Although MRD negativity is increasingly replacing complete response as the surrogate endpoint in clinical trials, its role in real-world practice is less established. We retrospectively analyzed EuroFlow MRD results from patients with newly diagnosed MM (NDMM) who underwent bortezomib, cyclophosphamide and dexamethasone (VCD) induction and high dose melphalan conditioned autologous stem cell transplant (ASCT) at the Alfred Hospital between January 2016 and December 2020. Next generation flow MRD evaluation was performed 3 months following ASCT using the standardised EuroFlow platform. 112 patients with available MRD data were identified to have received VCD induction followed by ASCT. Post ASCT MRD was undetectable in 28.6% of patients. Those who achieved MRD negativity had significantly longer progression free survival (PFS) than those with persisting MRD (24-month PFS of 85% [95% CI: 72.4-99.9%] vs 63% [95% CI: 52.9-75.3%], p = 0.022). Maintenance therapy was associated with improved PFS regardless of MRD status (24-month PFS of 100% [95% CI: NA, p = 0.02] vs 73% [95% CI: 53.1-99.6%] in MRD negative, and 75% [95% CI: 64.2-88.6%] vs 36% [95% CI: 20.9-63.2%, p = 0.00015] in MRD positive patients). Results from this retrospective study of real-world practice demonstrate that Euroflow MRD analysis following standard VCD induction and ASCT in NDMM is feasible and allows more accurate prognostication, providing a platform for response adaptive therapies.

Effective Treatment of Ph-Negative Acute Lymphoblastic Leukemia for Uninsured Hispanic Adolescents and Young Adults with a Low-Cost Outpatient Regimen

IntroductionPediatric inspired regimens can achieve good outcomes in adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) by delivering intense non-myelosuppressive chemotherapy and are considered standard. Experience with the implementation of these regimens outside of academic centers in high-income countries is limited. Furthermore, Mexican patients (with “hispanic ethnicity”) have increased risk for relapse and treatment related complications.ObjectivesPrimary objective: to determine 2-year overall survival (OS) and event-free survival (EFS). Secondary objectives: to determine the impacts of treatment abandonment and measurable residual disease (MRD) on outcomes, and to compare treatment costs with a widely used standard regimen in the United States.Patients and MethodsConsecutive patients 16-45 years diagnosed with Ph-negative B-cell acute lymphoblastic leukemia after 2016 were included. The salient features of our modified-BFM regimen include the use mitoxantrone, E. coli L-asparaginase, without systemic cytarabine or high dose methotrexate designed to be delivered entirely in an outpatient basis for maximum affordability (Table 1), given that we treat an uninsured population that must cover their own treatment costs out of pocket. Genetic risk assessment was limited to BCR/ABL. Thereafter, relapse risk assessment was based exclusively on “next generation” flow cytometry measurable residual disease (MRD) after consolidation, with a planned allogeneic transplant for MRD-positive patients (≥0.001%). Treatment abandonment was defined as a missed ≥14-day period during intensive treatment or ≥1 month during maintenance. Statistical analysis was performed as intent-to-treat. Lastly, drugs included in our protocol were compared to those of CALGB 10403 with current local pricing in USD.ResultsNinety-one AYAs have been treated, 47 women and 44 men, with a median age of 21 years (range, 15-45), mostly with a good functional capacity and no comorbidities (ECOG≤2: 92.1%; HCT-Ci 0-1: 97.8%); 43.8% of patients had ≥30x10 9/L white blood cells at diagnosis and 31.7% had grade ≥1 obesity. Notable grade ≥3 adverse events during induction were infections/neutropenic fever (35.6%),hepatotoxicity (11%) and thrombosis/bleeding (8.1%) with 44.3% eventually requiring hospitalization. Induction related mortality was 11%. Only n=3 were refractory to induction and the remainder assessed achieved complete remission (n=63; 95.5%) with a median follow-up of 15 months (range, 0.9-50.1). N=29 received induction and consolidation entirely on an outpatient basis, ulterior hospitalizations during therapy were rare. Treatment abandonment was common (n=24; 26.4%) usually during induction (n=8; 32%) or consolidation (n=12; 48%) and mostly related to unaffordability. For the same reason, transfers to social security healthcare systems were also frequent (n=19; 20.9%). Most patients assessed were MRD negative (n=38; 74.5%) Early relapse incidence was 32.9%; 44.4% in MRD-positive and 27.5% in MRD-negative patients (p=0.43). OS at 24 months was 61.5% (95% CI 47-73%) and EFS 49.8% (95% CI 37-62%) with excellent outcomes for MRD-negative patients (Figure 1, Panels A and B). Treatment abandonment and MRD positivity were the only independent predictors of mortality in a multivariate analysis (HR 7.8 [95% CI 2.8-21.9] and HR 4.5 [95% CI 1.4-14], respectively). Lastly, the total cumulative price for medications included in our regimen was calculated at $16,750 vs. $36,061 USD in CALGB 10403, representing a cost reduction of 53.5%.ConclusionsThe treatment of Hispanic ALL patients with our regimen has shown promising outcomes at a reduced cost for patients. Genetic risk assessment, induction mortality, treatment abandonment and lack of access to novel therapies for MRD positive patients remain the main barriers for improving outcomes further. [Display omitted] DisclosuresGomez-De Leon: Novartis: Honoraria; ASH: Research Funding; Sanofi: Honoraria; Abbvie: Honoraria. González López: JANSSEN: Honoraria; AMGEN: Honoraria. Gomez-Almaguer: Roche: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Bristol-Myers-Squibb: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau.

Prognostic Value of Measurable Residual Disease Assessed By Multiparameter Flowcytometry in Patients with NPM1-Mutated Acute Myeloid Leukemia

Prognostic Value of Measurable Residual Disease Assessed By Multiparameter Flowcytometry in Patients with NPM1-Mutated Acute Myeloid Leukemia

Next-Generation Sequencing-Based Measurable Residual Disease (MRD) Monitoring Is Highly Predictive for Outcome after Allogeneic Stem Cell Transplantation

Background: Molecular predictors for relapse following allogeneic haematopoietic stem cell transplantation (alloHSCT) are urgently needed as 30-40% of AML patients experience recurrence of disease after HSCT. Measurable residual disease monitoring (MRD) for nucleophosmin 1 (NPM1 ) mutations has proven to be highly predictive for relapse in AML patients treated with or without alloHSCT. However, the majority of AML patients undergoing alloHSCT do not have the favorable NPM1 marker so that alternative markers and techniques are required. We studied a next-generation sequencing (NGS)-based error-corrected sequencing approach that is applicable to all mutations for its ability to prognosticate relapse and survival following alloHSCT.Aim: To evaluate the prognostic impact of MRD before alloHSCT in AML patients in morphologic complete remission (CR) using a novel approach of error-corrected sequencing applicable to the majority of AML patients.Patients and Methods: We studied 75 patients who underwent myeloablative (MA) (n=36) or reduced-intensity conditioned (RIC) (n=39) alloHSCT for AML in morphologic CR for the presence of MRD shortly before alloHSCT. All patients had at least one mutation in genes other than NPM1 or DNMT3A at the time of diagnosis that was identified by NGS with a myeloid panel on the Illumina platform. Amplicon-based error-corrected sequencing and bioinformatics was developed and applied to CR samples before alloHSCT analyzing 1-3 diagnostic mutations. Genomic DNA from peripheral blood (n=46) or bone marrow (n=29) was used for MRD assessment. Mutations in the following genes were used for MRD analysis in the indicated number of patients: IDH2 (n=12), FLT3 (n=10), RUNX1 (n=7), SF3B1 (n=6), NRAS (n=5), IDH1 and TP53 (n=4 each), KRAS and WT1 (n=3 each), CBL, ETV6, EZH2, STAG2 (n=2 each), BCOR, BCORL1, DDX41, PHF6, PTPN11, RAD21 , and SMC3 (n=1 each). 55 mutations were single nucleotide variants and 14 mutations were indels. The sensitivity of the assay was determined for each analysis and ranged from 10-4 to 10-5. Six patients (8%) had molecular persistence at high copy number in CR (variant allele frequency, VAF 31-51%) and were excluded from further analysis.Results: 31 of 69 patients (45%) were found MRD positive before alloHSCT with a median VAF of 0.19% (range 0.012% to 14.5%). Clinical and transplantation-associated characteristics were similarly distributed between MRD positive and negative patients. Cytogenetic risk according to MRC, ELN risk groups and molecular aberrations showed no significant differences between MRD positive and negative patients apart from more MRD positive patients being SF3B1 mutated. The median follow up was 6.1 years. 19 of 31 MRD positive patients (61%) and 7 of 38 MRD negative patients (18%) relapsed after alloHSCT. In MRD positive patients the MRD marker was also found in the majority of available relapse samples (9 of 11 patients, 82%). MRD negative patients who relapsed had lost the MRD marker in 4 of 5 available relapse samples (80%), suggesting high accuracy of our MRD assay. By competing risk analysis for cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) patients with positive MRD had a significantly higher CIR than MRD negative patients (P<.001; HR 4.85, 95% CI 1.95-12.1; 5 year CIR 67.7 vs 19%, Figure 1A), while NRM was not significantly different (P=.31; HR 0.44, 95% CI 0.09-2.14). Overall survival (OS) was significantly shorter in MRD positive compared to MRD negative patients (P=.029; HR 2.26, 95% CI 1.07-4.79; 5 year OS 38 vs 70%, Figure 1B). In multivariate analysis MRD status was an independent predictor of CIR (P<.001, HR 5.80, 95% CI 2.18-15.48) besides cytogenetic risk, and of OS (P=.013, HR 2.57, 95%CI 1.22-5.38) besides cytogenetic risk and WBC count.Conclusion: We provide evidence that NGS-based MRD monitoring can be applied to a large proportion of AML patients using almost any available molecular aberration. This approach requires morphologic confirmation of CR status in order to exclude patients with molecular persistence at high copy number, likely originating from preleukemic clones or germline mutations. NGS-based MRD is highly predictive of relapse and survival and may help refining transplant and posttransplant management in AML patients. [Display omitted] DisclosuresChaturvedi:Bayer Pharma AG, Berlin, Germany: Research Funding. Fiedler:Amgen, ARIAD/Incyte: Membership on an entity's Board of Directors or advisory committees; Amgen: Patents & Royalties; Amgen, Pfizer: Research Funding; Amgen, Gilead, GSO, Teva, Jazz Pharmaceuticals: Other: Support for meeting attendance.

Use of Measurable Residual Disease to Evolve Transplant Policy in Acute Myeloid Leukemia: A 20-Year Monocentric Observation

Simple SummaryUpfront genetics/cytogenetics and minimal measurable disease (MRD) are becoming relevant biomarkers in the process of post-remission transplant allocation in AML. However, until recently the transplantation choice relied on the availability of a fully matched familiar donor, whereas individual patient- and disease-related characteristics played a secondary role in transplant allocation. In this paper we analyzed the evolution of the transplantation policy at our center in a 20-year time interval. At the beginning of our observation patients were submitted to allogeneic transplant, per protocol, mostly if a fully matched family donor was available or to autologous transplant if no fully matched family donor was identified (“donor vs. no donor” strategy) regardless of upfront genetics/cytogenetics or MRD status. Thereafter, persistence of MRD after consolidation cycle was included in the decision-making process for transplant selection. Patients with favorable and intermediate-risk cytogenetic risk were to receive allogeneic or autologous stem cell transplantation if MRD positive or negative, respectively, (“transplant vs. no transplant” strategy). In this cohort, patients with FLT3-ITD or adverse risk karyotype were submitted to allogeneic transplant as well. Measurable residual disease (MRD) is increasingly employed as a biomarker of quality of complete remission (CR) in intensively treated acute myeloid leukemia (AML) patients. We evaluated if a MRD-driven transplant policy improved outcome as compared to a policy solely relying on a familiar donor availability. High-risk patients (adverse karyotype, FLT3-ITD) received allogeneic hematopoietic cell transplant (alloHCT) whereas for intermediate and low risk ones (CBF-AML and NPM1-mutated), alloHCT or autologous SCT was delivered depending on the post-consolidation measurable residual disease (MRD) status, as assessed by flow cytometry. For comparison, we analyzed a matched historical cohort of patients in whom alloHCT was delivered based on the sole availability of a matched sibling donor. Ten-years overall and disease-free survival were longer in the MRD-driven cohort as compared to the historical cohort (47.7% vs. 28.7%, p = 0.012 and 42.0% vs. 19.5%, p = 0.0003). The favorable impact of this MRD-driven strategy was evident for the intermediate-risk category, particularly for MRD positive patients. In the low-risk category, the significantly lower CIR of the MRD-driven cohort did not translate into a survival advantage. In conclusion, a MRD-driven transplant allocation may play a better role than the one based on the simple donor availability. This approach determines a superior outcome of intermediate-risk patients whereat in low-risk ones a careful evaluation is needed for transplant allocation.

MRD Tailored Therapy in AML: What We Have Learned So Far.

Acute myeloid leukemia (AML) is a heterogeneous clonal disease associated with a dismal survival, partly due to the frequent occurrence of relapse. Many patient- and leukemia-specific characteristics, such as age, cytogenetics, mutations, and measurable residual disease (MRD) after intensive chemotherapy, have shown to be valuable prognostic factors. MRD has become a rich field of research where many advances have been made regarding technical, biological, and clinical aspects, which will be the topic of this review. Since many laboratories involved in AML diagnostics have experience in immunophenotyping, multiparameter flow cytometry (MFC) based MRD is currently the most commonly used method. Although molecular, quantitative PCR based techniques may be more sensitive, their disadvantage is that they can only be applied in a subset of patients harboring the genetic aberration. Next-generation sequencing can assess and quantify mutations in many genes but currently does not offer highly sensitive MRD measurements on a routine basis. In order to provide reliable MRD results, MRD assay optimization and standardization is essential. Different techniques for MRD assessment are being evaluated, and combinations of the methods have shown promising results for improving its prognostic value. In this regard, the load of leukemic stem cells (LSC) has also been shown to add to the prognostic value of MFC-MRD. At this moment, MRD after intensive chemotherapy is most often used as a prognostic factor to help stratify patients, but also to select the most appropriate consolidation therapy. For example, to guide post-remission treatment for intermediate-risk patients where MRD positive patients receive allogeneic stem cell transplantation and MRD negative receive autologous stem cell transplantation. Other upcoming uses of MRD that are being investigated include: selecting the type of allogeneic stem cell transplantation therapy (donor, conditioning), monitoring after stem cell transplantation (to allow intervention), and determining drug efficacy for the use of a surrogate endpoint in clinical trials.

Impact of gemtuzumab ozogamicin on MRD and relapse risk in patients with NPM1-mutated AML: results from the AMLSG 09-09 trial

AbstractMonitoring of measurable residual disease (MRD) provides prognostic information in patients with Nucleophosmin1-mutated (NPM1mut) acute myeloid leukemia (AML) and represents a powerful tool to evaluate treatment effects within clinical trials. We determined NPM1mut transcript levels (TLs) by quantitative reverse-transcription polymerase chain reaction and evaluated the prognostic impact of NPM1mut MRD and the effect of gemtuzumab ozogamicin (GO) on NPM1mut TLs and the cumulative incidence of relapse (CIR) in patients with NPM1mut AML enrolled in the randomized phase 3 AMLSG 09-09 trial. A total of 3733 bone marrow (BM) samples and 3793 peripheral blood (PB) samples from 469 patients were analyzed. NPM1mut TL log10 reduction ≥ 3 and achievement of MRD negativity in BM and PB were significantly associated with a lower CIR rate, after 2 treatment cycles and at end of treatment (EOT). In multivariate analyses, MRD positivity was consistently revealed to be a poor prognostic factor in BM and PB. With regard to treatment effect, the median NPM1mut TLs were significantly lower in the GO-Arm across all treatment cycles, resulting in a significantly greater proportion of patients achieving MRD negativity at EOT (56% vs 41%; P = .01). The better reduction in NPM1mut TLs after 2 treatment cycles in MRD positive patients by the addition of GO led to a significantly lower CIR rate (4-year CIR, 29.3% vs 45.7%, P = .009). In conclusion, the addition of GO to intensive chemotherapy in NPM1mut AML resulted in a significantly better reduction in NPM1mut TLs across all treatment cycles, leading to a significantly lower relapse rate.