MRD-positive Group Research Articles

Allogeneic stem cell transplantation in de novo core-binding factor acute myeloid leukemia in first complete remission: data from the EBMT.

Core-binding factor acute myeloid leukemia (CBF-AML) represents 12-15% of all AML cases. Although CBF positivity infers a survival advantage, overall survival (OS) remains dismal. Treatment is with cytarabine/anthracycline-based chemotherapy induction followed by high-dose cytarabine (HiDAC) consolidation. Allogeneic hematopoietic stem cell transplantation (allo-SCT) is reserved for relapse or for patients having not achieved MRD-negativity at high risk for relapse. The role of SCT in first complete remission (CR1) remains controversial and is considered in high risk conditions. In this retrospective, multi-national, European Society for Blood and Marrow Transplantation (EBMT)-based study, we identified 1901 patients with de novo CBF-AML who received an allo-SCT or autologous transplantation (ASCT) in CR1. 65.5% harbored t(8;21) and 34.4% inv(16). In this group, the majority (77%) were treated with allo-SCT in CR1. In multivariate analysis, treatment with allo-SCT was an independent and significant, negative predictor of NRM and OS (HR 4.26, p < 0.0001 and HR 1.67, p = 0.003) and among patients treated with allo-SCT, those treated with MSD had the best outcomes, comparable to those treated with ASCT.There was no interaction between the type of transplant and MRD status at time of SCT. In both, MRD-negative and MRD-positive groups, NRM was worse in the allo-SCT group (MRD-: 12.9% vs 5.2%, p = 0.007; MRD+: 10.6% vs 0%, p = 0.004). We therefore demonstrated that consolidation in CR1 with allo-SCT results in worse outcomes than ASCT. Whether consolidation with ASCT yields better outcomes than chemotherapy alone or chemotherapy in combination with Gemtuzumab Ozogamicin is yet to be investigated.

Efficacy and safety of venetoclax combined with decitabine, modified HA regimen and DLI in the treatment of relapsed pediatric AML/MDS after allogeneic hematopoietic stem cell transplantation

Objective: To investigate the efficacy and safety of venetoclax combined with the decitabine, cytarabine, and homoharringtonine (HHT) regimen and donor lymphocyte infusion (DLI) for the preventive and salvage therapy of pediatric acute myeloid leukemia (AML) /myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (HSCT) . Methods: A total of 29 relapsed pediatric/minimal residual disease-positive AML after HSCT were recruited at the Peking University Institute of Hematology from January 1, 2021, to June 1, 2023. They were treated with the above combination regimen and administered with DLI after 24-48 hours at the end of chemotherapy, and the treatment response and adverse reactions were regularly assessed. Results: The overall response rate (ORR) was 75.8%, CR rate was 88.9% (8/9) in the hematologic relapse group, and MRD negativity rate was 61.1% (11/18) in the MRD-positive group. The incidence of agranulocytosis, anemia, and thrombocytopenia with a classification above grade 3 were 100%, 82.7%, and 100%, respectively. The median time of the granulocyte deficiency period was 15 days. Acute graft-versus-host diseases (aGVHD) with a classification of grades Ⅲ-Ⅳ occurred in 11.1% of the patients after DLI, while moderate or severe cGVHD occurred in 7.4% of the patients. The single risk factor for ORR was MNC counts of less than 10×10(8)/kg, and the relapse occurred within 100 days. At a median follow-up of 406 days, the 1-year OS was 65%, and the 1-year OS was 57% in the group with no reaction (P=0.164) compared with 71% in the group who had an overall reaction. Conclusion: The combined regimen based on the DAC, VEN, and modified HA regimen showed a high response rate in the salvage therapy for pediatric AML after the relapse of HSCT. However, bridging to transplantation should be performed immediately after remission to result in a long survival rate.

Survival benefit of adjuvant chemotherapy based on molecular residual disease detection in resected colorectal liver metastases: subgroup analysis from CIRCULATE-Japan GALAXY

The prognostic role of circulating-tumor DNA (ctDNA)-based molecular residual disease (MRD) detection and its utility for postsurgical risk-stratification has been reported in colorectal cancer. In this study, we explored the use of ctDNA-based MRD detection in patients with colorectal liver metastases (CLM), for whom the survival benefit of adjuvant chemotherapy (ACT) after surgical resection remains unclear. Patients with CLM without extrahepatic disease from GALAXY study (UMIN000039205) were included. The disease-free survival (DFS) benefit of ACT was evaluated in MRD-positive and -negative groups after adjusting for age, gender, number and size of liver metastases, RAS status, and previous history of oxaliplatin for primary cancer. ctDNA was detected using a personalized, tumor-informed 16-plex mPCR-NGS assay. ctDNA-based MRD status was evaluated 2 to 10 weeks after curative surgery, before the start of ACT. Among 6,061 patients registered in GALAXY, 190 surgically resected CLM patients without any preoperative chemotherapy were included with a median follow-up of 24 (1-48) months. ctDNA positivity in the MRD window was 32.1% (61/190). ACT was administered to 25.1% (48/190) of patients. In the MRD-positive group, 24-month DFS was higher for patients treated with ACT (33.3% vs. not reached, adjusted HR: 0.07, P <0.0001); whereas no benefit of ACT was seen in the MRD-negative group (24-month DFS: 72.3% vs. 62.2%, adjusted HR: 0.68, P =0.371). Multivariate analysis showed that the size of liver metastases (HR: 3.94, P =0.031) was prognostic of DFS in the MRD-positive group. However, in the MRD-negative group, none of the clinicopathological factors were prognostic of DFS. Our data suggest that ACT may offer notable clinical benefits in MRD-positive patients with CLM. MRD status-based risk-stratification could be potentially incorporated in future clinical trials for CLM.

Single-cell immune landscape of measurable residual disease in acute myeloid leukemia.

Measurable residual disease (MRD) is a powerful prognostic factor of relapse in acute myeloid leukemia (AML). We applied the single-cell RNA sequencing to bone marrow (BM) samples from patients with (n=20) and without (n=12) MRD after allogeneic hematopoietic stem cell transplantation. A comprehensive immune landscape with 184,231 cells was created. Compared with CD8+ T cells enriched in the MRD-negative group (MRD-_CD8), those enriched in the MRD-positive group (MRD+_CD8) showed lower expression levels of cytotoxicity-related genes. Three monocyte clusters (i.e., MRD+_M) and three B-cell clusters (i.e., MRD+_B) were enriched in the MRD-positive group. Conversion from an MRD-positive state to an MRD-negative state was accompanied by an increase in MRD-_CD8 clusters and vice versa. MRD-enriched cell clusters employed the macrophage migration inhibitory factor pathway to regulate MRD-_CD8 clusters. These findings revealed the characteristics of the immune cell landscape in MRD positivity, which will allow for a better understanding of the immune mechanisms for MRD conversion.

Investigation of the immune profile of multiple myeloma patients achieving long-term survival after autologous stem cell transplantation

Objective: To identify the characteristics of the bone marrow immune microenvironment associated with long-term survival in multiple myeloma (MM) patients. Methods: In the follow-up cohort of patients with newly diagnosed MM and who received "novel agent induction therapy and subsequent autologous stem cell transplantation and immunomodulator maintenance therapy" in the First Affiliated Hospital of Sun Yat-sen University, a cross-sectional study was carried out between August 2019 and May 2020. Using NanoString technology, the RNA expression of 770 bone marrow immune-related markers was compared between 16 patients who had progression-free survival ≥5 years and 5 patients with progressive disease. Among the 16 patients who achieved long-term survival, 9 achieved persistent minimal residual disease (MRD) negative while the other 7 had persistent positive MRD. The functional scores of each kind of immune cells were calculated based on the expression level of characteristic genes, so as to indirectly obtained the proportion of each immune cell subset. The Mann-Whitney U test and the Kruskal Wallis test were used for statistical analysis. Results: The proportion of neutrophils was significantly higher in long-surviving MM patients than in patients with progressive disease [functional scores, 13.61 (13.33, 14.25) vs. 12.93 (12.58, 13.38); Z=2.31, P=0.021]. Among long-surviving patients, those who were MRD-positive had a significantly greater number of mast cells compared with those who were MRD-negative [functional scores, 7.09 (6.49, 8.57) vs. 6.03 (5.18, 6.69); H=2.18, P=0.029]. Compared with patients with progressive disease, four genes (CTSG, IFIT2, S100B, and CHIT1) were significantly downregulated and six (C4B, TNFRSF17, CD70, IRF4, C2, and GAGE1) were upregulated in long-surviving patients. Among long-surviving patients, only gene CMA1 was significantly upgraded, 10 genes (ISG15, OAS3, MX1, IFIT2, DDX58, SIGLEC1, CXCL10, IL1RN, SERPING and TNFSF10) were significantly downregulated in the MRD-positive group compared with that in the MRD-negative group, the first 5 of which are related to the interferon response pathway. Conclusions: The increased neutrophil and mast cell numbers may be related to long-term survival in MM. Interferon signaling activation may be a key bone marrow immune profiling feature for MRD-negative, long-surviving patients with MM.

Evaluating the safety and efficacy of cryopreserved ovarian tissue transplantation in leukemia patients with different bone marrow remission status using xenotransplantation.

Leukemia patients undergoing cryopreserved ovarian tissue transplantation (OTT) may carry a high risk of disease induction. Measurable residual disease (MRD) in bone marrow is linked to an elevated risk of relapse. It is controversial whether leukemia patients must be allowed to achieve measurable residual disease negative (MRD-negative) status instead of measurable residual disease positive (MRD-positive) status before ovarian tissue cryopreservation (OTC). To explore the safety and efficacy of OTT in acute leukemia patients with different MRD status by using xenotransplantation. Cryopreserved ovarian tissue from 19 leukemia patients was thawed and xenotransplanted to ovariectomized BALB/C nude mice (n=36). The mice were divided into 2 groups based on the patient's MRD status before OTC: MRD-negative group (n=18) and MRD-positive group (n=18), additionally, a control group consisted of ovariectomized mice (n=9). Body weight was measured weekly and mortality, emaciation, and other abnormalities were recorded. Twenty-six weeks post-surgery, livers, spleens, uteruses, and ovarian grafts were removed for macroscopic and histological examinations to evaluate the efficacy of xenotransplantation and assess malignant cell contamination in mice. Follicle growth was visible in the ovarian grafts of the MRD-negative and MRD-positive groups. Compared with the ovariectomized group, a significant decrease in body weight (p<0.01) was noted, the uterine volume was notably larger, estradiol (E2) levels were significantly higher (p<0.01), and follicle-stimulating hormone (FSH) levels were significantly lower (p<0.001) in the other two groups. Mice in the MRD-positive group showed a significantly higher incidence of death (p<0.001) and emaciation (p<0.01), compared to the MRD-negative group. Histological observation revealed the presence of malignant cells in the grafts, livers, and spleens of 3 mice in the MRD-positive group. No abnormalities were observed in the mice from the MRD-negative group in both macroscopic and histological observations except one mouse was sacrificed for ascites unrelated to leukemia relapse. For leukemia patients having ovarian tissue preserved in the first and only centralized human ovarian tissue cryobank in China, immunodeficient mice xenotransplantation can be a method to evaluate the safety and efficacy of OTT; the risk of malignant cell reimplantation due to OTT is higher in leukemia patients with MRD-positive status than those with MRD-negative status before OTC.

Intensified conditioning regimens with total marrow irradiation/etoposide/cyclophosphamide and busulfan/etoposide/cyclophosphamide overcome the impact of pre-transplant minimal residual disease on outcomes in high-risk acute lymphoblastic leukemia patients in complete remission.

Among high-risk acute lymphoblastic leukemia (ALL) patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), those with positive minimal residual disease (MRD) are susceptible to poor outcomes. Therefore, it is necessary to determine the most suitable preparatory regimen for these patients. Data were analyzed from 141 patients who received allo-HSCT and were diagnosed with high-risk ALL. These patients underwent intensified conditioning regimens, including either total marrow and lymphoid irradiation (TMLI)-etoposide (VP16)-cyclophosphamide (CY) or busulfan (BU)-VP16-CY between October 2016 and November 2022. A total of 141 individuals were in complete remission (CR) before transplantation and, among all patients, 90 individuals exhibited a negative MRD status and 51 patients had a positive MRD status. In patients who tested negative for MRD, the incidence of relapse within a 2-year timeframe was 25.0% (24.8%-25.5%), compared with 32.2% (31.2%-33.2%) in MRD-positive patients; however, this difference was not statistically significant. There were no significant differences in the 2-year disease-free survival (DFS) and 2-year overall survival (OS) rates between the MRD-negative and MRD-positive groups (DFS: 67.2% (57.9%-78.1%) vs. 55.5% (42.6%-72.3%); OS: 69.0% (61.9%-88.2%) vs. 66.7% (53.9%-82.5%)). Furthermore, no notable variations were observed in the occurrence of transplant-related mortality (TRM) and graft-versus-host disease (GVHD) across the two groups. This study reveals the benefits of TMLI-VP16-CY and BU-VP16-CY conditioning regimens in high-risk ALL patients with CR and MRD-positive status. A large-scale prospective clinical trial is warranted in the future.

Impact of pretransplant minimal residual disease in patients with multiple myeloma and a very good partial response or better receiving autologous hematopoietic stem cell transplantation.

The prognostic significance of minimal residual disease (MRD) status before autologous hematopoietic stem cell transplantation (autoHCT) in patients with multiple myeloma (MM) has not been clearly elucidated. Retrospective single-center study of adult MM patients who achieved ≥very good partial response (VGPR) after induction therapy from 2015 to 2021 received upfront autoHCT and had available pretransplant MRD status by next-generation flow cytometry. The cohort was divided into pretransplant MRD-negative (MRDneg) and MRD-positive (MRDpos) groups. A total of 733 patients were included in our analysis; 425 were MRDneg and 308 MRDpos at autoHCT. In the MRDpos group, more patients had high-risk cytogenetic abnormalities (48% vs. 38%, respectively; p=.025), whereas fewer patients achieved ≥CR before autoHCT (14% vs. 40%; p<.001). At day 100 after autoHCT, 37% of the MRDpos versus 71% of the MRDneg achieved ≥CR, and at best posttransplant response 65% versus 88% achieved ≥CR, respectively. After a median follow-up of 27.6months (range, 0.7-82.3), the median PFS was significantly shorter for patients in the MRDpos group compared to the MRDneg group: 48.2months (95% confidence interval [CI], 0.3-80.5) versus 80.1months (95% CI, 0.5-80.1), respectively (p<.001). There was no significant difference in overall survival between the two groups (p=.41). Pretransplant MRDpos status was predictive of shorter PFS in multivariate analysis (hazard ratio, 1.80; 95% CI, 1.31-2.46; p<.001). The impact of pretransplant MRD status was retained in most of the examined subgroups. In patients achieving ≥VGPR to induction, pretransplant MRDpos status was associated with a lower CR rate after autoHCT and a shorter PFS.

Evaluation of the Impact of the Disease Risk Index and Pre-Transplant Measurable Residual Disease By Flow Cytometry As Prognostic Factors in Allogeneic Hematopoietic Cell Transplantation in Patients with Acute Myeloid Leukemia

Introduction: Allogeneic hematopoietic cell transplantation (HCT) is the therapy with the best curative potential for patients with intermediate/high-risk acute myeloid leukemia (AML). Although many factors may influence the outcomes of allogeneic HSCT, risk stratification and disease status at the time of transplant are two of the strongest prognostic factors of post-transplant survival². In this context, the Disease Risk Index (DRI) was developed and validated in a cohort of more than 13.000 patients and stratifies patients into 4 groups with different overall survivals (OS)². Measurable residual disease (MRD) is also an important and consolidated biomarker for the prognosis, monitoring, and treatment effectiveness evaluation³. Objective: To compare the impact of the pre-transplant DRI and MRD in patients with AML in OS and leukemia-free survival of patients treated with allogeneic HSCT in a private institution in Brazil from January 2017 to May 2023. Methods: This is a retrospective, unicentric study. MRD was evaluated immediately before transplantation by 10-color flow cytometry and was considered positive if ≥0.1%. DRI was grouped into two groups: low/intermediate risk and high/very high risk. Statistical analyzes were performed using the Cox regression model. Results: With a median follow-up of 18 months, a total of 57 patients were included, 34 of whom had negative MRD and 23, positive. The mean ages in these groups were 55 and 60 years, respectively. HCT-CI was 0-2 in 91% of the patients in the MRD-negative group, and in 78% of the MRD-positive group. The type of donors was similar in both group (MRD positive or negative): 20-30% of related donors, 25-40% of haploidentical and 40-45% unrelated donors. The reduced-intensity conditioning regimen (RIC) was the used in 70% of the patients. In the MDR + group, peripheral stem cell source was more used than in the MDR negative group. In univariate analysis, DRI had an impact on overall survival (OS) with an HR=3.52 (95%CI 1.46 - 8.5) and p=0.075 for low/intermediate risk compared with high/very high risk, while in the multivariate analysis this impact was not maintained with HR=2.31 (95%CI 0.92 - 5.82) and p=0.075. A pre-transplant positive MRD was a risk factor for death in univariate analysis, with an HR=5.99 (95%CI 2.93- 26.82) and p&amp;lt;0.001. The impact of MRD HR 8.87 (2.93 - 26.83) and p &amp;lt; 0.001, age HR 1.09 (1.04 - 1.15) with p = 0.001 and bone marrow source HR 0.29 (0.08 - 1.06) are prognostic factors even when controlled for age, cell source and type of transplant. One-year overall survival in the MRD-negative group was 90% (79-100%), and 53% (36-80%) in the MRD-positive group. Additionally, one-year leukemia-free survival in the MRD-negative group was 70% (55-89%) and 45% (28-72%) in MRD-positive. Conclusion: Our results show that both DRI and pre-transplant MRD may have an impact on OS and LFS, although pre-transplant MRD seemed to perform better than DRI in multivariable analysis in patients with acute myeloid leukemia undergoing hematopoietic cell transplantation.

The Prognostic Significance of 1-Year Persistent MRD Negativity in Chinese ALL Patients: 5-Year Follow-up Results from RJ-ALL 2014 Trial

Background Minimal residual disease (MRD) monitoring is an important predictor of outcomes in acute lymphoblastic leukemia (ALL), and flow cytometry is widely used to monitor MRD with a detection depth of 10 -4~10 -5. Post induction MRD is the most commonly applicated timepoint for risk stratification of ALL. About half of the patients (pts) with post induction CR/CRi achieved simultaneous MRD negativity, however, among them some pts subsequently relapse. Thus, how to better interpret the MRD results has always been a topic of interest among clinicians. Hence, in this report, we monitored MRD at different timepoints and focus on the 1-year persistent MRD negativity and its impact on the prognosis. Method In this prospective long-term follow-up study, we analyzed 202 cases of Ph/BCR-ABL1 negative BCP-ALL. All pts were treated with RJ-ALL 2014 protocol as follow: The induction regimen was VDPCP, the consolidation regimen was hyper-CVAD + Pegasparagase (PEG) and the maintenance regimen was POMP + PEG. CNS prophylaxis was integrated. Pts eligible for allogeneic hematopoietic stem cell transplantation (allo-HSCT) were recommended to transplant. MRD was monitored by 8-color flow cytometry. MRD negativity is defined as MRD &amp;lt; 10 -4. MRD monitoring was performed at the end-of-induction (EOI), the 3 rd month and every 3 months afterwards during 5 years. 1-year persistent MRD negativity (1-yr-MRDneg) was defined as sustained 1-year MRD negative from EOI or 3 rd month. Results From May 2014 to Nov 2021, a total of 202 pts were enrolled. The median age of pts at diagnosis was 35 years (range 14~65). After induction, 179 / 193 (92.7%) pts achieved CR/CRi, among them 102 (57%) pts were MRD negative (MRDneg). There were 9 (4.5%) early death during induction due to hemorrhage or infection. At the third month, 171 pts were in CR/CRi, among them, 120 (75%) of the 160 evaluable pts were MRDneg. At one year, 123 pts were in CR/CRi, among them, 48 (70.6%) of the 68 evaluable pts were MRDneg. By Jul 2023, the median follow-up time was 56 months. Ten pts were lost to follow-up. The 5-yr OS rate is 52.6% and the 5-yr RFS rate is 50.7%. Regarding the EOI MRD status, the MRDneg group trend to have better OS (5-yr OS 63.6% vs 51.2%, p=0.128) and RFS (5-yr RFS 53.4% vs 48%, p=0.088) compare to MRD positive (MRDpos) group. Regarding the MRD status at the third month, the OS (5-yr OS 66.9% vs 38.4%, p=0.000) and RFS (5-yr RFS 64.6% vs 28.2%, p=0.000) of MRDneg group was significantly better than that of MRDpos group. Totally, 80 pts received allo-HSCT, among them, 78 pts achieved CR and 49 pts were MRDneg before HSCT. After HSCT, 18 pts relapsed and 22 pts died, among them 7 pts died of relapse and 15 pts dead of treatment toxicity. For transplanted pts, the 5-yr OS rate is 65% and the 5-yr RFS rate is 58.6%. We further analyzed the 1-year persistent MRD status of non-transplanted pts. Among 113 non-transplanted pts, 68 pts had 1-year complete MRD data. Of which 48 pts had 1-yr-MRDneg and 20 pts had rising MRD within 1 year. For pts with 1-yr-MRDneg, 5-yr OS rate is 86.9% and 5-yr RFS rate is 85.7%. For pts with rising MRD, 5-yr OS rate is 11.3% and 5-yr RFS rate is 16.7%. Comparing their survival with transplanted pts we found that the OS and RFS of non-transplanted 1-yr-MRDneg pts were significantly better than allo-HSCT (OS p&amp;lt;0.01, RFS p&amp;lt;0.01), and allo-HSCT were significantly better than non-transplanted pts with rising MRD within 1 year (OS p&amp;lt;0.01, RFS p&amp;lt;0.01) (figure 1). Conclusion In this long-term follow-up study, we found that in Ph/BCR-ABL1 neg patients, 1-year persistent MRD negativity is a stronger prognostic predictor than EOI or 3 rd month MRD negativity. Non-transplanted pts with 1-yr persistent MRD negativity have better 5-year survival than those who receive allo-HSCT, suggesting that pts with 1-yr persistent MRD negativity may be spared from allo-HSCT.

Stem Cell Autograft Minimal Residual Disease Negativity Improves Outcomes after Autotransplant for Multiple Myeloma

Background: Autologous hematopoietic stem cell transplantation (AHCT) in the up-front setting is the standard-of-care for newly diagnosed multiple myeloma (NDMM). Contemporary induction regimens generate deeper responses, with higher rates of minimal residual disease (MRD) negativity in the bone marrow (BM) leading to improved progression-free survival (PFS) and overall survival (OS). However, it is unclear whether stem cell autograft (AG) contamination with myeloma cells and/or their precursors contributes to relapse after AHCT. To address this, we examined MM contamination of AG by next-generation flow cytometry (NGF) to determine the predictive value of AG MRD status on outcomes after AHCT. Methods: This study included 119 NDMM patients with prospectively collected BM and AG MRD results by NGF who underwent stem cell collection and up-front AHCT at our institution between Sept 2017 and Feb 2020. AG MRD status was assessed in peripheral blood at the time of stem cell collection (SCC). BM MRD status was assessed post-induction/pre-SCC and at 3-months post-AHCT. Additional BM MRD results were also available at 1- and 2-years post-AHCT for most patients. Patients were dichotomized based on AG MRD status (negative vs positive). A Kaplan-Meier model compared median PFS and OS between cohorts. A cox proportional hazards model determined prognostic impact, adjusting for high-risk cytogenetics by FISH and induction therapy. Results: Baseline characteristics were balanced between the MRD-negative and positive groups, with median age at AHCT of 61 (range, 55-67) years in the MRD-negative group and 60 (range, 54-67) years in the MRD-positive group. Patients received a median of 6 (range, 2-12) induction cycles with daratumumab, carfilzomib, lenalidomide, and dexamethasone (D-KRd, n=20), KRd (n=38), bortezomib, lenalidomide, and dexamethasone (VRD, n=51), or other therapy (n=10). Patients with MRD-positive AG were not enriched for high-risk cytogenetics. AG MRD-negativity rates after D-KRd, KRd, VRd, and other therapy were 95.0%, 78.9%, 58.8%, and 50%, respectively. All patients with MRD-positive AG (n=35) also had MRD-positive pre-AHCT BM, whereas 71% of patients with MRD-negative AG had MRD-positive pre-AHCT BM (p <0.001). Sustained or conversion to MRD-negativity in the BM at 3-months and 1-year post-AHCT was observed more for patients with MRD-negative AG than MRD-positive AG (40% vs 9%). At a median follow-up of 40 months (range 33- 46) after AHCT, patients with MRD-negative AG, compared with MRD-positive AG counterparts, had a significantly improved PFS (3-y PFS 78%, CI: 69 ‒ 87, vs. 54%, CI: 39 ‒ 73, p=0.021)(Fig1A) and trend toward better OS (3-y OS 96%, CI: 92 ‒ 100, vs. 82%, CI: 70 ‒ 96)(Fig1B) . The 3-year PFS of the MRD-negative AG group treated with D-KRd, KRd, VRd, and other therapy were 84% (CI: 69 ‒ 100), 79% (CI: 65 ‒ 96), 76% (CI: 71 ‒ 98), and 60% (CI:29 ‒ 100), respectively, while for the MRD-positive AG group treated with KRd, VRd, and other therapy (no D-KRd in this group), 3-year PFS rates were 73% (CI: 47 ‒ 100), 57% (CI: 39 ‒ 83), and 20% (CI:3.5 ‒ 100), respectively (p = 0.4). The 3-year PFS for patients with or without high-risk cytogenetics were 59% (CI: 44 ‒79) and 90% (CI: 81 ‒ 100), respectively, in the MRD-negative AG group, and 40% (CI: 22 ‒ 74) and 67% (CI: 49 ‒ 93), respectively, in the MRD-positive AG group (p = 0.002). The 3-year OS rates were 93% (CI: 85 ‒ 100) and 100% (CI: 100 ‒ 100) for the MRD-negative AG group and 76% (CI: 61 ‒ 100) and 84% (CI: 69 ‒ 100) for the MRD-positive group (p not calculated). On univariate analysis of PFS, the presence of high-risk cytogenetics (HR 3.2, CI: 1.55 ‒ 6.57), R-ISS stage (HR 3.01, CI 1.42 ‒6.41 for R-ISS=3), and AG MRD positive (HR 2.14, CI: 1.10 ‒ 4.16) were significant prognostic factors. Multivariate analysis identified high-risk cytogenetics (HR 3.16, CI: 1.51 ‒ 6.60) as the only significant factor for PFS. Conclusion: Patients with MRD-negative AG have improved PFS and OS following AHCT. These findings support the potential utility of AG MRD status as a prognostic parameter for clinical outcomes, with implications for guiding post-AHCT therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Association of hematologic response and assay sensitivity on the prognostic impact of measurable residual disease in acute myeloid leukemia: a systematic review and meta-analysis.

Measurable residual disease (MRD) is associated with relapse and survival in acute myeloid leukemia (AML). We aimed to quantify the impact of MRD on outcomes across clinical contexts, including its association with hematologic response and MRD assay sensitivity. We performed systematic literature review and meta-analysis of 48 studies that reported the association between MRD and overall survival (OS) or disease-free survival (DFS) in AML and provided information on the MRD threshold used and the hematologic response of the study population. Among studies limited to patients in complete remission (CR), the estimated 5-year OS for the MRD-negative and MRD-positive groups was 67% (95% Bayesian credible interval [CrI], 53-77%) and 31% (95% CrI, 18-44%), respectively. Achievement of an MRD-negative response was associated with superior DFS and OS, regardless of MRD threshold or analytic sensitivity. Among patients in CR, the benefit of MRD negativity was highest in studies using an MRD cutoff less than 0.1%. The beneficial impact of MRD negativity was observed across MRD assays and timing of MRD assessment. In patients with AML in morphological remission, achievement of MRD negativity is associated with superior DFS and OS, irrespective of hematologic response or the MRD threshold used.

ALL-237 Bortezomib and Rituximab in De Novo Adolescent/Adult CD20-Positive, Ph-Negative Pre-B-Cell Acute Lymphoblastic Leukaemia: Updated 3-Year Results

CD20 expression in B-cell precursor acute lymphoblastic leukemia (B-ALL) is associated with inferior outcomes. Treatment approaches involve the incorporation of rituximab (variable doses and scheduling between trials), intensification of chemotherapy, and allogeneic stem cell transplant in patients who continue to remain MRD- positive post-induction. Treatment intensification with chemotherapy or allogeneic stem cell transplantation for EOI MRD-positive patients is limited in resource constraint areas due to cost and infection-related morbidity and mortality. Hence, there is an unmet need to identify active and safe drugs to improve EOI MRD negative rates which can reduce the need for transplant and chemotherapy intensification. To test the activity of bortezomib and rituximab in combination with a pediatric-inspired regimen during induction therapy in newly diagnosed adolescents and adults (aged >14 years) with CD20 positive, Philadelphia-negative precursor B-ALL. Here we present updated results with longer follow up. Single-center, phase 2, nonrandomized open-label trial (Simon's two-stage design) conducted between December 2017 and August 2019. The primary endpoint of the study was the rate of (end of induction) EOI BM-MRD negativity. Secondary endpoints were EFS and OS. A total of 35 patients were enrolled between December 2017 and August 2019. EOI MRD negative rates were 70.1% compared with 51.7% in a historical cohort treated with chemotherapy. On longer follow up (median follow up 38months), 3-year EFS and OS rates were 75.6% (95% CI 62.3-91.9%), and 75.6% (95% CI 62.3-91.9%) respectively. 3-year rates of EFS based on post-induction (week 4) MRD status was 55.6% (31-99.7%) in MRD positive group compared with 86.1% (72.7-100%) in MRD negative group. 3-year rates of OS based on EOI MRD status was 55.6% (31-99.7%) in MRD positive group compared with 86.1% (72.7-100%) in MRD negative group. The median OS for patients who attained CR was not reached versus 8 months in patients who fail to achieve CR. On longer follow-up, the activity of the combination of bortezomib and rituximab is maintained without any new safety concerns. EOI MRD positivity and lack of complete remission post-induction are strong predictors of poor outcomes.

Prognostic impact of natural killer cell recovery on minimal residual disease after autologous stem cell transplantation in multiple myeloma

IntroductionNatural killer cells are a potent effector lymphocyte subset that can induce cytotoxicity without the need for antigen sensitization or presentation. NK cells are a tempting target –for immune therapy, monoclonal antibody, or genetic engineering-to enhance immune surveillance mechanisms against myeloma cells. Materials and methodsWe hypothesized an association between natural killer cell recovery after autologous stem cell transplantation (ASCT) and disease outcomes in multiple myeloma patients.We concluded a prospective study that started enrolling patients in January 2020 to identify the association between absolute NK cell count two to three after ASCT and disease outcomes after autologous stem cell transplantation in multiple myeloma using univariate and multivariate analysis. ResultsNatural killer cell recovery was evaluated during the third month after ASCT, day +60 to +90 post-ASCT. Our patients had a mean NK cell count of 90.53, ranging from 14 to 282 Cell/μL (Std Dev 84.64 Cell/μL). The odds of having a minimal residual disease (MRD-positivity) among patients with partial remission before transplantation is four times higher than patients with very good partial response or better (95% confidence interval 0.45–35.79). Our patients were classified into two groups based on MRD status after ASCT, an MRD-negative group of eight participants and an MRD-positive group of seven participants. The mean absolute NK cell count was significantly higher in the MRD-negative cohort, 131.38 Cell/μL, versus 43.86 Cell/μL in the MRD-positive group (p = 0.049). ConclusionWe conclude that for multiple myeloma patients treated with ASCT, high absolute NK cell counts two to three months after ASCT is an independent predictor for MRD negativity.

Longitudinal Assessment and Prognostic Importance of Minimal Residual Disease (MRD) By Multiparametric Flow Cytometry in Patients with Systemic Light Chain (AL) Amyloidosis

Background:Minimal residual disease (MRD) assessment can provide an index of robust disease control, particularly if MRD negativity is sustained over time. Whereas MRD status has well-established prognostic implications in multiple myeloma, its role in light chain (AL) amyloidosis-a related but biologically distinct plasma cell disorder-is presently under investigation.Aims:The aims of our study were to evaluate (1) major organ deterioration-progression-free survival (MOD-PFS) based on MRD status and (2) MRD evolution patterns during disease surveillance for patients with AL amyloidosis in hematologic complete response (hemCR) after therapy.Methods:We established MRD status using multiparametric 10-color flow cytometry of bone marrow aspirates. At least 2 x 10 6 events were measured using a Beckman Coulter Navios Flow Cytometer and analyzed by Kaluza Software (sensitivity level of ≤10 -5). Sequential MRD testing was performed (≥12 months apart) for patients returning for follow-up. We evaluated hematologic and organ responses or progression based on consensus guidelines (Palladini, 2012). MOD-PFS was defined as time from hemCR achievement to major organ deterioration (i.e., the kidney or heart), hematologic progression or death from any cause (whichever occurred first). Presence of MRD was not used to guide treatment decisions.Results:A total of 96 patients with hemCR after therapy were tested, of whom 46 (48%) were MRD negative and 50 (52%) MRD positive on first assessment. The median estimated clone size for those with MRD positivity was 3.4 x 10 -4 (range 1.4 x 10 -5 to 5.7 x 10 -3). Baseline characteristics were similar between groups, except for greater use of daratumumab and ≥2 lines of therapy to achieve hemCR in the MRD-negative group. MRD positivity correlated with a higher level of involved free light chains (iFLC) in the serum at the time of MRD assessment (23.4 mg/L vs 17.3 mg/L, P = .011). In regard to organ responses, patients with MRD negativity had a significantly higher rate of renal response (91% vs 67%, P = .017) but a similar rate of cardiac response (74% vs 68%, P = .668).After a median follow-up of 50 months from hemCR achievement, the MRD-negative group demonstrated a superior MOD-PFS (HR 0.38, 95% CI 0.16-0.88, P = .034). Progression or organ deterioration events in the MRD-negative group occurred early after hemCR achievement, while in the MRD-positive group these events continued to occur over time. A total of 8 patients had died, including 4 in each group.Sequential MRD testing (median 12 months apart, range 12-28 months) was performed for 43 patients, of whom 16/19 (84%) had sustained MRD negativity; 21/24 (88%) had persistent MRD positivity; and 6/43 (14%) had MRD conversion. No patient received therapy between MRD assessments. Among those with sustained MRD negativity, there were 2 major organ deterioration events. The 3 patients who experienced loss of MRD negativity (which occurred at 12, 107 and 114 months after last treatment) had no progression or organ deterioration events. Of those with persistent MRD positivity, 13 (62%) had durable hemCR and organ responses; moreover, 4/14 (29%) and 1/11 (9%) of these patients attained even deeper renal and cardiac responses, respectively, in the interval between sequential MRD testing. Clone progression (defined as >1-log growth in MRD clone size) was observed in 3/21 (14%) patients with persistent MRD positivity, none of whom demonstrated hematologic relapse.Conclusions:We evaluated the dynamics of MRD status in relation to clinical outcomes and found that patients with MRD negativity had longer survival free from hematologic progression, major organ deterioration or death. Longer prospective follow-up is needed to determine whether this translates into an overall survival benefit. MRD conversion occurred in a small proportion (14%) of patients, but was not linked to adverse outcomes. Understanding the role of cross-sectional MRD testing for clinical disease tracking in AL amyloidosis requires further analysis with larger sample size. [Display omitted] DisclosuresSanchorawala: Prothena: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Research Funding; Pfizer: Honoraria; Karyopharm: Research Funding; Sorrento: Research Funding; Celgene: Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees, Research Funding; Regeneron: Membership on an entity's Board of Directors or advisory committees; Proclara: Membership on an entity's Board of Directors or advisory committees; Oncopeptide: Research Funding.

MRD abnormal expression predict poor outcomes for refractory or relapsed acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

We retrospectively analyzed data from 197 patients with refractory or relapsed acute myeloid leukemia (r/rAML) who underwent allo‐HCT between January 2013 and February 2020 in our center (patients with promyelocytic leukemia were excluded). Of all patients, 86 achieved a complete morphological remission (CR) before transplant, while 111 failed to do so (NR). In the CR group, 32 patients displayed minimal residual disease (MRD‐positive). According to their immunophenotype pre‐HCT, we divided the MRD‐positive group and NR group into three subgroups: MRD 0+ group (without any antigen abnormal expression of CD7+, CD56+, CD38−, or HLA‐DR−) 28 patients, MRD 1+ group (with one abnormal antigen expression of CD7+, CD56+, CD38−, or HLA‐DR−) 63 patients, MRD 2+ group (with two or more abnormal antigens expression of CD7+, CD56+, CD38‐, or HLA‐DR‐) 52 patients. 3‐year estimates of disease‐free survival (DFS) for MRD 0+, MRD 1+ and MRD 2+ patients were 59.5 ± 9.5%, 29.9 ± 6.1%, and 9.4 ± 5.1%, and 3‐year estimates of overall survival (OS) were 59.5 ± 9.5%, 34.5 ± 6.3%, and 14.5 ± 10.8%, respectively. Multivariate analysis adjusted for genetic risk, blast cell level, secondary disease, age, sex, and donor relationship pre‐HCT, the hazard ratios of abnormal expression of CD7+, CD56+, HLA‐DR−, and CD38‐ were 6.69 (range 2.08–21.52; p = 0.001) for DFS, 2.24 (range 1.21–4.14; p = 0.010) for OS, and 7.18 (range 2.23–23.10; p = 0.001) for relapse compared with CD7−, CD56−, HLA‐DR+, and CD38+ patients. Our finding suggested that abnormal expression of CD7+, CD56+, HLA‐DR−, and CD38− is associated with poor outcomes, and the more number of abnormal antigens expression predict worse outcomes.

The Duration of MRD-Negative Status in Multiple Myeloma (MM) Patients after Auto-HSCT Is a Criterion for Prolonged Remission without Maintenance Therapy

Background:Achievement of MRD-negative status in MM patients following auto-HSCT is a prognostic factor that has a positive effect on relapse-free survival (RFS). However, the time after which the loss of MRD-negative status occurs have not been established so far. The duration of MRD-negative status can be expected to allow determination of the necessity and duration of maintenance therapy (MT) received by MM patients who have achieved a stringent complete remission (CR) following auto-HSCT.Aims: To evaluate the duration of MRD-negative status achieved in MM patients following auto-HSCT; to assess the effects of MRD-negative status achievement on RFS and treatment-free survival (TFS).Patients and Methods: From March 2014 to October 2016, 29 patients with MM (12 males and 17 females) aged 40 to 66 years (median 56 years) who had achieved CR, following auto-HSCT, were enrolled in this prospective study. Disease stages (ISS) were as follows: stage I, II and III were observed in 9, 11 and 9 patients, respectively. Induction of remission included bortezomib-containing regimens (VCD, PAD) in all 29 patients. Immunomodulatory drugs and bendamustine were each used twice. Distribution of patients by type of anti-tumor responses (IMWG) after induction was as follows: CR, very good partial remission and partial remission were observed in 16 (55%), 12 (41%) and 1 (4%) patients, respectively. Single and tandem auto-HSCT were conducted in 25 and 4 patients, respectively. In order to determine MRD status, bone marrow examination using a six-color flow cytometric assay was performed on Day 100 following auto-HSCT with the use of an antibody panel to the following antigens: CD38, CD138, CD45, CD56, CD117, CD19. MRD-negative status was defined as presence of less than 20 clonal plasmatic cells among 2,000,000 white blood cells (<0.001%, detection limit - 10-5).After auto-HSCT, all patients were followed up and received no MT. The analysis of MRD status was conducted every 3 months until the development of a disease relapse with the use of a six-color flow cytometric assay. The follow-up period since the moment of MRD detection on Day 100 following auto-HSCT was 3 to 33 months (median value = 12 months). The evaluated parameters included the time to loss of MRD-negative status (period since the moment of detection of MRD-negative status on Day 100 following auto-HSCT till the appearance of minimal residual population), RFS (period since the moment of detection of MRD-status on Day 100 following auto-HSCT till the assertion of a disease relapse according to IMWG 2014 criteria), TFS (period since the moment of detection of MRD-negative status on Day 100 following auto-HSCT till the initiation of the next line of therapy). Statistical analysis was done using SAS 9.4. The compared groups were overall balanced for known significant factors.Results: Following auto-HSCT, stringent CR was achieved in 21 (72%) patients, while MRD-positive status was detected in 8 (28%) cases. Loss of MRD-negative status was ascertained in 7 (33%) out of 21 patients during the period from 3 to 13 months. MRD positive free survival was 60% within 33 months (Fig. 1).Immunochemical disease relapse was established in 3 (15%) patients with MRD-negative status and 5 (63%) patients with MRD-positive status achieved after auto-HSCT. Two-year RFS in patients with MRD-positive status was significantly lower compared to the patients with MRD-negative status: 25% vs. 80% (log-rank test, p=0.05, hazard ratio = 2.5, 95% CI = 0.9-6.4) (Fig. 2).TFS was significantly higher in patients with MRD-negative status achieved after auto-HSCT: 90% versus 20% within 28 months (p=0.03). It should be noted that only one patient from MRD-negative group required the initiation of the next line of therapy throughout the entire follow-up period as compared to 5 (63%) patients in MRD-positive group (Fig. 3).Conclusion: The values of time to loss of MRD-negative status in MM patients following auto-HSCT, which were determined in the study, confirmed the hypothesis of favorable prognosis without the use of MT. Prescription of additional treatment to patients who have achieved a stringent complete remission after auto-HSCT does not have any pathogenetical basis, is related to the risk of adverse events and requires the use of concomitant therapy. High values of RFS and TFS rates observed in patients with MRD-negative status following auto-HSCT also confirm our hypothesis. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Minimal Residual Disease after Allogeneic Stem Cell Transplantation Was Associated with Poor Outcomes in Patients with Acute Myeloid Leukemia

Introduction: Allogeneic hematopoietic stem cell transplantation (HSCT) is potentially curative for patients with acute myeloid leukemia (AML), but AML relapse remains a crucial issue in this setting. Monitoring of minimal residual disease (MRD) is valuable for risk stratification of relapse in patients with AML. The association between MRD (after induction, consolidation, and pre-transplantation) and outcomes had been well studied. A few studies have shown evidence of MRD in the early phase post-allogeneic HSCT, using flow cytometry. The aim of this single center retrospective observational study was to investigate the effect of MRD post-allogeneic HSCT in patients with AML.Patients and methods: A retrospective case analysis was performed involving 88 patients with AML who were treated with allogeneic HSCT at our hospitals from January 2011 to December 2016. We excluded 27 patients in whom MRD could not be evaluated for various reasons, six patients without bone marrow examination, and four patients with early relapse before the MRD assessment. The remaining 51 patients were included in the analysis. Flow cytometry analysis was performed on bone marrow aspirates obtained approximately 28 days post-allogeneic HSCT. The cutoff value of MRD was set as 0.01%. We set the primary endpoint as the cumulative incidence of relapse rate. The overall survival (OS), progression free survival (PFS), and cumulative incidence of non-relapse mortality (NRM) were also evaluated. To evaluate the impact of MRD on the primary endpoint, we employed the Fine and Gray analysis. Adjusted covariates were as follows: age, sex, karyotype, disease status before HSCT, and myeloablative conditioning (MAC) (vs. reduced intensity conditioning).Results: Among the study patients, the median age was 48 years (range: 40-59 years), and 31 patients (60.8%) were male. Regarding the risk of karyotype, five (9.8%), 17 (33.3%), and 28 (54.9%) patients had favorable, intermediate, and high-risk karyotype, respectively. One patient had no data for karyotype at diagnosis because his bone marrow was dry tap. Before HSCT, 15 patients were not complete remission, 27 were MRD positive, and 9 were MRD negative. The MAC regimen was administered in 45 patients (88.2%). Thirty-two patients had MRD in the early phase post-HSCT. There were no significant differences in patient characteristics between MRD-positive and MRD-negative groups. Regarding the primary endpoint, cumulative incidence of relapse was 44.5% (95% confidence interval [CI] 29.4-58.6%) in the total population, 16.4% (3.8-36.9) in the MRD-negative group and 59.6% (38.7-75.4%) in the MRD positive group (p = 0.007) (Figure A). In the multivariate analysis, MRD-positive status early after HSCT was independently associated with a high relapse rate with the adjusted hazard ratio of 4.86 (95% CI 1.51-15.7, p = 0.008), whereas disease status before HSCT was not. Regarding the secondary endpoints, PFS was 45.6% (95% CI 30.6-59.3%) in the total population, 67.1% (40.9-83.7) in the MRD-negative group, and 34.2% (17.7-51.4%) in the MRD-positive group (p = 0.035) (Figure B). There were no significant differences in the NRM and OS (Figure C, D).Conclusion: Our study showed that MRD-positivity early after allogeneic HSCT was associated with a higher relapse rate and poor PFS. Patients with MRD had a higher risk of relapse, and therefore, a prophylactic donor lymphocyte infusion or chemotherapy such as azacitidine may be considered. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Highlighting the Prognostic Importance of Measurable Residual Disease Among Acute Myeloid Leukemia Risk Factors

Objective:The optimal timing of measurable residual disease (MRD) evaluation in acute myeloid leukemia (AML) patients has not been well defined yet. We aimed to investigate the impact of MRD in pre- and post-allogeneic hematopoietic stem cell transplantation (AHSCT) periods on prognostic parameters.Materials and Methods:Seventy-seven AML patients who underwent AHSCT in complete morphological remission were included. MRD analyses were performed by 10-color MFC and 10-4 was defined as positive. Relapse risk and survival outcomes were assessed based on pre- and post-AHSCT MRD positivity.Results:The median age of the patients was 46 (range: 18-71) years, and 41 (53.2%) were male while 36 (46.8%) were female. The median follow-up after AHSCT was 12.2 months (range: 0.2-73.0). The 2-year overall survival (OS) in the entire cohort was 37.0%, with a significant difference between patients who were MRD-negative and MRD-positive before AHSCT, estimated as 63.0% versus 16.0%, respectively (p=0.005). MRD positivity at +28 days after AHSCT was also associated with significantly inferior 2-year OS when compared to MRD negativity (p=0.03). The risk of relapse at 1 year was 2.4 times higher (95% confidence interval: 1.1-5.6; p=0.04) in the pre-AHSCT MRD-positive group when compared to the MRD-negative group regardless of other transplant-related factors, including pre-AHSCT disease status (i.e., complete remission 1 and 2). Event-free survival (EFS) was significantly shorter in patients who were pre-AHSCT MRD-positive (p=0.016). Post-AHSCT MRD positivity was also related to an increased relapse risk. OS and EFS were significantly inferior among MRD-positive patients at +28 days after AHSCT (p=0.03 and p=0.019).Conclusion:Our results indicate the importance of MRD before and after AHSCT independently of other factors.

Clinical value of minimal residual disease assessed by multiparameter flow cytometry in amyloid light chain amyloidosis.

To assess the feasibility and prognostic value of minimal residual disease (MRD) evaluated by multiparameter flow cytometry (MFC) in newly diagnosed amyloid light chain (AL) amyloidosis. Clinical data from 25 consecutive newly diagnosed AL amyloidosis patients with MRD data tested at 3 months after first-line therapy completion were retrospectively analysed in a single centre from 2012 to 2019. First-line therapy included 8 courses of VD or 4 courses of VD plus sequential autologous stem cell transplantation (ASCT), both without maintenance therapy. Of 25 patients with very good partial response (VGPR) or better, 19 (76%) achieved MRD negativity. Baseline characteristics were not different between MRD-negative and MRD-positive patients. More ASCT patients than non-ASCT patients (90.0% vs 53.3%, p = 0.043) achieved MRD negativity. In the MRD-negative and MRD-positive groups, cardiac response was observed in 93% and 25% (p = 0.019) and any organ response in 94% and 50%, respectively (p = 0.023). At a median follow-up of 25.1 months, MRD-negative patients showed significantly longer progression-free survival (PFS) from diagnosis than MRD-positive patients (24.52 vs 76.39 months, p = 0.004). MRD negativity measured by MFC at 3 months after first-line therapy completion in patients with AL amyloidosis is measurable and associated with improved organ response rates and PFS over a long follow-up.