Bone Marrow Minimal Residual Disease Research Articles

Continuous Clinical Remisssion with High MRD Negativity and High PB and BM MRD Concordance during Venetoclax Monotherapy in R/R CLL Patients

Introduction Venetoclax, a novel BCL2 inhibitor, used either as monotherapy or in combinations, induces rapid disease control , with durable clinical remissions, especially in patients with deep responses. In the Venetoclax era, minimal residual disease(MRD) is a new endpoint in CLL studies. MRD negativity is associated with better clinical outcomes (Jain N, et al. ASH 2019, abstract 186, Tam CS, et al. ASH 2019, abstract 642). Aim We present our single-center MRD data from a cohort of patients with relapsed/refractory(RR) CLL, treated with venetoclax monotherapy. Patients and Methods We collected data from 24 R/R CLL patients who have been treated with venetoclax monotherapy until progression, in the context of VENICE-1 study (NCT02756611) in our department between 11/2016 and 1/2018. MRD was locally evaluated with 10-colour flow cytometry(FC) according to ERIC guidelines, with the cut off of <10-4 (<0.01%) as negative, >10-4-<10-2 (>0.01%-<1%) as low-positive and >10-2 (>1%) cut off as high-positive. Peripheral blood(PB) MRD was assessed every 3-6 months. At week48 (1 year), CT scans were performed for response assessment. Bone marrow (BM) biopsy and BM MRD at week48 were also performed in pts with CT confirmed CR. Results Between 11/2016 and 1/2018, 24 patients started treatment with venetoclax monotherapy. Our patients' baseline characteristics are shown in table 1. Disease responses and patients' treatment status as of end-July 2020 are shown in table 2. Progression free survival(PFS) and overall survival at 34 months is estimated 91.6% and 87.5% respectively. Four patients (16.7%) had to reduce their daily Venetoclax dose due to hematological toxicity: 2 to 300mg due to neutropenia and 2 to 200 and 100mg due to thrombocytopenia. MRD results at week 48 are shown in table 3. Sixteen patients have paired PB and BM MRD results (15 at week 48 and 1 at week 24) with 87.5% concordance (14 patients). In seven MRD negative patients MRD conversion (2 consecutive samples) was observed, after a median time of 16 m(6-28): six patients to low-positive and one to high-positive. The high-positive MRD-converted patient presented clinical relapse at the 2nd high-MRD positive sample, according to iwCLL criteria. One of 6 low-positive MRD-converted patients, became MRD negative again at a later time-point. Conclusion Our single-center data from 24 CLL patients enrolled in the Venice-1 study reveal high concordance of PB and BM MRD at week48. Higher PB MRD negativity rate at week 48 is observed (79.2%) in comparison to Venice trial (Kater A, et al. EHA 2020, S156) due to differences in MRD methodology/number of evaluable patients. Our FC MRD data show that MRD conversion from negative to low-positive may be observed during continuous Venetoclax treatment, without clinical disease progression. This observation, along with high PFS at 34 months (91.5%) confirms the importance of continuing Venetoclax therapy in RR CLL patients when given as monotherapy. Disclosures Kyrtsonis: Genesis pharma SA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Panayiotidis:Genesis: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Janssen: Honoraria; Gilead: Honoraria; Takeda: Honoraria; Phizer: Honoraria; ASH: Honoraria.

To Explore the Effect of Haploidentical Transplantation in the Treatment of Pediatric T-ALL with Sil-TAL1 Fusion Gene Positive and Analysis of Prognostic Factors

Introduction SIL-TAL1 rearrangement is relatively common among patients with T-cell acute lymphoblastic leukemia (T-ALL). Pediatric patients with SIL-TL1 positive T-ALL generally have a poor response to early intensive treatment and a lower median relapse-free survival (RFS) and overall survival (OS) rates compared to pediatric T-ALL patients who do not harbor the SIL-TAL1 gene fusion. Therefore, we explored the clinical effect of haploid transplantation among pediatric SIL-TAL1-gene fusion positive T-ALL and aimed to identify potential patient prognostic factors. M ethods We performed a retrospective analysis of 21 children with SIL-TAL1 gene fusion positive T-ALL who underwent haploidentical transplantation at the Lu Daopei Hospital in Langfang, China between July 2014 and June 2020. The median patient age was 9 years (range: 1.6 to 18 years), the male to female ratio was 19:2, and the median white blood cell count at initial onset was 193.65×109/L (range: 3.6-582.17×109/L). Prior to transplantation, 18 patients were bone marrow minimal residual disease (MRD) negative, three patients were bone marrow MRD-positive and the overall median value for MRD positivity by flow cytometry was 0.05% (range: 0.03%-0.35%). Eighteen patients were SIL-TAL1 gene fusion negative and three patients were SIL-TAL1 gene fusion positive prior to transplantation. The quantitative median number is 0.04% (range: 0.033%-0.05%). 13 patients with CR1 and 8 patients with CR2. 11 of 21 patients harbored the SIL-TAL1 gene fusion along with at least one other gene mutation. All patients were given myeloablative pretreatment, of which 17 patients received cyclophosphamide/total body irradiation (TBI/Cy) and 4 patients received Busulfan/cyclophosphamide (Bu/Cy). The median follow-up time was 9.5 months (range: 2 to 51 months). Results The white blood cells (WBCs) of 21 patients were all completely engrafted , two patients did not have platelet engraftment . At one month after transplantation, all patients were bone marrow MRD negative and the quantification of SIL-TAL1 fusion gene was 0% among all the patients. For 20 of these 21 patients, the chimerism rate of peripheral blood CD3+ cells and bone marrow was 100% donor type. The 4-year disease-free survival (DFS) and overall survival (OS) rate were 56.5% and 55.1%, respectively (Figure 1). Causes of death were recurrence (5 patients all of whom had bone marrow recurrence), infection (3 patients) and alveolar hemorrhage after reinfusion (1 patient). Six patients relapsed after transplantation with a median time to relapse of 90 days (range: 54-180 days). The OS rate following transplantation in the CR1 group was higher than in the CR2 groups (69.2% vs 31.3%, respectively) but there was no statistical difference between the two groups (P=0.147) (Figure 2). The OS rate of MRD-negative patients and MRD-positive patients prior to transplantation was 58.4% and 33.4% respectively, (P=0.287) (Figure 3). Prior to transplantation, the OS rate of SIL-TAL1 gene fusion-negative patients was 64.3%, while the OS rate of SIL-TAL1 gene fusion-positive patients was 0.0%--the difference between the two groups was statistically significant (P=0.001) (Figure 4). The OS rate of 11 patients that harbored the SIL-TAL1 gene fusion along with another gene mutation was 47.7% (Figure 5). Among these 11 patients, the OS rate of 9 patients who switched from SIL-TAL1 positive to SIL-TAL1 negative prior to transplantation was 58.3%. In contrast, two patients that remained SIL-TAL1 gene fusion positive had an OS rate of 0% (P=0.027) (Figure 6). Conclusion Pediatric T-ALL patients harboring the SIL-TAL1 gene fusion achieved a higher OS rate through haploid transplantation and were able to avoid extramedullary recurrence. We conclude that if patients with the SIL-TAL1 gene fusion do not switch to SIL-TAL1-negative prior to transplantation, we showed that even if the myeloablative pretreatment program is adopted, the survival rate cannot be improved, and the mortality rate is 100%. Harboring another gene mutation besides SIL-TAL1 at the initial onset of disease did not affect the prognosis in our cohort analysis. We conclude that for pediatric T-ALL patients, intensive chemotherapy should be adopted to make the bone marrow MRD negative and SIL-TAL1 gene fusion negative, and allogeneic hematopoietic stem cell transplantation should be performed as soon as possible to improve OS. Disclosures No relevant conflicts of interest to declare.

Phase II Study of Blinatumomab and Concurrent Oral Tyrosine Kinase Inhibitor Therapy As Consolidation and Maintenance Therapy for Patients with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Following Chemotherapy-Sparing Induction

Background: Combining oral ABL-targeted tyrosine kinase inhibitors (TKIs) with (w/) multi-agent chemotherapy has improved the long-term disease-free survival of adults w/ Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). However, Ph+ ALL occurs more commonly in older adults, and toxicities of multi-agent chemotherapy, including sequelae of prolonged myelosuppression, are amplified in this population. Others have previously reported rates of morphologic complete response (mCR) approaching 100% among adults w/ Ph+ ALL treated w/ corticosteroids (CS) and dasatinib (DAS) alone as induction therapy, but w/ low rates of minimal residual disease (MRD) negativity by flow cytometry (FACS) and BCR-ABL1 PCR (complete molecular response, CMR) and high rates of relapse in the absence of further consolidation. The bispecific T-cell engager blinatumomab (BLIN) has considerable efficacy in clearing MRD in patients (pts) w/ Ph- B-cell ALL. We have previously reported our institutional experience combining ABL TKIs w/ BLIN in pts w/ Ph+ ALL and MRD, including encouraging safety data and high rates of MRD eradication (King/Geyer et al., Leuk Res, 2019). The ongoing D-ALBA study (GIMEMA LAL2116) is also investigating BLIN + DAS consolidation following 12 weeks of induction (prednisone + DAS followed by DAS), w/out protocol-specified maintenance, and has demonstrated preliminary evidence of efficacy (Chiaretti et al., ASH Meeting, 2019). As such, we designed a phase II study of BLIN as part of a chemotherapy sparing strategy in pts w/ Ph+ ALL (BLISSPHALL), introducing BLIN as early as 6 weeks into treatment for pts in morphologic CR, w/ aim of enhancing early MRD negativity and suppressing resistant clones early in disease course. Study design and methods: Our institution is leading a phase II trial of TKI + BLIN consolidation and maintenance in adults w/ newly-diagnosed Ph+ ALL, w/ potential multicenter expansion (NCT04329325). Pts are eligible if they are ≥18 years-old w/ Ph+ ALL confirmed by cytogenetic or molecular studies, ECOG performance status 0-2, w/out prior therapy for ALL beyond CS, hydroxyurea, or intrathecal chemotherapy, w/out known active extramedullary disease and/or CNS-3 disease, and w/ appropriate organ function. See Figure 1: pts will receive a CS pre-phase (days [d] -6 - 0) followed by modified GIMEMA LAL1205 induction (dexamethasone [DEX] 10 mg/m2 [max 24 mg/d], d1-24, tapered off d25-32) + DAS 140 mg/d (dose adjustments or TKI change permitted per protocol) w/ intrathecal methotrexate (IT MTX) d22, 43 and bone marrow (BM) assessments including FACS and BCR-ABL1 PCR. Pts in mCR on d43 (or optional reassessment ≤ 3 weeks later) will be eligible to proceed to consolidation w/ 3 cycles (C) BLIN 28 mcg/d IVCI, d1-28, concurrent w/ TKI, w/ 14d off BLIN between cycles and BM MRD assessment/IT MTX after each cycle. C1 BLIN + TKI is required to begin inpatient x72 hours. TKI is given continuously including between BLIN cycles. Pts in CMR after consolidation may proceed to maintenance (C4-7 BLIN + TKI, 28d off between cycles). Pts may come off study to proceed to hematopoietic cell transplant (HCT) at any point, though it is recommended such pts receive ≥2C of BLIN + TKI. The primary objective is to determine the proportion of evaluable pts achieving CMR by the end of consolidation (≤ 3C BLIN + TKI). Secondary objectives include safety/toxicity of BLIN + DAS, duration of CMR, incidence of relapse, event-free/overall survival. Exploratory objectives include safety/toxicity of non-DAS TKIs + BLIN, defining patterns/mechanisms of resistance to BLIN+TKI (including ABL kinase mutations), and outcomes among pts not undergoing HCT. The trial utilizes a Simon's minimax two-stage design; 20% CMR rate is considered not promising, a 50% CMR rate is considered promising, and probabilities of type I/II error are set at 0.10/0.10. If ≥ 3 of the first 10 pts achieve CMR we will continue enrollment to max 17 pts. If ≥ 6 pts achieve CMR, then BLIN + TKI will be considered promising for further investigation. The investigators are hopeful this study will add to the currently limited prospective data supporting TKI + BLIN consolidation/maintenance for pts w/ Ph+ ALL and efforts to develop chemotherapy-sparing and immunotherapeutic strategies for older pts w/ ALL. Disclosures Geyer: Amgen: Research Funding. King:Abbvie: Other: advisory board. Park:Novartis: Consultancy; Genentech/Roche: Research Funding; Intellia: Consultancy; Artiva: Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Research Funding; Takeda: Consultancy, Research Funding; Servier: Consultancy, Research Funding; AstraZeneca: Consultancy; Allogene: Consultancy; Incyte: Consultancy, Research Funding; Kite: Consultancy, Research Funding; Juno Therapeutics: Research Funding; GSK: Consultancy; Autolus: Consultancy, Research Funding; Minverva: Consultancy; Amgen: Consultancy, Research Funding. OffLabel Disclosure: Blinatumomab is not approved to be given in combination with ABL tyrosine kinase inhibitors for treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia.

Late Relapsing Multiple Myeloma ≥ 10 Years after Treatment on Total Therapy Protocols Are Associated with Good Outcome

Introduction Novel agents are incorporated into a backbone of multi-agent chemotherapy and tandem transplantation in successive Total Therapy (TT) protocols for multiple myeloma (MM) patients. The TT protocols extend the duration of remission with a significant proportion of patients achieving long-term disease control. However, a small percentage of patients have documented late relapse and we theorize that these relapses are indolent with overall good clinical outcome. While even a late relapse is seemingly an undesirable outcome, defining the clinical implications is imperative to understanding the impact on long-term prognosis and management. Methods Our MM database was interrogated to identify patients that presented with relapsing disease ≥ 10 years from diagnosis and were treated on TT protocols. All patients had myeloma markers every 2 to 3 months and bone marrows with either PET-CT or MRI at least once a year. In the group of patients with documented relapse, we obtained the pattern of relapse, clinical and laboratory markers, cytogenetics, FISH, gene expression profile (GEP), bone marrow (BM) minimal residual disease (MRD), imaging (PET-CT and MRI, use of salvage transplant, and response assessment including best response to treatment. Patterns of relapses were evaluated based on elevated serum myeloma markers, BM plasmacytosis and presence of macrofocal relapse/extramedullary disease. Clinical relapses were classified based on the International Myeloma Working Group criteria. Indolent relapse was defined as a biochemical relapse with a rising M-protein or free light chains, less than 30% bone marrow plasmacytosis involvement, absence of focal lesion on imaging and of CRAB criteria, low riskGEP70 signature at relapse or no abnormal metaphase cytogenetics. Results A total of 2055 patients were enrolled and treated on successive TT protocols (TT1 to TT7) of which 658 patients had ≥10 years follow up from initial study enrollment. Among these 658 patients, 8% (53/658) had a clinical relapse ≥ 10 years from diagnosis. The median time to clinical relapse was 11. 8 years (range, 9.8 - 17.6). Median age at the time of relapse was 67.7 years with 28% being females. Gene expression profiling showed that 45% (24/53) belonged to the molecular CD2 and LB subgroups. The most common pattern of relapse is with BM plasmacytosis in 49% (26/53) with 36% (19/53) presenting with CRAB clinical features. Focal lesions by MRI and/or CT-PET were present in 35.8% (19/53). Overall, 56.6% (30/53) of patients had indolent relapses; of these 9 and 7 belonged to the CD2 and LB molecular subgroups, respectively. BM MRD assessment by 8-color flow cytometry was available in 17 patients and MRD positivity preceded clinical relapse by a median 17.9 months (range: 0 - 60.8). Forty-one patients required treatment for disease relapse with 11 patients managed expectantly without treatment. While most patients (73.1%, 30/41) received initial treatment with either PI/IMiD/PI IMiD combinations, 8 patients later underwent salvage ASCT. A response of ≥ VGPR was attained in 70% (31/47) of the treated patients with the large majority (87%) achieving a sCR/CR. The overall survival from relapse at 5 years was 73.3% (95% CI: 55.0% to 85.1%). A total of 14/53 patients died during follow-up;7 patients died to progressive disease; 6 of these 7 presented with focal lesions detected on imaging and had an aggressive relapse. Three patients died to treatment related complications, 1 had an unrelated pneumonia, the cause of death was indeterminate in 2 and unknown in 1. Overall, in these 14 patients, median time to death from initial diagnosis was 15.4 years (range: 11.8 - 18.0) and a median time to death from relapse was 3.2 years (range: 0.3 - 6.0). Conclusions Late relapses (>10 years) in MM are a rare event occurring in 8% of long-term survivors and accounting for 2.6% of all patients treated on the TT protocols. Intriguingly, most patients with late relapsing MM belong to the GEP subtype LB and CD2 and accounted for 51% of the indolent relapses. These findings have clinical implications and emphasizes the importance of extended and close follow-up even in patients with prolonged clinical remission. Disclosures van Rhee: Karyopharm: Consultancy; Adaptive Biotech: Consultancy; Takeda: Consultancy; EUSA: Consultancy; CDCN: Consultancy.

Phase Ib Study of Ianalumab (VAY736) and Ibrutinib in Patients with Chronic Lymphocytic Leukemia (CLL) on Ibrutinib Therapy

Phase Ib Study of Ianalumab (VAY736) and Ibrutinib in Patients with Chronic Lymphocytic Leukemia (CLL) on Ibrutinib Therapy

Ibrutinib Plus Venetoclax in Patients With Relapsed/Refractory Mantle Cell Lymphoma: Results From the Safety Run-In Period of the Phase 3 Sympatico Study

Ibrutinib Plus Venetoclax in Patients With Relapsed/Refractory Mantle Cell Lymphoma: Results From the Safety Run-In Period of the Phase 3 Sympatico Study

Venetoclax, Lenalidomide and Rituximab for Patients with Relapsed or Refractory Mantle Cell Lymphoma - Data from the Nordic Lymphoma Group NLG-MCL7 (VALERIA) Phase I Trial: Stopping Treatment in Molecular Remission Is Feasible

Venetoclax, Lenalidomide and Rituximab for Patients with Relapsed or Refractory Mantle Cell Lymphoma - Data from the Nordic Lymphoma Group NLG-MCL7 (VALERIA) Phase I Trial: Stopping Treatment in Molecular Remission Is Feasible

A Phase 1/2 Study of Umbralisib, Ublituximab, and Venetoclax (U2-Ven) in Patients with Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL)

A Phase 1/2 Study of Umbralisib, Ublituximab, and Venetoclax (U2-Ven) in Patients with Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL)

Ibrutinib (Ibr) Plus Venetoclax (Ven) for First-Line Treatment of Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL): 1-Year Disease-Free Survival (DFS) Results From the MRD Cohort of the Phase 2 CAPTIVATE Study

Ibrutinib (Ibr) Plus Venetoclax (Ven) for First-Line Treatment of Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL): 1-Year Disease-Free Survival (DFS) Results From the MRD Cohort of the Phase 2 CAPTIVATE Study

Assessment of Minimal Residual Disease By Next-Generation Sequencing and Fluorodeoxyglucose-Positron Emission Tomography in Patients with Relapsed/Refractory Multiple Myeloma Treated with Venetoclax in Combination with Carfilzomib and Dexamethasone

Assessment of Minimal Residual Disease By Next-Generation Sequencing and Fluorodeoxyglucose-Positron Emission Tomography in Patients with Relapsed/Refractory Multiple Myeloma Treated with Venetoclax in Combination with Carfilzomib and Dexamethasone

Molecular response after obinutuzumab plus high-dose cytarabine induction for transplant-eligible patients with untreated mantle cell lymphoma (LyMa-101): a phase 2 trial of the LYSA group

Obinutuzumab monotherapy has shown promising efficacy in mantle cell lymphoma. We aimed to investigate the activity of obinutuzumab plus DHAP (dexamethasone, high-dose cytarabine, and cisplatin), measured by minimal residual disease quantitative (q)PCR status in the bone marrow after four cycles. LyMa-101 was a prospective, open-label, single-arm, phase 2 trial. Participants were enrolled from 28 hospitals in France. Newly diagnosed patients with mantle cell lymphoma (aged 18 to <66 years) who were eligible for autologous stem-cell transplantation received four cycles of obinutuzumab plus DHAP (obinutuzumab 1000 mg/m2 intravenously on days 1, 8, and 15 at cycle 1 and day 1 at cycles 2, 3, and 4; dexamethasone 40 mg intravenously on days 1-4, cytarabine 2 g/m2 intravenously every 12 h on day 1, and according to local investigator, cisplatin 100 mg/m2 by continuous infusion over 24 h on day 1 or carboplatin area under the curve 5 or oxaliplatin 130 mg/m2) every 21 days before transplantation, and 3 years of obinutuzumab (1000 mg/m2 every 2 months) maintenance followed by minimal residual disease-based obinutuzumab on-demand maintenance. The primary outcome was minimal residual disease negativity in the bone marrow after four cycles of obinutuzumab plus DHAP at the end of induction, measured in the efficacy set (all minimal residual disease-informative [bone marrow or peripheral blood] patients who received at least one dose of obinutuzumab). Obinutuzumab plus DHAP was considered effective if bone marrow minimal residual disease negativity was 70% or more by intention to treat. The trial is closed to recruitment and registered with ClinicalTrials.gov, NCT02896582. 86 patients were enrolled between Nov 29, 2016, and May 2, 2018. 81 patients completed induction, 73 underwent autologous stem-cell transplantation, and 69 started maintenance therapy. 55 (75%) of 73 patients in the efficacy set reached minimal residual disease negativity in bone marrow at end of induction. According to the protocol definition, 18 (25%) of 73 patients in the efficacy set were minimal residual disease-positive: 12 patients who were minimal residual disease-positive in the bone marrow, plus two patients who progressed during induction, and four patients who did not have minimal residual disease assessment. The most common grade 3-4 treatment-emergent adverse events were anaemia (grade 3, 26 [31%] of 85 patients; grade 4, three [4%] of 85 patients) and neutropenia (grade 3, 13 [15%] of 85 patients; grade 4, 32 [38%] of 85 patients). 58 serious adverse events occurred during the induction phase. There were no treatment-related deaths. Obinutuzumab plus DHAP is a well tolerated regimen and has good activity for inducing minimal residual disease negativity in the bone marrow of transplant-eligible patients with mantle cell lymphoma. Obinutuzumab plus DHAP has potential activity as induction chemotherapy, with bone marrow minimal residual disease negativity potentially predicting long-term disease control. Roche SAS.

CAR T-cell bridging to allo-HSCT for relapsed/refractory B-cell acute lymphoblastic leukemia: the follow-up outcomes

目的研究嵌合抗原受体T细胞（CAR-T）细胞治疗桥接异基因造血干细胞移植（allo-HSCT）治疗复发/难治急性B淋巴细胞白血病（R/R B-ALL）的疗效及安全性。方法回顾性分析2017年1月至2019年5月于苏州大学附属第一医院行CAR-T细胞治疗桥接allo-HSCT的50例R/R B-ALL患者的临床资料，分析CAR-T细胞治疗前、后及allo-HSCT前不同骨髓微小残留病（MRD）水平患者总生存（OS）率、无事件生存（EFS）率、累积复发率（CIR）、移植相关死亡率（TRM）。结果全部患者共行55例次CAR-T细胞治疗，CAR-T细胞治疗反应率、严重细胞因子释放综合征（CRS）发生率分别为92％、28％。未发生治疗相关死亡。CAR-T细胞输注至allo-HSCT的中位时间为54（26～232）d。CAR-T细胞输注后中位随访637（117～1097）d，1年OS、EFS率分别为（80.0±5.7）％、（60.0±6.9）％。移植后1年CIR、TRM分别为（28.0±0.4）％、（8.0±0.2）％。CAR-T细胞输注后及allo-HSCT前骨髓MRD<0.01％患者1年EFS率更高［（70.0±7.2）％、（20.0±12.6）％，P<0.001；（66.7±7.5）％对（36.4±14.5）％，P＝0.008］，CIR更低［（25.0±0.5）％、（70.0±2.6）％，P<0.001；（23.1±0.5）％、（45.4±2.6）％，P＝0.038］。结论CAR-T细胞治疗桥接allo-HCT对于复发/难治B-ALL是一种安全有效的治疗策略。

Comparison of NGS and MFC Methods: Key Metrics in Multiple Myeloma MRD Assessment.

In order to meet the challenges in data evaluation and comparability between studies in multiple myeloma (MM) minimal residual disease (MRD) assessment, the goal of the current study was to provide a step-by-step evaluation of next-generation sequencing (NGS) and multicolor flow cytometry (MFC) data. Bone marrow (BM) sample pairs from 125 MM patients were analyzed by NGS and MFC MM MRD methods. Tumor load (TL) and limit of detection (LOD) and quantification (LOQ) were calculated. The best-fit MRD cut-off was chosen as 1 × 10−5, resulting in an overall 9.6% (n overall = 12 (NGS n = 2, MFC n = 10)) nonassessable cases. The overall concordance rate between NGS and MFC was 68.0% (n = 85); discordant results were found in 22.4% (11.2% (n = 14) of cases in each direction. Overall, 55.1% (n = 60/109) and 49.5% (n = 54/109) of patients with a serological response ≥ very good partial response (VGPR) showed BM MRD negativity by NGS and MFC, respectively. A good correlation in the TL assessed by both techniques was found (correlation coefficient = 0.8, n = 40, p < 0.001). Overall, our study shows good concordance between MM BM MRD status and TL when comparing NGS and MFC at a threshold of 10–5. However, a sufficient number of analyzed events and calculation of MRD key metrics are essential for the comparison of methods and evaluability of data at a specific MRD cut-off.

Analysis of treatment efficacy in the GEM-CESAR trial for high-risk smoldering multiple myeloma patients: Comparison between the standard and IMWG MRD criteria and QIP-MS including FLC (QIP-FLC-MS).

8512 Background: The GEM-CESAR trial is a potentially curative strategy for high-risk smoldering multiple myeloma (HRsMM) patients (pts) in which the primary endpoint is the achievement of sustained minimal residual disease (MRD) negativity in the bone marrow (BM) by next generation flow (NGF). The value of BM MRD assessment in MM is proven, but alternative, non-invasive methods, accurately reflecting disease burden are needed. Methods: Pts received six 4-week cycles of KRd as induction (K:36mg/m2 twice weekly, R: lenalidomide 25mg po od days 1-21 and d:dexamethasone 40mg po weekly) followed by melphalan 200mg/m2, two further cycles of KRd as consolidation and up to 2 years of Rd (R:10mg/d, d:20mg/week). Efficacy was analyzed in parallel in BM samples by NGF and in serum by SPEP/IFE and QIP-MS/QIP-FLC-MS in 52 out of the 90 pts enrolled in the trial. Standard and MRD responses were carried out as per the IMWG guidelines. For QIP-MS serum immunoglobulins were purified using polyclonal antibodies (anti-IgG, -IgA, -IgM, -total κ and -total λ light chain, -free κ and -free λ light chain). Mass spectra were generated on a MALDI-TOF-MS system. Results: Overall response rate (ORR) was 98% post-induction, 98% post-ASCT, and 100% post-consolidation; 38.4%, 61.5% and 68.6% of pts reached ≥ complete response at each time-point and, among them, 23%, 44% and 55% achieved flow MRD-negativity. Using the combination of QIP-MS/QIP-FLC-MS, the percentage of pts without detectable disease at each timepoint lowered to 12%, 27% and 38% reflecting the higher sensitivity of the method. Against NGF, QIP-MS/QIP-FLC-MS provided negative predictive values of 67%, 92% and 89% (p = 0,0206; p &lt; 0,001; p = 0,003) and identified disease in 95%, 97% and 92% of pts that were positive by NGF-MRD at each respective timepoint. Three pts from this cohort have progressed so far: two were NGF+/MS+ at the three timepoints whilst 1 remained NGF- but QIP-MS/FLC-MS+ throughout. Conclusions: The GEM-CESAR treatment strategy induces a high ORR in HRsMM pts, and the % of cases achieving flow-MRD negativity post-ASCT meets the primary endpoint of the trial. The combined use of QIP-MS and FLC-MS offers higher sensitivity relative to standard methods and may provide relevant information about the right timing for performing a BM aspirate/biopsy. Clinical trial information: NCT02415413 .

Clinical implications of loss of minimal residual disease (MRD) negativity in multiple myeloma.

8514 Background: Attainment of MRD negativity in multiple myeloma (MM) patients is increasingly considered an optimal therapeutic endpoint, but little is known about the MRD evolution in those who achieve this milestone. We investigated the clinical implication of loss of MRD negativity or MRD conversion in patients with ≥VGPR. Methods: We identified and followed 606 patients achieving a sustained ≥VGPR with bone marrow MRD negativity(≥ 2 consecutive reading) following treatment on a total therapy protocol and with a median follow-up of 10 y. All patient had negative PET and MRI DWIBS at enrollment. Serial BM aspirate MRD was determined by 8-color next generation flow (NGF, EuroFlow) with a minimal sensitivity of 10−5 cells. Results: Most MM patients were considered low risk with a UAMS GEP70 score of ≤ 0.66 (92%; 495/538) . While 60% (364/606) of patients had sustained MRD negativity, the remaining 40% (242/606) experienced MRD conversion with a 5.7 y median time from ASCT and 6.3 y from diagnosis. The risk of clinical relapse was significantly elevated in patients with MRD conversion compared to sustained MRD negativity (73%, 177/242 vs. 5%, 18/364; R.R. = 3.5; P&lt; 0.0001). The median level of MRD positivity (&gt; 0.2 ratio of MM cells to normal plasma cells) also highly correlated with relapse ( P&lt; 0.0001). Loss of MRD negativity preceded clinical relapse by a median time of 1.1 years. Loss of MRD negativity without clinical relapse was seen in 27% (65/242). MRD conversion was associated with an inferior PFS and OS (PFS: 10.2 y vs. NR; P &lt; 0.0001, H.R. 18.7; 95% CI 13.3 - 26.3 and OS: 26.1 y vs. NR; P= 0.01, H.R. 1.7; 95% CI 1.1 - 2.6). Furthermore, when MRD conversion was within 5 y of diagnosis compared &gt; 5 y, patients had a worse OS ( P &lt; 0.0001, H.R. 17.2; 95% CI 7.8 – 37.8). We also observed that MRD conversion later than 5 years from diagnosis did not affect the OS. In a subset of patients (n = 144) the timing of first MRD negativity following treatment was available. Attainment of MRD negativity within 6 months of diagnosis compared to any time after 6 months was predictive of future MRD conversion (65%, 17/26 vs.42%, 49/118; P = 0.03) and clinical relapse (54%, 14/26 vs.28%, 33/118; P = 0.02). Conclusions: MRD conversion occurs in a significant proportion of MM patients (40%) on long-term follow-up and predicts future clinical relapse. Significance of MRD conversion has a temporal relationship from diagnosis and portray inferior clinical outcome particularly within 5 years of diagnosis.

Real-world sustained minimal residual disease (MRD) negativity using NGS in multiple myeloma.

e19280 Background: MRD assessment has been increasingly incorporated into guidelines and routine care for patients (pts) with multiple myeloma (MM). It has been widely shown that pts who achieve deep MRD negativity (MRD-) have longer PFS/OS. Clinical guidelines now include sustained MRD- (two consecutive MRD- results; (10−5, 12 mo. apart) as a response criterion. . NGS MRD (clonoSEQ; Adaptive Biotechnologies; Seattle, WA) is the only FDA authorized method for bone-marrow MRD assessment in MM. A large longitudinal database of quantitative NGS MRD values from routine patient care now enables real-world analysis. We used our data to provide insight into testing patterns and sustained MRD-. Methods: The population included internal data of NGS MRD clinical samples from Jan 2018 to Jan 2020. We examined MRD- achievement overall and sustained MRD- as defined by guidelines. For pts who achieved sustained MRD- and had subsequent MRD testing, we examined if they remained in an MRD- state. Results: We identified 1,675 pts with MM who had ≥1 MRD tests after baseline Clonality (ID) assessment. The age/sex distribution (med. age = 65; 58% male) was consistent with epidemiologic data. 837 (49.9%) and 541 (32.2%) achieved MRD- at 10−5 or 10−6 thresholds, respectively. Of the 190 pts with ≥2 MRD tests at least 12 mos. apart, 82 (43.2%) and 45 (23.7%) had sustained MRD- at 10−5 and 10−6 thresholds, respectively. Of 82 pts who achieved 12 mo. sustained MRD- at 10−5, 15 had a subsequent MRD test, of which all remained MRD-. Of 45 pts who achieved 12 mo. sustained negativity at 10−6, 4 had a subsequent MRD test, of which all remained MRD-. Conclusions: We believe this represents one of the earliest real-world study examining NGS MRD attainment of sustained MRD- defined by guidelines. It is notable that many pts reached deep MRD negativity, with a significant percentage having sustained MRD negativity meet guideline-defined criteria. Long-term follow-up and incorporation of clinical parameters &amp; outcomes data will enable further insights from this real-world dataset. [Table: see text]

Angiogenesis and Minimal Residual Disease in Patients with Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) is the most prevalent acute leukemia in adults. Bone marrow angiogenesis is crucial for pathogenesis of leukemia, and increasing bone marrow Mean Vascular Density (MVD) and level of angiogenesis factors are seen in patients with AML. Higher level of bone marrow MVD is associated with poor prognosis of AML according to previous studies. The present study aimed to compare bone marrow MVD in AML patients and controls and evaluate the relation between bone marrow MVD and number of residual blast cells after AML treatment. Materials and Methods: This study is a longitudinal study on AML patients who were admitted to Omid hospital. The bone marrow biopsies of patients with AML and patients with normal diagnosis -as control group- were taken from archives of pathology laboratory. Immunohistochemistry staining was used for all specimens by using thrombomodulin markers for calculating MVD. Flow cytometry findings of AML patients were assessed for percent of minimal residual disease (MRD) after AML treatment in AML patients group. Results: In this study, 27 AML patients and 24 healthy individuals with mean age of 40.92±15.13 years were evaluated, of whom 56.86% were male. The mean bone marrow MVD was significantly higher in AML patients than controls. The mean bone marrow MVD was significantly higher in males and there was insignificant reverse correlation between bone marrow MVD and MRD. About 59.3% of AML patients had response to treatment and there was no significant relationship between MVD and response to treatment. Conclusion: Bone marrow MVD was higher in AML patients than controls and there was no remarkable relationship between bone marrow MVD and MRD and response to treatment.

Application progress of novel Bruton tyrosine kinase inhibitors in B-cell lymphoma

The Bruton tyrosine kinase (BTK) inhibitor ibrtinib has excellent results in B-cell lymphoma. However, there are still unmet treatment needs in clinical practice. New BTK inhibitors are highly selective and specific, reducing off-target effects. The overall response rate (ORR) of acalabrutinib combination therapy is more than 90%, and high rates of peripheral blood and bone marrow minimal residual disease (MRD)-negative are obtained. Orelabrutinib is a new domestic BTK inhibitor, the results of a phase Ⅱ study showed that the ORR in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma is 88.5%, and in mantle cell lymphoma is 82.5%. Another new domestic BTK inhibitor zanubrutinib, international multi-center study showed that ORR is 95.9% in relapsed/refractory CLL, and in treatment-naive chronic lymphocytic leukemia with del (17p) is 92.2%. In addition, non-covalent BTK inhibitors are also emerging, which are expected to overcome the problem of resistance to BTK inhibitors. Key words: Lymphoma, B-cell; Protein-tyrosine kinases; Protein kinase inhibitors; Bruton tyrosine kinase

Impact of minimal residual negativity using next generation flow cytometry on outcomes in light chain amyloidosis.

We evaluated bone marrow minimal residual disease (MRD) negativity in 44 patients with light chain (AL) amyloidosis using next generation flow cytometry (sensitivity ≥1 × 10-5 ; median events analyzed: 8.7 million, range: 4.8 to 9.7 million). All patients underwent MRD testing in 2 years from start of therapy (median: 7 months). The overall MRD negative rate was 64% (n = 28). The MRD-negative rate after one-line of therapy was 71% (20/28). And, MRD negative rates were higher with stem-cell transplant as first-line therapy (86%, 18/21) vs chemotherapy alone as first-line treatment (29%, 2/7), P = .005. The MRD negative rate amongst patients in complete response was 75% (15/20), and in very good partial response, 50% (11/22). There were two patients in partial response/rising light chains (with renal dysfunction) who were MRD negative. There were no differences in baseline characteristics of MRD negative vs MRD positive patients, except younger age amongst MRD-negative patients. Patients with MRD negativity were more likely to have achieved cardiac response at the time of MRD assessment, 67% (8/12) vs 22% (2/7), P = .04. Renal response rates were similar in both groups. Progression free survival was assessed in the 42 patients achieving CR or VGPR. After median follow-up of 14 months, the estimated 1-year progression free survival in MRD negative vs MRD positive patients was 100% (26 patients, 0 events) vs 64% (16 patients, five events), P = .006, respectively. MRD assessment should be explored as a surrogate endpoint in clinical trials and MRD risk-adapted trials may help optimize treatment in AL amyloidosis.

Circulating microRNAs as minimal residual disease biomarkers in childhood acute lymphoblastic leukemia

BackgroundTreatment stratification based on bone marrow minimal residual disease (MRD) at set time points has resulted in considerably improved survival in pediatric acute lymphoblastic leukemia (ALL). Treatment response is assessed using bone marrow samples. MicroRNAs (miRs) easily traffic among fluid spaces and are more stable than most other RNA classes. We examined the role of circulating miRs as putative less invasive MRD biomarkers.MethodsIn an exploratory experiment, expression of 46 preselected miRs was studied in platelet-free blood plasma samples of 15 de novo, 5 relapsed ALL patients and 10 controls by Custom TaqMan Array Advanced MicroRNA Card. Based on their high expression in ALL compared to controls, and on the reduction observed along the induction therapy, four miRs were selected for further analyses: miR-128-3p, -181a-5p, -181b-5p and 222-3p. Their expression was measured by qPCR at 4 time points in 27 de novo ALL patients treated in the ALL IC-BFM 2009 study.ResultsThe expression of all 4 miRs significantly decreased over the first week of therapy (miR-128-3p: log2 fold change − 2.86; adjusted p 3.6 × 10−7; miR-181b-5p: log2 fold change − 1.75; adjusted p 1.48 × 10−2; miR-181a-5p: log2 fold change -1.33; adjusted p 3.12 × 10−2; miR-222-3p: log2 fold change − 1.25; adjusted p 1.66 × 10−2). However, no significant further reduction in miR expression was found after the 8th day of therapy. Measured drop in expression of 2 miRs at day 8 strongly correlated with day 15 bone marrow flow cytometry MRD results (miR-128-3p: Pearson’s r = 0.88, adjusted p = 2.71 × 10−4; miR-222-3p: r = 0.81, adjusted p = 2.99 × 10−3).ConclusionIn conclusion, these circulating miRs might act as biomarkers of residual leukemia. MiR-128-3p and miR-222-3p in blood predict day 15 flow cytometry MRD results 7 days earlier. Although, their sensitivity falls behind that of bone marrow flow cytometry MRD at day 15.