Minimal Residual Disease Negative Patients Research Articles

Prognostic Significance of Minimal Residual Disease in Patients with Secondary Acute Myeloid Leukemia

BACKGROUNDSecondary acute myeloid leukemia (AML) is defined as AML that develops from a prior myelodysplastic or myeloproliferative disorder, or from exposure to chemotherapy, radiation, or environmental toxins. Patients with secondary AML have inferior prognosis compared to those with de novo AML,1 and are more likely to be elderly with increased comorbidities and worse performance status.2 The detection of minimal residual disease (MRD) also has independent prognostic value in patients with AML.3-6 In elderly AML patients, MRD predicts worse outcomes independent of the poor treatment risk factors associated with increased age.7Due to the similar disease pathogenesis between elderly AML and secondary AML patients, it is likely that MRD testing will have similar implications. However, there is limited data on the prognostic role of MRD testing in secondary AML. METHODSWe retrospectively analyzed de novo and secondary AML patients at Washington University Medical Center who received post-induction, post-consolidation, pre-transplant, or post-transplant MRD testing during their treatment. MRD testing was performed with multiparameter flow cytometry testing using the “different from normal” method at one reference laboratory,8,9 with positive MRD defined as detection of an abnormal myeloblast population above 0.1%. A total of 180 patients were included. Any patient with at least one positive MRD was considered “MRD positive.” Baseline pretreatment characteristics were compared between groups with Mann-Whitney, Chi-square, or Fisher's exact test, when appropriate. We evaluated overall survival (OS) and relapse rates in de novo and secondary AML patients stratified by MRD status using Kaplan-Meier curves and the log rank test, or cumulative incidence function, as appropriate. Multivariate Cox proportional hazards model was also fitted to determine if MRD testing has similar prognostic value across de novo and secondary AML patients. RESULTSOur analysis included 133 patients with de novo and 47 patients with secondary AML. Secondary AML patients were significantly older at age of diagnosis (mean age 59.85 versus 51.17, p<0.001), however had similar rates of MRD positivity (28% versus 29%, p=0.830). There was a trend toward poorer cytogenetic risk profiles and worse Karnofsky Performance Status in secondary AML (Table 1). In all patients, we confirmed that MRD positivity confers significantly worse OS (45.5% versus 70.8%, p=0.020) and relapse rates at 2 years (53% versus 25.5%, p=0.029) (Figure 1). In de novo AML patients, MRD positivity continued to demonstrate significantly worse 2-year OS (44.1% versus 76.3%, p=0.006) and relapse rates (57.6% versus 20.7%, p=0.008). However, in secondary AML patients, there were no differences in OS (p=0.69) or relapse rates (p=0.98) between MRD positive and negative patients. Multivariate analysis demonstrated significant interaction (p=0.042) between MRD status and AML subtypes. MRD positivity emerged as an independent prognostic indicator of worse OS in de novo patients (HR 2.8, 95% CI 1.524-5.405) but not in secondary patients (HR 1.5, 95% CI 0.188-2.336). DISCUSSIONWe confirm that MRD status is a poor prognostic indicator in all AML patients, and this also holds true in patients with de novo AML. However, we found that MRD status has less prognostic value in secondary AML patients. This may be due to the overall poor prognosis seen in secondary AML patients, suggesting that MRD monitoring in this group of patients may be less useful for risk stratification. However, our study is limited by the small sample size, particularly in the number of secondary AML patients who displayed MRD positivity (N=13). In addition, we defined MRD positivity across all time points of testing, which may decrease patient homogeneity. A larger study with increased follow-up is necessary to confirm our findings, as these results have important implications in risk-stratification and treatment of patients with secondary AML. [Display omitted] DisclosuresDiPersio:BMS, Asterias, Amphivena, Bluebird: Other: Travel, Accomodations, Expenses; Hemedicus, DAVA Oncology: Speakers Bureau; Celgene, Bioline, Vasculox, Cellworks, Rivervest: Consultancy; Magenta Therapeutics: Equity Ownership.

Minimal Residual Disease (MRD) Assessment after Induction Chemotherapy in Children and Adults with Acute Lymphoblastic Leukemia (ALL): A Valuable Strategy in Resource Constraint Settings in the Indian Subcontinent

Background: In a developing country with limited resources and insurance coverage, it is very important to risk stratify patients early in the treatment of Acute Lymphoblastic Leukemia (ALL). This strategy will enable better utilization of resources and also identify a subset of patients who will benefit from early haematopoeitic stem cell transplant (HSCT). Historically, clinical and laboratory features such as age, gender, white blood cell counts at diagnosis, organomegaly, mediastinal mass, morphology, immunophenotyping and cytogenetics have been used to assess the outcome of patients with ALL. However recent studies have shown that assessment of minimal residual disease (MRD) was the most important prognostic determinants of both childhood and adult ALL. Currently multiparameter flow cytometry and quantitative polymerase chain reaction (PCR) of the immunoglobulin or TCR genes are most commonly used for the assessment of MRD. However availability of this technology is very limited. In this present study, we assessed the MRD at day 33 post induction chemotherapy by flowcytometry at our center, and risk stratified patients to determine outcomes.Methods: We analyzed a cohort of 70 de novo ALL patients who presented to our Hospital (Mazumdar Shaw Medical Center, Narayana Health City, Bangalore, India) between April 2014 and April 2017. Diagnosis was confirmed by bone marrow aspiration based on the morphology, cytochemistry, immunophenotyping and cytogenetics. Clinico-pathological features, immunophenotyping, cytogenetics were recorded at the time of presentation. Day 8 prednisolone response was recorded and MRD assessment was done at day 33, using 8 Color multiparameter Flowcytometry. The cost of MRD analysis is 220 US$.Results: Out of 70 patients, 47 (67%) were male. The median age was 9 years (range: 8 months, 69 years). Among the subtypes, B-ALL was found in 83% (n=58) and T-ALL in 17% (n=12). The most common presenting symptom was fever (66%). Hepatosplenomegaly was seen in 35% (n=23), lymphadenopathy in 35% (n=24). CNS involvement at presentation was seen in 8.6% (n=6). The median WBC count at presentation was 11x103/µl (0.8-437). Majority of adults (39%) and pediatric patients (44%) had normal cytogenetics. This was followed by hyperdiploidy (27%, n=11) in children and t(9;22) in adults (26%, n=6). Intermediate risk cytogenetics were seen in most of the patients (44%, n=26). 57 patients (81%) showed good prednisolone response at day 8. Twenty-seven (40%) patients were MRD positive at day 33. Among the MRD positive cases, nearly 50% patients were aged <1 yr or >10 yr. Seventy-five percent of patients in the age group between 1-9 yrs were MRD negative. 72% patients with WBC >50x103/µl, 40% of patients with CNS involvement and 50% of patients with PPR group had MRD positivity. The incidence of MRD positivity was similar in both B-ALL and T-ALL patients (40% vs 42%). The MRD status and clinical details are summarized in table 1. The disease free survival was significantly higher in MRD negative patients compared to MRD positive patients at 24 months (97% vs 58%, p<0.01) (Figure 1).CONCLUSION: MRD assessment at day 33 post chemotherapy is the most important factor in determining risk of relapse in patients with ALL, surpassing the prognostic information obtained from analysis of pretreatment characteristics alone. This determinant helps to take the decision on offering stem cell transplant to MRD positive patients, on the background of resource constraints, and poor outcomes of CR2 transplants. [Display omitted] Figure 1: Overall Survival at 24 months: MRD positive vs. MRD negative DisclosuresNo relevant conflicts of interest to declare.

Risk-adapted, ofatumumab-based chemoimmunotherapy and consolidation in treatment-naïve chronic lymphocytic leukemia: a phase 2 study

High-risk cytogenetics and minimal residual disease (MRD) after chemoimmunotherapy (CIT) predict unfavorable outcome in chronic lymphocytic leukemia (CLL). This phase 2 study investigated risk-adapted CIT in treatment-naïve CLL (NCT01145209). Patients with high-risk cytogenetics received induction with fludarabine, cyclophosphamide, and ofatumumab. Those without high-risk cytogenetics received fludarabine and ofatumumab. After induction, MRD positive (MRD+) patients received 4 doses of ofatumumab consolidation. MRD negative (MRD-) patients had no intervention. Of 28 evaluable for response, all responded to induction and 10 (36%) achieved MRD-. Two-year progression-free survival (PFS) was 71.4% (CI95, 56.5–90.3%). There was no significant difference in median PFS between the high-risk and the standard-risk groups. Ofatumumab consolidation didn’t convert MRD + to MRD-. In the MRD + group, we saw selective loss of CD20 antigens during therapy. In conclusion, risk-adapted CIT is feasible in treatment-naïve CLL. Ofatumumab consolidation didn’t improve depth of response in MRD + patients. Loss of targetable CD20 likely reduces efficacy of consolidation therapy.

Early autologous and allogeneic peripheral blood stem cell transplantation for adult patients with acute B and T cell precursor neoplasms: a 12-year single center experience

Adult acute lymphoblastic leukemia/lymphoma (ALL/LBL) is a rare and heterogeneous malignancy characterized by uncontrolled proliferation of B or T cell precursor cells. Here, we retrospectively analyzed the outcome of early autologous stem cell transplantation in standard-risk patients in first complete remission (n=24) and of allogeneic transplantation in high and highest risk, and relapsed/refractory patients (n=35). The 10-year overall survival after autologous transplantation was 45%. The 10-year overall survival after allogeneic transplantation was 58%. The cumulative incidence of relapse was 29% after allogeneic and 67% after autologous transplantation. The cumulative incidence of non-relapse mortality was 0% after autologous and 12% after allogeneic transplantation. This retrospective single center analysis in a limited number of standard-risk patients clearly demonstrates that early autologous transplantation in first complete remission leads to an acceptable long-term outcome with a short overall treatment duration of less than 6 months compared with more than 2 years with conventional chemotherapy. More sensitive and standardized methods to detect minimal residual disease (MRD) will further help to identify those patients more accurately who are most likely to benefit from such a short and intensive treatment strategy (i.e., MRD negative standard-risk patients) or those who require early targeted therapy (e.g., blinatumomab) in case of MRD positivity. Early allogeneic transplantation results in long-term survival/cure in nearly two-thirds of all high and highest risk, and relapsed/refractory patients.

The Bone Marrow Microenvironment of Multiple Myeloma Long-Term Survivors at Single Cell Resolution

The Bone Marrow Microenvironment of Multiple Myeloma Long-Term Survivors at Single Cell Resolution

Weekly Carfilzomib, Lenalidomide, Dexamethasone and Daratumumab (wKRd-D) Combination Therapy in Newly Diagnosed Multiple Myeloma: Final Results from a Clinical and Correlative Phase 2 Study

Weekly Carfilzomib, Lenalidomide, Dexamethasone and Daratumumab (wKRd-D) Combination Therapy in Newly Diagnosed Multiple Myeloma: Final Results from a Clinical and Correlative Phase 2 Study

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 &amp;lt;10-4 (&amp;lt;0.01%) as negative, &amp;gt;10-4-&amp;lt;10-2 (&amp;gt;0.01%-&amp;lt;1%) as low-positive and &amp;gt;10-2 (&amp;gt;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.

Minimal Residual Disease Defines the Risk and Time to Biochemical Failure in Patients with Pt2 and Pt3a Prostate Cancer Treated With Radical Prostatectomy: An Observational Prospective Study.

To compare Gleason score (GS), pathological stage, minimal residual disease (MRD) and outcome after prostatectomy radical for prostate cancer. 290/357 men with GS 6 or 7 and pT2 or pT3a disease treated with radical prostatectomy participated. Blood and bone marrow were obtained one month after surgery. Circulating prostate cells (CPCs) were detected using differential gel centrifugation and immunocytochemistry with anti PSA, micro-metastasis weas detected using immunocytochemistry with anti-PSA. Biochemical failure free survival (BFFS) and restricted mean survival times (RMST) were calculated according to GS and stage. MRD was classified as negative, patients only positive for micro-metastasis and patients positive for CPCs; BFFS and RMST were calculated according to MRD sub-type. GS7 (HR 3.03) and pT3a (HR 3.68) cancers were associated with a higher failure rate, shorter time to failure and associated with CPC positive MRD (p < 0.001), while G6 and pT2 with MRD negative disease (p<0.001). Men with CPC (+) MRD were at high risk of early treatment failure; 15% BFFS at 10 years, RMST 3.0 years. Men positive for only micro-metastasis were at risk of late failure, 50% BFFS at 10 years, RMST 8.0 years compared with MRD negative patients; 80% BFFS at 10 years, RMST 9.0 years. The sub-type of MRD identifies Gleason 6 pT2 patients with a poor prognosis and Gleason 7 pT3a patients with a good prognosis and could be used to classify men according to personal risk characteristics for the use of adjuvant treatment.

Impact of Minimal Residual Disease Detected By Multiparameter Flow Cytometry on Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia Patients in First Complete Remission

Introduction. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be curative for acute myeloid leukemia (AML) patients. However, the disease relapse after allo-HSCT lead to poor outcomes almost in all cases. Minimal residual disease (MRD) is a strong prognostic marker of increased risk of relapse and reflects overall (OS) and relapse-free survival (RFS) in patients with AML. Immunophenotypic evaluation using multiparameter flow cytometry (MFC) is an important strategy for detecting MRD, because of its simplicity and wide availability. Aim. Determine the impact of MRD detected by MFC before allo-HSCT on clinical outcomes. Patients and methods. To assess the impact of MRD status before transplantation we include 56 AML patients who underwent allo-HSCT in National Research Center for Hematology between July 2016 and June 2019. Patient's characteristics are shown in table 1. All these patients were in first compete morphologic remission at the time of allo-HSCT. MRD was evaluated by MFC. Bone marrow samples were obtained before allo-HSCT and were analyzed by 6-color MFC (BD FACS Canto II, USA). Positive MRD was identified as a cell population deviating from the normal patterns of antigen expression on specific cell lineages at specific stages of maturation for all patients. In addition, for patients with LAIP at diagnosis, positive MRD was also defined as a cell population carrying LAIP markers at diagnosis. The probabilities of OS and RFS were estimated using the Kaplan-Meier method. Results. Among 56 AML patients before allo-HSCT (all were in CR at the time of MRD analysis). Median of follow-up was 9.3 months.11 patients (19,6%) were identified as MRD+ (0,011%-5,08%, mean 1%). And 5 of them relapsed (45,5%). Out of 45 MRD negative patients before HSCT relapse was registered in one (relapse rate 2,2%). Statistical analysis revealed significant differences between MRD- and MRD+ patients: MRD+ had much worse OS (22,9% vs. 85.5%, p=0.0047, Fig.1A) and RFS (26% vs. 97.4%, p&lt;0,0001, Fig.1B). Conclusions. Despite the presence of morphological CR before allo-HSCT, MRD persistence can lead to worse probabilities of OS and RFS, which is comparable to patients who were transplanted in relapse. Because of the association between MRD and relapse risk, it can be assumed, that testing for MRD before allo-HSCT may help to identify a subgroup of patients at high risk of relapse who might benefit from preemptive posttransplantation treatment. Disclosures No relevant conflicts of interest to declare.

Effect of FOLFOX on minimal residual disease in Stage III colon cancer and risk of relapse.

Introduction25% of Stage III colon cancer patients relapse within 5 years due to minimal residual disease (MRD) not eliminated by surgery and chemotherapy. We hypothesise that sub-types of MRD, defined by circulating tumour cells (CTCs) and bone marrow micro-metastasis (mM) have different types and kinetics of relapse.Patients and MethodsOne month of curative surgery and 1 month after completing six cycles of FOLFOX chemotherapy blood and bone marrow samples were taken to detect CTCs and mM using immunocytochemistry with anti-carcino-embryonic antigen (CEA). Follow up was up to 5 years or disease progression defined as new images on CT scanning. Survival curves using Kaplan–Meier (KM) and Restricted Mean Survival Time (RMST) were calculated for three prognostic groups: CTC and mM negative, CTC negative mM positive, and CTC positive.Results76 patients (39 men) participated, mean age 67 years, median follow-up 3.6 years. The response to chemotherapy was heterogeneous and MRD pre-treatment did not predict response to therapy. Of 21 patients MRD (−), 20 remained MRD negative and one patient became mM (+); of 21 patients mM (+), 10 became MRD (−), 8 remained the same and 3 became CTC (+); of the 34 CTC positive, 8 became MRD (−), 8 with only mM, and 18 remained positive.After chemotherapy, 38 patients were negative for CTC and mM, 17 were positive for only mM, and 21 for CTCs. For the whole cohort, the 5 year KM was 58%, the median survival was not reached. For the three prognostic groups, the KM 5-year survivals were 87%, 58%, and 4%, respectively, the median survival for patients MRD negative and mM only was not reached. RMST for the whole cohort was 3.6 years, for the three prognostic groups the RMST was 4.6 years, 4.0 years, and 1.5 years, respectively. Serum CEA was significantly higher pre-surgery in the CTC positive group. There were no significant differences with respect to age or sex between the three groups.ConclusionsMRD subtypes pre-chemotherapy did not predict treatment response. Post-chemotherapy MRD subtypes were associated with the pattern of failure and time to failure. MRD negative patients had an excellent prognosis with 87% disease-free survival at 5 years. Those with only mM had a similar outcome up to 2 years and then were at increasing risk of late failure. Patients who were CTC positive had a high risk of early failure. MRD subclassification may be useful to define the risk of relapse in Stage III colon cancer patients and warrants further studies with a larger number of patients.

PF266 COMBINING FLOW CYTOMETRY‐BASED LEUKEMIC CELL ENRICHMENT AND MUTATIONAL ANALYSIS FOR DETECTION OF RESIDUAL DISEASE IN ACUTE MYELOID LEUKEMIA: A PILOT STUDY

Background:Persistent minimal residual disease (MRD) is an independent prognostic marker in acute myeloid leukemia (AML) that has become increasingly important for risk stratification and treatment planning. MRD can be evaluated by multi‐parameter flow cytometry (MFC) and molecular methods including PCR‐based methods detecting leukemia‐specific fusion transcripts and targeted deep sequencing of genes recurrently mutated in AML. However, while MFC is highly operator‐dependent, PCR‐based methods are only available for a minority of AML patients. In addition, targeted deep sequencing approaches are hampered to distinguish between mutations responsible for preleukemic clonal hematopoiesis and true leukemia‐specific mutations.Aims:In this study we aimed for developing a highly sensitive and broadly applicable method for MRD detection in AML by combining MFC‐based leukemic cell enrichment followed by mutational analysis.Methods:To identify markers suitable for leukemic cell enrichment, AML samples from 150 newly diagnosed patients were analyzed for 24 surface markers using MFC with a strictly standardized protocol. In 25 cases, samples were also available at relapse. To assess the normal hematopoietic stem and progenitor cell (HSPC) compartments normal bone marrow (BM) samples were obtained from 12 lymphoma patients without any evidence of disease in the BM. For validation of our method, BM samples were prospectively collected from a total of 42 patients in complete remission (CR) after induction chemotherapy. Mutational analysis of sorted leukemic cell enriched samples was done using targeted deep sequencing of 39 recurrently mutated genes using an Ion Torrent sequencing platform. In some NPM1‐mutated samples analysis was performed using a mutation‐specific digital droplet PCR assay.Results:A combination of antibodies against CLL‐1, TIM‐3, CD123 and CD117 was identified to perform best for leukemic cell enrichment by enabling staining of &gt;90% of AML cells in 137 of 150 diagnostic AML samples (91.3%) and in 25 of 25 (100%) relapse samples. In dilution experiments using NPM1‐mutated samples and normal BM, leukemic cell enrichment by these markers followed by mutational analysis showed a sensitivity of 10–5 for residual disease detection. In contrast, NPM1‐mutations were not detected in cells negative for the marker combination in dilutions higher than 1:100. Using this marker combination for cell sorting allowed a 30‐ to 250‐fold cell enrichment in prospectively collected BM samples of 42 patients in complete remission. In 39 samples DNA quality of sorted cells was sufficient for sequencing. Twenty‐one samples tested MRD positive whereas 18 were negative. With a median follow‐up of 372 days 71% of MRD positive (15/21) and 28% (5/18) of MRD negative patients relapsed (p = 0.007). Accordingly, median relapse free survival was significantly longer in MRD negative patients (497 vs. 242 days, p = 0.0035). Of note, in 8 out of 10 MRD positive remission samples, in which we also analyzed marker negative cells, mutations were exclusively found in marker positive cells emphasizing the importance of MFC‐based cell enrichment prior to sequencing.Summary/Conclusion:MFC‐based leukemic cell enrichment using antibodies against CLL‐1, TIM‐3, CD123 and CD117 followed by mutational analysis is feasible for MRD detection with high sensitivity and informative on relapse risk in AML patients. Standardization of this method as well as its comparability to other approaches of MRD detection need to be evaluated in a multi‐center clinical trial.

PS1011 MEASURABLE RESIDUAL DISEASE BY MULTIPARAMETRIC FLOW‐CYTOMETRY IS A RELIABLE TOOL FOR RISK‐STRATIFICATION OF FLT3‐MUTATED AML PATIENTS

Background:Mutations of the gene encoding Fms Related Tyrosine Kinase 3 (FLT3), both at the tyrosine kinase domain (TKD) and the juxta‐membrane level (ITD), represent the most common lesions found in Acute Myeloid Leukemia (AML),identifying a subgroup of patients with mainly unfavorable prognosis.FLT3 mutations are considered an unreliable tool for measurable (previously minimal) residual disease (MRD) monitoring, due to their intraclonal heterogeneity and instability during the course of disease. Instead, multiparametric flow cytometry (MFC) may represent a reliable tool to monitor MRD in this molecular subset. In fact,through the recognition and monitoring of leukemia associated immunophenotypes,MFC is applicable in up to 90% of AML patients with a sensitivity up to 10–4.Aims:The aim of our study was to investigate the feasibility of MRD assessment by MFC in FLT3 mutated AML. Furthermore, we investigated if MRD persistence in FLT3 mutated AML affects prognosis in terms of overall (OS) and disease‐free survival (DFS), as compared with FLT3 wildtype ones.Methods:We retrospectively analyzed a series of 39 patients with de novo AML carrying FLT3 mutations (34/39,87% ITD, 2/39, 5% TKD, 3/39, 8% ITD/TKD). We compared MRD status and clinical outcome with a matched group of FLT3 wildtype AML (n = 128). Both groups were treated according to intensive EORTC/GIMEMA protocols. MRD was measured by MFC at the post‐consolidation timepoint. Patients were defined as MRD‐negative, when obtaining a residual leukemic cells (RLCs) count below the threshold of 3.5x10–4 (0.035%).Results:Overall median age was 47 (range 17–72). The 2 cohorts were balanced in terms of age and sex distribution. In the FLT3 mutated group, 22 out of 37 (59%) cases carried a concomitant NPM1 mutation vs 32 out of 124 (26%) of FLT3 wildtype ones (p &lt;0.001). Furthermore, FLT3 mutation was significantly associated with a WBC count &gt;50x109/L (20/39, 51%) vs 30/128 (23%) of those FLT3 wildtype (p &lt; 0.001). Post remission treatment allocation was different between FLT3 mutated patients as compared to. FLT3 wildtype ones; 16 out of 39 (41%) FLT3 mutated patients were submitted to allogenic stem cells transplantation (ASCT) as compared to 34 out of 128 (27%) FLT3 wildtype ones (p = 001). At the post‐consolidation time‐point, MRD negativity rate was significantly lower in FTL3 mutated patients (4/39, 10%) as compared to those FLT3 wildtype (40/128, 31%), (p = 0.009). In particular, 32 out of 35 (91%) FLT3 mutated patients were above the ELN recommended threshold of positivity (0.1%) and 11/35 (31%) were above 1% of RLC.Among FLT3 mutated patients, OS was significantly longer for patients obtaining MRD‐negativity as compared to those who did not (67% vs. 31%, p = 0.9). As for as DFS, we observed the same difference for MRD negative patients vs. MRD positive ones (67% vs. 29%, p = 0.8). The negative impact of MRD was proportional to the amount of RLC at post‐consolidation time‐point (Figure 1) (p = 0.045). However, among FLT3 mutated patients, ASCT was the only post remission treatment allowing a prolonged OS to be achieved as compared to autologous SCT or standard chemotherapy (4‐years OS 63% vs. 0% vs. 15%, p = 0.019, respectively).Summary/Conclusion:In conclusion, MRD as measured by MFC is a biomarker of response also in FLT3 mutated patients. In these patients, ASCT delivery is associated with a satisfactory long term outcome, however a longer duration of response can be pursued by administering FLT3 inhibitors before or after transplant, in order to improve the quality of remission and prevent leukemic recurrence.image

Impact of minimal residual disease detection after treatment of multiple myeloma

Prognostic impact of the detection of minimal residual disease (MRD) in multiple myeloma (MM) has been confirmed in numerous studies. Retrospective examination of our patient database (107 newly diagnosed multiple myelomas between 2007 and 2017). Flow cytometry (FCM) was performed as MRD assessment. MRD assessment was performed in 56 patients (median age: 68 years), after induction treatment of multiple myeloma. The treatment contained bortezomib in 91%, autologous haematopoetic stem cell transplantation (ASCT) was perfomed in 50%. MRD detection was performed on bone marrow samples, predominantly in our hospital (BD FACScan, 3 colour, panel: CD38, CD138, CD19, CD45, CD56, CD28, CD117, cyKappa, cyLambda, 100000 events). SPSS 13.0. The progression-free survival (PFS) and the overall survival (OS) were significantly longer in MRD negative (n = 22) patients (PFS: 54 months, OS: 79% after 5 years) than MRD positive patients (n = 34, PFS: 22 months, OS 21% after 5 years, p = 0.001). Patients achieving complete response (CR) (n = 29) have different PFS (MRD negative CR: 60 months, MRD positive CR: 21 months, p<0.001). Patents achiving MRD negative very good partial response (n = 5) have similar PFS (54 months) as patients with MRD negative CR. The longest PFS (68 months) was observed in MRD negative patients, after ASCT (n = 11), while the PFS was significantly (p<0.001) shorter in patients who were MRD positive after ASCT (n = 18, PFS: 25 months), similarly in MRD positive patients without ASCT (n = 15, PFS 21 months). Cox regression analysis (stage, cytogenetic risk, ASCT) confirmed that MRD is an independent prognostic factor of PFS and OS. We did not find significant relationship between MRD and stage, cytogenetic risk, number of treatment cycles, ASCT. The depth of response after induction treatment of MM is an independent predictor of survival. MRD assessment with FCM is recommended to define response. Consideration of maintenance treatment in MRD positive patients and eradication of MRD are also recommended. Orv Hetil. 2019; 160(13): 502-508.

Minimal Residual Disease (MRD) Assessment before and after Autologous Hematopoietic Cell Transplantation (AutoHCT) and Maintenance for Multiple Myeloma (MM): Results of the Prognostic Immunophenotyping for Myeloma Response (PRIMeR) Study

PRIMeR is the first U.S.-based ancillary study of MRD assessment by multiparameter flow cytometry (MFC). Patients were enrolled on a national 3-arm RCT (BMT CTN 0702, STAMiNA trial, ClinicalTrials.gov Identifier: NCT01109004) comparing 1) tandem auto-HCT, 2) single auto-HCT and 3) single auto-HCT, 4 cycles of lenalidomide, bortezomib, dexamethasone consolidation (auto+RVD); all 3 treatment arms included continuous lenalidomide maintenance until MM progression. STAMiNA opened to accrual before PRIMeR initiated, therefore 437 of 758 patients enrolled in STAMiNA provided consent and at least one analyzable sample for MRD by MFC to PRIMeR. Disease responses and progressions were adjudicated by an independent review committee. All analyses of treatment arm were performed using intent-to-treat. The MFC panel included 10 monoclonal antibodies (CD38, CD138, CD45, CD56, CD19, CD20, CD27, CD28, kappa, lambda) measured via 3 tubes of 6 colors each with a target of analyzing 2.5 × 105-1.5 × 106 events, depending on sample quality and quantity, yielding a sensitivity of 10−5 to 10−6. All samples were interpreted by two experienced flow cytometrists who were blinded to treatment arm and other patient, disease and treatment characteristics. MRD was assessed at Baseline/pre-AutoHCT (BL), Pre-maintenance (PM), and 1 year (Y1) post AutoHCT with the primary endpoint of MRD negative at Y1. At a median follow-up of 38 months, there was no significant difference in PFS or OS by treatment arm in the subset of PRIMeR patients. Univariate analysis demonstrated that being MRD negative at PM and Y1 was associated with better PFS, and at Y1, patients who were MRD negative also had longer OS (Table 1, Figures). Multivariate analysis of time to progression or death, adjusting for disease risk, demonstrated hazard ratios (HR) in MRD negative patients compared to MRD positive patients at BL, PM and Y1 were 0.66 (p=0.07), 0.48 (0

Depth of Response and Outcomes in Patients with Multiple Myeloma Undergoing Autologous Stem Cell Transplantation

Background: For multiple myeloma (MM) patients, depth of response after induction therapy and after autologous hematopoietic stem cell transplantation (AHCT) has been shown to be important for progression free (PFS) and overall survival (OS) in some studies. Furthermore, the impact of minimal residual disease (MRD) on outcomes and treatment decisions has been widely discussed. We aimed to evaluate outcomes by depth of response after induction and AHCT.Methods: MM patients who received their first AHCT within 1 year of starting induction were identified from the institutional registry. MRD was assessed by non-10 color flow cytometry. Response was defined by the International Myeloma Working Group criteria. Summary statistics were used to describe the population. Kaplan-Meier methodology estimated PFS and OS by response status pre-AHCT and at post-AHCT restaging.Results: Between 2012 - 2014, 182 MM patients met our inclusion criteria, with 83% alive at last follow-up. The median age at AHCT was 60 years (range 29-76) with 57% male. By the International Staging System (ISS), 50% were stage I, 26% stage II, and 24% stage III. High risk cytogenetics were detected in 24%. Isotype was IgG in 55%, IgA 21%, Kappa Free Light Chain (KFLC) 11%, and lambda FLC (LFCL) 9%. First induction therapy included bortezomib in 90% and lenalidomide in 79%. Median time to AHCT was 5.5 months (range 2.8-11.7). The median follow-up from AHCT was 3.7 years (range 0.22 - 4.6 years), with 84% of patients receiving lenalidomide maintenance, and 9% receiving an additional autologous or allogenic transplant at relapse.Response prior to the initial AHCT was a complete remission (CR) in 13.7% (MRD negative 6.6%, positive 4.4%, unknown 2.7%), very good partial remission (VGPR) 38%, partial remission (PR) 40%, stable disease (SD) 5%, and progressive disease (PD) 4%. At post-AHCT restaging, responses had improved to 42% CR (MRD negative 23%, positive 6%, unknown 13%), 35% VGPR, 19% PR, 2% SD, and 3% PD.Median PFS from AHCT for the entire cohort was 3.2 years (95% CI 2.4 - 4 years) with 1-year and 3-year PFS 85% and 52%, respectively. Median OS was not reached (NR) (95% CI 4.4 years - NR) with 1-year and 3-year OS 97% and 88%, respectively (Figure 1).PFS from AHCT was significantly longer in patients with an MRD negative CR prior to AHCT with median PFS not reached (95% CI 1.7 - NR) compared to MRD positive/unknown CR, VGPR, and ≤ PR [3.64 years (95% CI 1.09-3.64), 3.46 years (95% CI 2.4 - NR), and 2.44 years (1.68-3.56 years), respectively, p=0.048] (Figure 2A). From post-AHCT restaging, PFS was also significantly longer in patients with an MRD negative CR prior to AHCT with median PFS not reached compared to MRD positive/unknown CR, VGPR, and ≤ PR [3.49 years (95% CI 0.86-3.49), 3.56 years (95% CI 2.5 - NR), and 2.4 years (1.6-3.33 years), respectively, p=0.026] (Figure 2B). However, there was no difference in PFS based on the post-AHCT restaging with median PFS in MRD negative CR, MRD positive/unknown CR, VGPR, and ≤ PR of 3.49 years (95% CI 2-NR), not reached (95% CI 1.4-NR), 2.96 years (95% CI 1.7-NR), and 2.86 years (95% CI 1.7 - NR) (p=0.78, Figure 2C), respectively.OS from AHCT was not significantly different by pre-AHCT response, and the median was not reached in any group (p=0.33, Figure 3A). Finally, the median OS from post-AHCT restaging by pre-AHCT response or by post-AHCT response was also not reached in any group (p=0.32 and 0.31, respectively; Figure 3B & C).Conclusion: For MM patients, AHCT deepened responses and increased the CR rate. We were unable to show a significant difference in outcomes at post AHCT restaging, which may be due to the effect of maintenance therapy, the small numbers of MRD negative patients, or the sensitivity of the MRD assay available during this time period, though potentially show that MRD positive patients do as well as MRD negative patients after AHCT. We plan to add additional patients treated in the more recent years who were assessed by more sensitive methods. DisclosuresShah:Janssen: Research Funding; Amgen: Research Funding. Korde:Amgen: Research Funding. Lesokhin:Janssen: Research Funding; Genentech: Research Funding; Takeda: Consultancy, Honoraria; Serametrix, inc.: Patents & Royalties: Royalties; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Squibb: Consultancy, Honoraria. Mailankody:Janssen: Research Funding; Physician Education Resource: Honoraria; Takeda: Research Funding; Juno: Research Funding. Smith:Celgene: Consultancy, Patents & Royalties: CAR T cell therapies for MM, Research Funding. Landgren:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy; Merck: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Survival of AML Patients Relapsing after Hematopoetic Stem Cell Transplantation: A Single Center Experience

Although it is presumed to be a curative strategy for intermediate and high risk acute myeloid leukemia (AML), many patients relapse after allogeneic hematopoietic stem cell transplantation. This prompt us to examine the ways to improve the outcomes. We retrospectively evaluated 76 AML patients who were transplanted between 2007-2017 years in our clinic. We tried to identify the factors associated with posttransplant relapse, postrelapse survival and if there was a survival benefit of pretransplant consolidation and minimal residual disease (MRD) negativity. We examined the effect of the acute-chronic graft versus host disease (GVHD) and salvage therapy after the posttransplant relapses. The mean age of the patients was 44.6±1.21 years (ranges 21-67). 42.1% were females and 57.9% were males. 43.3% of the patients were in complete remission (CR) MRD positive state before the transplantation whereas 35.5% were in CR MRD negative and 3.9% were in progressive disease state. In 13 patients who were in CR state, the MRD status were not known. 11 (14.5%) patients were considered as in favorable risk, 52 (68.4%) in intermediate risk and 13 (17.1%) in unfavorable risk with respect to cytogenetic analysis before the transplantation. The donors were HLA compatible relatives (77.6%), HLA compatible non-relatives (10.5%), haploidentical people (9.2%), one HLA incompatible relative (1.3%) and one HLA incompatible nonrelative (1.3%). 74 bone marrow transplantations (97.4%) were allogeneic and the remaining two (2.6%) were autologous. Myeloablative conditioning regimen was applied to 57 patients (75%) and 19 patients got (25%) reduced intensity conditioning regimen. GVHD developed in 51.3% after transplantation and 61.5% of these were chronic extensive. Relapse occurred in 27 patients (35.5%), hematological relapse being the most common (31.6%). The median time for the development of relapse was found to be 5.5 months (range: 1.5-37). The overall probability for the development of a relapse was found to be 48.7% (95% CI: 40.9-56.5)(Figure1A). 23 patients (30.3%) died during the study period with a median survival of 9.6 months (range: 1.6-45). In the studied population the overall survival probability was found to be 52.8% (95% CI: 45.4 - 60.2) [Figure 1B]. 36.4%, 28.8% and 30.8% of the patients with favorable, intermediate and unfavorable cytogenetic status died respectively during the study period. The comparison of the survival probability of the patients with favorable, intermediate and unfavorable cytogenetic status was depicted in Figure 2. The overall survival probability of the patients with favorable, intermediate and unfavorable cytogenetic status were 46.6% (95% CI: 26.2-66.9), 54.6% (95 % CI: 45.9 - 63.2) and 36.9 % (95% CI: 25.4 - 48.5) respectively (p=0.807).MRD status of 60 patients were known. At the end of the study period 75.8% of the CR MRD positive and 70.4% of the CR MRD negative patients remained alive. The comparison of the survival of patients in CR with respect to MRD status is shown in Figure 3. The overall survival probability of CR MRD positive patients was 56.3 % (95% CI: 45.3 - 67.3) and this rate was 52.5 % (95% CI: 40.8 - 64.3) in MRD negative patients (p=0.770) [Figure 3].Patients who developed GVHD had similar overall survival probability with the patients who did not developed the disease; 47.0% vs 57.2%, p=0.115 (Figure 4A). Even the patients with chronic extensive GVHD had similar overall survival rates with the patients who had none or acute GVHD; 49.3 % vs 58.2%, p=0.27 (Figure 4B).66.7% of the patients with a progressive disease before the transplantation died during the study period and this rate was 27.1% in the patients with CR (p=0.005).In conclusion the overall survival rate of the transplanted AML patients was 52.8% in the study group. The overall survival did not seem to be affected by pre-transplant MRD status, cytogenetic risk factors and administration of consolidation therapy. The only patients who had significantly worse results were the ones who had progressive disease before the transplantation. From this point it would be logical to make transplantation whenever the patient is in first CR regardless of the MRD status and a matched donor is found so that the toxic effects of the consolidation chemotherapy may be prevented. DisclosuresNo relevant conflicts of interest to declare.

The Prognostic Significance of Minimal Residual Disease Detection after Induction and ASCT to the Patients with Multiple Myeloma

Objective: In the last decade the outcome in multiple myeloma in CHINA has greatly improved due to the new, effective therapies including PIs and Imids. But responses to treatment and survival remains heterogeneous because of patient characteristic, disease biology and mechanisms of drug resistance. More and more studies have established the link between depth of response and improved PFS and OS. multiparameter-flow cytometry (MFC) is a main method to detect minimal residual disease(MRD) in myeloma. Sensitivity will be at least at 10-4 to 10-5 by 10-color MFC. Imaging techniques such as PET-CT are important for EMD and bone MRD detection. whole body DWI-MRI is a new imaging technique by mean of the apparent diffusion coefficient(ADC) which can qualify the depth of response to antineoplastic treatment. This study was designed to evaluate the prognostic significance of MRD by 10-color MFC and imaging to the MM patients after induction.Methods: 102 patients with newly diagnosed MM were enrolled at the First Affiliated Hospital of Soochow University from July 2015 to July 2017. All patients were diagnosed and the response were assessed by IMWG criteria. The median of age was 58 (31-75).There were 46 patients with IgG type , 24 IgA , 14 light chain, 18 others. 34 Patients in ISS stageⅠ,34 in stage Ⅱ, 30 in stage Ⅲ. All patients received 4-6 cycles of triplet bortezomib based or lenalidomide based induction therapy. Transplantation available patients received APBSCT with BUCY condition followed by 4-6 cycles of bortezomib based or lenalidomide based consolidation which were given to transplantation unavailable patients too. Lenalidomide and thalidomide were used for over 2y of maintenance therapy. Bone marrow aspirates for MRD imaging MRD assessment were obtained at the end of induction and 1year after ASCT.The median of follow-up was 13 (2-29) months.Results: According to MRD by MFC and imaging after induction therapy and 1 year after ASCT, the patients were divided into different groups. MFC negativity was 33%(29/88) after induction therapy compared with 63%(32/51) after ASCT (X2=11.636,P=0.001). After induction therapy, the median PFS was 22 months for MRD positive group compared with not reached with MRD negative group by MFC (P=0.042) in patients with very good partial remission(VGPR) and above. The 2 years PFS was 100% for those with MRD negative compared with 60% for MRD positive by imaging. The 2 years PFS was 80% for those have multiclonal normal plasma cells compared with 52.6% for those without. The median PFS was not reached for MFC MRD negative patients 1 year after ASCT compared with 20 months for positive patients. (P=0.002). Multivariate analysis including high risk cytogenetics(17p-, t(4;14), t(14;16)), sex, age, ISS, chemotherapy, ASCT, CR/VGPR, normal PCs showed that the MFC MRD and ASCT were independent prognostic factor.Conclusions: Patients with MFC MRD negative after induction therapy or ASCT is a better prognostic marker than CR or even the best marker. Imaging MRD negativity and the appearance of normal plasma cells in the bone marrow suggests a better prognosis.We will have a try to do more research on overall survival(OS),include longer follow-up and a larger number of patients enrolled. DisclosuresNo relevant conflicts of interest to declare.

Long-Term Follow-Up of the Gem2010 Trial of Bortezomib-Melphalan-Prednisone and Lenalidomide-Dexamethasone in Elderly, Newly Diagnosed Multiple Myeloma Patients: Impact of Age, High-Risk Cytogenetics and Minimal Residual Disease

Background: Bortezomib plus melphalan and prednisone (VMP) and lenalidomide plus lowdose dexamethasone (Rd) are standards of care for elderly untreated multiple myeloma patients. Methods: We did a phase 2b, parallel-group, multicentre, open-label randomised trial at 44 hospitals in Spain. We randomly assigned 242 patients (1:1) to receive 9 cycles of VMP followed by 9 cycles of Rd or alternating cycles of VMP and Rd for 18 cycles. The primary endpoints were 18-month progression-free survival and safety profile, which were similar between arms at an initial analysis after a median follow-up of 30·3 months. We did an updated pooled analysis of progression-free and overall survival, overall and by age, cytogenetic risk and minimal residual disease status. Findings: After a median follow-up of 51 months, the median progression-free survival and overall survival were 31·2 and 63·5 months, respectively. The median progression-free survival was 33, 32, and 24 months for patients aged 65-75, 75-80, and >80 years, respectively, (p=0·017); median overall survival was not reached vs 57 vs 33 months (p<0·0001). In patients with high-risk versus standard-risk cytogenetics the median progression-free survival was 26 versus 33 months (p=0·3). Patients who were minimal residual disease-negative had 5-year progression-free and overall survival rates of 57% and 76%, respectively. Interpretation: VMP plus Rd represents a feasible option for patients aged up to 80 years, with excellent outcomes in minimal residual disease-negative patients. Clinical Trial Number: This trial is registered with ClinicalTrials.gov (NCT01237249). Funding Statement: Spanish Ministry of Health; European Regional Development Fund; Asociacion Espanola contra el Cancer. The trial was sponsored by PETHEMA (Spanish Programme for the Treatment of Haematological Diseases) Declaration of Interests: MVM reports personal fees from Janssen, Celgene, Takeda and Amgen, outside the submitted work. EO reports personal fees from Novartis, Takeda, Abbvie, Pharmamar, Seattle Genetics, Amgen, Celgene, BMS, Janssen, Array Pharmaceuticals, Mundipharma and Sanofi, outside the submitted work. LR reports honoraria from Janssen, Celgene and Amgen. AO reports membership of advisory boards for Janssen and Amgen, participation in sponsored events for Amgen, Janssen and Takeda, and provision of expert opinion for Celgene. JPdO reports consultancy with Celgene and Janssen. BP reports personal fees from Amgen, grants and personal fees from Celgene, personal fees from BMS, personal fees from Janssen, grants and personal fees from Sanofi, personal fees from Novartis, grants from EngMab, and grants and personal fees from Takeda, during the conduct of the study. NP reports personal fees from Celgene and Janssen, outside the submitted work. JB has received honoraria for lectures from Celgene, Janssen and Amgen. JSM reports membership of advisory boards for Amgen, BMS, Celgene, Janssen, MSD, Novartis, Takeda, Sanofi, and Roche. All other authors declare no competing interests. Ethics Approval Statement: The institutional review board and/or independent ethics committee of each participating centre approved the study (See page 76, 77 of the report for the list of the IEC's). All patients provided written informed consent before screening in accordance with the Declaration of Helsinki. Data were monitored by an external contract research organisation and centrally assessed.

Predictive value of minimal residual disease in Philadelphia-chromosome-positive acute lymphoblastic leukemia treated with imatinib in the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia, based on immunoglobulin/T-cell receptor and BCR/ABL1 methodologies

The prognostic value of minimal residual disease (MRD) in Philadelphia-chromosome-positive (Ph+) childhood acute lymphoblastic leukemia (ALL) treated with tyrosine kinase inhibitors is not fully established. We detected MRD by real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes (IG/TR) and/or BCR/ABL1 fusion transcript to investigate its predictive value in patients receiving Berlin-Frankfurt-Münster (BFM) high-risk (HR) therapy and post-induction intermittent imatinib (the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia (EsPhALL) study). MRD was monitored after induction (time point (TP)1), consolidation Phase IB (TP2), HR Blocks, reinductions, and at the end of therapy. MRD negativity progressively increased over time, both by IG/TR and BCR/ABL1. Of 90 patients with IG/TR MRD at TP1, nine were negative and none relapsed, while 11 with MRD<5×10−4 and 70 with MRD≥5×10−4 had a comparable 5-year cumulative incidence of relapse of 36.4 (15.4) and 35.2 (5.9), respectively. Patients who achieved MRD negativity at TP2 had a low relapse risk (5-yr cumulative incidence of relapse (CIR)=14.3[9.8]), whereas those who attained MRD negativity at a later date showed higher CIR, comparable to patients with positive MRD at any level. BCR/ABL1 MRD negative patients at TP1 had a relapse risk similar to those who were IG/TR MRD negative (1/8 relapses). The overall concordance between the two methods is 69%, with significantly higher positivity by BCR/ABL1. In conclusion, MRD monitoring by both methods may be functional not only for measuring response but also for guiding biological studies aimed at investigating causes for discrepancies, although from our data IG/TR MRD monitoring appears to be more reliable. Early MRD negativity is highly predictive of favorable outcome. The earlier MRD negativity is achieved, the better the prognosis.

Effect of minimal residual disease monitoring by multiparameter flow cytometry pre-conditioning on prognosis of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation

目的分析预处理前多参数流式细胞术（MFC）监测的骨髓微小残留病（MRD）对急性髓系白血病（AML）异基因造血干细胞移植（allo-HSCT）预后的影响，探讨MFC监测MRD在AML allo-HSCT预后评估中的价值。方法回顾性分析2012年4月至2015年3月行allo-HSCT的186例AML患者，预处理前骨髓细胞形态学均达第1次完全缓解（CR1）。采用8色MFC对预处理前骨髓进行MRD检测，任何水平异常均定义为MRD阳性。结果①186例AML患者中151例MRD阴性；35例MRD阳性，其中25例MRD<1%，10例MRD为1%~3%。②2年总体无病生存（DFS）率为80.0%（95% CI 68.5%~92.3%）。与MRD阴性组比较，MRD阳性组DFS率低[62.9%（95% CI 50.6%~75.2%）对88.9%（95%CI 76.6%~100.0%），P<0.001]、复发率高[11.4%（95%CI 4.1%~29.0%）对3.3%（95%CI 0.6%~20.9%），P=0.003]、非复发死亡率（NRM）高[25.7%（95%CI 8.1%~43.3%）对7.9%（95%CI 1.3%~26.5%），P=0.001]。继发性AML组DFS率低（P=0.004），NRM高（P=0.003）。③多因素分析结果显示预处理前MFC检测的MRD阳性是DFS[HR=4.565（95%CI 2.918~9.482），P<0.001]、复发[HR=5.854（95% CI 1.538~22.288），P=0.010]及非复发死亡[HR=3.379（95%CI 1.361~8.391），P=0.009]的独立危险因素。结论预处理前MFC监测的MRD阳性是影响allo-HSCT治疗CR1-AML独立危险因素，MFC监测MRD可用于AML allo-HSCT的预后评估。