scholarly journals Duplex Sequencing for Ultra-Low Frequency Measurable Residual Disease Detection in Adult Acute Myeloid Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3475-3475
Author(s):  
Jacob Higgins ◽  
Megan Othus ◽  
Laura W. Dillon ◽  
Thomas H. Smith ◽  
Elizabeth Schmidt ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Advisory Committees ◽  
Diagnostic Samples ◽  
Duplex Sequencing ◽  
Measurable Residual Disease ◽  
Acute Myeloid ◽  
Time Point

Abstract Background: The presence of measurable residual disease (MRD) is strongly associated with treatment outcomes in acute myeloid leukemia (AML). However, > 20% of MRD negative cases (as assessed by flow cytometry) subsequently relapse. We sought to determine if ultrasensitive Duplex Sequencing (DS), which relies on double-stranded consensus-making to achieve an error rate below one-in-ten-million, yields better prognostic performance via molecular MRD detection. Methods: Retrospective targeted DNA sequencing of 29 genes recurrently mutated in adult AML was performed on paired diagnostic and remission bone marrow samples from patients enrolled on the SWOG trial S0106 (randomized 7+3 versus 7+3 + gemtuzumab ozogamicin (GO)). Patients were selected if they had remission samples with flow cytometry results (n=67). Non-error corrected sequencing was performed on diagnostic samples (average depth 279x) and DS was performed on remission samples (average duplex molecular depth 27,002x). For each patient, potential germline variants were identified and excluded from the analysis if the variant allele fraction (VAF) was ≥ 35% at both diagnosis and remission, or ≥ 40% at either time point and a gnomAD allele frequency ≥ 0.05. Somatic variants present at diagnosis were classified as potentially deleterious if computationally predicted as such and with a VAF ≥ 5% (≥ 1% for FLT3-ITD/NPM1 insertions). For analysis of residual disease in remission, we evaluated the following outcomes (events): overall survival (OS; death), relapse-free survival (RFS) and time to relapse (TTR; relapse with death a competing event). All outcomes were measured from date of morphologic remission to date of event, with patients without event censored at date of last contact. Associations between residual disease and outcomes were assessed using Cox regression models (cause-specific model for TTR). Results: The median age was 48 years (range 8-60). 32 patients were randomized to 7+3 and 30 to 7+3+GO. A total of 172 potentially deleterious variants were identified in the diagnostic samples. Variants had an average VAF of 31% (range 1.4-91.5%) at diagnosis and were detected in 23 of the 29 genes, with FLT3 being the most frequently mutated. Of the 67 patients analyzed, 93% (n=62) had at least one variant detected at diagnosis (median 2, range 0-9) and 68% (n=42) had at least one residual diagnostic variant also found in the remission sample. We defined the presence of DS MRD as non-DTA (DNMT3A, TET2, ASXL1) time-of-diagnosis mutations identified at the remission time point with a VAF > 0.1% and/or an NPM1 VAF > 0.01% (PMID:31860405). DS MRD was strongly associated with all outcomes, with hazard ratios (and 95% CI) for TTR: 7.1 (2.7-18.9); RFS: 4.9 (2.2-10.9) and OS: 5.1 (2.1-12.3). As a comparator, we correlated treatment outcomes with the results of a flow cytometry MRD assay previously carried out on the same samples during the S0106 trial. The prognostic association of flow MRD with TTR, RFS and OS was less strong (i.e., a smaller hazard ratio) than DS MRD, with TTR: 2.5 (0.9-6.7); RFS: 2.2 (0.9-5.4) and OS: 2.4 (1.0-6.1). RFS and TTR for DS MRD and flow cytometry are plotted below for the 62 patients with a variant detected at diagnosis. Comparing DS MRD with flow cytometry, discordance was found in 20 cases: 15 cases where DS was positive and flow negative, and 5 cases in the opposite direction. Among the 15 discordant cases with DS positive and flow negative, 9 relapsed and 2 died without relapse and 4 were alive without relapse at last contact. Among the 5 discordant cases with DS negative and flow positive, 1 relapsed, 1 died without relapse, and 3 were alive without relapse at last contact. Conclusions: Among the 67 patients evaluated in this prospectively collected study, the presence of MRD defined by DS was strongly associated with adverse disease outcomes. The vast majority of patients had at least one time-of-diagnosis mutation that could be tracked as a measure of MRD. When compared with flow cytometry, DS exhibited superior negative and positive predictive values for foretelling future relapse, although this could potentially reflect the historical version of the flow cytometry assay used. These findings suggest that DS is a powerful tool that could be used in patient management and for early treatment assessment in clinical trials. Figure 1 Figure 1. Disclosures Hourigan: Sellas: Research Funding. Radich: Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees.

scholarly journals A Prospective Phase 2 Study of Venetoclax and Low Dose Ara-C (VALDAC) to Target Rising Molecular Measurable Residual Disease and Early Relapse in Acute Myeloid Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1261-1261
Author(s):  
Ing S Tiong ◽  
Sun Loo ◽  
Emad Uddin Abro ◽  
Devendra Hiwase ◽  
Shaun Fleming ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Phase 2 ◽  
Advisory Committees ◽  
Early Relapse ◽  
Phase 2 Study ◽  
Measurable Residual Disease ◽  
Acute Myeloid

Abstract Introduction Rising molecular measurable residual disease (MRD) is an arbiter of clinical relapse in acute myeloid leukemia (AML). Venetoclax (VEN) is active against IDH and NPM1 mutant (mt) AML as monotherapy (Konopleva et al, 2016 and Chua et al, 2020) and can yield MRD negative remission when combined with low dose ara-C (LDAC) in patients unfit for intensive chemotherapy (DiNardo and Tiong et al, 2020). In a retrospective study, we showed that VEN in combination with hypomethylating agents or LDAC could erase rising NPM1mt MRD in 6/7 cases (Tiong et al, 2020). We now present a prospective phase 2 study of VEN and LDAC in patients with molecular MRD failure or oligoblastic AML relapse. Methods This multicenter phase 2 study stratified patients into oligoblastic relapse (marrow blasts 5-15%; Group A), or molecular MRD failure (Group B) as defined by the European LeukemiaNet (ELN) recommendations (failure confirmed by 2 interval samples) (Schuurhuis et al, 2018). Patients received VEN 600 mg (days 1-28) and LDAC 20 mg/m 2 (days 1-10). Primary objectives were morphologic or MRD response (≥1 log reduction) in groups A and B, respectively. Key secondary objectives were allogeneic hematopoietic cell transplantation (allo-HCT) realization and relapse-free (RFS) and overall survival (OS). The study had Alfred Health ethics approval (196/19). NPM1mt and other fusion transcript levels (per 10 5 ABL) from bone marrow were analyzed by RT-qPCR, IDH1 and IDH2 by Bio-Rad TM droplet digital PCR. Results The study enrolled 32 patients, with 29 evaluable (cut-off date 15/7/21). The median age of the study population was 62 years; 79% had intermediate cytogenetic risk, 66% NPM1mt, 11% FLT3-ITD and 37% IDH1/IDH2 mt. Most received prior intensive chemotherapy (93%) and 2 (7%) allo-HCT in first remission. Median interval from AML diagnosis to study entry was 12.6 months (Table 1). After a median follow-up of 7.9 months, patients had received a median of 3 cycles (range 1-14) of VEN-LDAC, with 13 patients ongoing. The main reasons for treatment cessation were allo-HCT (n=10; 34%) or donor lymphocyte infusion (n=2; 7%), treatment failure (n=3) or an adverse event (n=1). Hematologic complete/incomplete response (CR/CRi) among 11 patients with oligoblastic relapse (group A) was 73% and included: CR (n=5, 45%) or CRi (n=3, 27%), with an additional patient with morphologic leukemia-free state and 2 patients with stable disease. Overall, across both groups, median RFS and OS were not reached, estimated at 78% and 91% at 1 year, respectively. Among 18 patients with molecular MRD failure (group B) treated with VEN+LDAC, molecular response (≥1 log reduction) was achieved in 72%, and the RFS and OS were estimated at 83% and 87% at 1 year, respectively. Analysis of a sub-group of patients with NPM1mt (n=18); 6 and 12 from Groups A and B, respectively revealed the median NPM1mt transcript level at study entry to be 8985 copies (IQR 826, 94,431). A molecular response was achieved in 14 (78%) patients, including 9 (50%) with complete molecular remission (CR MRD-), with most responses achieved within 2 cycles of therapy (Figure B). Treatment with VEN-LDAC was generally well tolerated, with 15 serious adverse events reported within the first 2 cycles, including infection (n=6; 19%) and febrile neutropenia (n=3; 9%). Only one subject discontinued treatment due to stroke. Conclusions In this prospective study, in patients with first oligoblastic relapse or MRD failure, VEN in combination with LDAC induced a high rate of molecular MRD remission that was rapidly achieved, resulting in a high rate of survival at 12-months (>90%) and with low toxicity. Follow-up is ongoing to determine the durability of response. Treatment of patients with MRD or early clinical failure may represent an attractive clinical trial setting for investigation of novel, non-intensive AML therapies. This approach will be investigated in a future multi-arm, precision-based platform trial called INTERCEPT (Investigating Novel Therapy to Target Early Relapse and Clonal Evolution as Pre-emptive Therapy in AML). Figure 1 Figure 1. Disclosures Tiong: Servier: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Pfizer: Consultancy. Hiwase: Novartis: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Fleming: Amgen Inc: Research Funding. Bajel: Amgen: Speakers Bureau; Abbvie, Amgen, Novartis, Pfizer: Honoraria. Fong: Amgen, BMS: Speakers Bureau; Amgen: Research Funding; AbbVie, Amgen, Novartis, Pfizer, Astellas: Honoraria. Wei: Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Genentech: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Macrogenics: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: This presentation will discuss the use of venetoclax in targeting measurable residual disease and early relapse of acute myeloid leukemia.

scholarly journals Day 14 Measurable Residual Disease As a Predictor of Post-Induction Response in Patients with Acute Myeloid Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1287-1287
Author(s):  
Reyes María Martín-Rojas ◽  
Jon Badiola ◽  
Pablo Silva De Tena ◽  
Ana Pérez-Corral ◽  
Ignacio Gómez-Centurión ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Bone Marrow Aspiration ◽  
Advisory Committees ◽  
Post Induction ◽  
Measurable Residual Disease ◽  
Acute Myeloid

Abstract INTRODUCTION Several studies have shown that morphological remission at day 14 is a predictor of post-induction response in patients with acute myeloid leukemia (AML) undergoing an intensive treatment. However, the role of measurable residual disease (MRD) by multiparameter flow cytometry (MFC) at day 14 remains unknown. The aim of our study is to explore the role of MRD at day 14 and its association with outcomes of patients with AML undergoing an intensive treatment. METHODS We conducted a retrospective study in adult patients with newly a diagnosed AML in our center between 2007 and 2020. Adult patients who received intensive chemotherapy, excluding those with an acute promyelocytic leukemia, were included. Bone marrow aspiration was performed at day 14 after induction to assess morphological response and MRD by MFC. Early blast clearance (EBC) was defined as <5% of blasts and negative MRD was defined as <0.1% abnormal cells within mononucleated cells by MFC. Day 14 aspiration findings were compared with clinical data. This study was approved by our Institutional Ethics Committee. Data were analyzed using IBM SPSS Statistics version 24. RESULTS A total of 131 patients were analyzed. Median age was 55.6 years (IQR 42.3-64.2). The most frequent AML subtype was AML with myelodysplasia-related changes (34.4%), followed by NPM1-mutated AML (32.1%). The most commonly used induction regimen was "7+3" (96.2%) (Table 1). On day 14 bone marrow aspiration, median cellularity was 0.5/5 (IQR 0.5-1). 107 patients (81.7%) showed a blast reduction >50% compared to diagnosis and 87 patients (66.4%) had less than 5% of blasts. In this latter group, 28.6% of patients had a positive MRD and 71.4% had a negative MRD. NPM1-mutated AML showed the highest EBC rates while AML with myelodysplasia-related changes had the lowest rates (83.3% versus 55.5%; p=0.04). Furthermore, there were statistically significant differences in EBC rates based on the 2017 European Leukemia Net risk stratification, with 80% of EBC in low risk, 66.6% in intermediate risk and 53.4% in high risk AML (p=0.038). No differences were observed in MRD at day 14 based on AML subtypes or risk stratification. We subsequently analyzed the negative (NPV) and positive predictive values (PPV) of day 14 bone marrow aspiration results by morphology and MFC to predict post-induction results. As a predictor of post-induction CR, day 14 EBC had a NPV of 82% and a PPV of 69%, while day 14 MRD had a NPV of 86% and a PPV of 49%. However, for predicting post-induction MRD, day 14 EBC had a NPV of 49% and a PPV of 15%, while day 14 MRD had a NPV of 71% and PPV of 74%. The correlation between day 14 and post-induction bone marrow aspiration is shown in Table 2. Bivariate analysis showed that achieving CR with negative MRD in post-induction bone marrow aspiration was associated with EBC (p<0.001) and negative MRD (p=0.04) at day 14 bone marrow aspiration. No statistically significances were observed based on marrow cellularity. A multivariate analysis using logistic regression showed that negative MRD by MFC at day 14 was the only independent predictor variable to achieve post-induction CR with negative MRD (OR 4.95% CI 1.0-15.9; p=0.04). CONCLUSION Patients showing EBC with negative MRD on day 14 bone marrow aspiration are more likely to achieve post-induction CR with negative MRD, with day 14 MRD by MFC being the only independent factor able to predict post-induction CR with negative MRD in our cohort. However, further prospective studies are needed to confirm our findings. Figure 1 Figure 1. Disclosures Martín-Rojas: Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Kwon: Novartis, Celgene, Gilead, Pfizer: Consultancy, Honoraria.

scholarly journals Measurable Residual Disease Detected by Multiparameter Flow Cytometry and Sequencing Improves Prediction of Relapse and Survival in Acute Myeloid Leukemia

2021 ◽  
Vol 11 ◽  
Author(s):  
Fu-Jia Liu ◽  
Wen-Yan Cheng ◽  
Xiao-Jing Lin ◽  
Shi-Yang Wang ◽  
Tian-Yi Jiang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Prognostic Significance ◽  
Multiparameter Flow Cytometry ◽  
Net Reclassification Improvement ◽  
Measurable Residual Disease ◽  
Acute Myeloid ◽  
Time Point

The clinically ideal time point and optimal approach for the assessment of measurable residual disease (MRD) in patients with acute myeloid leukemia (AML) are still inconclusive. We investigated the clinical value of multiparameter flow cytometry-based MRD (MFC MRD) after induction (n = 492) and two cycles of consolidation (n = 421). The latter time point was proved as a superior indicator with independent prognostic significance for both relapse-free survival (RFS, HR = 3.635, 95% CI: 2.433–5.431, P <0.001) and overall survival (OS: HR = 3.511, 95% CI: 2.191–5.626, P <0.001). Furthermore, several representative molecular MRD markers were compared with the MFC MRD. Both approaches can establish prognostic value in patients with NPM1 mutations, and FLT3, C-KIT, or N-RAS mutations involved in kinase-related signaling pathways, while the combination of both techniques further refined the risk stratification. The detection of RUNX1–RUNX1T1 fusion transcripts achieved a considerable net reclassification improvement in predicting the prognosis. Conversely, for patients with biallelic CEBPA or DNMT3A mutations, only the MFC method was recommended due to the poor prognostic discriminability in tracking mutant transcripts. In conclusion, this study demonstrated that the MFC MRD after two consolidation cycles independently predicted clinical outcomes, and the integration of MFC and molecular MRD should depend on different types of AML-related genetic lesions.

scholarly journals Comparison of Acute Myeloid Leukemia Measurable Residual Disease Detection By Flow Cytometry in Peripheral Blood and Bone Marrow

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2729-2729
Author(s):  
Colin D. Godwin ◽  
Yi Zhou ◽  
Megan Othus ◽  
Carole M. Shaw ◽  
Kelda M. Gardner ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Correlation Coefficient ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Spearman Correlation ◽  
Advisory Committees ◽  
Measurable Residual Disease ◽  
Acute Myeloid

BACKGROUND: The current recommendation against the need for bone marrow aspiration (BMA) in routine follow-of persons with acute myeloid leukemia (AML) in remission preceded the recognition that multiparameter flow cytometry (MFC) is a sensitive and specific means to detect imminent morphologic relapse. Given this recognition, we wondered whether BMA is now necessary, or if concordance between MFC results in peripheral blood (PB) and BMA is such as to make BMA unnecessary, at least for evaluation of measurable residual disease (MRD) by MFC. Previous studies have demonstrated a strong correlation between disease detection by MFC in PB and BMA. Here we examined 724 paired PB and BMA samples from 482 patients to further examine the concordance between PB and BMA blast detection by MFC, particularly among patients in morphologic remission. PATIENTS AND METHODS: We included adults in our institutional AML database, covering 2008-2018. Our Hematopathology database was queried to identify PB and BMA MFC sample pairs with samples considered "paired" if measured within one week of each other. If an individual had multiple pairs, all were included unless otherwise specified. Ten-color MFC was performed routinely on BMA aspirates with a panel of three antibody combinations, with the same antibody combinations applied to PB samples. When identified, the abnormal population was quantified as a percentage of the total CD45+ white cell events. Any level of residual disease was considered positive. Complete remission (CR) and relapse were defined according to the European LeukemiaNet 2017 classification. Relationship between PB and BMA blast % was measured using Spearman's Rank-Order Correlation. Relationship between PB and BMA samples identified as positive or negative is illustrated using 2 X 2 tables (Table 1). RESULTS: Considering all 724 sample pairs, the Spearman correlation coefficient between PB and BMA blast percentage was 0.93, and was 0.91 considering only the first sample pair for each individual patient (n= 482). 315 sample pairs were positive by PB, 97% of which were also positive by BMA while 95% of 409 pairs negative by PB were also negative by BMA. Similar results were seen considering only a patient's first pair. Restricting analysis to patients with pairs obtained between the dates of CR and relapse, the Spearman correlation coefficient was 0.82 with 91% of 35 cases positive in PB also positive in BMA; 93% of 114 pairs negative in PB were also negative in marrow. As a complementary means to compare pairs when AML burden was low, we examined only pairs where the BMA MFC showed <5% blasts. Here, the Spearman correlation coefficient between PB and BMA blasts was 0.83. 90% of 70 positive PB cases were also positive by BMA while 95% of 295 negative PB cases were also negative by BMA. Examining pairs taken from patients in morphologic remission immediately prior to undergoing hematopoietic cell transplant yielded a Spearman correlation coefficient of 0.92, with all 9 PB positive cases also being positive in BMA and 96% of PB negative cases being negative in BMA. CONCLUSIONS: This is the largest cohort of AML PB and BMA sample pairs analyzed by MFC to-date. The percentages of blasts measured in PB and BMA are strongly correlated. In the 365 pairs from patients with MRD-level disease, the predictive value of PB MFC positivity for BMA positivity was 90% (63/70) while the predictive value PB MFC negativity for BMA negativity was 95%. Disclosures Othus: Glycomimetics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Gardner:Abbvie: Speakers Bureau. Walter:BioLineRx: Consultancy; BiVictriX: Consultancy; Boehringer Ingelheim: Consultancy; Boston Biomedical: Consultancy; Covagen: Consultancy; Daiichi Sankyo: Consultancy; Kite Pharma: Consultancy; New Link Genetics: Consultancy; Pfizer: Consultancy, Research Funding; Race Oncology: Consultancy; Seattle Genetics: Research Funding; Argenx BVBA: Consultancy; Aptevo Therapeutics: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy; Astellas: Consultancy; Agios: Consultancy; Amgen: Consultancy; Amphivena Therapeutics: Consultancy, Equity Ownership.

scholarly journals Clonal Hematopoiesis and Its Implications for Flow Cytometric Assessment of Measurable Residual Disease in Patients with NPM1-mutated Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 38-39
Author(s):  
Sanam Loghavi ◽  
Courtney D. DiNardo ◽  
Koichi Takahashi ◽  
Rashmi Kanagal-Shamanna ◽  
Tomoyuki Tanaka ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Advisory Committees ◽  
Clonal Hematopoiesis ◽  
Hla Dr ◽  
Measurable Residual Disease ◽  
Acute Myeloid ◽  
Myeloid Progenitors

INTRODUCTION: NPM1 mutations (NPM1mut) occur in ∼30% of acute myeloid leukemia (AML) and frequently co-occur with mutations in other genes including those attributed to clonal hematopoiesis (CH) including DNMT3A and TET2, among others. CH mutations may persist beyond attaining NPM1mut-negative remission. Persistent CH may be associated with immunophenotypic alterations in myeloid progenitors detected by flow cytometry (FC) which poses an interpretive challenge in assessment of measurable residual disease (MRD) by FC. The aim of this study was to characterize the immunophenotypic alterations associated with persistent CH in the setting of NPM1mut clearance and to determine their possible clinical or biologic significance. METHODS: The cohort included 67 consecutive patients (pts) with NPM1mut AML treated at our institution between 01/2017 and 11/2019. FC assessment for MRD was performed an eight-color panel using FACSCanto II instruments (BD Biosciences, San Diego, CA) with a sensitivity of 10-3 to 10-4. Whole bone marrow (BM) DNA was interrogated for mutations with an 81-gene myeloid next-generation sequencing (NGS) panel using an Illumina MiSeq sequencer (Illumina, Inc., San Diego, CA, USA) with a sensitivity: 1% variant allelic frequency (VAF). RESULTS: Pts included 26 men and 41 women with a median age of 64 (range, 19-84) years with newly diagnosed NPM1mut AML. AML blasts had the following immunophenotype at baseline: promyelocytic-like phenotype (CD34-, CD117+, HLA-DR-) in 18 (27%), aberrant myeloid CD34-/CD117+/HLA-DR+ in 15 (22%), aberrant myeloid CD34+ in 13 (19%), myelomonocytic in 11 (16%), and monocytic in 10 (15%) cases. All pts had additional co-mutations at baseline (Fig 1). The most frequently co-mutated genes were DNMT3A (58%) FLT3 (51%), TET2 (27%), IDH2 (24%), PTPN11 (19%), IDH1 (18%), NRAS (16%), and SRSF2 (12%). Pts were treated with intensive (35;52%) and non-intensive induction regimens (32; 48%) (Fig 1); 22 (33%) received an allogeneic hematopoietic stem cell transplant as post-remission consolidation. We compared FC and NGS results in follow-up samples in pts achieving NPM1mut negative remission with adequate data available for comparison (n=50). 13 (26%) pts cleared all mutations whereas 37 (74%) had persistent CH. The most common mutations in the setting of residual CH involved DNMT3A (70%), TET2 (27%), IDH2 (19%) and IDH1 (11%). Among 37 pts with residual CH, 19 (51%) had no phenotypic alterations detected by FC while 17 (49%) had myeloid progenitors with alterations in intensity of antigen expression (increased CD13, CD123, CD117 and/or decreased CD38) or deviation from normal maturation but not diagnostic for AML MRD (herein referred to as pre-leukemic (PL) phenotype); 1 sample was MRD+ by FC. Mutation VAF of ≥5% was significantly more common (p=0.008) in cases with FC PL+ (100%) vs cases with normal FC phenotype (63%). IDH2 and SRSF2 mutation were exclusively observed in PL+CH+ cases with the former being statistically significant when compared with the FC-normal group (p=0.016). PL phenotype by FC did not correlate with intensity of induction therapy (41% treated with intensive regimens vs 59% non-intensive). The CH+/PL+ cohort had more pts ≥60 yrs old (67%) but the difference was not significant. There was no significant association between PL+ and residual mutation count. Presence of PL+ phenotype was not associated with a shorter relapse-free survival (RFS) (median not reached for both groups). CONCLUSIONS: Post-remission clonal hematopoiesis in the setting of NPM1mut clearance is common, and may result in immunophenotypic changes in myeloid progenitors, posing interpretive challenges for MRD assessment by FC. These alterations may be attributable to specific CH characteristics, such as IDH2 and SRSF2 mutations and VAF, but are not associated with a shorter RFS and thus should not be interpreted as residual AML or considered a high-risk attribute. Additional studies in other AML subtypes are warranted to further delineate these changes and their clinical significance. Figure 1 Disclosures DiNardo: Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Notable Labs: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Takeda: Honoraria; Jazz: Honoraria; ImmuneOnc: Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Syros: Honoraria; Agios: Consultancy, Honoraria, Research Funding; Calithera: Research Funding; MedImmune: Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Short:AstraZeneca: Consultancy; Takeda Oncology: Consultancy, Honoraria, Research Funding; Amgen: Honoraria; Astellas: Research Funding. Kadia:JAZZ: Honoraria, Research Funding; Ascentage: Research Funding; Astra Zeneca: Research Funding; Incyte: Research Funding; Celgene: Research Funding; Novartis: Honoraria; Cyclacel: Research Funding; Genentech: Honoraria, Research Funding; Amgen: Research Funding; Abbvie: Honoraria, Research Funding; Cellenkos: Research Funding; Pulmotec: Research Funding; Astellas: Research Funding; BMS: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Konopleva:Sanofi: Research Funding; Eli Lilly: Research Funding; AstraZeneca: Research Funding; Rafael Pharmaceutical: Research Funding; Amgen: Consultancy; F. Hoffmann La-Roche: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Stemline Therapeutics: Consultancy, Research Funding; Kisoji: Consultancy; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Ascentage: Research Funding; Calithera: Research Funding; Forty-Seven: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Cellectis: Research Funding; Agios: Research Funding; Ablynx: Research Funding. Kantarjian:Adaptive biotechnologies: Honoraria; Aptitute Health: Honoraria; BioAscend: Honoraria; Delta Fly: Honoraria; Janssen: Honoraria; Oxford Biomedical: Honoraria; Ascentage: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; BMS: Research Funding; Immunogen: Research Funding; Jazz: Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Sanofi: Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Research Funding; Amgen: Honoraria, Research Funding. Ravandi:Macrogenics: Research Funding; Celgene: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Xencor: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Orsenix: Consultancy, Honoraria, Research Funding.

scholarly journals Multiparametric Flow-Cytometry Is a Reliable Tool for Measurable Residual Disease Assessment and Risk-Stratification of FLT3-Mutated AML Patients

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5083-5083
Author(s):  
Raffaele Palmieri ◽  
Luca Maurillo ◽  
Alfonso Piciocchi ◽  
Maria Ilaria Del Principe ◽  
Valentina Arena ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Board Of Directors ◽  
Residual Disease ◽  
Cell Transplant ◽  
Advisory Committees ◽  
Npm1 Mutation ◽  
Multiparametric Flow Cytometry ◽  
Reliable Tool ◽  
Measurable Residual Disease

Background: Mutations of the gene encoding Fms Related Tyrosine Kinase 3 (FLT3), at the juxta-membrane level (ITD), represent the most common lesions found in Acute Myeloid Leukemia (AML), identifying a subgroup of patients (pts) with unfavorable prognosis. FLT3-ITD mutations are considered an unreliable tool for measurable residual disease (MRD) monitoring, due to their intraclonal heterogeneity and instability during the course of disease. Instead, multiparametric flow cytometry (MFC) may represent an alternative to monitor MRD in this molecular subset. In fact, through the recognition and monitoring of leukemia associated immunophenotypes, MFC is applicable to > 90% of AML patients with a sensitivity of 10-4. Aims: The aim of our study was to investigate the reliability of MFC in MRD assessment of 72 FLT3-ITD positive pts whose treatment allocation was prospectively decided according to the genetic/cytogenetic profile at diagnosis and post consolidation MRD. FLT3-ITD pts were to receive, after induction and consolidation, allogeneic stem cell transplant (ASCT), whatever the source of stem cells. In this subgroup analysis, we investigated if FLT3-ITD mutated pts have a different propensity to achieve high quality (e.g. MRD negative) complete remission as compared to FLT3 wildtype ones. Furthermore, we seek for a correlation between different levels of MRD and overall (OS) and disease-free survival (DFS). Methods: We included in the analysis 72 pts with de novo AML carrying FLT3-ITD mutations whose MRD assessment at the post-consolidation timepoint was available. Pts were defined as MRD-negative, when obtaining a residual leukemic cells count below the threshold of 3.5x10-4 (0.035%). MRD positive pts (with MRD ≥ 3.5x10-4 RLC) were stratified into 3 classes according to the levels of MRD (0.035%-0.1%; >0.1%-1%; >1%). We compared the MRD status and clinical outcome with a matched group of FLT3 wildtype AML (n = 203) treated in the same protocol. Results: Overall median age was 49 (range 18-60.9). The 2 cohorts were balanced in terms of age and sex distribution. In the FLT3-ITD group, 80/126 (64%) cases carried a concomitant NPM1 mutation vs 107/374 (28.6%) of FLT3 wildtype ones (p <0.001). Furthermore, FLT3 mutated pts had a median WBC count of 35x109/L vs 9.5x109/L of those FLT3 wildtype (p < 0.001). MRD determination after consolidation cycle was available in 72/126 FLT3-ITD pts (57%) and in 203/374 FLT3 wildtypeones (54.3%), respectively. After having received induction and consolidation course, 47/72 FLT3-ITD pts (65,2%) were submitted to allogenic stem cells transplantation (ASCT). At the post-consolidation time-point, MRD negativity rate was significantly lower in FTL3-ITD pts (27/72, 37.5%) as compared to those FLT3 wildtype (94/203, 46.3%). Furthermore, 38/72 (52.8%) and 10/72 (13.9%) FLT3-ITD pts had a level of MRD > 0.1% and > 1%, respectively as compared to 65/203 (33.0%) and 15/203 (7.4%) of FLT3 wildtypeones, respectively (p=0.017). When considering the different MRD stratification levels of FLT3-ITD pts, OS probability at 24 months was 57.2% (27 pts), 71.4% (7 pts), 53.6% (28 pts) and 20% (10 pts), for the MRD categories <0.035%, 0.035%-0.1%, >0.1%-1%, >1%, respectively (p=0.028). DFS probability at 24 months was 53.8% (27 pts), 71.4% (7 pts), 34.9% (27 pts) and 20% (10 pts), for the MRD categories <0.035%, 0.035%-0.1%, >0.1%-1%, >1%, respectively (p=0.038). Summary/Conclusion: We demonstrated that MRD determination by MFC is a reliable tool to assess remission quality and prognosis in FLT-ITD positive patients. This subpopulation shows a lower propensity to obtain a MRD negative CR, with the majority of pts maintaining an amount of MRD > 0.1% after standard treatment. Even though most of these pts were addressed to ASCT, post-consolidation MRD maintained its negative impact on OS and DFS, particularly for those pts with MRD >1%. In the attempt to improve the quality of response, prevent leukemia recurrence and pursue a durable remission, delivery of FLT3 inhibitors as a maintenance after transplant may represent a promising option. Disclosures Venditti: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees. Buccisano:Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

scholarly journals Venetoclax and Azacitidine for Older Newly Diagnosed Patients with Acute Myeloid Leukemia: A Single-Institution Pilot Study Using Measurable Residual Disease to Guide Therapy

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2638-2638 ◽  
Author(s):  
Amanda Winters ◽  
Jonathan A Gutman ◽  
Enkhtsetseg Purev ◽  
Brett M. Stevens ◽  
Shanshan Pei ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Refractory Disease ◽  
Advisory Committees ◽  
Ras Pathway ◽  
Measurable Residual Disease ◽  
Count Recovery

Background: Venetoclax (ven) was approved for older untreated acute myeloid leukemia (AML) patients due to high response rates and durable remissions. As a participating site in the dose escalation study, we observed deeper/more durable responses in some who received >400mg ven. We also noted 16/33 discontinued azacitidine (aza) after achieving a response; 9 relapsed and 7 remained in long term remission on ven only. Based on these observations, we designed a study that hypothesized: A)Higher initial doses of ven would allow deeper/more durable responses, and B)Multi modality high sensitivity measurable residual disease (MRD) testing could identify patients able to discontinue aza and remain on maintenance ven. Methods: This is an ongoing phase 2 study (NCT03466294) of 42 untreated AML patients ≥60 who decline/are ineligible for induction. Patients have adequate organ function and white blood cell counts <25x109/L (hydrea permitted). In cycle 1, patients receive aza 75mg/m2 on days (d) 1-7 and ven, escalated from 100 to 200 to 400 to 600mg on d 1-4. Ven continues at 600mg d 5-28 and bone marrow biopsies (BMBXs) are performed on d 8 and 28. Patients who achieve morphologic remission without count recovery have up to 14 days off therapy before subsequent cycles, with growth factor support; "upgraded" responses are recorded if count recovery occurs. Non responders discontinue or receive up to two additional cycles of aza and ven 600mg. Responders who remain MRD+ by multiparameter flow cytometry (MPFC, Hematologics) and/or digital droplet PCR (ddPCR) for as many identifiable diagnostic genes as possible also receive up to 2 additional cycles of aza and ven 600mg. MRD+ responders after 3 cycles continue aza and ven 400mg until toxicity/progression. Patients who experience MRD- responses at any time stop aza and continue ven 400mg daily (Fig 1). Results: 30 patients enrolled between May 2018 and July 2019; median age is 71 (60-88), 10% evolved from MDS and 10% and 73% had intermediate and unfavorable risk disease by ELN, respectively (Table 1). 732 adverse events (AEs) occurred; 46 (6%) were serious, the most common were neutropenic fever (37%) and pneumonia (13%). The most common >grade 2 related AEs were leukopenia (53%), thrombocytopenia (44%) and neutropenia (35%); there were no related grade 5 AEs. The overall response rate was 70% (21/30; CR=19, MLFS=2). Median number of cycles to achieve best response was 1. Significant blast reductions were seen on day 8; of the 28 with interpretable day 8 BMBXs, 10 achieved MLFS on day 8. 4 completed ≥1 cycle and were refractory. An additional 4 did not complete cycle 1: 1 died of disease and 3 elected to come off therapy (all subsequently died of disease). Four (19%) responders relapsed, after a median 180 days (27-279). With median follow up of 214 days, median response duration has not been reached. 10 patients died, after a median 65 days (29-256); 1/30 died within 30 days. Median overall survival has not been reached. Of the 26 who completed ≥1 cycle, 19 were MRD- by MPFC, including 18/19 who achieved CR. Of these 26, 3 were not monitored by ddPCR: for 2 patients this was due to the absence of detectable baseline mutations and for 1 patient it was due to refractory disease. The remaining 23 had ddPCR monitoring; 3 became MRD- by this modality (Fig 2). All 3 were also MRD- by MPFC and per protocol discontinued aza and initiated ven maintenance (Fig 1). MRD negativity by both parameters occurred after cycles 1, 2 and 3, respectively. One MRD- patient relapsed after 216 days; two remain in remission after 301 and 124 days. An additional 4 who achieved MRD+ responses discontinued aza at their insistence (and in violation of the protocol); 1 relapsed after 279 days, and 3 remain in ongoing remission. Univariate predictors of refractory disease were FAB M0/M1 (OR 0.070, p=0.02) and RAS pathway mutations (OR 14.25, p=0.02). Conclusions: Higher initial doses of ven are tolerated in this population. Blast reduction occurs quickly in many patients (day 8), for this low intensity regimen. Response rates are consistent with lower doses of ven. Very deep responses, as measured by highly sensitive MRD methods (MPFC and ddPCR are capable of sensitivity up to 0.02%), are attainable. Longer follow up time will determine if higher ven doses and MRD-driven decisions related to continuation of aza result in more durable responses. Increased maturation of blasts and RAS pathway mutations are predictors for refractory disease. Disclosures Lyle: Pfizer: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo Incyte: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Pollyea:Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees; Diachii Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Forty-Seven: Consultancy, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Dissecting Signaling Network Responses to PAK4 Allosteric Modulators (PAMs) in Cell Subsets within Primary Human Acute Myeloid Leukemia Samples

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3686-3686
Author(s):  
Paul Brent Ferrell ◽  
William Senapedis ◽  
Alexander Cook ◽  
Erkan Baloglu ◽  
Yosef Landesman ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Board Of Directors ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Leukemia Stem Cells ◽  
Allosteric Modulators ◽  
Advisory Committees ◽  
Acute Myeloid

Abstract Background: Acute myeloid leukemia (AML) is the most common acute leukemia in adults and has a poor outcome with limited treatment options in patients with relapsed or resistant disease. Therapy resistance in AML is likely related to the inadequacy of therapy within leukemia cell subsets, including leukemia stem cells (LSCs). The p21-activated kinase (PAK) family of proteins was shown to be overexpressed in cancer cells and to play a key role in proliferation, survival, and maintenance of cellular structure. The series of orally bioavailable PAK4 allosteric modulators (PAM) have previously been shown to have activity in hematological cancer cell lines, including those derived from acute myeloid leukemia (AML) (Senapedis et al. Blood124, 2208-2208). Understanding how therapies target cellular subsets within primary patient samples could aid drug development by revealing any subset specific drug effects. In this project, we studied the effects of p21-activated kinase 4 (PAK4) modulation in AML samples. PAK4 modulation has been shown to have significant effects on many intracellular signaling pathways, including PI3K/AKT, MAPK/ERK and WNT/β-catenin pathways (Senapedis et al. Blood124, 2208-2208). It is unknown whether PAMs will have similar activity in primary leukemia cells. Likewise, it is currently unclear to what extent PAMs will differentially impact primary cell subsets including leukemia stem cells and non-malignant cell subsets that may be critical to recovery of bone marrow functions. We have previously shown that the single cell biology platform of flow cytometry is well-suited for dissecting clinically relevant signaling network mechanisms in primary human AML (Irish et al. Cell, 118(2):217-28). Methods: Flow cytometry was used to dissect the impact of an orally bioavailable PAM in AML cell lines and primary patient tissue. Cell lines chosen for this study included NRAS mutant KG-1 and Kasumi-1, which carry t(8;21) and express the AML1:ETO fusion protein. Primary AML biopsies were acquired from bone marrow or blood prior to any treatment and patients were identified and consented for this study according to a local Institutional Review Board-approved protocol. AML tissue samples were viably cryopreserved and then assayed ex vivo. Established protocols were used for phospho-specific flow cytometry, fluorescent cell barcoding, and data analysis in Cytobank (Irish et al. Cell, 118(2):217-28, Doxie and Irish, Curr Top Microbiol Immunol. 377:1-21). Results: Differential effects of PAK4 inhibition were observed between cell lines and among cell subsets from AML patient bone marrow. In leukemia cell lines and patient samples, p-ERK and p-S6 showed marked inhibition via PAM, though degree of inhibition varied. In AML patient samples, PAMs blocked signaling responses in p-ERK specifically in AML blasts, but spared normal CD45hi mononuclear cells (0.88 vs. 0.29-fold reduction (arcsinh scale) in p-ERK at 10 nM). Within the AML blast population, CD34+ CD38- and CD34+ CD38+ AML subsets showed similar PAM dose response via p-ERK. Conclusions: Single cell analysis effectively distinguishes effects of PAK4 inhibition via a series of allosteric modulators of PAK4 (PAMs) on leukemia and non-leukemia subsets in the same sample. PAM reduced immediate p-ERK and p-S6 levels in primary leukemia and cell lines. Notably, inhibition in various subsets within human AML was successfully measured by phospho-flow cytometry. Signaling changes in p-ERK were minimal within non-leukemic mature CD45+ mononuclear cells found in primary patient biopsies. Analysis of CD34+ CD38- cells indicates that PAMs could have activity within leukemia stem cells, and, at least, effect the AML progenitors. These findings support further investigation into the mechanism of action and treatment potential of PAMs in AML. Disclosures Senapedis: Karyopharm Therapeutics, Inc.: Employment, Patents & Royalties. Baloglu:Karyopharm Therapeutics Inc.: Employment, Equity Ownership. Landesman:Karyopharm: Employment. Irish:Novartis: Honoraria; Cytobank, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Research Funding; InCyte: Research Funding. Savona:Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals Loss of Plasmacytoid Dendritic Cell Differentiation Is Highly Predictive for Persistent Measurable Residual Disease and Poor Outcomes in Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1523-1523
Author(s):  
Wenbin Xiao ◽  
Aaron D Goldberg ◽  
Christopher Famulare ◽  
Sean Delvin ◽  
Minal Patel ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Advisory Board ◽  
Post Induction ◽  
Equity Ownership ◽  
Poor Outcomes ◽  
Measurable Residual Disease ◽  
Acute Myeloid

Abstract Background Measurable residual disease (MRD) is associated with inferior outcomes in patients with acute myeloid leukemia (AML). MRD monitoring enhances risk stratification and may guide therapeutic intervention. Post-induction MRD is frequently cleared with further therapy and the clearance may lead to better outcomes. In contrast, persistent MRD is associated with poor outcomes. At present it is not possible to predict which patients are likely to clear MRD with further therapy. Here we report a simple, objective, widely applicable and quantitative MFC approach using the ratio of blast/PDC to predict persistent MRD and poor outcomes in AML. Patients and Methods A cohort of 136 adult patients with a confirmed diagnosis of AML by WHO criteria who underwent standard induction therapy at a single center between 4/2014 and 9/2017 was initially included. 69 patients achieved complete morphologic remission (36 MRD-neg. and 33 MRD-pos.). MRD status was assessed by MFC using a different from normal (DfN) approach. PDC were quantified as the percent of total WBC by flow cytometry based on low side scatter, moderate CD45, CD303, bright CD123 and HLA-DR expression. Results The proportion of PDC was markedly decreased in patients with AML (≥20% blasts) (N=136) with a median of 0.016% (interquartile range IQR: 0.0019%-0.071%, Figure 1A), more than 10-fold lower than observed in normal controls (median 0.23%, IQR 0.17%-0.34%) (N=20). While there was no difference between MRD-neg. and normal control groups (median 0.31%, IQR: 0.17%-0.49%; vs. 0.28%, IQR: 0.17%-0.34%), MRD-pos. group had significantly reduced PDC proportion compared to the control (median 0.074%, IQR: 0.022%-0.33%, Wilcoxon rank sum, p=0.019). In an attempt to achieve better separation and to eliminate possible effects of hemodilution, the ratio of blast/PDC was calculated by using the proportions of blasts and PDCs out of total WBCs as quantitated by flow cytometry. A cut-off threshold of the blast/PDC ratio of 10 was chosen to separate each group (Figure 1B). Importantly, a ratio cut-off of 10 had a corresponding specificity of 97.4% for predicting MRD positivity status. MRD positivity was significantly associated with inferior overall survival (OS) and relapse-free survival (RFS) in our study cohort (OS HR 4.11 (95% CI: 1.30-13.03), p=0.016; RFS HR 4.20 (95% CI: 1.49-11.82), p=0.007, Figure 1C and D). The 2-year cumulative incidence of relapse in the MRD-neg. group compared to MRD-pos. group was 10% (95% CI: 2-24%) vs. 37% (95% CI: 18-56%, p=0.014). Importantly, blast/PDC ratio ≥10 was also strongly associated with inferior OS and RFS (OS HR 3.12 (95% CI: 1.13-8.60), p= 0.028; RFS HR 4.05 (95% CI: 1.63-10.11), p=0.003, Figure 1E and F), which is similar in magnitude to MRD positivity. Furthermore, MRD-pos. patients with blast/PDC ratio <10 had 4 times higher MRD clearance rate than MRD-pos. patients with a ratio ≥10 (6/11, 55% vs 2/17, 12%, Fisher exactp=0.02). Conclusion We have established an objective and quantitative MFC method to risk stratify post induction AML patients by risk for relapse, MRD clearance and likelihood of survival. Loss of PDC correlates with residual leukemia, is highly specific for MRD positivity in post-induction patients, and strongly predicts poorer overall survival and higher likelihood of relapse. Loss of PDC also predicts persistent MRD in post-induction MRD-pos. patients despite further therapy, suggesting that MRD-pos. patients with normal PDC may benefit from further therapy prior to transplant, while MRD-pos. patients with loss of PDC may not. Figure 1. Figure 1. Disclosures Goldberg: AROG: Research Funding; Pfizer: Research Funding; Celgene: Consultancy. Geyer:Dava Oncology: Honoraria. Levine:Isoplexis: Equity Ownership; C4 Therapeutics: Equity Ownership; Gilead: Honoraria; Qiagen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Prelude: Research Funding; Imago: Equity Ownership; Roche: Consultancy, Research Funding; Loxo: Consultancy, Equity Ownership; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Epizyme: Patents & Royalties; Janssen: Consultancy, Honoraria. Tallman:BioSight: Other: Advisory board; AROG: Research Funding; AbbVie: Research Funding; Cellerant: Research Funding; ADC Therapeutics: Research Funding; Orsenix: Other: Advisory board; Daiichi-Sankyo: Other: Advisory board.

Clearance of leukemic blasts by flow cytometry versus minimal residual disease as predictors of clinical outcome in elderly patients with acute myeloid leukemia.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e19514-e19514
Author(s):  
Giovanni Rossi ◽  
Vincenzo Giambra ◽  
Maria Marta Minervini ◽  
Chiara de Waure ◽  
Irene Giacchetta ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Elderly Patients ◽  
Older Patients ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Morphological Response ◽  
Log Reduction ◽  
Minimal Residual ◽  
Acute Myeloid ◽  
Time Point

e19514 Background: Lower-intensity regimens, such as hypomethylating agents (HMAs) are better tolerated and more effective than standard chemotherapy in elderly patients( > 65 years old) with acute myeloid leukemia (AML). Scoring systems to predict clinical outcome in these patients are mainly based on cytogenetic assays and morphological response to therapy. Minimal residual disease (MRD) represents a powerful risk- stratification in younger AML patients but it remains poorly investigated in older patients, particularly in those undergone HMAs. In this subset, the survival benefit is not limited to patients achieving morphologic complete remission (CR). The clearance of leukemic blasts was never be valued as a predictive parameter of outcome in older patients. Thus, in this study we evaluated the most effective and predictive factor of outcome at the optimal time-point among leukemic blasts clearance by flow cytometry (FC), MRD and morphological response in older patients treated with HMAs. Methods: From april 2015 to may 2019, 76 older patients ( > 60 years old) with newly diagnosed AML were treated con azacitidine and decitabine. Among them, 56 completed at least six cycles but 31were properly monitored by FC. Log Clearance was defined as logarithmic ratio between the percentage of blast cells at specific time point and that at the diagnosis. Results: A total of 31 elderly patients with a median age 72 (60-85) were evaluated after 4(T4) and 6(T6) cycles of HMAs. A Median of 10 cycles were administered, equally distributed between azacitidine and decitabine. A higher frequency of CR (73.3%vs 20%) and MRD negativity (16.6% vs 0) was found at T6 compared to T4, thus T6 was chosen for the analysis. Performance status (PS > 2),Hgb < 10 g/dl, MRD positivity and a Log-reduction lower than 2 log predicted a significantly shorter DFS at univariate analysis. However, Log-reduction and PS only confirmed to predict a short DFS also at multivariate analysis, together with CRi (CR with incomplete recovery) and partial remission (PR). When the OS was investigated, only PS represented a strong indicator of prognosis at both univariate and multivariate analysis. Conclusions: Our results suggest that patients achieving 2 Log at least of blasts-reduction by FC had a longer DFS. Dynamic monitoring of blast –reduction stratified better and more widely than the absolute value of MRD in older AML patients. Having a high PS and achieving a CRi instead of a CR showed an unfavorable outcome in terms of both DFS and OS

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