scholarly journals Measurable Residual Disease in Extracellular Vesicles from Bone Marrow and Peripheral Blood of Patients with Multiple Myeloma: A Proof-of-Concept Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4712-4712
Author(s):  
Rui Bergantim ◽  
Mélanie A.G. Barbosa ◽  
Sara Peixoto da Silva ◽  
Bárbara Polónia ◽  
Hugo R. Caires ◽  
...  

Abstract BACKGROUND: Multiple myeloma (MM) treatment improved substantially in the last years, with unprecedented survival outcomes. However, even when achieving complete remission, patients ultimately relapse. Therefore, monitoring measurable residual disease (MRD) is crucial to assess treatment response and define the depth of patients' remission status. However, this currently still requires invasive bone marrow (BM) aspirates, which severely hinders real-time monitoring of the disease. Therefore, the identification of biomarkers of MRD in the peripheral blood (PB) of patients would allow a more frequent and minimally invasive monitoring of MRD. Extracellular Vesicles (EVs) are small particles (30-1000nm) shed by all cells, which are found in all biofluids including the BM and PB. These particles carry a specific cargo from their cell of origin, including proteins, enclosed by a lipidic layer. Therefore, they have been described as a possible source of cancer biomarkers, with potential to monitor MRD. AIMS: This study aimed to implement a protocol for the isolation of EVs from the BM and PB of MM patients at distinct stages of the disease (diagnosis and remission), in order to detect and compare the levels of known MRD biomarkers in their cargo. METHODS: The study was previously approved by the Ethical Committee of CHSJ and patient's consent was obtained. EVs from BM and PB Platelet-Poor Plasma (PPP) were isolated by size-exclusion chromatography (SEC), and further concentrated by ultrafiltration (UF). Then, the EVs were characterized according to their size and concentration (by Nanoparticle Tracking Analysis), morphology (by Transmission Electron Microscopy), protein concentration (Lowry protein assay) and presence of EV-associated protein markers (Western Blot - WB). In addition, 16 known MRD and MM biomarkers were analyzed by WB in the isolated EVs from PB and BM of seven patients, at two main stages of the disease - diagnosis versus response after autologous stem cell transplant (ASCT). Clinical features regarding cytogenetics and immunophenotypic markers using multi-parameter flow cytometry (MFC) were analyzed and compared. RESULTS: The two-step protocol described allowed the isolation of size-resolved EVs from both PB and BM of MM patients. The EVs isolated (both from PB and BM) presented a size-range from 50 to 500nm and presented EV-associated protein markers, such as CD81 and CD63. Moreover, several MM MRD biomarkers (e.g. CD56, CD45, CD38 and light chain) were detected in the cargo of the EVs from BM and PB at diagnosis and complete remission. The biomarkers of MM and MRD detected in the cargo of PB EVs were mainly the same as the ones detected in the cargo of BM EVs. The complete remission after ASCT was mostly associated with a decrease in the expression of EV-associated MM markers in both the BM and the PB; however, in some patients a few of the markers persisted at this stage when compared to diagnosis. In fact, the expression of CD45 and HLA-DR persisted at the remission stage in 3 and 2, respectively, out of 5 patients presenting these markers at diagnosis. Moreover, an increased expression of CD56 was also detected at remission in 3 out of 7 patients. By correlating these data with patient's routine work-up it was found that patients with persistent CD45 didn't reach 10^-5 MRD negative by flow cytometry. CONCLUSIONS: Taken together, this work suggests that it is possible to detect MM markers in EVs from either BM or PB of MM patients and compare their expression at different stages of the disease (diagnosis and remission after ASCT). Importantly, our results demonstrate the importance and potential of analyzing EVs cargo from PB, suggesting the possibility of using them for minimally invasive monitoring of MRD in MM patients. ACKNOWLEDGEMENTS: The authors acknowledge Celgene/BMS for providing funding to this work (Project Looker - Grant_138800). The authors acknowledge Cytogenetics Laboratory, Department of Clinical Hematology, Centro Hospitalar e Universitário São João and Flow Cytometry Laboratory, Department of Clinical Pathology, Centro Hospitalar e Universitário São João. Disclosures Bergantim: Amgen: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; BMS: Consultancy, Research Funding, Speakers Bureau; Takeda: Consultancy, Speakers Bureau. Barbosa: BMS: Research Funding. Silva: BMS: Research Funding. Polónia: BMS: Research Funding. Caires: BMS: Research Funding. Guimarães: BMS: Research Funding; Amgen: Research Funding. Vasconcelos: BMS: Research Funding; Amgen: Research Funding.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Hiroyuki Takamatsu ◽  
Naoki Takezako ◽  
Takeshi Yoroidaka ◽  
Takeshi Yamashita ◽  
Ryoichi Murata ◽  
...  

Background: Autologous stem cell transplantation (ASCT) in conjunction with novel therapeutic drugs can dramatically improve response rates and the prognoses of patients with multiple myeloma (MM). However, most patients with MM ultimately relapse due to minimal residual disease (MRD). Next-generation multiparameter flow cytometry (MFC) (EuroFlow-NGF) and next-generation sequencing (NGS) are currently the standard methods to assess MRD. Aims: To compare the prognostic value of MRD detection in autografts and bone marrow (BM) cells using 8-color MFC (EuroFlow-NGF) and NGS (Adaptive Biotechnologies), and also MRD levels between fresh and cryopreserved autografts using NGF. Methods: The study enrolled 52 newly-diagnosed MM patients who underwent ASCT. The median age ASCT was 61 (range 41-69) years and included 29 males and 23 females at ISS I (n = 17), II (n = 23), and III (n = 12). Of these, 18 patients harbored high-risk chromosomal abnormalities including t(4;14) (n = 15), del17p and t(4;14) (n = 2), and complex (n = 1). Bortezomib-based chemotherapy was used for induction together with melphalan at 140 mg/m2 (n = 1) and 200 mg/m2 (n = 51) for conditioning before ASCT. 39 of 52 (75%) patients received maintenance therapy until progressive disease. The best responses achieved post-ASCT included 30 sCR, 4 CR, 15 VGPR, and 3 PR. Forty autografts, one from each MM patient, were analyzed using NGF and NGS protocols, and BM cells at pre/post-ASCT and autografts derived from 16 patients were analyzed using NGS. The EuroFlow-NGF method uses standard sample preparation; large numbers of cells are evaluated using an optimized 8-color antibody panel that facilitates accurate identification of discrimination between phenotypically aberrant plasma cells (aPCs) and their normal counterparts (Flores-Montero et al., Leukemia 2017). NGS-based MRD assessment was performed using Adaptive's standardized NGS-MRD Assay (Seattle, WA) (Martinez-Lopez et al., Blood 2014). Eight additional autografts were used to assess MRD in both fresh and cryopreserved samples by NGF. Results: MRD was evaluated in 48 of 52 autografts (92%) using NGF and in 44 of 52 autografts (85%) using NGS. We identified aPCs in autografts based on multivariate analysis of individual cell populations (e.g., CD56+, CD19−, CyIgκ+, and CD117+). As the results of NGF revealed a strong correlation with respect to MRD in fresh vs. thawed autografts (r = 0.999, P < 0.0001), MRD was subsequently evaluated in thawed autografts. The sensitivity of NGF was 1 × 10−5-2 × 10−6; the sensitivity of NGS was 1 × 10−6. 28 of 48 (58%) of the autografts were MRD-positive by NGF; 30 of 44 (68%) of the autografts were MRD-positive by NGS. MRD levels in autografts using NGF and NGS correlated with one another (r = 0.69, P < 0.0001; Fig. 1A). MRD negative in autografts by NGF cases (MRDNGF (-)) and MRDNGS (-) tended to show better progression-free survival (PFS) than MRDNGF (+) (P = 0.195) and MRDNGS (+) (P = 0.156), respectively. Furthermore, MRDNGS (-) showed significantly better overall survival (OS) than MRDNGS (+) (P = 0.03) (Fig. 1C) while MRDNGF (-) showed better OS than MRDNGF (+) (P = 0.09) (Fig. 1B). Our data revealed only a minimal correlation between MRD in the autografts (median 1.1 × 10−5,range 0-7.29 × 10−4) and in the BM cells at pre-ASCT (median 5.05 × 10−3,range 6 × 10−6-2.64 × 10−1; r = 0.09, P = 0.7) or at post-ASCT (median 2.11 × 10−4,range 0-9.09 × 10−3; r = 0.14, P = 0.6); MRD detected in the autografts was > 27 times lower than that detected in pre-ASCT BM cells, and MRD detected in the post-ASCT BM cells was > 3 times lower than that detected in pre-ASCT BM cells except for one case in which the ratio was increased by two times. Interestingly, while MRD was detected in all BM cells at pre-ASCT (n = 16), 4 of 16 (25%) of these autografts were MRDNGS-negative. The median of MRD levels of the 4 cases in pre-ASCT and post-ASCT BM cells were 4.14 × 10−4 (range 6-583 × 10−6)and 1.8 × 10−5 (range 0-27 × 10−6), respectively. Conclusion: Although EuroFlow-NGF is a rapid and accurate method for detecting MRD, NGS was more sensitive and provided greater prognostic value than EuroFlow-NGF. Disclosures Takamatsu: Adaptive Biotechnologies: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Janssen Pharmaceutical: Consultancy, Honoraria, Research Funding; Ono pharmaceutical: Honoraria, Research Funding; SRL: Consultancy, Research Funding. Takezako:Bristol-Myers Squibb: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Research Funding; Abbvie: Research Funding. Nakao:Symbio: Consultancy; Kyowa Kirin: Honoraria; Alexion: Research Funding; Novartis: Honoraria.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1726-1726
Author(s):  
Habibe Kurt ◽  
Carlos E. Bueso-Ramos ◽  
Joseph D Khoury ◽  
Mark Routbort ◽  
Rashmi Kanagal-Shamanna ◽  
...  

Abstract Background Isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations are important prognostic biomarkers in acute myeloid leukemia (AML). Although the clinicopathologic correlates of IDH mutations have been extensively studied, the distribution of abnormal myeloid cells carrying these mutations has not been studied. Specific localization of cells carrying IDH mutations will be useful in further understanding the pathophysiology and post-treatment biology of IDH mutant cases of AML. This characterization is becoming particularly relevant for identification of minimal residual disease, especially for patients treated with novel IDHinhibitors. In this study, we characterized IDH1 p.R132H clones in bone marrow specimens involved by AML using a mutation specific antibody. Materials and Methods Bone marrow tissue sections (biopsy or clot specimens) from 32 AML cases with IDH1 p.R132H mutation were stained with IDH1 p.R132H-mutation specific antibody. These cases include 20 de novoAML and 12 cases of AML with myelodysplasia-related changes (AML-MRC). We also included 10 AML cases with wild-type IDH1 as a control. After confirmation of the positive IDH1 immunohistochemical (IHC) signal in the primary specimens, follow up bone marrow specimens (n=67) including (a) persistent disease, (b) minimal residual disease by flow cytometry, (3) complete remission by morphology and flow cytometry, but, positive for mutation by PCR, as well as (4) relapsed cases after complete remission were included in the study (in progress). We also included pre- and post-treatment (unresponsive with increasing blast counts, stable disease, persistent disease with decreasing blast counts, complete remission, and relapse) bone marrow specimens (n=72) from 16 patients treated with IDH inhibitors (in progress). Results All the IDH1 wild type AML cases were negative for IDH1 IHC stain showing 100% specificity. Positive signal was detected in all de novo AML and AML-MRC (allelic frequency ranges from 1.8% to 47% by PCR) except one AML case with 8.9% allele burden which was a limited sample; overall sensitivity was 96%. The IHC signal was detected in the cytoplasm of myelomonocytic cells, their precursors, and megakaryocytes. Erythroid precursors, lymphoid cells, endothelial cells, and osteoblasts were consistently negative. The signal intensity ranged from weak (n=10) to moderate (n=9), to strong (n=13). The positive cells predominantly showed an interstitial distribution in the bone marrow. In the de novo AML group, only the immature cells were positive in 100% of pre-treatment AML cases. However, both mature and immature cells were positive in 7/13 (54%) post-treatment AML cases (6 cases treated with hypomethylating agents). One case was transformed from MPN which also showed positivity in mature and immature cells. In two cases with complete morphologic remission and one case with minimal residual disease detected by flow cytometry, IHC signal was detected in both mature and immature cells; both patients relapsed in 8 and 11 months. In the AML-MRC group, both immature and mature cells were positive in 11/12 (92%) cases of which 2 were not previously treated indicating the possibility that IDH1 mutation is an early event. Since the remaining 9 patients were treated with hypomethylating agents, the positivity of both mature and immature cells as a result of maturation effect versus an early event cannot be assessed. Additional studies for follow-up AML cases, including cases on an IDH inhibitor clinical trial are in progress. Conclusions Our preliminary data indicate that IDH1 IHC is a highly specific and sensitive tool to detect IDH1 R132H mutated cases and can be used as a primary method to localize the population of mutation-bearing cells in the bone marrow. IHC also allows determination of whether the IDH1 mutation in the post-treatment setting is arising from immature or mature cells. IHC provides an opportunity to understand the difference between these two populations and, based on characterization of cell type and distribution, may be helpful to predict whether the risk of relapse is high. Disclosures DiNardo: Agios: Other: advisory board, Research Funding; Novartis: Other: advisory board, Research Funding; Daiichi Sankyo: Other: advisory board, Research Funding; Celgene: Research Funding; Abbvie: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4656-4656
Author(s):  
Veit Bücklein ◽  
Alexandra Stein ◽  
Benjamin Tast ◽  
Thomas Koehnke ◽  
Karsten Spiekermann ◽  
...  

Patients with Acute Myeloid Leukemia (AML) frequently relapse due to chemorefractory AML cells persisting after intensive chemotherapy at levels below the 5% morphological detection threshold (measurable residual disease, MRD). MRD has been established as an important prognostic factor for relapse-free and overall survival, making it highly relevant for post-remission treatment stratification. In contrast to MRD assessment by molecular techniques, multiparameter flow cytometry (MFC)-based MRD measurements are applicable in more than 95% of AML patients, while still offering a sensitivity of 10-4 to 10-5. Current MFC MRD assessment strategies measure 8-10 fluorochromes in parallel, resulting in a high-dimensional data set. However, evaluation of this data is usually performed by scatterplot-based manual, two-dimensional analysis. This leads to loss of information and significant inter-observer variability in MRD diagnostics. We therefore established a computational data analysis strategy for MFC MRD diagnostics, based on the unsupervised FlowSOM algorithm. By comparison with healthy bone marrow (HBM) data, FlowSOM analysis can identify aberrant (sub-)populations of cells, clustered in nodes (according to similarity of their antigen profile). These nodes can be denoted as "nodes of interest" (NOI) to simplify MRD analysis after clustering. Aim of the project was to establish FlowSOM analysis protocols and retrospectively evaluate their prognostic significance in a cohort of 46 patients with known outcomes. Bone marrow samples of these patients were analyzed at aplasia (day 16 after initiation of induction chemotherapy). Only patients with morphological blast clearance at aplasia were included. Healthy reference FlowSOM trees were established by merging flow data of 17 HBM. Analysis protocols were developed to report individual ("any node" approach) and cumulative ("sum node" approach) differences in NOI percentages when comparing HBM and MRD samples. We then performed FlowSOM MRD analyses in a patient subcohort of 19 AML patients. Importantly, for these analyses, we excluded patients who underwent allogeneic stem cell transplantation in first remission (non-HSCT subcohort). Median follow-up time was 8.3 (range 2-40) months for this subcohort. Receiver operating characteristic (ROC) analyses were used to determine optimal threshold values to differentiate relapse (n=5) and non-relapse (n=14) patients within the cohort. For "sum node" analysis strategies (defining MRD levels as cumulative difference of NOI percentages) a threshold of -2.44% was identified, optimized for Youden (Y) index and diagnostic odds ratio (DOR). For the "any node" strategy (defining MRD levels by the maximum difference of any NOI), a threshold of 0.04%, also optimized for the Y-index and DOR, discriminated best between relapse and non-relapse patients. Relapse-free survival (RFS) was significantly shorter for MRD-positive (MRDpos) patients identified by "sum node" analysis (median 8 months vs. not reached, p=0.016) and tended to be shorter for MRDpos patients by "any node" analysis (median 8 months vs. not reached, p=0.1). When applying the thresholds identified in the non-HSCT cohort to the full set of 46 patients (median follow-up interval 10.6 months, range 2-40), median RFS was not reached for the MRD-negative group (both for "sum node" and "any node" analysis), and was 14 ("sum node", p=0.098) and 14 months ("any node", p=0.360) for the MRDpos patients. Median overall survival for MRDpos patients by "sum node" analysis was 27 months, whereas it was not reached for MRD-negative patients. However, this difference did not reach statistical significance (p=0.335), probably due to the small sample size. Taken together, FlowSOM-based analysis strategies seem well suited to identify patients with MRD positivity after intensive induction chemotherapy. MFC MRD positivity at aplasia, defined by FlowSOM-based analysis, is associated with inferior RFS in retrospective analyses of small patient cohorts. Due to the underlying computational, unsupervised data analysis, FlowSOM-based assessment can be a means to harmonize MFC MRD evaluation. These promising results need to be verified in larger cohorts, with inclusion of post-induction assessments, and should be followed by prospective analyses to delineate the diagnostic validity of FlowSOM for AML MRD diagnostics in clinical trials. Disclosures Subklewe: Janssen: Consultancy; Morphosys: Research Funding; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; Miltenyi: Research Funding; Oxford Biotherapeutics: Research Funding; Pfizer: Consultancy, Honoraria; AMGEN: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Research Funding.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 17-18
Author(s):  
David Böckle ◽  
Paula Tabares Gaviria ◽  
Xiang Zhou ◽  
Janin Messerschmidt ◽  
Lukas Scheller ◽  
...  

Background: Minimal residual disease (MRD) diagnostics in multiple myeloma (MM) are gaining increasing importance to determine response depth beyond complete remission (CR) since novel agents have shown to induce high rates of deep clinical responses. Moreover, recent reports indicated combining functional imaging with next generation flow cytometry (NGF) could be beneficial in predicting clinical outcome. This applies in particular to the subset of patients suffering from relapsed/refractory multiple myeloma (RRMM) who tend to show a higher incidence of residual focal lesions despite serological response. Here, we report our institutions experience with implementing both functional imaging and NGF-guided MRD diagnostics in clinical practice. Methods: Our study included patients with newly diagnosed multiple myeloma (NDMM) and RRMM achieving VGPR, CR or sCR. Bone marrow aspirates were obtained for MRD-testing according to IMWG 2016 criteria. Samples were collected between July 2019 and July 2020 and analyzed with NGF (according to EuroFlowTM guidelines) at a sensitivity level of 10-5. Results were compared to functional imaging obtained with positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DW-MRI). High-risk disease was defined as presence of deletion 17p, translocation (14;16) or (4;14). Results: We included 66 patients with NDMM (n=39) and RRMM (n=27) who achieved VGPR or better. In patients with RRMM the median number of treatment lines was 2 (range 2-11). Fifteen patients suffered from high-risk disease. Median age at NGF diagnostics was 64 years (range 31-83). Among patients achieving VGPR (n=27), CR (n=10) and sCR (n=29) seventeen (26%) were MRD-negative by NGF testing. CR or better was significantly associated NGF MRD-negativity (p=0.04). Notably, rates of NGF MRD-negativity were similar among patients with NDMM (28%) and RRMM (26%). Even some heavily pretreated patients who underwent ≥ 4 lines of therapy achieved MRD-negativity on NGF (2 of 9). Functional imaging was performed in 46 (70%) patients with DW-MRI (n=22) and PET (n=26). Median time between NGF and imaging assessment was 2 days (range 0-147). Combining results from imaging and NGF, 12 out of 46 (26%) patients were MRD-negative with both methods (neg/neg). Three patients displayed disease activity as measured with both, imaging and NGF (pos/pos). Twenty-nine of the remaining patients were MRD-positive only according to NGF (pos/neg), while two patients were positive on imaging only (neg/pos). More patients demonstrated combined MRD-negativity on NGF and imaging (neg/neg) in the NDMM setting than in RRMM (32% versus 19%). We also observed that 30% of the patients with high-risk genetics showed MRD-negativity on both imaging and NGF. Of note, none of the patients with very advanced disease (≥4 previous lines) was MRD-negative on both techniques. Conclusion In the clinical routine, MRD diagnostics could be used to tailor maintenance and consolidation approaches for patients achieving deep responses by traditional IMWG criteria. Our real-world experience highlights that MRD-negativity can be achieved in patients suffering from high-risk disease and also in late treatment lines, supporting its value as endpoint for clinical trials. However, our data also support MRD diagnostics to be combined with functional imaging at least in the RRMM setting to rule out residual focal lesions. Future studies using MRD for clinical decision-making are highly warranted. Disclosures Einsele: Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; GlaxoSmithKline: Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau. Rasche:Celgene/BMS: Honoraria; GlaxoSmithKline: Honoraria; Oncopeptides: Honoraria; Skyline Dx: Research Funding; Janssen: Honoraria; Sanofi: Honoraria.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2946-2946
Author(s):  
Carlos Fernández de Larrea ◽  
Natalia Tovar ◽  
María Rozman ◽  
Laura Rosiñol ◽  
Juan I. Aróstegui ◽  
...  

Abstract Abstract 2946 Background: The achievement of complete remission (CR) is the crucial step for a long-lasting response and prolonged survival after autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). The European Group for Blood and Marrow Transplantation (EBMT) criteria for CR include the negativity of serum and urine immunofixation (IFE) and less than 5% of bone marrow plasma cells (BMPCs). Additionally, the International Myeloma Working Group (IMWG) has even proposed a stringent CR category, which requires to rule out the clonal nature of the BMPCs. However, few studies have addressed this issue in patients with MM and negative IFE. The aim of the present study was to determine the impact of plasma cell count in the bone marrow aspirate on the long-term outcome of patients with MM with negative IFE after ASCT. Methods: Thirty-five patients (16M/19F; median age at ASCT 55 years, range 26–68) with MM who underwent ASCT from March 1994 to December 2008, were studied. All patients had achieved a negative serum and urine IFE after high dose therapy with melphalan-based regimens. Bone marrow aspirate was performed when negative serum and urine IFE was achieved and at least three months from ASCT (median 3.24 months). The analysis was based on microscopic revision for May-Grünwald-Giemsa stained bone marrow smears performed according to standard procedures. BMPC percentage was calculated independently by two observers counting 500 bone marrow total nucleated cells in random areas from two different slides (1000 cells on each patient). Results: Median BMPCs percentage was 0.8 (range 0.1–5.8). Only two patients had more than 3% BPMCs. These results are in contrast with a recent report from the Mayo Clinic group, where 14% of the patients with MM and negative IFE had 5% or more BMPCs. In univariate Cox-model regression analysis, the number of BMPCs significantly correlated with progression-free survival (PFS)(p=0.021) with no impact on overall survival (OS)(p=0.92). This statistical significance on PFS was retained in the multivariate analysis, when baseline prognostic factors such as age, hemoglobin level, serum creatinine, β2-microglobulin and Durie-Salmon stage were added to the model (p=0.003). To establish the best predictive cut-off for progression and survival, a receptor-operator curve (ROC) analysis was developed. It showed the value of 1.5% BMPCs, with a sensitivity of 53%, specificity of 90% and area under the curve of 0.66 for predicting progression. Ten patients had more than 1.5% BMPC, and 25 equal or less than 1.5% BMPC. Median PFS was 8.5 years (CI 95% 2.6 to 14.3) and was not reached in patients with ≤1.5% BMPCs versus 3.1 years in patients with >1.5% BMPCs, with a hazard ratio probability to progression of 3.02 (CI 95% 1.18 to 9.71)(p=0.016) in the group with more than 1.5% of BMPCs (Figure 1). Median OS was not reached in patients with ≤1.5% compared with a median of 9.7 years in those with more than 1.5% BMPCs (p=0.195) (Figure 2). It is likely that serological CR with very low percentage of BMPCs (i.e. ≤1.5%) is equivalent to negative MRD assessed by MFC or molecular studies. In fact, all 8 patients in continued CR between 9 and 16 years beyond ASCT (“operational cures”) are in the group with ≤1.5% BMPCs, while all patients in the group with >1.5% BPMC have relapsed within the first 9 years from ASCT (Figure 1). Conclusion: The percentage of BMPCs in patients with MM in CR after ASCT is a strong predictor of progression. Bone marrow morphology examination is an easy, inexpensive, and non-time consuming test and it should be the first step in the estimation of the residual tumor mass in patients with MM in CR after ASCT. Disclosures: Rosiñol: Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cibeira:Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Blade:Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Hematology ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 37-45
Author(s):  
Andrew J. Yee ◽  
Noopur Raje

Abstract Improvements in multiple myeloma therapy have led to deeper responses that are beyond the limit of detection by historical immunohistochemistry and conventional flow cytometry in bone marrow samples. In parallel, more sensitive techniques for assessing minimal residual disease (MRD) through next-generation flow cytometry and sequencing have been developed and are now routinely available. Deep responses when measured by these assays correspond with improved outcomes and survival. We review the data supporting MRD testing as well as its limitations and how it may fit in with current and future clinical practice.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2729-2729
Author(s):  
Colin D. Godwin ◽  
Yi Zhou ◽  
Megan Othus ◽  
Carole M. Shaw ◽  
Kelda M. Gardner ◽  
...  

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.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1523-1523
Author(s):  
Wenbin Xiao ◽  
Aaron D Goldberg ◽  
Christopher Famulare ◽  
Sean Delvin ◽  
Minal Patel ◽  
...  

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.


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