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 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, &gt; 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 &gt; 0.1% and/or an NPM1 VAF &gt; 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.

Evolution of Multiparametric Flow Cytometry Testing for Minimal Residual Disease Assessment in Multiple Myeloma and Its Impact on Clinical Outcomes: A Single Institution Experience

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2274-2274 ◽  
Author(s):  
Nischala Ammannagari ◽  
Paul K. Wallace ◽  
Theresa Hahn ◽  
Yali Zhang ◽  
Christine M. Ho ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Flow Cytometry ◽  
Board Of Directors ◽  
Clinical Outcomes ◽  
Research Funding ◽  
Plasma Cells ◽  
Residual Disease ◽  
Advisory Committees ◽  
Multiparametric Flow Cytometry ◽  
Minimal Residual

Abstract Minimal residual disease (MRD) after autologous hematopoietic cell transplant (AHCT) in multiple myeloma (MM) has been shown to be an important predictor of clinical outcomes, suggesting that MRD negativity may be a new goal of therapy. Multiparametric flow cytometry (MFC) is a commonly used method for MRD assessment, however this technique is still evolving and efforts are underway to standardize this testing. The key factors which enable detection of residual malignant plasma cells by MFC remain an area of active investigation. We performed a retrospective review of 172 consecutive MM patients who received AHCT between 10/1/2007 and 5/31/2015 at our institution and had undergone MRD assessment by MFC at day +100 post-AHCT. Day +100 post-AHCT response was determined using the International Myeloma Working Group (IMWG) Uniform Response Criteria (URC) and was correlated with MRD assessment as well as progression free survival (PFS) and overall survival (OS). Data were collected on the specific MFC panel utilized, including the epitopes analyzed and the total plasma cell number (PCN) counted (normal and malignant PC). These variables were correlated with clinical outcomes including day +100 MM response, PFS and OS. Of 172 patients, 30 were MRD-positive, 133 MRD-negative, and 9 were equivocal at day +100 post-AHCT, the latter of which were excluded from further analyses. Day+100 MRD-negative status by MM response was: 31/37(84%) for VGPR, 35/41 (85%) for CR, and 42/42 (100%) for sCR. Patients who achieved a CR or sCR had improved PFS and OS rates compared with patients who achieved ≤VGPR: 3-year PFS: 61% (95% CI 49-74%) vs 46% (95% CI 32-59%), P=0.03; 3-year OS: 96% (95% CI 91-100%) vs 69% (95% CI 56-81%), P=0.005)). Patients with MRD-negative disease at day +100 post-AHCT had significantly superior PFS and OS compared to those with MRD-positive disease: 3-yr PFS 62% (95% CI 52-72%) vs 33% (95% CI 12-53%), P <0.0001) (Figure 1); 3-year OS 85% (95% CI 78-93%) vs 64% (95% CI 44-85%), P=0.004). There was no association between MRD status and age (<60 vs ≥60 years), sex, race (white vs other), performance status (KPS ≤80 vs ≥90), or subsequent transplant (P>0.1). The details of the four different MRD MFC panels are shown in Table 1. Panels C and D were compared, at a similar PCN level, but different epitopes tested, and found no significant difference in PFS or OS. Further analysis of PCN within the MRD-negative cohort revealed a trend towards improved 3-yr PFS rates with increasing numbers of PCN analyzed: 42% (95% CI 20-63%) for PCN<250,000, 68% (95% CI 52-83%) for PCN=250,000-500,000, 59% (95% CI 42-76%) for PCN >500,000-1,000,000 and 89% (78-100%) for PCN>1,000,000 (P=0.099) (Figure 2). The 3-yr OS rates for MRD-negative patients were higher for increasing PCNs analyzed, but the PCN categories were not statistically significantly different: 74% (95% CI 54-94%) for PCN<250,000, 88% (95% CI 77-99%) for PCN=250,000-500,000, 85% (95% CI 73-98%) for PCN >500,000-1,000,000 and 100% for PCN>1,000,000 (P=0.2). Sensitivity analysis revealed similar trends when a cut-off of above or below 500,000 or 1,000,000 was used. Our results confirm that achievement of MFC MRD negativity at day +100 post-AHCT is associated with improved PFS and OS. Factors such as the long-half lives of immunoglobulins, the quality of the bone marrow aspirate obtained, and the presence of occult extramedullary disease may account for the patients who were MRD negative but did not achieve a CR at day +100 post AHCT by IMWG URC. MRD assessment by MFC at our institution has evolved over time to include higher numbers of acquired and analyzed events. Notably, there was a trend towards improved outcomes with greater numbers of plasma cells analyzed, suggesting that continued development of MRD assessment by MFC should focus on increasing PCN analyzed in order to improve detection of residual MM clones. Disclosures Hahn: Novartis: Equity Ownership; NIH: Research Funding. McCarthy:The Binding Site: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: 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, Research Funding; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gamida Cell: Honoraria, Membership on an entity's Board of Directors or advisory committees. Holstein:Millennium: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Leukemic Stem Cells Persistence Measured By Multiparametric Flow Cytometry Is a Biomarker of Poor Prognosis in Adult Patients with Acute Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2688-2688
Author(s):  
Francesco Buccisano ◽  
Raffaele Palmieri ◽  
Maria Irno Consalvo ◽  
Alfonso Piciocchi ◽  
Luca Maurillo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Poor Prognosis ◽  
Leukemic Stem Cells ◽  
Advisory Committees ◽  
Multiparametric Flow Cytometry ◽  
Significant Difference ◽  
Acute Myeloid

Introduction: Despite the recent advances in chemotherapy regimens, relapse still substantially affects prognosis of intensively treated adult acute myeloid leukemia (AML) patients. There is growing evidence that a residual populations of leukemic cells may survive chemotherapy and outgrow, eventually causing relapse. These chemo-resistant cells are particularly abundant in the fraction of leukemic stem cells (LSC), which are endowed with pronounced self-renewal properties allowing to initiate and maintain leukemic clone. These cells can be detected, by high sensitivity multiparametric flow-cytometry (MFC), in the CD34+/CD38- fraction of the leukemic populations and can be distinguished from normal hematopoietic stem cells by the expression of specific markers. In recent clinical trials, LSC have been demonstrated to represent a biomarker of poor prognosis when detected at diagnosis but also during treatment course. Moreover, the combined estimate of measurable residual disease (MRD) and LSC refines the prognostic assessment as determined by the sole application of MRD detection. Aim: We analyzed a series of patients (pts) treated in the context of GIMEMA trials, in whom the LSC frequency was assessed by MFC at diagnosis. Pts with measurable levels of LSC were tested again after the consolidation cycle. At the same timepoint "standard" MRD was also determined. The purpose of the study was to demonstrate a correlation between LSC burden at baseline and prognosis in terms of overall (OS) and disease-free survival (DFS). Furthermore, we wanted to investigate the relationship between LSC and "standard" MRD persistence (>0.035%) after consolidation, and possible correlation with outcome. Methods: LSC were evaluated by MFC as described elsewhere (Terwijn, PLoS 2014). LSC were quantified exploiting the expression of the C-type lectin-like molecule-1 (CLL1) and applying a sequential gating strategy that contained the CD34+/CD38- population. Pts were defined as LSC negative (LSCneg) in case of zero LSC count, LSClow or LSChigh when LSC were >0<0,03% or >0.03%, respectively. After consolidation, any level >0 was considered as a LSC persistence. Methods of analysis and thresholds were set according to previous publications (Zeijlemaker, Leukemia 2019). Results: We analyzed 130 pts with de novo AML, in whom LSC determination was available at the baseline. Fifty-nine (45,4%) pts were LSCneg, 49 (37,7%) LSClow, 22 (16,9%) LSChigh. We did not observe any correlation between baseline LSC level and genetic/cytogenetic risk at diagnosis. There was not a significant difference in terms of OS duration according to the 3 LSC levels, however, pts who were LSChigh had the shortest OS (36-month estimate OS of 71.5% vs. 65.4 % vs 52.4 % for the LSCneg, LSClow and LSChigh categories respectively; p=0.21). A statistically significant difference, regardless of the belonging to the LSClow or LSChigh category was observed when we focus on the subgroup of 30 pts with intermediate-risk AML, with a 36-month estimate OS of 76% vs. 77.8% vs 25% for the LSCneg, LSClowand LSChigh categories respectively (p=0.023) (Figure 1A). In 19 patients, LSC persistence was assessed at the post-consolidation time-point. Nine LSChigh pts who failed to eradicate residual LSC at this timepoint had a worse outcome as compared to those belonging to the same category but achieving a LSC clearance or those who were LSClow (36-month OS of 62.5% vs. 59.2% vs. 66.7% vs. 25% for the LSClow converted into LSCneg, LSClow not converted into LSCneg, LSChigh converted into LSCneg and LSChigh not converted into LSCneg categories, respectively; P=0.062) (Figure 1B). In 27 pts LSC and "standard" MRD determination was available. LSC persistence determined a worse 3-years OS both in MRD negative (66.7% vs 85.7%, p=0.44) and MRD positive pts (<20% vs 75.0%, p=0.041). Conclusions: In line with the experience of other European groups, we demonstrated that MFC monitoring of LSC is feasible and provides prognostic information when performed at diagnosis and during treatment course. MFC assessment of LSC also offers the opportunity to monitor pts who lack aberrant phenotypes suitable for "standard" MRD investigation. When the 2 approaches - standard "MRD" and LSC assessment - are combined together, the prognosis prediction of AML can be further refined. Finally, LSC assessment can potentially represent an effective tool to monitor the effect of LSC targeting agents. Disclosures Buccisano: Astellas: Membership on an entity's Board of Directors or advisory committees; Janssen: 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. Venditti: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; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy.

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.

CLL2007FMP, a Phase III Randomized Multicentric Trial of the French Cooperative Group On CLL and WM (FCGCLL/MW) and the “Groupe Ouest-Est D'etudes Des Leucémies Aigües Et Autres Maladies Du Sang” (GOELAMS): Immunochemotherapy with Fludarabine (F), Cyclophosphamide (C), and Rituximab (R) (FCR) Yields a Significantly Better Response Than Fludarabine (F), Cyclophosphamide (C) and MabCampath (Cam) (FCCam) In Previously Untreated B-Chronic Lymphocytic Leukemia Patients as Evaluated by a Sensitive 6 Color Flow Cytometry MRD

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 698-698 ◽  
Author(s):  
Letestu Remi ◽  
Stéphane Leprêtre ◽  
Arnoulet Christine ◽  
Baseggio Lucille ◽  
Campos Lydia ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Board Of Directors ◽  
Residual Disease ◽  
Phase Iii ◽  
Advisory Committees ◽  
Color Flow ◽  
Phase Iii Trial ◽  
Mutational Status

Abstract Abstract 698 Introduction: Between 11/2007 and 01/2009, the FCGCLL/MW and the GOELAMS conducted a multicenter phase III trial, CLL2007FMP, to evaluate the efficacy of FCCam versus FCR in previously untreated medically fit patients. PFS was the primary-end-point of this trial. The trial was discontinued after randomisation of 165 patients for unacceptable toxicity in the FCCam arm. PFS and OS are not yet evaluable but as a sensitive 6 color flow cytometry technique was used to assess MRD in blood and bone marrow at month 9, we were able to evaluate the quality of the response in both arms. Methods and patients: A cohort of 178 medically fit patients (cumulative illness rating scale (CIRS) score < or = 6 and creatinine clearance ≥ 60 ml/min), younger than 65 years old, were enrolled. 165 patients were randomized to receive six oral courses of FC (F 40mg/m2 d1-3 and C 250 mg/m2 d1–3; q 28 days) in combination with either R (n=83; 375 mg/m2 i.v. d 0 at first cycle and 500 mg/m2 d1 all subsequent cycles; q 28 days) or Cam (n=82; 30 mg s/c d1-3; q 28 days). Patients were stratified according to IGHV mutational status and presence of 11q deletion. Cases with 17p deletion were excluded. The trial recruitment was discontinued because of an excess of mortality in the FCCam arm (6 deaths versus 0 in FCR arm), and the last 13 patients enrolled were not randomized. Clinical response was evaluated based on IWCLL criteria. We established a sensitive and specific approach for the evaluation of minimal residual disease (MRD) at month 9, using a 6-color flow cytometry technique with 3 combinations including characteristic markers and light chain expression. We determined the limit of detection (LOD) of the assay by studying normal blood samples, LOD varied from 0.5 to 0.7×10-5 depending on the combination considered. Result: The Overall Response Rate (ORR) was 91% in the FCR arm and 85% in the FCCam arm (ns). Clinical responses were as follows: CR (FCR: 56/80=70%, FCCam: 45/79 =59%, ns), CR I (FCR:13/FCCam: 11), PR (FCR:5/FCCam:15), and stable and progressive cases (FCR: 6/FCCam:8). When considering together CR and CR I, response rate appeared significantly higher in the FCR arm (86%) than in FCCam arm (70%) (p=0.03). MRD was assessed both in blood and bone marrow at month 9, and was undetectable in 58% patients in blood and only in 36 % in bone marrow. No patient had an undetectable MRD in marrow when detectable in blood. Similarly, MRD was detectable in bone marrow in 15 cases with histologically normal bone marrow biopsy, whereas no nodal PR had undetectable MRD. Therefore, flow cytometry MRD in bone marrow appears as the most sensitive technique for the evaluation of response. Of note, 9 patients had a very good PR with presence of a residual lymphnode, and had undetectable blood and bone marrow MRD (4 in FCCAm arm and 5 in FCR arm). When considering MRD independently from clinical response, the number of MRD negative cases was not significantly different between the two arms (FCR: 45%/FCCam: 26 %) arm. But when combining MRD negativity with clinical complete response, the number of MRD negative CR was significantly higher with FCR (40%) than with FCCam (15%)(p= 0.029). The number of courses of chemotherapy received was slightly but significantly lower in the FCCam arm. Nonetheless, this difference was not accountable for the difference in the quality of response as the number of MRD negative CR remained significantly higher with FCR than with FCCam when considering only the patients having received at least 4 courses of either chemotherapy. The quality of response was not influenced by either presence of deletion11q or mutational status as well. In conclusion, detection of MRD in bone marrow by flow cytometry is a sensitive technique for the evaluation of minimal residual disease. Combining clinical CR with flow cytometry bone marrow MRD allows detecting the best responders. In this randomized phase III trial, besides leading to a lower rate of toxicity, the FCR regimen yielded a significantly higher rate of MRD negative CR than FCCam, and therefore had a positive impact on the quality of the response. Disclosures: Veronique: roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; mundipharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; genzyme: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; jansen: Membership on an entity's Board of Directors or advisory committees.

Targeting Cell-Bound MUC1 on Myelomonocytic and Monocytic Leukemias and Leukemic Stem Cells: Therapeutic Implications

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2899-2899
Author(s):  
Thierry Guillaume ◽  
Virginie Dehame ◽  
Patrice Chevallier ◽  
Pierre Peterlin ◽  
Marc Grégoire ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Cell Surface ◽  
Board Of Directors ◽  
Leukemic Cell ◽  
Muc1 Expression ◽  
Leukemic Stem Cells ◽  
Advisory Committees ◽  
Alpha Chain ◽  
Myelomonocytic Leukemia

Abstract Monocytic neoplasms comprise a heterogeneous group of hematologic malignancies including chronic myelomonocytic leukemia (CMML), juvenile myelomonocytic leukemia (JMML), acute myelomonocytic and monocytic leukemia (AML-M4 and AML-M5), and monocytic sarcoma. Monocytic or granulomonocytic hyperplasia is a finding frequently-if not invariably-shared by these different entities, as is a poor therapeutic outcome in the absence of hematopoietic stem cell transplantation. Cell surface molecules aberrantly expressed or overexpressed by leukemic cells represent potential disease-specific therapeutic targets. MUC1, a polymorphic type I high molecular weight glycoprotein represents such a molecule. MUC1 consists of an extracellular domain containing 20 to 125 tandem repeats of a 20 amino acid-long sequence, followed by a transmembrane domain and a short cytoplasmic tail leading to intracellular signaling. Cleavage of MUC1 yields two unequal chains: a large extracellular alpha subunit containing the tandem repeat array bound in a strong non-covalent interaction to a smaller beta subunit containing the transmembrane and cytoplasmic domains. Essentially all anti-MUC1 antibodies reported to date target the highly immunogenic tandem repeat of the MUC1 alpha chain. Because the alpha chain binds the cell-bound domains of MUC1 only intermittently in an 'on-and-off' manner, agents directed against the alpha chain will not effectively target MUC1+ cells. In contrast, the MUC1 SEA domain represents a stable structure fixed to the cell surface at all times. We therefore generated mAbs that specifically recognize the cell-bound MUC1 SEA domain. One of them, a partially humanized murine mAb termed DMB-5F3 was used to examine the expression of MUC1 on AML cells by flow cytometry. A series of twenty-two AML samples (blood-derived n=12; bone marrow-derived n=10; AML0=2, AML1=2, AML2=10, AML4=1, AML5=5, AML6=2) collected either at the time of diagnosis or at relapse were analysed for MUC1 expression by flow cytometry. A murine mammary tumor cell line stably transfected with human MUC1 DNA served as control. Blasts cells from 5 AML samples highly expressed MUC1, and significantly, all were of monocytic or myelomonocytic lineage (AML4=1, AML5=4). Leukemic stem cells (CD34pos or CD34neg linneg) from the MUC1+ AMLs were examined and likewise found to express MUC1. In addition, AML cell lines MV411, MOLM14, and SHI-1 derived from monocytic leukemic lineage clearly expressed cell surface MUC1, while non- monocytic leukemic cell lines U937, K562, and HL60 had little or no expression. Normal monocytes and monocytes derived from patients with activated monocytosis were also found to express MUC1. Based on these findings we examined MUC1 expression in a series of myelomonocytic leukemia (CMML and JMML). In fifteen CMML samples examined (type 1 n=11, type 2 n=4) (blood n=7, BM n=7) 92%-100% (median 99.7%) of CD14+CD56+ CMML cells bound mAb DMB-5F3 to cell-surface MUC1. CD14+CD16+CD56+ blast cells from 2 pts with JMML were also found to express MUC1 (between 64% and 71 % positive). Based on these findings we conclude that expression of MUC1 is restricted to monocytic and myelomonocytic leukemias and that MUC1 represents an effective target for leukemic immunotherapy. Significantly, anti-MUC1 mAb also targets monocytic leukemic stem cells, reinforcing its therapeutic potential. The fact that the anti-MUC1 antibody DMB-5F3 can enter cells and thereby ferry Ab-bound toxin opens the way for us to demonstrate leukemic cell killing with anti-MUC1 mAb-immunotoxin conjugates. Disclosures Moreau: Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; 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; Millennium: Honoraria, 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 (&gt;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 &lt;5% of blasts and negative MRD was defined as &lt;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 &gt;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&lt;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 Next-Generation Sequencing to Assess the Impact of Low Dose Melphalan on Residual Disease before High-Dose Melphalan and Stem Cell Transplant in Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4933-4933
Author(s):  
Ehsan Malek ◽  
Mary Hislop ◽  
Leland Metheny ◽  
Molly Gallogly ◽  
Marcos J.G. de Lima ◽  
...  
Keyword(s):  
Sample Size ◽  
Board Of Directors ◽  
Research Funding ◽  
Disease Burden ◽  
Residual Disease ◽  
Tumor Burden ◽  
High Dose ◽  
Cell Transplant ◽  
Size Estimation ◽  
Advisory Committees

Abstract High-Dose Melphalan (HDM) followed by stem cell transplant (SCT) remains the standard-of-care for transplant-eligible patients newly-diagnosed with multiple myeloma (MM). However, ~1/3 of patients relapse &lt;2 years after undergoing HDM-SCT, indicating that melphalan-sensitivity is limited to a subset of patients and is currently not predictable. Currently, models that predict melphalan-resistance before proceeding to transplant are lacking. Rather, transplant-eligibility is defined mostly based on adequate organ function and performance status. Therefore, there is an urgent and unmet clinical need to develop strategies that accurately predict melphalan sensitivity among MM patients prior to HDM-SCT and save melphalan-resistant patients from undergoing this highly morbid procedure, if no demonstrable benefit is expected from it. Traditional disease-measurement methods based on International Myeloma Working Group (IMWG) criteria rely on the secretory function of myeloma cells and measure monoclonal protein levels. Following induction therapy, pre-transplant monoclonal protein levels are usually very low, and further reduction in myeloma secretory function are not detectable. In addition, the long half-life of monoclonal proteins makes assessing short-term disease changes problematic. Methods to accurately detect minor changes in disease burden following a low dose of melphalan (LDM) as a marker of melphalan sensitivity are needed to better predict patient responses to LDM. Next-generation sequencing (NGS), is an alternative approach that may allow for the highly sensitive, rapid, real-time detection of minuscule changes in tumor volume that are not influenced by the long half-life of monoclonal proteins. Here, we propose to use NGS-based tumor assessment to evaluate changes in disease volume following LDM before proceeding to HDM-SCT. Evidence is lacking to determine whether a single LDM generates a decrease in myeloma burden that is measurable by NGS. Our central hypothesis is that NGS of bone marrow aspirates from newly-diagnosed, post-induction transplant-eligible MM patients will provide a method to precisely determine the effect of LDM on disease burden. ClonoSEQ assay is an FDA-cleared, highly sensitive, specific, and standardized method to detect and monitor MRD, in MM patients. clonoSEQ leverages the power of NGS and offers an accurate and reliable way to assess how disease burden changes over time in response to treatment. Therefore, we propose a proof-of-principle study to assess the validity of this strategy and to provide essential data for future trial design investigating individualized approaches based on NGS sequencing and low doses of therapeutic agents. We will test the central hypothesis that LDM, administered at 16 mg/m 2, generates a detectable reduction in tumor burden measured by NGS. A detectable reduction in tumor burden is defined as a ≥ 20% decrease in NGS clonal count in at least 30% of subjects. We will administer propylene glycol-free melphalan formulation (EVOMELA) due to greater stability upon reconstitution than AlKERAN formulation in order to diminish the variability in the effective administered dose. The primary and secondary objectives and endpoints of the study are listed in Table-1,2. Statistical Considerations: Clonoseq detects measurable residual disease at the level of a single cell given sufficient sample input. The specific hypothesis of this pilot trial is LDM produces a measurable disease reduction that is readily detectable by clonoSEQ with at least a 20% reduction in at least 30% of patients. Assuming a 100% yield for VJD clonal sequencing and calibration efficacy by clonoSEQ, the sample size required to test the null hypothesis of 5% patients with positive MRD test against alternative 30% patients with positive MRD test is 16 patients. The sample size estimation is using two-sided chi-square test with 80% power. The sample size estimation is n = 21, when power = 90% based on one sample Binomial distribution theory. We will assume 20% failure rate for VJD clonal sequencing and calibration efficacy by clonoSEQ. Therefore, by enrolling 20 patients, we expect that at least 16 patients will have MRD assessable by NGS method. Figure 1 Figure 1. Disclosures Malek: BMS: Honoraria, Research Funding; Amgen: Honoraria; Bluespark Inc.: Research Funding; Sanofi: Other: Advisory Board; Cumberland Inc.: Research Funding; Takeda: Honoraria; Janssen: Other: Advisory board ; Medpacto Inc.: Research Funding. Metheny: Incyte: Speakers Bureau; Pharmacosmos: Honoraria. de Lima: Miltenyi Biotec: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees.

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