Highly Sensitive Droplet Digital PCR to Identify CML Patients with a High Probability of Achieving Treatment-Free Remission

Abstract Introduction: Treatment Free Remission (TFR) is the ultimate goal of therapy for most CML patients. Despite adopting consensus eligibility criteria of a sustained deep molecular response and more than 4 years of TKI therapy, the relapse rate after TKI cessation is still around 50%. More sensitive detection of residual leukaemia has the potential to improve our capacity to predict TFR outcomes for individual patients. Aim: To correlate droplet digital PCR (ddPCR) assay results with TFR outcome, especially in the setting of undetectable levels measured by qRT-PCR. Method: ddPCR was performed on blood samples from 51 TFR-eligible CML patients at the time of TKI cessation. 5 µg RNA per sample was used in 8 wells/sample using the BioRad QXDx BCR-ABL %IS kit on QX200 ddPCR system which yielded BCR-ABL1% (IS) directly. All these patients achieved MR4.5 that was sustained for ≥ 2 years. Results: 100% of patient were in MR4.5 via qRT-PCR at the time of stopping. 61% of the 51 patients evaluated relapsed within 12 months. Median duration of TKI therapy for the whole group was 5.8 years (range 2.2- 14 years). 20 patients achieved TFR success with a median follow up of 24 months (TFR group; sustained BCR-ABL1 <0.1% (IS) after TKI discontinuation for ≥12 months), while 31 patients relapsed (Relapse group; BCR-ABL1 >0.1% (IS) after stopping; median time of relapse 3 months, range 1-10 months). A ROC curve analysis correlated TFR outcome with ddPCR results, with BCR-ABL1 level ≥0.003% via ddPCR at the time of stopping identified as an optimal cut-off. Kaplan-Meier analysis showed that 89% of the patients with ddPCR ≥0.003 relapsed after TKI cessation, whereas the ddPCR <0.003 demonstrated a significantly reduced relapse rate to 54% (p=0.01, Figure 1A). In addition, the TFR group (median BCR-ABL1 0.00065%) demonstrated approximately two-fold lower levels of BCR-ABL1transcript level compared to the relapse group (median 0.0012%). Interestingly, 7/31 (23%) of the relapsed group had undetectable BCR-ABL1 transcript even with the current highly sensitive method, while this undetectable level was only observed in 35% of the TFR group. We next assessed other known predictors of TFR success relative to ddPCR results in a Cox proportional hazard model. We have previously demonstrated that the BCR-ABL1 halving time after commencing therapy is highly predictive of TFR. At a univariate level, transcript type (e13a2 versus e14a2, p=0.01), BCR-ABL1 halving time (p>0.0001), and mRNA quantitation by ddPCR ≥ 0.003% (p=0.02) were all significantly associated with clinical outcome. Other variables including gender, age, ELTS score, Sokal score, MR4.5 duration and TKI duration were not associated with clinical outcome in this cohort (Figure 1B). In the multivariate analyses (Figure 1C), ddPCR remained an independent predictor after adjusting for ELTS, TKI duration and MR4.5 duration. Interestingly, ddPCR was not an independent predictor after adjusting for BCR-ABL1 transcript type or halving time. Conclusion: QXDx ddPCR assay is a promising tool for molecular residual disease monitoring in CML, especially when the BCR-ABL1 is undetectable by conventional method. The CML patients with levels of detectable BCR-ABL1 ≥0.003% measured by ddPCR have a significantly higher probability of relapse compared to patients with lower levels of the transcript. The ≥0.003% BCR-ABL1 level cut-off value could be a potential tool to aid decision-making when attempting TKI discontinuation in CML. However, even though a measurable level of BCR-ABL1 above 0.003% via ddPCR identified patients at high risk of relapse after a TFR attempt, it does not rule out the possibility of TFR; and a negative ddPCR result does not exclude the risk of molecular relapse. ddPCR may be most useful where other TFR predictive factors including BCR-ABL1 transcript type and halving time are not available. In-kind support was received from Bio-Rad for this study. Figure 1 Figure 1. Disclosures Branford: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Cepheid: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Qiagen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hughes: Novartis: Honoraria, Research Funding; Incyte: Honoraria; BMS: Honoraria, Research Funding. Yeung: BMS: Honoraria, Research Funding; Amgen: Honoraria; Novartis: Honoraria, Research Funding; Pfizer: Honoraria.

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BCR-ABL1 qPCR-Based Doubling Time within the First 6 Months after Imatinib Discontinuation Is a Predictive of Successful TKI Treatment-Free Remission

Blood ◽

10.1182/blood-2019-131454 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 2933-2933

Author(s):

Georgina S. Daher-Reyes ◽

Isabelle Bence-Bruckler ◽

Lambert Busque ◽

Donna L. Forrest ◽

Lynn Savoie ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Doubling Time ◽

Recursive Partitioning ◽

Transcript Level ◽

Relapse Free Survival ◽

Advisory Committees ◽

Free Survival ◽

Treatment Free Remission ◽

Tki Discontinuation

Introduction: The Canadian tyrosine kinase inhibitor (TKI) discontinuation trial has reported a 59.1% and 21.5% molecular relapse-free survival (RFS) rate after first attempt of treatment free remission (TFR1) with imatinib (IM) discontinuation and after a 2nd attempt of TFR (TFR2) with dasatinib (DA) discontinuation, respectively. Throughout the first and second attempts of TKI discontinuation, the kinetics of BCR-ABL qPCR transcript rise were very similar after TFR1 and TFR2. This prompts us to have a better understanding of the dynamics of BCR-ABL qPCR rise after TKI discontinuation. Methods and materials: This prospective clinical trial (BMS CA180-543, Clinicaltrial.gov NCT#02268370) has 3 phases: 1) IM discontinuation phase, 2) DA rechallenge phase, 3) DA discontinuation phase. We have analyzed the monthly BCR-ABL1 qPCR value and doubling time (DT) in the first 6 months following IM discontinuation. The qPCR level before IM discontinuation or the qPCR level from the prior month was used as a baseline. DT at each measurement was calculated as x = ln(2)/K, where x is the DT and k is the fold BCR-ABL1 change from the previous value divided by the number of days between each measurement. The distribution of DT for all patients was assessed at each timepoint of DT measurement within the first 6 months. In order to define the best cut-off levels of BCR-ABL1 qPCR and DT showing the best risk stratification power throughout the first 6 months, DT values were collected and analyzed for molecular relapse-free survival (RFS) from the time of DT measurement. Then, a binary recursive partitioning method was applied using RFS which is calculated from the time of each DT measurement. Based on the DT cut-off value, the group was divided into 2 groups. The RFS was compared according to the groups. Results: As of March 25, 2019, out of 131 patients enrolled, 58 patients (44.3%) lost a molecular response. The 6- and 12-months' molecular relapse-free survival (mRFS) rate was estimated as 59.1% (50.1-67.0%) and 56.8 % (47.8-64.8%), respectively. BCR-ABL1 qPCR transcript level after IM discontinuation showed a rapid rise between the first 2-4 months, followed by a gradual rise after 4 months. The proportion of the patients showing DT less than 12.71 days but above 0 was 3.8% at 1 mo, 25.2% at 2 mo, 15.3% at 3 mo, 12.2% at 4 mo, 2.3% at 5 mo and 2.3% at 6 mo, respectively. DT values were collected and analyzed for molecular RFS from the time of DT measurement. Binary recursive partitioning method was applied and provided 12.71 days as the best DT cutoff value to stratify the patients according to the RFS from the time of each DT measurement. In other words, the patients having DT less than 12.71 days but above 0 at any time within the first 6 months had a higher risk of failing the TFR attempt, while those with DT equal to or over 12.71 days at any time has a lower risk of losing TFR after IM discontinuation. The best result was reported in the group with stable BCR-ABL qPCR transcript level. A rapid incline of BCR-ABL qPCR transcript level was observed 2-4 months after IM discontinuation. According to the DT measured at 2 months, the group with DT less than 12.71 days but above 0 showed the lowest mRFS rate of 5.0% (0.9-14.8%) at 12 months (HR 5.74), compared to the group with DT equal to/over 12.71 days (12 months' mRFS 47.4% [23.2-68.3%]) or the group with DT equal to/less than 0 days (12 months' mRFS 87.5% [77.3-93.3%]; p<0.001 [i.e. 3.5x10-32]). Decision tree analysis was performed including 4 variables such as DT below 12.71 days, DT equal to or below 0 days, total IM treatment duration and MR4 response duration. The first node was DT below 12.71 days, and the second was DT equal to/less than 0 days. Total IM duration or MR4 duration were not identified as significant in the decision tree analysis. Multivariate analysis confirmed that grouping based on the DT at 2 months is an independent risk factor for TFR. The group with DT below 12.71 but above 0 showed 5.74 times higher risk of losing TFR after IM discontinuation independent of the total duration of IM treatment. Conclusion: DT with cut off value of 12.71 days at 2 months based on the BCR-ABL1 qPCR transcript level measured in the first 6 months after IM discontinuation is predictive of TFR failure after IM discontinuation. Figure Disclosures Busque: ExCellThera: Patents & Royalties; BMS: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Paladin: Consultancy. Savoie:Pfizer: Consultancy; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Keating:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Seattle Genetics: Consultancy; Janssen: Membership on an entity's Board of Directors or advisory committees; Shire: Membership on an entity's Board of Directors or advisory committees; Hoffman La Roche: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees. Delage:Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Liew:Novartis: Consultancy, Honoraria. Leber:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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Second Attempt of TKI Discontinuation with Dasatinib for Treatment-Free Remission after Failing First Attempt with Imatinib: Treatment-Free Remission Accomplished By Dasatinib (TRAD) Trial

Blood ◽

10.1182/blood-2018-99-114656 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 787-787 ◽

Cited By ~ 6

Author(s):

Dennis Dong Hwan Kim ◽

Lambert Busque ◽

Donna L. Forrest ◽

Lynn Savoie ◽

Isabelle Bence-Bruckler ◽

...

Keyword(s):

Board Of Directors ◽

Null Hypothesis ◽

Research Funding ◽

Transcript Level ◽

Molecular Response ◽

Advisory Committees ◽

Log Reduction ◽

Relapse Pattern ◽

Treatment Free Remission ◽

Tki Discontinuation

Abstract Introduction: A Canadian tyrosine kinase inhibitor (TKI) discontinuation trial is ongoing to determine if using dasatinib (DA) can lead to a successful treatment-free remission (TFR) after failing a first attempt of TKI discontinuation after imatinib (IM) treatment. The preliminary result indicate : 1) The 6-month molecular relapse-free survival (mRFS) rate is estimated as 58.0%; 2) DA re-treatment is feasible and safe, with achievement of excellent rates of MMR and MR4. We report here the preliminary analysis of the TFR rate at 6 months after DA discontinuation for the second TFR attempt. Methods and materials: This prospective clinical trial (BMS CA180-543, Clinicaltrial.gov NCT#02268370) has 3 phases: 1) IM discontinuation phase, 2) DA rechallenge phase, 3) DA discontinuation phase. Molecular relapse is defined as an increase in BCR-ABL transcript level < MR4.0 on 2 consecutive occasions, or a single increase in BCR-ABL transcript level < MR3.0. 100mg daily of DA is started if molecular relapse is confirmed and is discontinued 12 months after achieving > MR4 for a 2nd TFR attempt. The null hypothesis was a TFR2 rate of 17.5% while the alternative hypothesis was a TFR2 rate of 35.0% and the study was designed to reject our null hypothesis if > 28% of patients remain in TFR after DA discontinuation. Results: As of Jun 15, 2018, 53 (40.4%) of 131 enrolled patients experienced molecular relapse after IM discontinuation with a mRFS rate of 58.0% at 12 months (95% CI, 42.1-71.0%). Of the 53 patients who lost response, 51 patients received DA. The incidence of MMR, MR4 and MR4.5 at 3 months was 97.7%, 89.9%, and 84.6%, respectively. 25/ 51 patients receiving DA attained MR4.5 for 12 months or longer and discontinued it for a 2nd TFR attempt (TFR2). 21/25 (84.0%) of these patients lost molecular response at a median of 3.7 months after DA discontinuation. The estimated TFR2 rate after DA discontinuation was 21.5±8.5% at 6 months (95% CI [7.9-39.5%], Fig 1A). Thus we cannot reject our null hypothesis based on this result. For risk factor analysis for maintaining TFR2, the variables analysed included Sokal risk score, IM duration, MR4/MR4.5 duration, monthly doubling time after IM discontinuation, time to molecular relapse after IM discontinuation, molecular relapse pattern after IM discontinuation (MMR loss vs MR4 loss), and BCR-ABL1 qPCR value prior to DA discontinuation. 1) Time to molecular relapse after IM discontinuation correlates with TFR2 (p<0.001, HR 0.485, 95% CI [0.302-0.778]), which implies that 1 additional month of TFR duration after IM discontinuation decreases the risk of molecular relapse after DA discontinuation by 51.5%. The 6 month TFR2 rate was 8.9% (median 2.79 mo) in the group who relapsed within 3 months of TFR1 (n=14) and 30.0% (median 4.25%) in the group who relapsed within 3-6 months of TFR1 (n=10). The one patient who relapsed beyond 6 months of TFR1 did not lose molecular response after DA discontinuation. Thus patients who lost molecular response within 3 months of IM discontinuation have a faster loss of response after DA discontinuation (median 2.8 mo) compared to those who lost response after 3 mo (median 4.3 mo; P=0.018; Fig 3A) 2) Molecular relapse pattern after IM discontinuation correlates with TFR2. The group who had loss of MMR after IM discontinuation lost molecular response faster after DA discontinuation (n=19; median 3.0 months) compared to those with two consecutive losses of MR4(n=6; 6.43 months; p=0.0435, HR 2.991; Fig 3B). 3) The group with 5.5 log reduction or deeper in BCR-ABL1 qPCR transcripts prior to DA discontinuation (n=19) showed a TFR2 rate of 28.7% at 6 months (median TFR2 duration of 4.04 months) versus 0% in the group with qPCR transcript level between 4.5 and 5.4 log reduction (n=6, median TFR2 duration of 2.89 months; p=0.017; Fig 3C). We did not identify any other risk factor for molecular relapse after DA discontinuation . The expansion kinetics of the leukemic clone after DA discontinuation is similar to that after IM discontinuation. Conclusion: These preliminary results suggest that rechallenge with DA after failing a first IM discontinuation attempt for TFR is well tolerated and effective as most cases rapidly regained at least MR4. However, more strict criteria should be considered for TFR2 attempt, including achievement of a 5.5 log reduction or deeper in BCR-ABL1 qPCR levels prior to the 2nd TKI discontinuation attempt, and a MR4 duration of more than 12 months. Disclosures Kim: Pfizer: Consultancy; Paladin: Consultancy; Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding. Busque:BMS: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Paladin: Consultancy. Savoie:Pfizer: Consultancy; Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Bence-Bruckler:Lundbeck: Membership on an entity's Board of Directors or advisory committees. Delage:BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Research Funding; Pfizer: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Liew:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Laneuville:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Paladin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Lipton:Bristol-Myers Squibb: Consultancy, Research Funding; ARIAD: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Leber:Novartis Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Treatment-Free Remission Accomplished By Dasatinib (TRAD): Preliminary Results of the Pan-Canadian Tyrosine Kinase Inhibitor Discontinuation Trial

Blood ◽

10.1182/blood.v128.22.1922.1922 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1922-1922 ◽

Cited By ~ 6

Author(s):

Dennis Dong Hwan Kim ◽

Isabelle Bence-Bruckler ◽

Donna L. Forrest ◽

Mary Lynn Savoie ◽

Stephen Couban ◽

...

Keyword(s):

Tyrosine Kinase Inhibitor ◽

Board Of Directors ◽

Research Funding ◽

Kinase Inhibitor ◽

Total Duration ◽

Transcript Level ◽

Molecular Response ◽

Advisory Committees ◽

Treatment Free Remission ◽

Tki Discontinuation

Abstract Introduction: Multiple studies have shown that tyrosine kinase inhibitor (TKI), usually imatinib (IM), can be successfully discontinued in chronic myeloid leukemia (CML) patients, achieving a 40-50% treatment free remission (TFR) rate. However, the remaining 60% of patients require reintroduction of TKI therapy. We have designed this study to answer the question if a second generation TKI, i.e. dasatinib, should be used after failing the first attempt of TKI discontinuation with IM. This prospective study attempts to evaluate whether the use of dasatinib after failure of a 1st attempt of TKI discontinuation with IM could improve TFR rate after a 2nd attempt of TKI discontinuation. Methods and materials: This is a prospective clinical trial (BMS CA180-543, Clinicaltrial.gov NCT#02268370) including all major CML centers across Canada (n=12). The primary objective is to determine the proportion of patients who remain in molecular remission (defined as maintaining ≥MR4.0) after dasatinib discontinuation following achieving ≥MR4.5. The present study has 3 phases: 1) IM discontinuation phase, 2) dasatinib rechallenge phase, 3) dasatinib discontinuation phase. A total of 135 patients is planned to be enrolled over 18-24 months. Key inclusion criteria include: 1) CML in chronic phase (CP), 2) total duration of IM therapy of minimum of 3 years, 3) total duration of MR4.5 or deeper response over 2 years with 2 consecutive confirmed MR4.5 or deeper response at the central lab with 3 months interval. Key exclusion criteria include prior allogeneic stem cell transplant or prior accelerated or blastic phase CML. Molecular recurrence was defined as an increase in BCR-ABL transcript level above MR4.0, on at least two consecutive occasions, or a single increase in BCR-ABL transcript level above MR3.0. Dasatinib is started at a dose of 100mg daily once molecular recurrence is confirmed. Results: The study was launched on March 2015. As of June 22 2016, 110 patients were entered into screening phase of whom 16 patients were not qualified due to 1) fluctuating transcripts (n=8) or 2) consent withdrawal (n=8). Two patients withdrew consent after losing their molecular response following IM discontinuation before starting dasatinib. Finally 75 patients were enrolled into IM discontinuation phase with 17 additional patients on screening in awaiting enrollment (Figure A). Of 67 patients evaluable for molecular relapse, 21 patients (31.3%) lost molecular response defined as loss of major molecular response (MMR; n=18) and loss of MR4 on 2 consecutive tests (n=3). The 6-month relapse free survival (RFS) rate was estimated as 58.0% (42.1-71.0%), while TFR rate using loss of MMR as an event was 64.7% (48.7-76.7%) at 6 months (Figure B) Of 21 patients who lost molecular response, 20 patients underwent dasatinib rechallenge phase, 14 of which were treated with dasatinib for at least 1 month and evaluated at least once with monthly BCR-ABL transcript monitoring (Figure C). Twelve patients achieved MMR at a median time of 56 days. The median time to achieve MR4.5 was 84 days. The incidence of MMR and MR4.5 at 3 months was 100% each (Figure D). Cox's proportional hazard regression model suggested strong correlation of RFS with total duration of IM therapy prior to IM discontinuation (p=0.001), duration of MR4 maintenance (p=0.004) or MR4.5 maintenance (p=0.006) prior to IM discontinuation, but not with time to achieve MR4 (p=0.289) or MR4.5 (p=0.330). Recursive partitioning method also defined the best cutoff for those variables: The group treated with IM for over 8.9 years (n=35) had RFS rate 81.1% vs 21.0% in those treated for less than 8.9 years (n=32; p<0.001, HR 0.125). The group who maintained MR4 for more than 7.7 years (n=29) had RFS rate 82.3% vs 36.3% in others (n=37; p=0.001, HR 0.192), while those who maintained MR4.5 for more than 7.9 years (n=21) had RFS rate 89.5% vs 39.2% in others (n=44; p=0.003, HR 0.141). Conclusion: Preliminary results of this Canadian TKI discontinuation trial show a RFS rate of 58-65% after IM discontinuation in CP-CML patients who attained MR4.5 for over 2 years, similar to other TKI discontinuation studies. Dasatinib can be safely administered in CML patients who lost molecular response after IM discontinuation with 100% of MMR rate at 3 months. Prolonged duration of IM treatment, or duration of MR4/MR4.5 maintenance with IM therapy could predict the chance of TFR success, but not time to achievement of MR4/MR4.5. Disclosures Bence-Bruckler: Lundbeck: Membership on an entity's Board of Directors or advisory committees. Savoie:Amgen: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy; Lundbeck: Consultancy. Busque:Pfizer: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Delage:BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: 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, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding. Laneuville:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Paladin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Liew:BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Xenocostas:Janssen Inc.: Research Funding. Kamel-Reid:BMS: Research Funding. Leber:BMS Canada: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Treatment Free Remission in Patients with Chronic Phase CML: A Single Center Experience

Blood ◽

10.1182/blood-2021-152787 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3612-3612

Author(s):

Quinto J Gesiotto ◽

Akriti G Jain ◽

Somedeb Ball ◽

Lisa Nodzon ◽

Amanda Rodriguez ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Univariate Analysis ◽

Chronic Phase ◽

Published Data ◽

Molecular Response ◽

Advisory Committees ◽

Treatment Free Remission ◽

Tki Discontinuation

Abstract Introduction: Treatment-free remission (TFR) is an emerging treatment goal in chronic phase chronic myeloid leukemia (CP-CML). The NCCN guidelines suggest patients must meet the following criteria in order to be eligible for an attempt at TKI discontinuation: use of a TKI for at least 3 years with no history of TKI resistance who have maintained a deep molecular response (MR4 - BCR-ABL IS ≤0.01%) for at least 2 years. The aim of this study was to identify predictors of long-term TFR in CP-CML patients who discontinue TKI therapy at our institution. Methods: We retrospectively identified all CP-CML patients who had discontinued TKIs after meeting TKI discontinuation criteria at Moffitt Cancer Center. Patient charts were reviewed to collect data on demographics, disease characteristics, and outcomes. TFR was calculated from date of TKI discontinuation to date of molecular recurrence (defined as loss of MMR (BCR-ABL IS ≥0.1%) or date of last follow up). Statistical analysis was performed utilizing Kaplan-Meier curves and log rank (Mantel-Cox) test. Results: A total of 102 patients met TKI discontinuation criteria and stopped treatment to attempt TFR. The median age at diagnosis was 53.5 years (19-83 years). The median age at TKI discontinuation was 61 years (28-92 years). Fifty (49.5%) patients were male. Four patients (3.9%) had previously received interferon α. At a median follow up of 29 months, the TFR rate was 56.8%, with molecular recurrence occurring in 44 patients. 93 patients had a follow up of at least 6 months. Of the 44 patients with molecular recurrence, 37 (84%) recurred within 6 months and 41 (93%) within 12 months of TKI cessation. The rate of TFR at 12 months and 24 months was 58% (95% CI: 48-68%) and 53% (95% CI: 43-64%), respectively [Figure 1]. Baseline characteristics along with univariate analysis of the 102 patients included in the study are shown in Table 1. Age, BMI at discontinuation, gender, Sokol risk index, last TKI prior to discontinuation, lines of therapy, or duration on TKI prior to discontinuation did not significantly affect rates of TFR. Patients with sustained MR4.5 (BCR-ABL IS <0.0032%) for 2 years prior to discontinuation showed a trend toward higher probability of TFR at 12 months compared to those in MR4 (62% vs 49%; p=0.055). Median time to regain MMR after restarting treatment in patients with molecular recurrence was 90 days (range 28-443 days). 32 patients (31%) developed TKI withdrawal syndrome with symptoms including headache, arthralgia, myalgia and fatigue. Conclusions: At our center, 102 CP-CML patients qualified for TKI cessation. The rate of TFR at 12 months was 58% which is consistent with published data from numerous TKI discontinuation clinical trials. We were unable to identify any factors that were predictive of successful TFR, however those patients with a deeper molecular response (MR 4.5) at the time of TKI cessation trended towards higher rates of TFR at 12 months, suggesting that the depth of response is important for achieving prolonged TFR. Identifying methods to further deepen molecular response in CP-CML patients may ultimately lead to higher rates of TFR in the future. Figure 1 Figure 1. Disclosures Nodzon: Takeda: Consultancy. Komrokji: Jazz: Consultancy, Speakers Bureau; Taiho Oncology: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; Acceleron: Consultancy; PharmaEssentia: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMSCelgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Geron: Consultancy. Sallman: Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Membership on an entity's Board of Directors or advisory committees; Magenta: Consultancy; Syndax: Membership on an entity's Board of Directors or advisory committees; Aprea: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Incyte: Speakers Bureau; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; Intellia: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees. Padron: Blueprint: Honoraria; Incyte: Research Funding; Stemline: Honoraria; Taiho: Honoraria; Kura: Research Funding; BMS: Research Funding. Kuykendall: BluePrint Medicines: Honoraria, Speakers Bureau; Celgene/BMS: Honoraria, Speakers Bureau; CTI Biopharma: Honoraria; Abbvie: Honoraria; Protagonist: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prelude: Research Funding; Novartis: Honoraria, Speakers Bureau; Incyte: Consultancy; PharmaEssentia: Honoraria. Lancet: Jazz: Consultancy; Astellas: Consultancy; Agios: Consultancy; Millenium Pharma/Takeda: Consultancy; ElevateBio Management: Consultancy; Daiichi Sankyo: Consultancy; Celgene/BMS: Consultancy; BerGenBio: Consultancy; AbbVie: Consultancy. Pinilla Ibarz: Sellas: Other: ), patents/royalties/other intellectual property; AbbVie, Janssen, AstraZeneca, Takeda: Speakers Bureau; AbbVie, Janssen, AstraZeneca, Novartis, TG Therapeutics, Takeda: Consultancy, Other: Advisory; MEI, Sunesis: Research Funding. Sweet: Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; AROG: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Bristol Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees.

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R-Interferon Treatment before Imatinib Reverses the Negative Impact of e13a2 Transcript Type on Treatment Free Remission Duration after Tyrosine Kinase Inhibitors Discontinuation in Chronic Myeloid Leukemia Patients

Blood ◽

10.1182/blood-2019-125313 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4146-4146

Author(s):

Mariella D'Adda ◽

Mirko Farina ◽

Angela Passi ◽

Rosa Daffini ◽

Doriana Gramegna ◽

...

Keyword(s):

Prognostic Factors ◽

Chronic Myeloid Leukemia ◽

Tyrosine Kinase ◽

Board Of Directors ◽

Median Time ◽

Myeloid Leukemia ◽

Prognostic Impact ◽

Advisory Committees ◽

Tki Discontinuation ◽

Transcript Type

BACKGROUND Tyrosine Kinase Inhibitor (TKIs) discontinuation has become, nowadays, under proper conditions, a feasible option for chronic myeloid leukemia (CML) also in "real life" setting. Different papers investigated which factors (age, sex, type of TKI, previous r-interferonα -r-INFα- therapy, line of therapy at stop, type of transcript, duration of TKI therapy and of sustained deep molecular response -sDMR-, Sokal risk score) could predict a successful TKIs discontinuation either within protocols or outside of clinical trials, and the results are not unique. AIM We retrospectively evaluated our CML pts who stopped TKI after sDMR in order to assess the variables that could influence the probability of a durable TFR. METHODS BCR-ABL transcripts were determined by RQ-PCR performed according to EAC protocol (Gabert et al, 2003) and to the standards of the Italian National Network Labnet. Criteria for TKI discontinuation was sustained DMR (MR4 or better) for at least 2 years. After TKI withdrawal, RQ-PCR for BCR-ABL was performed every month during the first year and every 2 months thereafter. TKI treatment was reintroduced if DMR loss occurred.TFR was assessed using the Kaplan-Meier method; potential prognostic factors were considered for multivariable analyses at a level less than .20. RESULTS Between October 2010 and January 2019, 68 patients discontinued TKIs, 18 of them after less than 5 years of treatment because of pregnancy desire (3), intolerance (6), patient's desire/non compliance (5), enrollment in study protocols (4). At discontinuation median age was 63 years (30-85), median time from TKI start 85 months (30-190), median duration of sustained DMR 48 months (24-153). Sokal distribution was 48%, 31% and 18% for low, intermediate and high risk respectively (2 patient was not evaluable). E14a2 transcript type was present in 52 pts and e13a2 in 16 pts. Thirty-eight patients stopped imatinib, 25 nilotinib (19 in 1st line, 6 in 2nd line), 5 dasatinib. Before imatinib 15 patients received r-IFNα, for a median time of 60 months (3-256). Median follow up after TKI stop was 39 months (5-105, >24 in 61, <12 in only 2 patients). Twenty-eight (41%) patients lost DMR. Median time off-therapy for these patients was 3 months (1-19), only 2 lost DMR after 6 months (at +16 and +19 months). One patient aged 87 years has not yet resumed therapy but remains in stable MR3 at 34 months after TKI discontinuation. Therapy was restarted in 27 patients (1 in MR1, 11 in MR2, 15 in MR3), 24 achieved a second DMR after a median interval of 2 months (1-18); 3/27 patients are in M3 after 2, 22 and 26 months. Neither cytogenetic relapses, nor progressions were documented. One patient died in DMR for pancreatic cancer. Univariate analysis showed no difference in relapse risk according to age, gender, type of TKI (imatinib vs 2nd generation TKIs), and Sokal score, while the e14a2 vs e13a2 transcript type (p = 0.011), duration of TKI therapy > 60 months (p = 0.025) and previous r-IFNα therapy (p=0.021) were significantly linked to better outcome after TKI discontinuation; sDMR > 72 months is very close to be a significant variable (p=0.055). At multivariate analysis only the type of BCR-ABL transcript (p=0.027) and previous r-IFNα ( p=0.016) remained independent significant prognostic factors -figure A and figure B-. CONCLUSION e14a2 transcript type was confirmed as a robust favorable prognostic factor for TFR maintenance. In our experience, 2GTKIs didn't impact favorably TFR duration after TKIs discontinuation, conversely r-IFNα treatment before TKI improved the probability of maintaining DMR after TKI withdrawal, particularly in e13a2 patients. In fact r-IFNα before imatinib reversed the negative prognostic impact on TFR maintenance of the e13a2 transcript type. Disclosures D'Adda: Novartis: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Rossi:Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Daiichi-Sankyo: Consultancy.

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Pre-Transplant Fecal Microbial Diversity Independently Predicts Critical Illness after Hematopoietic Cell Transplantation

Blood ◽

10.1182/blood-2019-124902 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3264-3264 ◽

Cited By ~ 1

Author(s):

Fatima I. Adhi ◽

Eric R. Littmann ◽

Ying Taur ◽

Molly A. Maloy ◽

Kate A Markey ◽

...

Keyword(s):

Intensive Care ◽

Respiratory Failure ◽

Critical Illness ◽

Board Of Directors ◽

Research Funding ◽

Independent Predictor ◽

Fecal Microbiota ◽

Advisory Committees ◽

Icu Admission ◽

Conditioning Intensity

Background Fecal microbiota composition is associated with important outcomes after allo-HCT including survival, relapse, GVHD, and infections. We previously demonstrated in a multicenter observational study that HCT patients present with fecal microbiota configurations that have lower diversity and are distinct from those of healthy individuals, and that pre-HCT microbiota injury predicts poor overall survival. Here, we hypothesized that pre-HCT fecal microbiota features predict development of critical illness post-HCT. Methods We analyzed 828 adults who received a first allo-HCT from 2009 to 2017 at a single institution who had an evaluable fecal sample in our biobank collected within the 10 days prior to cell infusion. The patients were heterogeneous with respect to transplant indication, conditioning intensity, graft source (cord blood, peripheral blood, marrow) and graft manipulation (CD34-selection). The V4-V5 regions of 16S rRNA genes of DNA extracted from fecal samples were amplified and annotated taxonomically. The outcome of interest was time to ICU admission, which was assessed using survival-analysis methods. The reason for admission to the ICU was evaluated for each subject. Results Seventy-five (9%) patients were admitted to the intensive care unit (ICU) between the day of cell infusion and day +50; the peak incidence of ICU admission occurred on day +10. The most common indications for ICU admission were respiratory failure (65%) and infection (27%). Patients were stratified based on fecal microbiota diversity, as assessed by 16S sequencing of stool samples collected prior to transplantation, into high (inverse Simpson index ≥4) and low (<4) diversity groups following a previously-published cutoff. Patients with low diversity pre-HCT had a strikingly higher risk of ICU admission than those with high diversity (HR 2.38 [95% CI 1.5-3.7], p <0.001, see the Figure). This association remained significant in a multivariate Cox proportional hazard model that accounted for conditioning intensity, graft source, graft manipulation, and the HCT-CI comorbidity index (multivariate p = 0.003). HCT-CI score was also an independent predictor of ICU admission. The association between pre-HCT fecal diversity and ICU admission was also significant when the outcome definition was limited to ICU transfers for reason of respiratory failure or sepsis (to the exclusion of such indications as hemorrhage, anaphylaxis, or isolated dysfunctions of the cardiac, renal, or neurological systems). Conclusion Pre-transplant fecal microbial diversity is an independent predictor of intensive-care-requiring critical illness in the post-HCT period. These observations highlight the pre-HCT period as a window of opportunity to (a) assess microbiota injury in conjunction with comorbidity evaluation, (b) inform selection of antibiotic prophylaxis, gut-decontamination, GVHD-prophylaxis, or conditioning regimens, and (c) intervene with microbiota injury-remediation or prevention strategies. Figure Disclosures Brereton: Seres Therapeutics: Other: Salary Support. Clurman:Seres Therapeutics: Research Funding. Slingerland:Seres Therapeutics: Other: Salary supported by Seres funding. Shah:Janssen Pharmaceutica: Research Funding; Amgen: Research Funding. Scordo:McKinsey & Company: Consultancy; Angiocrine Bioscience, Inc.: Consultancy. Politikos:Angiocrine Bioscience Inc: Research Funding. Gyurkocza:Actinium Pharmaceuticals: Research Funding. Barker:Angiocrine Bioscience Inc: Research Funding; Gamida Cell: Research Funding; Merck: Research Funding. Perales:Kyte/Gilead: Research Funding; Miltenyi: Research Funding; MolMed: Membership on an entity's Board of Directors or advisory committees; NexImmune: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Nektar Therapeutics: 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; Omeros: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria; Medigene: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees. Giralt:Amgen: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; Actinium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Kite: Consultancy; Johnson & Johnson: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy; Miltenyi: Research Funding; Takeda: Consultancy, Research Funding; Novartis: Consultancy. van den Brink:Merck & Co, Inc.: Consultancy, Honoraria; Acute Leukemia Forum (ALF): Consultancy, Honoraria; Magenta and DKMS Medical Council: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Other: Licensing; Amgen: Consultancy, Honoraria; Therakos: Consultancy, Honoraria; Seres Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Flagship Ventures: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Evelo: Consultancy, Honoraria; Jazz Pharmaceuticals: Consultancy, Honoraria. Pamer:Bristol Myers Squibb: Honoraria; Celgene: Honoraria; Seres Therapeutics: Honoraria, Patents & Royalties; MedImmune: Honoraria; Novartis: Honoraria; Ferring Pharmaceuticals: Honoraria. Peled:Seres Therapeutics: Research Funding.

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The Outcome of Treatment-Free Remission after First-Line Nilotinib or Dasatinib in Chronic Phase Chronic Myeloid Leukemia Patients Is Different

Blood ◽

10.1182/blood-2021-146722 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2552-2552

Author(s):

Franck E. Nicolini ◽

Vincent Alcazer ◽

Stephanie Dulucq ◽

Sandrine Hayette ◽

Jean-Michel Cayuela ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Chronic Phase ◽

Median Dose ◽

First Line ◽

Advisory Committees ◽

French Group ◽

Treatment Free Remission ◽

The Impact

Abstract Aims: The absolute number of chronic phase CML patients (pts) reaching the treatment-free remission (TFR) criteria has been substantially increased by the use of second-generation TKI (TKI2), initiated since diagnosis, comparing to Imatinib first-line. However, the relative rate of unsuccessful TFR (i. e. pts loosing their MMR after TKI2 cessation) still remains around 50% at 2 years and beyond, whatever the TKI2 was. The aim of this study is to analyse the rate of successful TFR in pts receiving Nilotinib (Nilo) or Dasatinib (Dasa) first-line obtaining the appropriate criteria. Methods: Observational retrospective study in 3 reference centers of the French group of CML lead between 2010 and 2021. Eligible pts were CP CML pts initiating either Nilo 300 mg BID or Dasa 100 mg daily since diagnosis, until cessation for sustained MR4.5 (i.e. ≥2 years on ≥4 datapoints). Data were retrospectively collected according to the national regulations with pts' information. All pts were assessed and followed according to ELN recommendations 2009, 2013 and 2020 along treatment and to the recommendations from the French group of CML (D. Rea et al., Cancer 2018) for TFR. In this regard, the TKI2 was resumed in case of loss of MMR. All BCR-ABL1 assessments were performed in the 3 reference laboratories, standardised and expressed in % (IS) with ≥32,000 copies of ABL1 as control. All patients were harbouring major BCR-ABL1 transcripts. The primary endpoint was the survival without loss of MMR after TKI2 cessation. The secondary endpoints were the kinetics of MMR loss, and the identification of factors influencing MMR loss. Results: Seventy-two pts were reported (47 Nilo, 25 Dasa) with 57% females with a median age at diagnosis of 48 (36.75-61.25) years. The median follow-up since diagnosis was 9.26 (3.75-13.75) years (8.8 for Nilo and 9.47 for Dasa p=ns) and after TKI2 cessation 3.94 (0.7-8.8) years (3.92 for Nilo and 3.90 for Dasa p=ns). Sokal scores were 42% Low, 41% Intermediate, 17% High in Nilo and 39% L, 25% I and 35% H in Dasa pts (p=ns). ELTS scores were 50% L, 22% I, 9.5% H (18.5% Uk) in Nilo and 46.5% L, 28.5% I and 3.5% H (21.5% Uk) in Dasa pts (p=0.95). Five (9%) pts harboured ACA at diagnosis in the Nilo group and 2 (7%) in the Dasa group (p=1.00). The median time from TKI2 initiation to sustained MR4.5 was 19 (3.12-36) months in the Nilo group and 16 (6.3-39) months in the Dasa group (p=0.644). The duration of sustained MR4.5 until cessation was 3.04 (1.5-9.3) years for Nilo and 2.65 (1.11-7.95) for Dasa (p=0.96). The median dosing of Nilo was 600 (300-800) mg daily and 80 (20-100) mg at TKI2 cessation. None of these patients switched to another TKI during the follow-up. TKI2 cessation occurred after 60.5 (43-74.5) months in the Nilo group and 68 (39-90) months in the Dasa group (p=0.581). Thirty-seven pts out of 47 (79%) were BCR-ABL1 undetectable at Nilo cessation 18/25 (72%) at Dasa cessation (p=0.60). At M3 after discontinuation, 58% of pts remained undetectable after Nilo cessation and 30.4% after Dasa cessation (p=0.05).The median survival of pts without loss of MMR was not reached in the Nilo group, and was 14 (4.73-NR) months in the Dasa group, (p=0.042) as analysed by the KM method (Figure 1.). Two patients died (1 Nilo, 1 Dasa) from competing events (solid tumours) after unsuccessful TFR. Twenty-eight pts (14 Dasa, 14 Nilo) restarted their TKI2 after MMR loss and all regained ≥ MMR after 3 months of Dasa at a median dose of 75 (40-100) mg daily and all except one (who regained MMR at M12) after resumption of Nilo at a median dose of 350 (300-600) mg daily. Univariate analysis identified pts with H+I Sokal (as compared to low) as an unfavourable factor for successful TKI2 cessation [HR=0.35 (0.15-0.83), p=0.017] and type of TKI2 (Nilo as reference vs Dasa) was discriminant [HR=2.1 (1.01-4.35), p=0.047]. Multivariate analysis identified the type of TKI2 as a significant factor impacting on TFR outcome [HR 2.11 (0.97-4.55], p=0.05]. Conclusions: As it is likely that no prospective head-to-head comparison will be performed in this setting, on this limited series of pts, we conclude that the outcome of TFR seems to be different according to the TKI2 used since diagnosis, suggesting the impact of distinct biological variables modified by the type of TKI2 on the long run (such as immunological system, BM micro-environment, others) on TFR outcome. Figure 1 Figure 1. Disclosures Nicolini: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Research Funding; Kartos Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sun Pharma Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Incyte Biosciences: Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Etienne: Incyte: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau. Rea: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees.

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Treatment Free Survival (TFS) in Patients (pts) with Chronic Myeloid Leukemia (CML) Carrying Atypical BCR-ABL1 Fusion Transcripts: The French CML Group (Fi-LMC) Experience

Blood ◽

10.1182/blood-2021-147537 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3604-3604

Author(s):

Hyacinthe Johnson-Ansah ◽

Aude Charbonnier ◽

Delphine Rea ◽

Gabriel Etienne ◽

Lydia Roy ◽

...

Keyword(s):

Confidence Interval ◽

Board Of Directors ◽

Cumulative Incidence ◽

Research Funding ◽

Residual Disease ◽

Real Life ◽

Major Type ◽

Advisory Committees ◽

Hematologic Response ◽

Tki Discontinuation

Abstract Aims Life expectancy of CML pts optimally responding to tyrosine kinase inhibitors (TKI) is close to that of the general population and recently, TFR has been acknowledged as a new goal of CML management. TKI discontinuation in the view of TFR requires the achievement of deep and long-lasting molecular responses (MR). The gold standard BCR-ABL mRNA quantification technology and MR definitions rely on internationally standardized (IS) RT-qPCR but atypical transcripts located outside the Major-BCR region, harbored by 1-2% of pts, cannot be expressed on the IS scale. Thus, most trials and clinical practice recommendations prevent such pts from attempting TFR. The Fi-LMC group retrospectively collected real-life observations to assess TFR likelihood in this rare population. Methods Data from CML pts with precise characterization of atypical transcripts in whom any line TKI was stopped for any reason but after at least 2 years of undetectable molecular residual disease (UMRD) by individualized non-standardized RT-qPCR were collected. RT-qPCR sensitivity varied depending on transcript type and local molecular biology laboratory. TFS was estimated by the Kaplan-Meier method. Relapse was analyzed using the cumulative incidence function, relapse being as UMRD loss at any time and any level during follow-up (FU). Results Our series comprised 16 adult CP CML pts with atypical BCR-ABL fusions including 12 males (75%). Median age at CML diagnosis was 56 years (range: 21-75) and that at TKI discontinuation was 67 years [range: 29-82]. Sokal score was low, intermediate and high in 7, 8 and 1 pts, respectively. ELTS score was low and intermediate in 10 and 4 pts, respectively and unknown in 2. Most pts expressed e19a2 (n=6) followed by e6a2 (n=4), b3a3 (n=3), b2a3 (n=2) and e8a2 (n=1). Seven pts discontinued imatinib, 4 stopped dasatinib, 4 nilotinib and 1 bosutinib. Number of lines of therapy was 2 in 8 pts, 1 in 5 pts and 3 in 3 pts. Median TKI treatment duration before discontinuation was 64 months (range: 31-218) and median duration of UMRD was 41 months (range: 21-168). The median FU after TKI discontinuation was 68 months (range: 3-149). Five pts experienced relapse leading to TKI resumption. Four relapses occurred within 3-6 months and included 2 loss of hematologic response in CP, 1 loss of hematologic response in accelerated phase CML and 1 molecular recurrence with BCR-ABL transcripts up to 1.5%. One relapse occurred at 49 months and consisted in loss of a complete cytogenetic response. These 5 pts resumed TKI and regained UMRD within 6 months, including 1 pt who died in UMRD from non-CML-related cause at the age of 82 years and 1 pt who rapidly failed a 2 nd TKI discontinuation attempt. In 1 additional pt, BCR-ABL transcripts became detectable intermittently with maximum transcript level of 0.15% and TKI was not resumed. The median FU of pts who remained treatment-free was 68 months (range: 8-149). Overall, the 5-year cumulative incidence of relapse regardless of whether TKI was resumed was 41.6% (95% confidence interval: 21.9%-78.7%) (Figure 1). The 5-year TFS rate was 65.2% (95% confidence interval: 40.3%-90.2%) (Figure 2). Conclusions Our observational study of TKI discontinuation in CML pts with atypical BCR-ABL transcripts is the largest reported so far. While effort must be made for proper assessment of deep MR, preliminary results suggest that TFS pattern might favorably compare with that obtained in pts with Major-type BCR-ABL transcripts. However, relapses may be more aggressive and caution is required in order to avoid loss of hematologic responses and progression. Whether the type of atypical fusion gene influences TKI discontinuation outcome, as well as other potential prognostic factors, need to be determined in a larger series. Figure 1 Figure 1. Disclosures Charbonnier: Novartis: Speakers Bureau; Incyte: Speakers Bureau. Rea: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Etienne: Novartis: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau. Rousselot: Incyte, Pfizer: Consultancy, Research Funding. Nicolini: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Research Funding; Kartos Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sun Pharma Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte Biosciences: Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; BMS: Honoraria.

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Highly Sensitive Droplet Digital PCR for MYD88L265P Mutation Detection and Minimal Residual Disease Monitoring in Waldenström Macroglobulinemia

Blood ◽

10.1182/blood.v126.23.2645.2645 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2645-2645

Author(s):

Daniela Drandi ◽

Elisa Genuardi ◽

Paola Ghione ◽

Daniele Grimaldi ◽

Barbara Mantoan ◽

...

Keyword(s):

Board Of Directors ◽

Mutation Detection ◽

Residual Disease ◽

Digital Pcr ◽

Droplet Digital Pcr ◽

Advisory Committees ◽

Highly Sensitive ◽

Sensitive Tool ◽

Minimal Residual

Abstract Background. Recently, the somatic MYD88L265P mutation has been found as the hallmark of Waldenström Macroglobulinemia (WM), being detectable in nearly 90% of cases, as well as in up to 50% of IgM MGUS, rarely in other non-Hodgkin lymphomas and never in multiple myeloma (MM). Beyond its potential diagnostic role, this mutation has been associated with tumor growth and therapy resistance. Moreover, MYD88L265P might represent an ideal marker for minimal residual disease (MRD) monitoring in a disease whose therapeutic scenario has been rapidly changing, with many new available and highly effective drugs (nucleoside analogues, proteasome and BTK-inhibitors). However, the current MYD88L265P allele-specific quantitative PCR (ASqPCR) diagnostic tool lacks sensitivity (1.00E-03) and thus is not suitable for MRD. Moreover, is not useful to test peripheral blood (PB), that harbors low concentrations of circulating tumor cells (especially after immunochemotherapy), neither to assess cell-free DNA (cfDNA), usually present at very low amount in plasma. Therefore, our study aims: 1) to assess whether a highly sensitive tool as droplet digital PCR (ddPCR) might be helpful in MYD88L265P screening; 2) to evaluate whether MYD88L265P might be a suitable marker for MRD monitoring in WM. Methods. Bone marrow (BM) and PB samples were collected at diagnosis and during follow-up from a local series of patients affected by WM, IgM MGUS and IgG-secreting lymphoplasmacytic lymphoma (LPL), as well as samples from healthy subjects and MM were used as negative controls. Genomic (gDNA) and cell-free DNA (cfDNA) were extracted as recommended (Qiagen). MYD88L265P was assessed on 100 ng of gDNA by ASqPCR as previously described [Xu 2013] and by ddPCR, using a custom dual labelled probe assay (Bio-Rad). When available, 50 ng of cfDNA were tested for MYD88L265P, only by ddPCR. ddPCR was performed on 20 µl of reaction at 55°C for 40 cycles, run on QX100 droplet reader and analyzed by QuantaSoft v1.6.6 (Bio-Rad). MYD88L265P ASqPCR level was estimated as described [Treon 2012]. ΔCT<8.4 identified a MYD88L265P positive sample. Similarly, MYD88L265P ddPCR cut-off was settled on the highest healthy samples level. IGH rearrangements identification and IGH-based MRD analysis were performed as previously described [van der Velden 2007]. Results. Once the ddPCR assay was optimized, the sensitivity of MYD88L265P ddPCR was compared to ASqPCR on a ten-fold serial dilution standard curves built with a 70% MYD88L265P mutated WM sample, previously identified by Sanger sequencing [Treon 2012]. Whereas ASqPCR confirmed the reported sensitivity of 1.00E−03, ddPCR reached a sensitivity of 5.00E−05. Thereafter, overall 105 samples (48 BM, 57 PB, 52 diagnosis and 53 follow up) from 58 patients (49 WM, 5 IgM MGUS and 4 LPL) as well as 20 controls (15 healthy subjects and 5 MM) were tested by both methods. 32/33 (97%) diagnostic BM scored positive for MYD88L265P by both ddPCR and ASqPCR (being the only one negative a WM), while ddPCR, was able to detect more mutated cases, than ASqPCR, among diagnostic PB samples: 15/19 (79%) vs 9/19 (47%) (Table1). Moreover, to investigate whether the MYD88L265P ddPCR tool could be used for MRD detection we compared it to the standardized IGH-based MRD. An IGH-based MRD marker was found in 40/53 (75%) patients (37 WM and 3 LPL). Five Patients, so far analyzed, with baseline and follow up samples (18 BM, 5 PB) showed highly superimposable results between the two methods. Finally, pivotal results on cfDNA from 10 patients showed higher median levels of MYD88L265P mutation in plasma if compared to PB. Conclusions. We developed a new tool for diagnosis and MRD monitoring in WM, showing that: 1) ddPCR is a highly sensitive tool for MYD88L265P detection, especially useful in low infiltrated samples, like PB; 2) MYD88L265P can be effectively and easily used for MRD monitoring in WM, achieving similar results to standardized IGH-based MRD; 3) cfDNA recovered from plasma might be an attractive alternative for MYD88L265P detection, deserving further investigation. Methodological validation against IgH-based MRD detection and Flow cytometry and correlations with clinical impact are currently ongoing on external samples series. Table 1.PATIENTSWM (45)LPL (2)IgM MGUS (5)TISSUEBMPBBMPBBMPBSAMPLES31141114MYD88L265P ddPCR/ASqPCR30/3011/71/10/01/14/2 TABLE 1. MYD88L265P mutation detection in diagnostic samples: ddPCR vs ASqPCR Disclosures Boccadoro: Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees.

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A CK1δ/CK1ε-to-Wnt/β-Catenin Circuit Is a Therapeutic Vulnerability in Primary and Drug Resistant Multiple Myeloma

Blood ◽

10.1182/blood.v128.22.2094.2094 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2094-2094

Author(s):

Karen L. Burger ◽

Mark B Meads ◽

Ariosto Silva ◽

Allison Distler ◽

Maria Coelho Siqueira Silva ◽

...

Keyword(s):

Multiple Myeloma ◽

Wnt Signaling ◽

Board Of Directors ◽

Cell Lines ◽

Research Funding ◽

Kinase Inhibitor ◽

Ex Vivo ◽

Advisory Committees ◽

Highly Sensitive ◽

Tumor Types

Abstract Aberrant canonical Wnt/β-catenin signaling has long been known to play a role in cancer development and progression, where Wnt binding provokes nuclear localization of β-catenin, which functions as a coactivator for the TCF/LEF family of transcription factors that induce an oncogenic transcriptional program. Indeed, hallmarks of several tumor types are gain-of-function somatic mutations in β-catenin, and loss-of-function mutations in components of the β-catenin destruction complex, including the scaffold proteins APC and Axin1 and the serine/threonine kinase casein kinase1-α (CK1α) that phosphorylates β-catenin, priming it for destruction by the βTrCP E3 ubiquitin ligase. Interestingly, the CK1α-related kinase CK1δ antagonizes CK1α in Wnt signaling, where CK1δ triggers disassembly of the β-catenin destruction complex by phosphorylation of disheveled-1 (Dvl1). Notably, we have shown that CK1δ is amplified, and is necessary and sufficient, for β-catenin activation and Wnt signaling in some tumor types. Interestingly, lenalidomide resistance in multiple myeloma (MM) cell lines and patients has been shown to correlate with increased expression and activity of Wnt/β-catenin signaling. Here, we report that roughly 40% of MM patients have mutations in the Wnt/β-catenin pathway and that this pathway is active in a large panel of human MM cell lines. Notably, a highly potent and selective in-house CK1δ/CK1ε kinase inhibitor coined SR-3029 rapidly compromises the growth and survival of MM cell lines. Importantly, the anti-MM activity of SR-3029 is augmented in MM cell lines with selected resistance to bortezomib and lenalidomide relative to paired naïve myeloma cells. In concordance with the anti-MM activity of SR-3029, treatment of MM cells with this kinase inhibitor leads to marked reductions in the levels of β-catenin target genes (e.g., MYC, CCND1 and WNT3) and also with the suppression of CK1δ and CK1ε. Further, using an ex vivo platform that accurately quantifies the sensitivity of primary MM samples to agents in a reconstructed tumor microenvironment, we examined CD138-selected patient specimens from 29 patients against a panel of 31 drugs simultaneously. Notably, MM patient samples, including those that are quad-resistant, were highly sensitive to SR-3029 with a mean LD50 of 300nM and a range between 30nM and 990nM. Indeed, SR-3029 was by far the most potent kinase inhibitor assessed in this platform, where its mean LD50 is an order of magnitude more potent than all other kinase inhibitors included in the screen. Finally, using the well-established 5TGM1/Kal-Ridge (C57B6/KaLwRijHsd) syngeneic mouse model of multiple myeloma, we show that tumors derived from 5TGM1 cells, which are highly sensitive to SR-3029 ex vivo, are also sensitive to CK1δ/CK1ε inhibition in vivo, where the SR-3029 treated cohort of animals demonstrated decreased tumor burden as assessed by IgG2b levels and imaging, and by significantly improved survival relative tovehicle treated recipients. Collectively, these findings demonstrate that SR-3029 has potent activity in both naïve and therapy resistant multiple myeloma and establish CK1δ and/or CK1ε as attractive targets for anti-MM therapy. Disclosures Shain: Novartis: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Signal Genetics: Research Funding; Takeda/Millennium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen/Onyx: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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