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High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days −6, –3, +1, and +4 and melphalan (200 mg/m2 IV) on day –2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM–treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Supplemental table 1: Sequence of hydrolysis probes and primers used for the ddPCR.

Purpose:Tyrosine kinase inhibitor (TKI) discontinuation is an emerging goal in chronic myelogenous leukemia (CML) management and several studies have demonstrated the feasibility of safely stopping imatinib. A sustained deep molecular response on long-term TKI is critical prior to attempting treatment-free remission. Reproducible results from several studies reported recently, failed to identify robust and reproducible predictive factors for the selection of the best candidates for successful TKI cessation.Patients and Methods:We conducted a prospective national phase II study evaluating the cessation of imatinib after at least 2 years of MR4.5 obtained on imatinib first-line in patients with chronic phase CML.Results:A total of 218 patients with de novo chronic phase CML were involved in the study. The median follow-up after imatinib cessation was 23.5 (1–64) months, 2 patients died from unrelated causes, and 107 experienced a confirmed increase in BCR-ABL1 levels defined as molecular recurrence. The molecular recurrence-free survival was 52% [95% confidence interval (CI), 45%–59%] at 6 months, and 50% (95% CI, 43%–57%) at 24 months. Droplet digital PCR (ddPCR) was used to evaluate more accurately low levels of BCR-ABL1 in 175 of 218 patients at imatinib cessation. To apply positive BCR-ABL1/ABL1 ratios on the international scale (IS), a conversion factor was calculated for ddPCR and the significant cut-off point was established at 0.0023%IS. In a multivariate analysis, the duration of TKI (≥74.8 months) and ddPCR (≥0.0023%IS) were the two identified predictive factors of molecular recurrence, with P = 0.0366 (HR, 0.635; 95% CI, 0.415–0.972] and P = 0.008 (HR, 0.556; 95% CI, 0.360–0.858), respectively.Conclusions:We conclude that the duration of TKI and residual leukemic cell load as determined by ddPCR are key factors for predicting successful treatment-free remission for patients with de novo chronic phase CML.See related commentary by Yan et al., p. 6561

International audience; Background During the 2005-2014 period, the GRAALL conducted the GRAALL-2005 trial in patients (pts) with Philadelphia chromosome (Ph)-negative ALL aged 18-59y. In this trial, all pts received a pediatric-inspired chemotherapy, whatever their age. Post-hoc analysis revealed an unacceptable TRM in pts aged 45-59y (Huguet et al. J Clin Oncol 2018; 36:2514-23). Allogeneic hematopoietic stem cell transplantation (HSCT) was offered in first complete remission (CR) to most CR pts, defined at high-risk (HR) by at least one baseline clinical or biological HR factor (CNS involvement, complex karyotype [≥5 abns.], low hypodiploidy/near triploidy, poor early blast clearance, late CR, as well as WBC ≥ 30x109/L, lack of CD10 expression, KMT2A rearrangement or TCF3::PBX1 fusion for B-cell precursor [BCP] ALL). Minimal residual disease (MRD) response was not considered for HSCT indication at that time.In the next GRAALL-2014 trial conducted in a similar population, we introduced two major changes in the treatment strategy. First, chemotherapy intensity (steroids, anthracycline and L-asparaginase) was reduced in pts aged 45-59y to decrease excessive TRM. Secondly, the indication for HSCT was modified, relying on IG/TR MRD response only (post-induction MRD ≥10-3 and/or post-consolidation MRD ≥10-4) while not on any former baseline HR criterion. Here, we compare the outcomes of the two trials, focusing on the impact of these two major evolutions.Patients & Methods A total of 743 pts treated in the GRAALL-2014 trial between 2015 and 2020 were compared to the 787 pts from the historical GRAALL-2005 trial, in terms of CR and induction death rates, rate of HSCT in CR1, cumulative incidence of TRM (CITRM) and relapse (CIR), relapse-free (RFS) and overall (OS) survival. It should be noted that two nested Phase 2 trials were introduced by amendment during the GRAALL-2014 course (in 2017 and 2018, respectively), aiming to evaluate post-remission addition of nelarabine and blinatumomab in 87 T-ALL and 94 BCP-ALL selected pts, respectively.Results Main patient characteristics, including age, gender, BCP/T-ALL, WBC, and historical baseline HR features, did not significantly differ between the two trial cohorts, even if CNS disease at diagnosis was more frequent in the 2014 cohort (12 vs 7%, p= 0.001).Outcome comparisons are shown in Table 1. Overall, the induction death rate was significantly reduced in the GRAALL-2014 (3 vs 6%, p= 0.005). As expected, this was only observed in pts aged 44-59y (3 vs 11%, p= 0.001), in whom dose-intensity reduction also translated into a higher need for second induction course (9 vs 5%, p= 0.05) eventually resulting in a higher CR rate (92 vs 86%, p= 0.05). Due to the newly introduced MRD-based stratification, the rate of pts with HSCT indication was markedly reduced (30 vs 65%, p

Superior rates of deep molecular response (DMR) have been reported with the combination of tyrosine kinase inhibitors and pegylated-interferon-alpha (Peg-IFN) in patients with newly diagnosed chronic phase-chronic myeloid leukaemia (CP-CML). In this setting, this study investigated the efficacy and safety of dasatinib combined to Peg-IFN-α2b (Dasa-PegIFN, NCT01872442). A total of 79 patients (age ≤65 years) started dasatinib; 61 were eligible for Peg-IFNα-2b add-on therapy at month 3 for a maximum 21-months duration. Dasatinib was continued thereafter. The primary endpoint was the cumulative rate of molecular response 4.5 log (MR

Bortezomib, lenalidomide, and dexamethasone plus transplant is a standard of care for eligible patients with multiple myeloma. Because responses can deepen with time, regimens with longer and more potent induction/consolidation phases are needed. In this phase 2 study, patients received eight 28-day cycles of carfilzomib (K) 20/36 mg/m2 (days 1-2, 8-9, 15-16), lenalidomide (R) 25 mg (days 1–21), and dexamethasone (d) 20 mg (days 1-2, 8-9, 15-16, 22-23). All patients proceeded to transplant after 4 cycles and received 1 year of lenalidomide maintenance (10 mg, days 1-21). The primary objective was stringent complete response at the completion of consolidation. Overall, 48 patients were screened and 46 enrolled; 21% had adverse cytogenetics. Among 42 evaluable patients after consolidation, 26 were in stringent complete response (CR; 61.9%), 27 were at least in CR (64.3%): 92.6% had undetectable minimal residual disease according to flow cytometry (≥2.5 × 10−5) and 63.0% according to next-generation sequencing (10−6). Median time to CR was 10.6 months. According to multiparametric flow cytometry and next-generation sequencing, 69.0% and 66.7% of patients, respectively, had undetectable minimal residual disease at some point. With a median follow-up of 60.5 months, 21 patients progressed, and 10 died (7 of multiple myeloma). Median progression-free survival was 56.4 months. There were no KRd-related deaths. Four patients discontinued the program due to toxicities; 56 serious adverse events were reported in 31 patients, including 8 cardiovascular events (2 heart failures, 5 pulmonary embolisms or deep vein thrombosis). Common grade 3/4 adverse events were hematologic (74%) and infectious (22%). In summary, 8 cycles of KRd produce fast and deep responses in transplant-eligible patients with newly diagnosed multiple myeloma. The safety profile is acceptable, but cardiovascular adverse events should be closely monitored. This clinical trial is registered at www.clinicaltrials.gov as #NCT02405364.

The Intergroupe Francophone du Myelome 2009 trial (NCT01191060) assessed health-related quality of life (HRQoL) in patients with newly diagnosed multiple myeloma (NDMM) receiving lenalidomide/bortezomib/dexamethasone (RVd) induction therapy followed by consolidation therapy with either autologous stem cell transplantation (ASCT) plus RVd (RVd-ASCT) or RVd-alone; both groups then received lenalidomide maintenance therapy for 1 year. Global HRQoL, physical functioning, and role functioning scores significantly improved for both cohorts from baseline to the end of consolidation and were sustained during maintenance and follow-up, with clinically meaningful changes (RVd-alone

In the context of chronic myeloid leukemia (CML) resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL1 tyrosine kinase domain (TKD) mutations still remain the sole biological marker that directly condition therapeutic decision. These recommendations aim at updating the use of BCR-ABL1 mutation testing with respect to new available therapeutic options and at repositioning different testing methods at the era of next generation sequencing (NGS). They have been written by a panel of experts from the French Study Group on CML (Fi-LMC), after a critical review of relevant publications. TKD mutation testing is recommended in case of treatment failure but not in case of optimal response. For patients in warning situation, mutation testing must be discussed depending on the type of TKI used, lasting of the treatment, kinetic evolution of BCR-ABL1 transcripts along time and necessity for switching treatment. The kind and the frequency of TKD mutations occasioning resistance mainly depend on the TKI in use and disease phase. Because of its better sensitivity, NGS methods are recommended for mutation testing rather than Sanger's. Facing a given TKD mutation, therapeutic decision should be taken based on in vitro sensitivity and clinical efficacy data. Identification by sequencing of a TKD mutation known to induce resistance must lead to a therapeutic change. The clinical value of testing methods more sensitive than NGS remains to be assessed.

Purpose: Tyrosine kinase inhibitor (TKI) discontinuation is an emerging goal in chronic myelogenous leukemia (CML) management and several studies have demonstrated the feasibility of safely stopping imatinib. A sustained deep molecular response on long-term TKI is critical prior to attempting treatment-free remission. Reproducible results from several studies reported recently, failed to identify robust and reproducible predictive factors for the selection of the best candidates for successful TKI cessation. Patients and Methods: We conducted a prospective national phase II study evaluating the cessation of imatinib after at least 2 years of MR4.5 obtained on imatinib first-line in patients with chronic phase CML. Results: A total of 218 patients with de novo chronic phase CML were involved in the study. The median follow-up after imatinib cessation was 23.5 (1–64) months, 2 patients died from unrelated causes, and 107 experienced a confirmed increase in BCR-ABL1 levels defined as molecular recurrence. The molecular recurrence-free survival was 52% [95% confidence interval (CI), 45%–59%] at 6 months, and 50% (95% CI, 43%–57%) at 24 months. Droplet digital PCR (ddPCR) was used to evaluate more accurately low levels of BCR-ABL1 in 175 of 218 patients at imatinib cessation. To apply positive BCR-ABL1/ABL1 ratios on the international scale (IS), a conversion factor was calculated for ddPCR and the significant cut-off point was established at 0.0023%IS. In a multivariate analysis, the duration of TKI (≥74.8 months) and ddPCR (≥0.0023%IS) were the two identified predictive factors of molecular recurrence, with P = 0.0366 (HR, 0.635; 95% CI, 0.415–0.972] and P = 0.008 (HR, 0.556; 95% CI, 0.360–0.858), respectively. Conclusions: We conclude that the duration of TKI and residual leukemic cell load as determined by ddPCR are key factors for predicting successful treatment-free remission for patients with de novo chronic phase CML. See related commentary by Yan et al., p. 6561

Introduction: Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) with high-risk genetics and/or measurable residual disease (MRD) are at high-risk of disease recurrence. In the previous GRAALL-2005 study, we identified KMT2A rearrangements (KMT2A-r), IKZF1 intragenic deletion (IKZF1del) and post-induction (TP1, week 6) MRD ≥ 0.01% as independent factors to predict relapse in Ph-negative B-cell precursor (BCP) ALL (Beldjord K, Blood 2014). In the GRAALL-2014 trial, high-risk (HR) patients were thus defined by the presence of at least one of these three factors. Among them, only those with higher MRD levels defined as TP1-MRD ≥ 0.1% and/or week 12 (TP2) MRD ≥ 0.01% were considered at very high risk (VHR) and proposed allogeneic hematopoietic stem cell transplant (alloSCT) in first remission (Dhedin et al., Blood 2015). Since October 2018, all these patients were eligible to be included in the GRAALL-2014-QUEST phase 2 study to receive blinatumomab as part of consolidation and maintenance phases or as a bridge to transplant. Methods: From October 2018 to December 2020, 95 patients with high-risk Ph-negative BCP-ALL without central nervous system involvement at diagnosis and in continuous complete remission after induction and consolidation 1, were prospectively included to start blinatumomab at week 12. One patient was excluded because of T-ALL phenotype (with CD19 aberrant expression). Patients with alloSCT indication and a stem cell source received blinatumomab 28 microg/d administered by continuous intravenous infusion (cIV) until transplant. A minimum of 4 weeks blinatumomab was recommended before proceeding to transplantation. All other patients received 5 cycles of blinatumomab 28 microg/day cIV (for 28 days), during consolidation 2 and 3 and at months 1/3/5 of the maintenance phase respectively. The primary objective was disease-free survival (DFS). Secondary objectives included post-blinatumomab MRD response at TP3 (after consolidation 2 or before alloSCT), overall survival (OS), and safety. Early results are reported here. Results: Median age was 35 years old (range, 18-60). Median white blood cell count (WBC) at diagnosis was 12 G/L (range, 1-449). Oncogenetic analyses allowed classifying ALL as Ph-like (18%), KMT2A-r (17%), DUX4/ERGdel (13%), ZNF384-r (11%), low hypodiploidy/near triploidy (7%), B-other (26%) or unknown (9%). An IKZF1del was found in 37/93 (40%). A TP1-MRD ≥ 0.01% was found in 46/94 patients (49%). Final risk group was HR for 45 patients and VHR for 49 patients. Last pre-blinatumomab MRD was Conclusion. In patients wih high-risk BCP-ALL, blinatumomab added to consolidation is safe and gives promising results. A comparison to similar patients treated in the same GRAALL-2014 study before October 2018 is planned with a longer follow-up. Figure 1 Figure 1. Disclosures Boissel: Novartis: Consultancy, Honoraria, Research Funding; Incyte: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; SANOFI: Honoraria; Servier: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; CELGENE: Honoraria; JAZZ Pharma: Honoraria, Research Funding; PFIZER: Consultancy, Honoraria. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. Rousselot: Incyte, Pfizer: Consultancy, Research Funding. Chalandon: Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Amgen: Other: Advisory Board; Incyte: Speakers Bureau; Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Gilead, Amgen, Jazz, Astra Zenec: Other: Travel EXpenses, Accomodation. Delabesse: Astellas: Consultancy; Novartis: Consultancy. Dombret: Abbvie: Honoraria; Amgen: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; NOVARTIS: Research Funding; pfizer: Honoraria, Research Funding; servier: Research Funding; BMS-Celgene: Honoraria; Daiichi Sankyo: Honoraria. OffLabel Disclosure: Blinatumomab in frontline high-risk acute lymphoblastic leukemia

Background: CASSIOPEIA part 1 showed superior depth of response and significantly improved progression-free survival with daratumumab, bortezomib, thalidomide, and dexamethasone (D-VTd) versus bortezomib, thalidomide, and dexamethasone (VTd) as induction and consolidation in patients with autologous stem-cell transplant (ASCT)-eligible newly diagnosed multiple myeloma. In part 2, we compared daratumumab maintenance versus observation only. Methods: CASSIOPEIA is a two-part, open-label, randomised, phase 3 trial of patients aged 18–65 years with newly diagnosed multiple myeloma and Eastern Cooperative Oncology Group performance status 0–2, done in 111 European academic and community practice centres. In part 1, patients were randomly assigned (1:1) to induction and consolidation with D-VTd or VTd. Patients still on study who had a partial response or better were randomly assigned (1:1) by an interactive web-response system to daratumumab 16 mg/kg intravenously every 8 weeks (a reduced frequency compared with standard daratumumab long-term dosing) or observation only for up to 2 years. Stratification factors were induction treatment and depth of response in part 1. The part 2 primary endpoint was progression-free survival from second randomisation. This preplanned interim analysis of progression-free survival was done after 281 events and shall be considered the primary analysis of progression-free survival. Sponsor personnel and designees who were involved in the analysis were masked to treatment group until the independent data monitoring committee recommended that the preplanned interim analysis be considered the main analysis of progression-free survival in part 2. Otherwise, treatment assignments were unmasked. The interaction between induction and consolidation and maintenance was tested at a two-sided significance level of 0·05 by a stratified Cox regression model that included the interaction term between maintenance treatment and induction and consolidation treatment. Efficacy analyses were done in the maintenance-specific intention-to-treat population, which comprised all patients who underwent second randomisation. Safety was analysed in all patients in the daratumumab group who received at least one dose and all patients randomly assigned to observation only. This trial is registered with ClinicalTrials.gov, NCT02541383. Long-term follow-up is ongoing and the trial is closed to new participants. Findings: Between May 30, 2016, and June 18, 2018, 886 patients (458 [84%] of 543 in the D-VTd group and 428 [79%] of 542 in the VTd group) were randomly assigned to daratumumab maintenance (n=442) or observation only (n=444). At a median follow-up of 35·4 months (IQR 30·2–39·9) from second randomisation, median progression-free survival was not reached (95% CI not evaluable [NE]–NE) with daratumumab versus 46·7 months (40·0–NE) with observation only (hazard ratio 0·53, 95% CI 0·42–0·68, p

Blinatumomab is a bispecific T-cell engager approved for B-cell precursor acute lymphoblastic leukemia (B-ALL) with persistent minimal residual disease (MRD) or in relapse. The prognostic impact of tumor load has been suggested before other immunotherapies but remains poorly explored before blinatumomab. We retrospectively analyzed the outcome of 73 patients who received blinatumomab either in first complete remission (CR) with MRD (n=35) or at relapse (n=38). Among MRD patients, 91% had MRD >0.01% before blinatumomab, and 89% achieved complete MRD response after blinatumomab. High pre-blinatumomab MRD levels were associated with shorter relapse-free survival (P=0.049) and overall survival (OS) (P=0.011). At 3 years, OS was 33%, 58% and 86% for pre-blinatumomab MRD >1%, between MRD 0.1- 1% and

International audience; Dasatinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor approved for patients with chronic myeloid leukaemia (CML). Dasatinib 100 mg per day is associated with an increased risk of pleural effusion (PlEff). We randomly evaluated whether therapeutic drug monitoring (TDM) may reduce dasatinib-associated significant adverse events (AEs) by 12 months (primary endpoint). Eligible patients started dasatinib at 100 mg per day followed by dasatinib (C)min assessment. Patients considered overdosed [(C)min ≥ 3 nmol/l) were randomised between a dose-reduction strategy (TDM arm) and standard of care (control arm). Out of 287 evaluable patients, 80 patients were randomised. The primary endpoint was not met due to early haematological AEs occurring before effective dose reduction. However, a major reduction in the cumulative incidence of PlEff was observed in the TDM arm compared to the control arm (4% vs. 15%; 11% vs. 35% and 12% vs. 39% at one, two and three years, respectively (P = 0·0094)). Molecular responses were superimposable in all arms. Dasatinib TDM during treatment initiation was feasible and resulted in a significant reduction of the incidence of PlEff in the long run, without impairing molecular responses. (NCT01916785; https://clinicaltrials.gov).

The effectiveness of tyrosine kinase inhibitors (TKIs) has made it possible to consider treatment discontinuation in chronic myeloid leukaemia (CML) patients that achieve an excellent response. However, a few of the patients included in the Europe Stop Tyrosine Kinase Inhibitors (EURO-SKI) trial reported musculoskeletal pain shortly after stopping TKIs, considered as a withdrawal syndrome (WS). To identify factors that may predispose to TKI WS, we analysed the pharmacovigilance declarations for the 6 months after stopping TKIs in a large cohort of CML (n = 427) that combined the French patients included in the STop IMatinib 2 (STIM2; n = 224) and EURO-SKI (n = 203) trials. Among these patients, 23% (99/427) developed TKI WS after stopping imatinib (77/373; 20·4%), nilotinib (12/29; 41·4%) or dasatinib (10/25; 40%). WS concerned mainly the upper body joints, and required multiple symptomatic treatments in 30% of patients. Univariate and multivariate analyses identified two risk factors: duration of TKI treatment [risk ratio (RR) = 1·68 (1·02-2·74)] with a 93-month cut-off time, and history of osteoarticular symptoms [RR = 1·84 (1·04-3·28)]. These findings confirm that WS is a TKI class effect. CML patients should be carefully screened before treatment initiation to identify pre-existent osteoarticular symptoms. Moreover, before TKI discontinuation, patients should be informed of the possibility of WS, particularly after a long treatment period.

Background Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder with a high risk of progression to symptomatic multiple myeloma (MM). The serum free light chain (sFLC) ratio is a powerful prognostic factor for SMM: an sFLC ratio ≥8 has been reported to be associated with a high risk of progression to MM, and an sFLC ratio ≥100 has been described as a criterion for ultra-high-risk SMM, and has been integrated into the definition criteria for MM since 2014. However, all recommendations were based on sFLC measured using the first commercialized assay, Freelite™, while other assays are now available. We aimed to evaluate the safety and accuracy of N-Latex sFLC to identify high-risk and ultra-high-risk SMM. Methods The sFLC ratio was measured at diagnosis with both Freelite and N-Latex assays in a cohort of 176 SMM patients on a BN Prospec nephelometer. Demographic, clinical, therapeutic and laboratory data were collected at the time of diagnosis and at follow-up. Results Sixty-two patients (35.2%) progressed to MM within 2 years. Compared to Freelite™ sFLC, N Latex sFLC ratios ≥8 and ≥100 provided similar performances for the identification of high-risk and ultra-high risk SMM patients. Conclusions Our results evidenced that the N-Latex assay could be used for SMM monitoring, like Freelite. However, an N-Latex sFLC ratio ≥70 appears to provide similar performances to a Freelite sFLC ratio ≥100, with a slightly better positive predictive value. Both assays provided accurate identification of high-risk and ultra-high risk SMM patients. These results should be confirmed in an independent study.

The STI571 prospective randomised trial (SPIRIT) French trial is a four-arm study comparing imatinib (IM) 400 mg versus IM 600 mg, IM 400 mg + cytarabine (AraC), and IM 400 mg + pegylated interferon alpha2a (PegIFN-α2a) for the front-line treatment of chronic-phase chronic myeloid leukaemia (CML). Long-term analyses included overall and progression-free survival, molecular responses to treatment, and severe adverse events. Starting in 2003, the trial included 787 evaluable patients. The median overall follow-up of the patients was 13.5 years (range 3 months to 16.7 years). Based on intention-to-treat analyses, at 15 years, overall and progression-free survival were similar across arms: 85%, 83%, 80%, and 82% and 84%, 87%, 79%, and 79% for the IM 400 mg (N = 223), IM 600 mg (N = 171), IM 400 mg + AraC (N = 172), and IM 400 mg + PegIFN-α2a (N = 221) arms, respectively. The rate of major molecular response at 12 months and deep molecular response (MR4) over time were significantly higher with the combination IM 400 mg + PegIFN-α2a than with IM 400 mg: p = 0.0001 and p = 0.0035, respectively. Progression to advanced phases and secondary malignancies were the most frequent causes of death. Toxicity was the main reason for stopping AraC or PegIFN-α2a treatment.

International audience; The prognostic value of IL7-receptor pathway (IL7Rp) mutations in T-cell acute lymphoblastic leukemia (T-ALL) remains unclear. We performed a comprehensive study of 200 adult patients with TALL included in the GRAALL2003/2005 protocols to address the clinical significance of IL7Rp mutations. Next-generation sequencing of the IL7Rp (IL7R/JAK1/ JAK3/STAT5B) revealed that IL7Rp mutations were frequent in adult TALL (28%) particularly in immature/early T-cell progenitor (ETP)-ALL. They were associated with mutations of NOTCH-pathway, PHF6, and PRC2 components but not with K/NRAS. IL7Rp mutated (IL7Rp mut) TALL were slow-responders, with a high rate of M2/M3 day-8 marrow compared with IL7Rp non-mutated (IL7Rp WT) TALL (p = 0.002) and minimal residual disease positivity at 6-weeks (MRD1) (p = 0.008) but no difference in MRD2 positivity at 12-weeks. Despite this, no adverse prognosis was evidenced when censored for allogeneic hematopoietic stem cell transplantation (HSCT). In time-dependent analysis, HSCT did not benefit IL7Rp mut patients whereas it was of marked benefit to IL7Rp WT cases. IL7Rp-mutations identify a subgroup of slow-responder T-ALLs which benefit from post-induction chemotherapy regimens but not from HSCT. Our data suggest that prior knowledge of the mutation status of IL7Rp may influence HSCT decision and help to guide therapy reduction.

The STI571 prospective randomised trial (SPIRIT) French trial is a four-arm study comparing imatinib (IM) 400 mg versus IM 600 mg, IM 400 mg + cytarabine (AraC), and IM 400 mg + pegylated interferon alpha2a (PegIFN-α2a) for the front-line treatment of chronic-phase chronic myeloid leukaemia (CML). Long-term analyses included overall and progression-free survival, molecular responses to treatment, and severe adverse events. Starting in 2003, the trial included 787 evaluable patients. The median overall follow-up of the patients was 13.5 years (range 3 months to 16.7 years). Based on intention-to-treat analyses, at 15 years, overall and progression-free survival were similar across arms: 85%, 83%, 80%, and 82% and 84%, 87%, 79%, and 79% for the IM 400 mg (N = 223), IM 600 mg (N = 171), IM 400 mg + AraC (N = 172), and IM 400 mg + PegIFN-α2a (N = 221) arms, respectively. The rate of major molecular response at 12 months and deep molecular response (MR4) over time were significantly higher with the combination IM 400 mg + PegIFN-α2a than with IM 400 mg: p = 0.0001 and p = 0.0035, respectively. Progression to advanced phases and secondary malignancies were the most frequent causes of death. Toxicity was the main reason for stopping AraC or PegIFN-α2a treatment.

Background The ultimate goal of chronic myeloid leukemia management in the tyrosine kinase inhibitor (TKI) era for patients who obtain deep molecular responses is maintaining a durable off-treatment response after treatment discontinuation; this situation is called treatment-free remission (TFR). Knowledge accumulated during the last 10 years justifies moving TFR strategies from research to clinical practice. Methods Twenty experts from the French Chronic Myeloid Leukemia Study Group (France Intergroupe des Leucemies Myeloides Chroniques), including 17 hematologists, 2 molecular biologists, and 1 cytogeneticist, critically reviewed published data with the goal of developing evidence-based recommendations for TKI discontinuation in clinical practice. Results Clinically relevant questions were addressed, including the selection of candidate patients (with known prognostic factors for outcomes taken into account), detailed monitoring procedures during the treatment-free phase, a definition of relapse requiring therapy resumption, and monitoring after treatment reintroduction. Conclusions This work presents consensus statements with the aim of guiding physicians and biologists by means of pragmatic recommendations for safe TKI discontinuation in daily practice. Cancer 2018;124:2956-63. © 2018 American Cancer Society.

Background: The prognosis of central nervous system (CNS) involvement in adult patients with acute lymphoblastic leukemia (ALL) has been historically associated with a dismal outcome. Whereas the prognosis of adult patients with ALL has greatly improved since the advent of pediatrics-inspired regimens, the prognostic impact of CNS involvement has not been formerly reevaluated. We report herein the impact of CNS involvement in patients included in the pediatric-inspired prospective GRAALL-2005 study. Methods: All patients received a 5-drug induction therapy with native E. Coli-ASP intravenous injections. Patients in complete remission (CR) received two consolidation courses with alternating cycles including high dose cytarabine (2g/m2/12h on days 1 and 2), high dose methotrexate (3 g/m2 on day 1), and cyclophosphamide. All patients in persistent CR and with no indication for allogeneic stem cell transplantation (SCT) received late intensification, followed by one last consolidation course. Patients with initial CNS involvement, clinically and/or cytologically (cerebrospinal fluid), were recommended to receive an increased number of triple intrathecal therapy, CNS irradiation, and were eligible for allogeneic SCT in first CR. They received less Asp injections during induction therapy to avoid CNS adverse events. CNS irradiation included two lateral fields encompassing the skull, facial, the base of the skull, and the first two cervical vertebrae at a dose of 24 grays for those not receiving allogeneic SCT and 15 grays for those receiving allogeneic SCT. Results: Between 2006 and 2014, 784 adult patients with newly diagnosed Philadelphia-negative ALL were included with 55 (7%) having initial CNS involvement. These patients were more likely to be of T-phenotype (51 versus 32%, p=.004) and had more white blood cells at diagnosis (median 23 G/l versus 11 G/l, p=.02). Most patients (36 pts, 66%) were classified as CNS-3 (> 5 white blood cells/µl and a positive cytospin and/or clinical signs) whereas 5 patients (9%) were CNS-2 (< 5 white blood cells/µl and a positive cytospin), and 14 (25%) have data pending. Among patients with details regarding CNS involvement, 25/41 (61%) had clinical signs including trigeminal anesthesia (9 pts, 36%), facial paralysis (4 pts, 16%), extremities paresthesia (4 pts, 16%), visual signs (2 pts, 8%), meningeal syndrome (2 pts, 8%), and motor deficit (2 pts, 8%), and 4/18 (22%) had radiological signs. Induction death, CR1 rate, and negative minimal residual disease after induction were similar whether patients had CNS involvement or not (6 vs 6%, 89 vs 89%, 73 vs 62%, 26 vs 22%, respectively). Patients with CNS involvement had a worse outcome than those without with a median event-free survival (EFS) of 391 days (versus not reached for patients without CNS involvement, HR: 1.7, 95% CI: 1.2 - 2.5, p=.002) and a median overall survival (OS) of 608 days (versus not reached for patients without CNS involvement, HR: 1.8, 95% CI: 1.3 - 2.6, p=.001) (figure). Similar results were observed when patients who received allogeneic SCT in CR1 were censored at the time of graft. As recommended, patients with CNS involvement were more likely to receive allogeneic SCT than those without (53 versus 34%, p=.01), with a median time of 169 days. A 150-day landmark analysis, excluding 12 patients with an EFS event before 150 days, was performed to study the impact of allogeneic SCT on the outcome of patients with CNS involvement. Allogeneic SCT had no impact on either EFS (HR: .5, 95% CI: .2 - 1.2, p=.15) or OS (HR: .8, 95% CI: .3 - 1.8, p=.53). Conclusion: Despite improved outcome in young adult ALL patients with pediatrics-inspired protocols, CNS involvement remains a poor-risk feature. The historical use of allogeneic SCT does not improve outcome. Specific regimens should be developed for adult ALL patients with CNS involvement. Figure 1 Figure 1. Disclosures Huguet: Amgen: Other: Advisor; BMS: Other: Advisor; Celgene: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Novartis: Other: Advisor; Pfizer: Other: Advisor. Barbieux: ASTRA-ZENECCA: Consultancy. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Dombret: Amgen: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Research Funding; Pfizer: Honoraria, Research Funding; Servier: Research Funding; Abbvie: Honoraria; BMS-Celgene: Honoraria; Daiichi Sankyo: Honoraria. Boissel: Bristol-Myers Squibb: Honoraria, Research Funding; Servier: Consultancy, Honoraria; Incyte: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; JAZZ Pharma: Honoraria, Research Funding; CELGENE: Honoraria; SANOFI: Honoraria; PFIZER: Consultancy, Honoraria. Mathilde: ABBVIE: Consultancy; SERVIER: Consultancy.

Background: The role of maintenance lenalidomide in myeloma, following autologous stem cell transplantation (ASCT) or not, is well established. However, 29% of patients discontinue the treatment with a median duration of less than 2 years with an increased rate of secondary primary malignancies (SPM). Pomalidomide could provide alternative maintenance therapy. Methods: This was a single arm phase II study of pomalidomide/dex (PD) maintenance therapy for MM patients (pts) in first relapse after treatment in the IFM 2009 trial. At first relapse, 100 pts received pomalidomide/cyclophosphamide/dex (PCD) for 4 cycles, after which half underwent ASCT (if no first line transplant) followed by 2 cycles of PCD consolidation (Arm A), or 5 cycles of PCD (if previously transplanted) (Arm B). All pts then received maintenance therapy consisting of 28-day cycles of pomalidomide 4 mg daily on days 1-21 and dex 20 mg once a week until progression (Blood 2018). The primary objective was to establish the safety and efficacy of PD as maintenance therapy. Results: A total of 75 pts were enrolled in the maintenance phase from January 2015 to November 2017 (Table 1) and the database was locked on 07/07/2021. The median age was 60 (range 39-70); 67% (50/75) were male. 53 pts had ISS stage I, 10 stage II and 3 stage III disease (9 missing). Infectious prophylaxis was antiviral in 94%, sulfamethoxazole/trimethoprim in 76%, penicillin in 69% and fluoroquinolone in 38%. A granulocyte colony stimulating factor was administered in 15 (20%) pts and immunoglobulins in 13 (17%). One quarter had thromboprophylaxis. The median follow-up was 73 months (95% CI: 68-75). Among the 75 pts, 63 (84%) left the study, 34 (54%) due to progressive disease, 19 (30%) due to AE/SAE, 7 (11%) on investigator (PI) discretion and 3 (5%) after consent withdrawal. 12 (16%) remained on therapy in July 2021.The median duration of maintenance was 23.7 months (IQR: 14.5-44). Pts received a median of 26 cycles (range 1-80) and 17 (23%) had 50 or more cycles. The reasons for pomalidomide discontinuation were progression or death in 54%, AE/SAE in 30%, PI decisions in 11% and patient decisions in 5%. 56 (75%) pts required a reduction in the dose of pomalidomide due to AE/SAE in 50%, omission in 19%, resumption of treatment in 11%, PI decisions in 16% and patient decisions in 2.7%. The reasons for dex discontinuation were progression or death in 30%, AE/SAE in 43%, PI decisions in 22% and patient decisions in 3%. 57 (76%) pts required a reduction in the dose of dex due to AE/SAE in 54%, omission in 3.4%, resumption of treatment in 0.3%, PI decisions in 38.7% and patient decisions in 3.1%. 31 SAE were reported in 22 pts: 13 (42%) infections, 5 tumors, 1 case of thrombosis, 1 diabetic ketoacidosis and 12 others. Grade 3/4 hematologic AE included neutropenia (51%), lymphopenia (35%), anemia and thrombocytopenia (0%). G3/4 drug-related non-hematologic AE (>5%) comprised 13% infections (5% pneumonia). G1/2 AE included 69% infections (49% bronchitis), 49.3% gastrointestinal disorders (20% diarrhea, 20% constipation), 48% fatigue, 31% skin disorders, 25% muscle spasms, 24% insomnia and 14.7% eye disorders (6.7% cataracts, 4% dry eyes). Concerning peripheral neuropathy, one patient had G3/4 and 45% G1/2. Eight pts developed SPM: 4 basocellular carcinoma, 1 epidermoid carcinoma, 1 melanoma, 1 colon carcinoma and 1 non small cell bronchial carcinoma. We observed an improvement in the response from the initiation of treatment: PR: 32.4 to 17.4%, VGPR: 56.8 to 49.3%, CR: 9.5 to 28%, sCR: 0 to 5.3% (at initiation to best response, respectively). A total of 33.4% of pts improved their response. The median PFS was 33.2 months (95% CI: 25.6-53.3). 41 pts died and the median OS was not reached (95% CI: 70.7-NR). All deaths were related to myeloma progression except 2 due to pulmonary infection, 1 lung carcinoma and 1 colorectal cancer. Conclusions: In the first relapse PCD trial, 75% initiated maintenance therapy. Long term administration of pomalidomide/dexamethasone as maintenance therapy is feasible. Thirty percent stopped pomalidomide because of SAE/AE, mostly related to hematologic AE, but this could be managed with dose reductions. There was generally G1/2 neuropathy, rare SPM and no other unexpected toxicity. One third of the pts improved their depth of response. The combination is safe, feasible and well tolerated and experience to date supports its further exploration with monoclonal antibodies. Figure 1 Figure 1. Disclosures Garderet: Amgen: Consultancy; Sanofi: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Janssen: Consultancy. Roussel: Amgen: Consultancy; BMS: Honoraria; GSK: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy. Leleu: Novartis: Honoraria; Mundipharma: Honoraria; Merck: Honoraria; Karyopharm Therapeutics: Honoraria; Janssen-Cilag: Honoraria; Gilead Sciences: Honoraria; Celgene: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Bristol-Myers Squibb: Honoraria; Amgen: Honoraria; AbbVie: Honoraria; Oncopeptides: Honoraria; Pierre Fabre: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Other: Non-financial support. Karlin: Takeda: Honoraria, Other: member of advisory board; Amgen: Honoraria, Other: travel support and advisory board ; Sanofi: Honoraria; Abbvie: Honoraria; oncopeptide: Honoraria; GSK: Honoraria, Other: member of advisory board; Janssen: Honoraria, Other: member of advisory board, travel support; Celgene-BMS: Honoraria, Other: member of advisory board. Perrot: Abbvie: Honoraria; BMS Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: 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, Research Funding; Sanofi: Honoraria, Research Funding; GSK: 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. Moreau: Abbvie: Honoraria; Oncopeptides: Honoraria; Celgene BMS: Honoraria; Amgen: Honoraria; Sanofi: Honoraria; Janssen: Honoraria. Macro: abbvie: Honoraria; sanofi: Honoraria; celgene bms: Honoraria; takeda: Honoraria; janssen: Honoraria. Jourdan: Novartis: Consultancy; Abbvie: Consultancy; bms/celgene: Consultancy. Jaccard: Pfizer: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria. Mohty: Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Sanofi: Honoraria, Research Funding; Gilead: Honoraria; Janssen: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Takeda: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Adaptive Biotechnologies: Honoraria. Hulin: Celgene/BMS: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; abbvie: Honoraria. OffLabel Disclosure: pomalidomide as maintenance treatment

Aims: Combining 2GTKI+pegylated IFN-a (Peg-IFN) represents an attractive approach for first-line treatment of CP CML, while providing somewhat light additional AEs, it induces high rates of deep molecular responses. We evaluated nilotinib (NIL) alone versus NIL+Peg-IFN in newly diagnosed CP-CML patients (pts) in a randomised phase III trial (PETALs, EudraCT 2013-004974-82) and analysed here the proportion of patients reaching Treatment-Free Remission (TFR) and outcome. Methods: Newly diagnosed CP CML pts ≤65 years, without vascular history were randomized 1:1 to get NIL 300 mg BID alone [M0 to M72 (unless TFR), arm A] vs Peg-IFN alone for 30 days (M-1→M0) 30 mg/wk, prior to NIL 300 mg BID + Peg-IFN 30 mg/wk 2 wks, upgraded to 45 mg/wk thereafter, for up to 2 y (M0 to M24, arm B) followed by NIL alone until M72 unless TFR. The primary endpoint was the rate of MR4.5 by M12, and after amendment, the trial was extended to 72 months follow-up in order to add, as a secondary endpoint, the TFR rate in pts reaching MR4.5 ≥2 y. The trigger for treatment resumption was loss of MMR. All molecular assessments were centralised until M36, and in case of TFR, MR4.5 was centrally confirmed at M0 TFR, and further molecular follow-up was then performed locally. All molecular quantifications are expressed as BCR-ABL1/ABL1 (IS) in % with ≥32,000 copies of ABL1 as control in the central lab and in the local labs all involved to the pluri-annual French external quality controls. Results are analysed in intention-to-treat. Results: As previously reported, 200 pts were randomized (99 in A, 101 in B), 130 M and 35 F in each arm, median age of 46 (18-66) y. The median follow-up (FU) since diagnosis is now 47.5 (33.77-62.39) Mo. and the median FU since discontinuation is 9.86 (5.8-23) Mo. in arm A and 15.57 (12.62-22.77) Mo. in arm B. Sokal and ELTS scores were high in 25% and 2.5%, intermediate in 33% and 16.5% and low in 42% and 81% pts respectively, equally balanced. All pts harboured a "Major" BCR transcript. We have previously shown that by M12, the rate of MR4.5 was 15.9% vs 21.5% (primary endpoint met, p=0.049) and that the overall cumulative incidence of MR4.5 was somewhat superior in arm B (54.6 [43.7-65.5] %) vs A (44 [31.5-54] %), p=0.05. Two pts died, one from myeloid blast crisis before TFR (arm A), one from a solid tumour (arm A). Overall, 40 pts (20%) reached the TFR criteria, 21 in arm A with a median FU of 9.86 (5.8-23) Mo. and 19 in arm B with a median FU since Nilo cessation of 15.57 (12.62-22.77) Mo, partly related to slightly different time for obtaining sustained MR4.5 in favour of arm B (16 vs 13 Mo.). For these 40 pts reaching TFR criteria, there was no statistical difference in terms of age at diagnosis and age at TFR, gender, Sokal, ELTS, FU since diagnosis, undetectability at cessation, BCR-ABL1 levels at 3 Mo. after cessation between the 2 arms. The survival without loss of MMR after cessation is illustrated in Figure 1. It looks superior in arm B over arm A, but did not reach statistical difference (p=0.445), but the FU is very short after cessation yet, especially in arm A. Once NIL was resumed in the pts that failed TFR, all pts recovered MMR within 6 Mo., with no difference between arms (p=1.00). In univariate analysis, we did not identify significant factor impacting on the TFR success (age at cessation, sex, undetectability at cessation, Sokal, ELTS) except the BCR-ABL1 value at M3-TFR (undetectable versus detectable, HR 7.15 [2.06-24.75], p=0.002), and the duration of MR4.5 before discontinuation (HR 1.11 [1.03-1.19], p=0.004). During this TFR phase 7 SAEs were reported in arm A (2 pregnancies, 1 obstructive sleep apnea, 1 fever episode, 1 carotid stenosis and 1 femoral stenosis in the same patient at 2 Mo. after cessation, 1 lung carcinoid tumor) and 2 in arm B (1 persistent atrial fibrillation, 1 cholecystectomy). Conclusions: The combination of NIL + Peg-IFN induces higher MR4.5 rates by M36 in newly diagnosed CP CML pts that may translate in higher successful TFR rates, however a longer follow-up is needed to see consistent significant differences. Updated data will be presented. Figure 1 Figure 1. Disclosures Nicolini: Kartos Therapeutics: 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, Other: travel, accommodations, expenses, Research Funding; Incyte Biosciences: Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; Sun Pharma Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria. Etienne: Incyte: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. Guerci-Bresler: Novartis: Speakers Bureau; Incyte: Speakers Bureau. Charbonnier: Incyte: Speakers Bureau; Novartis: Speakers Bureau. Rousselot: Incyte, Pfizer: Consultancy, Research Funding. Deconinck: Stemline Therapetutics: Membership on an entity's Board of Directors or advisory committees; Imunogen: Membership on an entity's Board of Directors or advisory committees; Chugai: Research Funding; Novartis: Research Funding; Pfizer: Other: Travel Grants, Research Funding; Abbevie: Research Funding. Rea: Pfizer: 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; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees.

On behalf of the GRAALL group. Introduction. Tyrosine kinase inhibitors (TKIs) have dramatically improved the outcome of patients diagnosed with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). In a previous randomized trial (GRAAPH-2005; Chalandon Y., Blood 2015), our group demonstrated that anthracycline and cyclophosphamide could be safely omitted during the first Hyper-CVAD chemotherapy cycle when combined to imatinib. In the present GRAAPH-2014 trial, we investigated whether the use of nilotinib, a 2 nd generation TKI, would allow further decreasing chemotherapy intensity through the omission of high-dose cytarabine (HD-AraC) during consolidation cycles 2 and 4. Methods. From March 2016, patients aged 18-60 years old were randomized frontline to receive 4 cycles (1=3, 2=4) of chemotherapy combined with continuous nilotinib 400 mg bid. Cycle 1 and 3 were similar in both arms, identical to the less-intensive first cycle of the previous GRAAPH-2005 trial with weekly vincristine and dexamethasone and nilotinib instead of imatinib. Cycle 2 and 4 differed between control arm A (MTX 1 g/sqm over 24h, HD-AraC 3 g/sqm/12h for 2 days) and experimental arm B (MTX 1 g/sqm over 24h only). Marrow minimal residual disease (MRD) was assessed by both BCR-ABL1 and IG-TCR qPCR after each cycle (MRD1-4). Patients in complete remission (CR) after cycle 4 were eligible to receive allogeneic stem cell transplant (alloSCT). Non allografted patients had the option to receive autologous SCT (autoSCT) if a major molecular response (MMolR) (MRD4 BCR-ABL1 40y) and BCR-ABL1 breakpoint region (M/m-bcr). MMolR rate at MRD4 was the primary endpoint of this non-inferiority study, with a margin set at 0.15. In February 2019, the study DSMB decided to stop the randomizations after an unplanned analysis demonstrating a significant excess of relapse in arm B (without HD-AraC). An intention-to-treat analysis is provided. All patients gave informed consent. The study is registered at EudraCT under the number: 2014-002146-44. Results. A total of 156 patients were randomized (77 in arm A, and 79 in arm B). Median age was 47.1 years old (range 18.1-59.9). One-hundred and ten patients had the m-bcr (70.5%) and 46 (29.5%) the M-bcr. An IKZF1 intragenic deletion was found in 87/153 (56.9%). Median follow-up was 2.8 years (95%CI 2.6-3.1). All evaluable patients reached CR after a maximum of two cycles. Three patients died during cycle 1 (2 in arm A, 1 in arm B), and 2 during cycle 2 (1 per arm). Most patients received the 4 scheduled cycles (n=143, 91,7%). AlloSCT was performed in 91 patients (58.3%), whereas 41 patients received an autoSCT (26.3%) with no difference in allo/autoSCT rates between arms. A non-inferiority in late MRD response (MRD4) between the two arms was observed (primary endpoint). MMolR was reached in 55/75 (73.3%) and 61/78 (78.2%) of CR patients in arm A and B, respectively, with an estimated 95% CI of difference of -11% to +16% (-9.2% to +20.8% in the ITT analysis treating missing data as failures). At 3 years, overall survival (OS) was 86.0% in arm A versus 74.2% in arm B (p=.08, Figure A). Progression-free survival (PFS) was 79.6% in arm A versus 57.2% in arm B (p=.008, Figure B). Thirty-one patients experienced hematological relapse (8 in arm A and 23 in arm B). Twenty-height out of 31 relapsed patients were tested for the acquisition of BCR-ABL1 mutations, 20/28 (71%) had at least one mutation and 10/28 (36%) had a T315I mutation. At 3 years, the cumulative incidence of relapse (CIR) was 21.3%, significantly higher in arm B than in arm A (30.8% vs 10.6%, p=.007). When analyzing the CIR considering alloSCT as a competing event for relapse, a significant higher CIR was still observed in arm B as compared to arm A (Figure C). Conclusion. Four cycles of the combined administration of nilotinib and chemotherapy is very efficient for bridging younger adults with Ph-positive ALL to SCT. However, omitting HD-AraC is associated with a higher relapse incidence despite non-inferior levels of BCR-ABL1 MRD4. Figure 1 Figure 1. Disclosures Rousselot: Incyte, Pfizer: Consultancy, Research Funding. Chalandon: Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Gilead, Amgen, Jazz, Astra Zenec: Other: Travel EXpenses, Accomodation; Incyte: Speakers Bureau; Incyte, BMS, Pfizer, Abbie, MSD, Roche, Novartis, Amgen: Other: Advisory Board. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. Vincent: Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Raffoux: PFIZER: Consultancy; CELGENE/BMS: Consultancy; ASTELLAS: Consultancy; ABBVIE: Consultancy. Boissel: Amgen: Consultancy, Honoraria, Research Funding; CELGENE: Honoraria; Servier: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Incyte: Honoraria; SANOFI: Honoraria; PFIZER: Consultancy, Honoraria; JAZZ Pharma: Honoraria, Research Funding. Dombret: Amgen: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Research Funding; Pfizer: Honoraria, Research Funding; Servier: Research Funding; Abbvie: Honoraria; BMS-Celgene: Honoraria; Daiichi Sankyo: Honoraria. OffLabel Disclosure: Nilotinib as a therapy for PH-positive acute lymphoblastic leukemia

Background: High dose melphalan (HDM) followed by autologous hematopoietic stem cell transplantation (ASCT) is widely used in multiple myeloma (MM) patients as upfront and salvage therapy. However, the safety and efficacy of ASCT in patients with renal insufficiency (RI) is controversial, which have led to an inconsistent arbitrary cut-off for creatinine clearance (CrCl) for performing ASCT. Here we analyzed prospectively the outcomes of MM patients with severe RI who underwent ASCT. Methods: We enrolled prospectively 50 newly diagnosed MM patients who had a serum CrCl of Results: The patients characteristics at enrollment are given in Table 1. We focused on 44 patients who were beyond 3 months post-ASCT. Light chain MM was frequent (12%), 10% had high risk cytogenetics, 36% increased serum LDH and 10% extramedullary disease. Induction chemotherapies included bortezomib plus IMiDs in 25/44 patients with ≥2 lines of chemotherapy in 12/44. The pre-transplant disease status was sCR in =5%, CR in =15%, VGPR in =39%, and PR in =41% of patients. The number of days of cytapheresis was 2 or less in 95% of cases and the median number of CD34+ cells collected was 3.3 x 106 (1.3-9.5). The median time from diagnosis to ASCT was 175 days (103-307). HDM was 140 mg/m2 in 42/44 patients and 200 mg/m2 in 2/44. All, except two, received consolidation post ASCT (34% missing) and 52% had maintenance therapy (all lenalidomide except two receiving bortezomib) and 7% had no maintenance (41% pending). Toxicity: We observed one death during the first 100 days post-ASCT, secondary to a septic shock on day 42. The median time to neutrophil engraftment was 12 days (9-68) and to platelet engraftment 13 days (10-70). Among patients receiving RBC transfusions (75%) and platelet transfusions (84%), the median number of RBC transfusions was 3 (1-6) and that of platelet transfusions was 3 (1-10). Response: Nine patients (70%) achieved dialysis independence from the time of diagnosis: 13 patients were on dialysis at diagnosis, 5 at the time of ASCT and 4 three months post-ASCT. Renal function improved post-ASCT in 34% of patients, 14% moving from a CrCl of Conclusions: In this preliminary analysis, HDM with ASCT proved to be safe and effective in MM patients with RI at transplant. We observed one death among 44 patients within the first 3 months post-ASCT. A more detailed report of the toxicity will be presented during the meeting along with the survival. Disclosures Vincent: takeda: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Congress support; janssen: Membership on an entity's Board of Directors or advisory committees, Other: Congress support. Mohty:Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Stemline: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau. Karlin:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Other: Personal fees; Sanofi: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees. Morel:Janssen: Honoraria. Rubio:Medac: Consultancy; Gilead: Honoraria; MSD: Honoraria; Novartis: Honoraria; Neovii: Research Funding.

Purpose Magnetic resonance imaging (MRI) and positron emission tomography–computed tomography (PET-CT) are important imaging techniques in multiple myeloma (MM). We conducted a prospective trial in patients with MM aimed at comparing MRI and PET-CT with respect to the detection of bone lesions at diagnosis and the prognostic value of the techniques. Patients and Methods One hundred thirty-four patients received a combination of lenalidomide, bortezomib, and dexamethasone (RVD) with or without autologous stem-cell transplantation, followed by lenalidomide maintenance. PET-CT and MRI were performed at diagnosis, after three cycles of RVD, and before maintenance therapy. The primary end point was the detection of bone lesions at diagnosis by MRI versus PET-CT. Secondary end points included the prognostic impact of MRI and PET-CT regarding progression-free (PFS) and overall survival (OS). Results At diagnosis, MRI results were positive in 127 of 134 patients (95%), and PET-CT results were positive in 122 of 134 patients (91%; P = .33). Normalization of MRI after three cycles of RVD and before maintenance was not predictive of PFS or OS. PET-CT became normal after three cycles of RVD in 32% of the patients with a positive evaluation at baseline, and PFS was improved in this group (30-month PFS, 78.7% v 56.8%, respectively). PET-CT normalization before maintenance was described in 62% of the patients who were positive at baseline. This was associated with better PFS and OS. Extramedullary disease at diagnosis was an independent prognostic factor for PFS and OS, whereas PET-CT normalization before maintenance was an independent prognostic factor for PFS. Conclusion There is no difference in the detection of bone lesions at diagnosis when comparing PET-CT and MRI. PET-CT is a powerful tool to evaluate the prognosis of de novo myeloma.

BACKGROUND Several studies have demonstrated that approximately one-half of patients with chronic myeloid leukemia (CML) who receive treatment with tyrosine kinase inhibitors (TKIs) and achieve and maintain a deep molecular response (DMR) are able to successfully discontinue therapy. In patients who have a molecular relapse, a DMR is rapidly regained upon treatment re-initiation. METHODS The authors report the results from RE-STIM, a French observational, multicenter study that evaluated treatment-free remission (TFR) in 70 patients who re-attempted TKI discontinuation after a first unsuccessful attempt. After the second TKI discontinuation attempt, the trigger for treatment re-introduction was the loss of a major molecular response in all patients. RESULTS The median follow-up was 38.3 months (range, 4.7-117 months), and 45 patients (64.3%) lost a major molecular response after a median time off therapy of 5.3 months (range, 2-42 months). TFR rates at 12, 24, and 36 months were 48% (95% confidence interval [CI], 37.6%-61.5%), 42% (95% CI, 31.5%-55.4%), and 35% (95% CI, 24.4%-49.4%), respectively. No progression toward advanced-phase CML occurred, and no efficacy issue was observed upon TKI re-introduction. In univariate analysis, the speed of molecular relapse after the first TKI discontinuation attempt was the only factor significantly associated with outcome. The TFR rate at 24 months was 72% (95% CI, 48.8%-100%) in patients who remained in DMR within the first 3 months after the first TKI discontinuation and 36% (95% CI, 25.8%-51.3%) for others. CONCLUSIONS This study is the first to demonstrate that a second TKI discontinuation attempt is safe and that a first failed attempt at discontinuing TKI does not preclude a second successful attempt. Cancer 2017;123:4403-10. © 2017 American Cancer Society.

International audience; BACKGROUND:Free light chain (FLC) assays are essential for diagnosis and follow-up of plasma cell dyscrasia. Two assays are available: Freelite (Binding Site) and N Latex FLC (Siemens). The aim of our study was to evaluate the impact of renal failure on concordance and correlation between the 2 FLC assays.METHODS:FLC measurements using both assays were performed on 1215 fresh serum samples from patients with or without monoclonal gammopathy and renal failure. Concordance and correlation were evaluated using Passing-Bablock regression, Pearson correlation coefficient, and the Cohen kappa coefficient, taking into account the renal failure stage (evaluated with Chronic Kidney Disease-Epidemiology Collaboration formulae) and evaluation of treatment response in patients' follow-up.RESULTS:A good correlation was demonstrated between both assays, irrespective of the renal failure stage (Pearson correlation coefficient > 0.90). For FLC ratio interpretation, there remained 7.6% to 20.8% discordances between the 2 methods throughout the whole range of renal impairment. To evaluate FLC evolution in patient follow-up, 41 patients were selected with at least 6 consecutive serum samples being collected during the study period: we observed a concordant evolution of FLC concentrations between both assays. However, few discrepancies were observed with 4 patients.CONCLUSIONS:Despite adjusted reference ranges for Freelite FLC ratio, there are approximately 12.5% discrepancies in interpretation of FLC ratio between the 2 available assays. They are not linked to renal failure stage and neither of the assays performed better than the other: results must be interpreted taking into account clinical data and the same assay must be used for patient follow-up.

In the context of chronic myeloid leukemia (CML) resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL1 tyrosine kinase domain (TKD) mutations still remain the sole biological marker that directly condition therapeutic decision. These recommendations aim at updating the use of BCR-ABL1 mutation testing with respect to new available therapeutic options and at repositioning different testing methods at the era of next generation sequencing (NGS). They have been written by a panel of experts from the French Study Group on CML (Fi-LMC), after a critical review of relevant publications. TKD mutation testing is recommended in case of treatment failure but not in case of optimal response. For patients in warning situation, mutation testing must be discussed depending on the type of TKI used, lasting of the treatment, kinetic evolution of BCR-ABL1 transcripts along time and necessity for switching treatment. The kind and the frequency of TKD mutations occasioning resistance mainly depend on the TKI in use and disease phase. Because of its better sensitivity, NGS methods are recommended for mutation testing rather than Sanger's. Facing a given TKD mutation, therapeutic decision should be taken based on in vitro sensitivity and clinical efficacy data. Identification by sequencing of a TKD mutation known to induce resistance must lead to a therapeutic change. The clinical value of testing methods more sensitive than NGS remains to be assessed.

Background: Bortezomib, thalidomide, and dexamethasone (VTd) plus autologous stem-cell transplantation is standard treatment in Europe for transplant-eligible patients with newly diagnosed multiple myeloma. We evaluated whether the addition of daratumumab to VTd before and after autologous stem-cell transplantation would improve stringent complete response rate in patients with newly diagnosed multiple myeloma. Methods: In this two-part, randomised, open-label, phase 3 CASSIOPEIA trial, we recruited transplant-eligible patients with newly diagnosed multiple myeloma at 111 European sites. Patients were randomly assigned (1:1) to receive four pre-transplant induction and two post-transplant consolidation cycles of VTd alone (VTd group) or in combination with daratumumab (D-VTd group). The primary endpoint of part 1 was stringent complete response assessed 100 days after transplantation. Part 2 (maintenance) is ongoing. The trial is registered with ClinicalTrials.gov, number NCT02541383. Findings: Between Sept 22, 2015, and Aug 1, 2017, 1085 patients were enrolled at 111 European sites and were randomly assigned to the D-VTd group (n=543) or the VTd group (n=542). At day 100 after transplantation, 157 (29%) of 543 patients in the D-VTd group and 110 (20%) of 542 patients in the VTd group in the intention-to-treat population had achieved a stringent complete response (odds ratio 1·60, 95% CI 1·21–2·12, p=0·0010). 211 (39%) patients in the D-VTd group versus 141 (26%) in the VTd group achieved a complete response or better, and 346 (64%) of 543 versus 236 (44%) of 542 achieved minimal residual disease-negativity (10−5 sensitivity threshold, assessed by multiparametric flow cytometry; both p

BACKGROUND: Isatuximab is a monoclonal antibody that binds a specific epitope on the human CD38 receptor and has antitumour activity via multiple mechanisms of action. In a previous phase 1b study, around 65% of patients with relapsed and refractory multiple myeloma achieved an overall response with a combination of isatuximab with pomalidomide and low-dose dexamethasone. The aim of this study was to determine the progression-free survival benefit of isatuximab plus pomalidomide and dexamethasone compared with pomalidomide and dexamethasone in patients with relapsed and refractory multiple myeloma. METHODS: We did a randomised, multicentre, open-label, phase 3 study at 102 hospitals in 24 countries in Europe, North America, and the Asia-Pacific regions. Eligible participants were adult patients with relapsed and refractory multiple myeloma who had received at least two previous lines of treatment, including lenalidomide and a proteasome inhibitor. Patients were excluded if they were refractory to previous treatment with an anti-CD38 monoclonal antibody. We randomly assigned patients (1:1) to either isatuximab 10 mg/kg plus pomalidomide 4 mg plus dexamethasone 40 mg (20 mg for patients aged ≥75 years), or pomalidomide 4 mg plus dexamethasone 40 mg. Randomisation was done using interactive response technology and stratified according to the number of previous lines of treatment (2-3 vs >3) and age (

IF 2.436 (2017); International audience; Ponatinib represents a remarkable progress in the treatment of heavily pretreated chronic myelogenous leukemia (CML) and de novo Philadelphia chromosome-positive ALL patients despite significant toxicity in clinical trials. To date, "real-life" data remain few and the use of ponatinib in this setting and its consequences remain mostly unknown. We report, within a national observational study, the use of ponatinib in unselected CML patients who had previously failed ≥2 lines of tyrosine kinase inhibitor (TKI) therapy (or one line if an Abelson (ABL)T315I mutation was identified), in real-life conditions (2013-2014) in a compassionate program. Our analysis has been focused on 48 chronic phase CML patients recorded. With a median follow-up of 26.5 months since ponatinib initiation, the overall survival (OS) rates (80.5% at 3 years) and cumulative incidence of major molecular response (81.8% at 18 months) were similar to those of the phase II study, with no influence of BCR-ABL mutations nor the reason of ponatinib prescription. A specific subanalysis of the preexisting cardiovascular risk factors and events occurring on ponatinib is described. These events occurred after a median time on ponatinib of 5.8 months (excluding hypertension) and were observed in 29/48 patients (47%), even in those already on anti-aggregants/coagulants. The majority were not severe and resolved, but two cases were fatal. Other hematological or nonhematological nonvascular adverse events were similar to those previously described in trials. This observational study reports similar rates of survival, molecular responses, and a slight increase in the cardiovascular toxicity of ponatinib in real-life conditions, prompting improved control of cardiovascular risk factors and selection of patients.

Background: Tyrosine kinase inhibitors (TKIs) are able to induce, in some chronic myeloid leukemia (CML) patients in chronic phase (CP), long-term molecular response 4.5 (MR4.5) and several studies have now demonstrated that TKIs could be safely discontinued in those patients with a Treatment-Free Remission (TFR) rate reaching ~50%. The French CML group had recently demonstrated that a failure of the first TKI discontinuation attempt does not preclude a 2nd successful attempt (RE-STIM study, Legros et al. Cancer 2017). Methods: The RE-STIM study is a national observational multicentre study collecting all cases of 2nd TKI discontinuation attempt of regardless the type, the duration of TKI, the duration of MR4.5 and the reason of discontinuation. CP-CML Patients in failure of a 1st attempt, had to recover a 2nd sustained MR4.5 on TKI to be eligible for this new analysis of the enlarged database (n=106). Loss of MMR loss was the trigger for therapy re-introduction. Results: At the time of analysis (1st June 2019), 106 patients (median age: 55 years (range: 25-81 years)) were included with 41 months (2-131) of follow-up after 2nd discontinuation. Fifty males and 56 females were enrolled. The Sokal risk score was low in 45%, intermediate in 26.5%, high in 20% and unknown in 8.5% of patients. The majority of patients (95%) were treated with imatinib as first-line, and the others with a 2nd generation TKI. The median total time on TKI prior to a 2nd discontinuation was 104 months (range: 38-235) and the median duration of a 2nd MR4.5 prior to a 2nd discontinuation was 68 months (range: 20-176). After a 1st discontinuation attempt, the reason for TKI re-challenge was in majority a loss of MMR (66%), a loss of MR4.5 in 33% of patients (missing data in 1%). The TFR rates after a 2nd discontinuation attempt were 44.3% [95% CI 35.48-55.41] at 24 months, 38.5% [95% CI 29.65- 50.09] at 36 months and 33.2% [95% CI 24.31- 45.39] at 48 months. In univariate analysis, we failed to find any association between TFR and: age, gender, Sokal score, prior exposure to IFN, TKI in combination versus monotherapy, TKI type, TKI treatment duration and uMR4.5 duration before the 1st and 2nd discontinuation attempts, and type of molecular relapse after the 1st discontinuation attempt (MR4.5 versus MMR loss). However, the speed of molecular relapse after the 1st TKI discontinuation remains a factor significantly associated with outcome. In patients who remained in uMR4.5 at 3 months after the 1st discontinuation, the TFR rate at 48 months was 53% [95% CI: 35.32-79.31] and 26% [95% CI: 16.88-40.28] for others. Another factor significantly associated with outcome is the TKI-free duration after the 1st attempt (Figure). The TFR rate at 48 months was 45 % [95% CI: 28.64- 69.62] in patients who remained without treatment more than 6 months after their 1st attempt and 27% [95% CI: 17.57- 41.34] for others. All patients are alive at last follow-up except 2 who died from CML-unrelated reasons. One patient developed a sudden blast crisis at 4 years from 2nd discontinuation. The last previous molecular biology 3 months before transformation was MR4. In patients in TKI re-challenge (n=63), median TKI-free duration was 6 months (2-64), 55% of patients regained their MMR within 3 months (0-35) and 41% regained MR4.5 within 5 months (2-53). Conclusions: This larger cohort confirms that TKIs could safely and successfully be discontinued a 2nd time in CP CML patients despite a 1st failure. The speed of molecular relapse after the 1st TKI discontinuation and TKI-free duration remain major factors significantly associated with TFR outcome. Figure: TFR according TKI-free duration after the 1st attempt of discontinuation Figure Disclosures Legros: Incyte Biosciences: Honoraria, Research Funding; BMS: Honoraria; Pfizer: Honoraria, Research Funding; Novartis: Honoraria. Nicolini:Sun Pharma Ltd: Consultancy; Incyte Biosciences: Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau. Etienne:BMS: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Rousselot:Pfizer: Research Funding; Incyte: Research Funding. Rea:Novartis: 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; BMS: Honoraria; Incyte Biosciences: Honoraria. Guerci:INCYTE: Consultancy, Honoraria. Huguet:Incyte Biosciences: Honoraria; Novartis: Honoraria; Servier: Honoraria; Jazz Pharmaceuticals: Honoraria; Amgen: Honoraria; BMS: Honoraria; Pfizer: Honoraria. Coiteux:Novartis: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau. Mahon:Novartis: Consultancy, Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau.

A high proportion of Ph-positive Acute Lymphoblastic Leukemia (Ph+ ALL) patients still undergo relapses despite the use of Tyrosine Kinase Inhibitors (TKIs) in addition to chemotherapy as frontline therapy. In this leukemia subtype, the role of BCR-ABL1 kinase domain (KD) mutations as a driver of resistance to TKIs has already been documented by previous studies and such mutations have been reported in up to 80% of the patients at relapse. Next-generation sequencing (NGS) has been proposed to characterize these mutations with a higher sensitivity than Sanger. We report here a prospective study aiming at detecting potentially resistant cell populations by NGS in Ph+ ALL patients enrolled in the GRAAPH 2014-trial. Between March 2016 and February 2019, 156 patients aged 18 to 59 years with newly diagnosed Ph+ and/or BCR-ABL1 positive ALL have been included in the GRAAPH 2014 trial (NCT02619630). BCR-ABL1 isoforms were E1A2 69%, B2A2/B3A2 29%, atypical 2%. After a prephase of steroid, treatment consisted of 4 blocks of chemotherapy + nilotinib. 118 patients (76%) underwent allogeneic or autologous stem cell transplantation (SCT). 22 medullary relapses were recorded within a median time of 9 months (range, 2 - 35). Blood and marrow samples harvested at diagnosis, after each treatment block, before and 3 months after SCT, and at relapse, were sequenced if BCR-ABL1/ABL1 ratio were above 0.001. Mutated BCR-ABL1 transcripts were detected by sequencing the KD of BCR-ABL1 transcripts by NGS with a limit of detection (LOD) of 0.03. T315I allele specific oligonucleotide (ASO) droplet digital RT-PCR (ddRT-PCR) with a LOD of 0.0005 was also performed at diagnosis on a subset of 63 patients, including 5 who have subsequently developed a T315I clone. NGS. At diagnosis, no KD mutation was found by NGS in pretreatment samples of 137 patients. During follow-up (FU), only 12 mutations were found by NGS in 7 out of the 88 patients tested (81, 45, 30, 20, 19, 9 after block 1, 2, 3, 4, before and 3 months after SCT, respectively). Mutations were T315I (N=6), Y253H (N=1), E255K (N=2), E255V (N=1), Q252H (N=1), Y253F (N=1). At relapse, 16 mutations were identified by NGS in 12 patients out of the 17 tested (71%). Mutations were T315I (N=7), Y253H (N=n=3), F359V (N=2), E255K (N=1), E255V (N=1), Q252H (N=1), Y253F (N=1). More than 1 mutated clone were present in 2 patients (E255V+T315I+F359V and Y253H+F359V), and a compound mutation was found in 1 patient (Q252H/Y253F). Out of the 7 patients found mutated during FU, 5 have relapsed with a rapid expansion (1 to 3 months) of the mutated clone. One patient harboring a sub-clonal (10%) E255K at MRD1 has relapsed 9 months later without any detectable mutation. One patient identified with 3 mutated clones (E255K 10%, E255V 10%, T315I 80%) underwent SCT and has not relapsed so far. We failed to anticipate expansion of any mutated clone in the 7 remaining patients found mutated at relapse. T315I ASO ddRT-PCR on diagnostic samples. Low-level T315I mutated BCR-ABL1 transcripts (0.00051 to 0.0013) were detected in 14 out of 63 patients (24%) tested. Only one has expanded a T315I clone later on. In the context of the GRAAPH 2014 trial, 71% of the 17 relapses tested so far were associated with BCR-ABL1 KD mutations. Expansion of the mutated clone could have been characterized before the onset of hematological relapses in only 5 out of 12 patients (42%). Unfortunately in these cases, lags between first detection and relapse were very short (1 to 3 months). On the contrary, occurrences of relapses associated with expansion of KD-mutated clones could not have been anticipated in 58%. All mutations identified, including T315I, F359V, E255K/V and Y253F/H, Q252H/Y253F are known for conferring resistance to nilotinib. NGS is a valuable method for KD mutation detection in Ph+ ALL. It allows a quantitative characterization of KD mutations at relapse. However in our hands and in the context of an intensive therapy combining chemotherapy, nilotinib and SCT, its enhanced sensitivity as compared to Sanger (3% vs 20%) does not translate into the capacity of anticipating expansion of KD-mutated clones. Moreover, in this study, NGS did not detect any mutation in pre-therapeutic samples while T315I mutated BCR-ABL1 transcripts were found at low-level in 24% of these samples by ddRT-PCR. However it should be emphasized that when detected, low-level T315I mutated sub-clones present at diagnosis failed to expand in most instances. Disclosures Cayuela: Incyte: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Chalandon:Pfizer: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Incyte Biosciences: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Rousselot:Pfizer: Research Funding. Thomas:PFIZER: Honoraria; ABBVIE: Honoraria; INCYTE: Honoraria; DAICHI: Honoraria. Huguet:Amgen: Honoraria; Servier: Honoraria; Jazz Pharmaceuticals: Honoraria; BMS: Honoraria; Pfizer: Honoraria; Incyte Biosciences: Honoraria; Novartis: Honoraria. Chevallier:Incyte: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Daiichi Sankyo: Honoraria. Boissel:NOVARTIS: Consultancy. Vey:Novartis: Consultancy, Honoraria; Janssen: Honoraria. Berthon:PFIZER: Other: DISCLOSURE BOARD; JAZZPHARMACEUTICAL: Other: DISCLOSURE BOARD; CELGEN: Other: DISCLOSURE BOARD.