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Oncogenic alterations underlying B-cell acute lymphoblastic leukemia (B-ALL) in adults remain incompletely elucidated. To uncover novel oncogenic drivers, we performed RNA sequencing and whole-genome analyses in a large cohort of unresolved B-ALL. We identified a novel subtype characterized by a distinct gene expression signature and the unique association of 2 genomic microdeletions. The 17q21.31 microdeletion resulted in a UBTF::ATXN7L3 fusion transcript encoding a chimeric protein. The 13q12.2 deletion resulted in monoallelic ectopic expression of the homeobox transcription factor CDX2, located 138 kb in cis from the deletion. Using 4C-sequencing and CRISPR interference experiments, we elucidated the mechanism of CDX2 cis-deregulation, involving PAN3 enhancer hijacking. CDX2/UBTF ALL (n = 26) harbored a distinct pattern of additional alterations including 1q gain and CXCR4 activating mutations. Within adult patients with Ph− B-ALL enrolled in GRAALL trials, patients with CDX2/UBTF ALL (n = 17/723, 2.4%) were young (median age, 31 years) and dramatically enriched in females (male/female ratio, 0.2, P = .002). They commonly presented with a pro-B phenotype ALL and moderate blast cell infiltration. They had poor response to treatment including a higher risk of failure to first induction course (19% vs 3%, P = .017) and higher post-induction minimal residual disease (MRD) levels (MRD ≥ 10−4, 93% vs 46%, P < .001). This early resistance to treatment translated into a significantly higher cumulative incidence of relapse (75.0% vs 32.4%, P = .004) in univariate and multivariate analyses. In conclusion, we discovered a novel B-ALL entity defined by the unique combination of CDX2 cis-deregulation and UBTF::ATXN7L3 fusion, representing a high-risk disease in young adults.

International audience

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

The aims of this study were to characterize the incidence and outcomes of severe toxicities following the administration of high-dose methotrexate (HD-MTX; ≥1 g/m2). Among the 468 patients included...

We retrospectively examined the results of a new chemo-free approach combining blinatumomab with ponatinib (blina/pona) in 26 relapsed/refractory Philadelphia positive (Ph+) acute lymphoblastic leukemia (ALL) patients. All but one achieved complete morphologic remission, and 23 achieved a complete molecular response. With a median follow-up of 34.4 months, the median overall (OS) and event-free (EFS) survivals were 20 and 15.3 months, respectively. After blina/pona, 8 patients underwent an allotransplant (allo), while among the 18 non-transplanted cases, 15 received ponatinib in maintenance. Fifteen relapse/progressions occurred with a significant difference between allo and non allo cases (12.5% vs 82.3%

The OPAL study is a French multicenter observational retrospective analysis of adults with relapsed/refractory Philadelphia chromosome-positive acute lymphoblastic leukemia treated in a real-life setting by ponatinib. Twenty-nine patients were included since 2012. Median age was 55 years. The initial dose of ponatinib, combined to chemotherapy in half of the patients, was 45 mg/day in most instances. The remission rate was 90% and seven patients received allogeneic stem cell transplantation. Median disease-free and overall survival were only 3.5 and 9.9 months respectively. The outcome of patients with

Acute myeloid leukemia (AML) relapse is defined as the presence of bone marrow blasts equal or superior to 5% or reappearance of blasts in the blood or development of extramedullary disease after h...

Classifications of acute myeloid leukemia (AML) patients rely on morphologic, cytogenetic, and molecular features. Here we have established a novel flow cytometry-based immunophenotypic stratification showing that AML blasts are blocked at specific stages of differentiation where features of normal myelopoiesis are preserved. Six stages of leukemia differentiation-arrest categories based on CD34, CD117, CD13, CD33, MPO, and HLA-DR expression were identified in two independent cohorts of 2087 and 1209 AML patients. Hematopoietic stem cell/multipotent progenitor-like AMLs display low proliferation rate, inv(3) or RUNX1 mutations, and high leukemic stem cell frequency as well as poor outcome, whereas granulocyte–monocyte progenitor-like AMLs have CEBPA mutations, RUNX1-RUNX1T1 or CBFB-MYH11 translocations, lower leukemic stem cell frequency, higher chemosensitivity, and better outcome. NPM1 mutations correlate with most mature stages of leukemia arrest together with TET2 or IDH mutations in granulocyte progenitors-like AML or with DNMT3A mutations in monocyte progenitors-like AML. Overall, we demonstrate that AML is arrested at specific stages of myeloid differentiation (SLA classification) that significantly correlate with AML genetic lesions, clinical presentation, stem cell properties, chemosensitivity, response to therapy, and outcome.

Guidelines for tyrosine kinase inhibitor (TKI)-treated chronic phase-chronic myeloid leukemia (CML) management are essentially based on data from clinical research trials; however, real-world data should be valuable for optimizing such recommendations. Here, we analyzed the data collected in the French CML Observatory database, a multicenter real-world cohort (n = 646), using a first-line "intention-to-treat" analysis strategy. This cohort included patients treated with first-line imatinib (n = 484), nilotinib (n = 103), dasatinib (n = 17), imatinib and interferon (n = 9), or second-generation (2G)-TKIs and interferon (n = 29). The cumulative incidence of major molecular response (MMR), MR4, MR4.5 and MR5 confirmed the faster response kinetics with 2G-TKIs. Multivariate analysis identified being a woman and residual disease at month 6 as the main predictive factors of deep molecular response (DMR). Moreover, 30% of patients met the criteria for treatment discontinuation (5 years of treatment and ≥ 2 years of DMR), but only 38% of them stopped treatment. Among the 92 patients who actually discontinued treatment due to optimal response, 31.5% relapsed (48% of them after 6 months of TKI discontinuation). Multivariate analysis identified age and TKI duration as factors positively correlated with treatment-free remission maintenance. Late ( 6 months) relapses were more frequent in patients with the e14a2 BCR::ABL transcript. Relapse rate was higher in patients who stopped TKI before than after 5 years of treatment (52.6% vs 26%; p = 0.040). These results advocate caution concerning early treatment withdrawal, including in patients receiving 2G-TKIs. This still recruiting database is a valuable source of information for the real-world follow-up of patients with CML.

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

Somatic mutations of isocitrate dehydrogenase 1 (IDH1R132) genes are found in 6–10% of AML [1]. IDH1R132 mutations are most frequent in cytogenetically normal AML and significantly associated with ...

This observational, prospective study assessed, in a daily clinical practice, the molecular response, safety, quality of life (QoL) and treatment adherence in 183 patients with chronic myeloid leukaemia in chronic phase (CML-CP), receiving nilotinib as first-line treatment. Premature study termination before 24 months of follow-up occurred in 61 patients (33·3%), and was essentially due to nilotinib treatment discontinuation (n = 53; 29%), motivated by treatment intolerance (n = 29; 15·8%) and inefficacy (n = 19; 10·4%). After 24 months of treatment, 112/122 patients (91·8%) had a molecular assessment, 95·5% of whom achieved a major molecular response (MMR), 32·1% achieved uMR4 , defined as an undetectable molecular disease with 4-log molecular response sensitivity (≥10 000 ABL1 transcripts). The Morisky Green Levine Medication Adherence Scale was completed by 94/122 patients (77·0%), and 89·4% of these patients obtained a satisfactory level of treatment adherence, defined as a score ≥3. Patients' QoL was good at baseline and stable during the follow-up period. The two most common nilotinib-related adverse events (AEs) were pruritus (14·8%) and asthenia (13·7%). Seven patients (3·8%) experienced at least one cardiovascular ischaemic AE. This French nationwide cohort study provides relevant information in daily clinical practice indicating that nilotinib is a valuable first-line treatment option for CML-CP patients.

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).

IDH1 and IDH2 mutations (IDH1/2Mut) are recognized as recurrent genetic alterations in acute myeloid leukemia (AML) and associated with both clinical impact and therapeutic opportunity due to the recent development of specific IDH1/2Mut inhibitors. In T-cell acute lymphoblastic leukemia (T-ALL), their incidence and prognostic implications remain poorly reported. Our targeted next-generation sequencing approach allowed comprehensive assessment of genotype across the entire IDH1 and IDH2 locus in 1085 consecutive unselected and newly diagnosed patients with T-ALL and identified 4% of, virtually exclusive (47 of 49 patients), IDH1/2Mut. Mutational patterns of IDH1/2Mut in T-ALL present some specific features compared to AML. Whereas IDH2R140Q mutation was frequent in T-ALL (25 of 51 mutations), the IDH2R172 AML hotspot was absent. IDH2 mutations were associated with older age, an immature phenotype, more frequent RAS gain-of-function mutations and epigenetic regulator loss-of-function alterations (DNMT3A and TET2). IDH2 mutations, contrary to IDH1 mutations, appeared to be an independent prognostic factor in multivariate analysis with the NOTCH1/FBXW7/RAS/PTEN classifier. IDH2Mut were significantly associated with a high cumulative incidence of relapse and very dismal outcome, suggesting that IDH2-mutated T-ALL cases should be identified at diagnosis in order to benefit from therapeutic intensification and/or specific IDH2 inhibitors.

T-cell acute lymphoblastic leukemia (T-ALL) is a group of aggressive hematological cancers with dismal outcomes that are in need of new therapeutic options. Polycomb repressor complex 2 (PRC2) loss-of-function alterations were reported in pediatric T-ALL, yet their clinical relevance and functional consequences remain elusive. Here, we extensively analyzed PRC2 alterations in a large series of 218 adult T-ALL patients. We found that PRC2 genetic lesions are frequent events in T-ALL and are not restricted to early thymic precursor ALL. PRC2 loss of function associates with activating mutations of the IL7R/JAK/STAT pathway. PRC2-altered T-ALL patients respond poorly to prednisone and have low bone marrow blast clearance and persistent minimal residual disease. Furthermore, we identified that PRC2 loss of function profoundly reshapes the genetic and epigenetic landscapes, leading to the reactivation of stem cell programs that cooperate with bromodomain and extraterminal (BET) proteins to sustain T-ALL. This study identifies BET proteins as key mediators of the PRC2 loss of function-induced remodeling. Our data have uncovered a targetable vulnerability to BET inhibition that can be exploited to treat PRC2-altered T-ALL patients.

Objectives Complete responses have been observed in NPM1-mutated AML patients with dactinomycin, a nucleolar stress-inducing drug. Here, we report a single-center experience of compassionate use of dactinomycin in untreated or relapsed/ refractory NPM1-mutated AML. Methods From September 2015 to February 2019, 26 adult patients with NPM1-mutated AML received dactinomycin in different situations: front-line treatment in 4 unfit patients (16%); morphologic (n = 16, 62%), molecular relapses (n = 4, 16%), refractory disease (n = 1, 13%), or postremission therapy in second complete response (n = 1, 13%). Results Median age was 62.5 years. Median number of dactinomycin cycle was 1 (1-8), and 7 patients (27%) received more than 3 cycles. Three out of 17 patients (18%) in morphologic relapse or refractory to chemotherapy achieved complete remission after the first cycle of dactinomycin. None of the 4 patients unfit for intensive chemotherapy responded to dactinomycin as front-line therapy. Grade 3-4 adverse events were thrombocytopenia (n = 11, 42%), neutropenia (n = 11, 42%), GI toxicity (n = 6, 23%), mucositis (n = 5, 19%), lung infection (n = 5, 19%), and skin rash (n = 2, 7.6%). Conclusions Dactinomycin is an inexpensive and easily available drug that may induce significant responses in few AML patients with NPM1 mutations with an acceptable safety profile.

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.

International audience; Patients undergoing treatment for acute lymphoblastic leukemia (ALL) are at risk for thrombosis, in part due to the use of L-asparaginase (L-ASP). Antithrombin (AT) replacement has been suggested to prevent VTE and thus might increase exposure to ASP. We report herein the results of the prophylactic replacement strategy in the pediatric-inspired prospective GRAALL-2005 study. Between 2006 and 2014, 784 adult patients with newly diagnosed Philadelphia-negative ALL were included. The incidence rate of VTE was 16% with 69% of them occurring during induction therapy. Most patients received AT supplementation (87%). After excluding patients who did not receive L-ASP or developed thrombosis before L-ASP, AT supplementation did not have a significant impact on VTE (8% versus 14%, OR: 0.6, p=0.1). Fibrinogen concentrates administration was associated with an increased risk of VTE (17% versus 9%, OR 2.2, p=0.02) whereas transfusion of fresh-frozen plasma had no effect. Heparin prophylaxis was associated with an increased risk of VTE (13% versus 7%, OR 1.9, p=0.04). Prophylactic measures were not associated with an increased risk of grade 3-4 bleeding complications. The rate of VTE recurrence after L-ASP reintroduction was 3% (1/34). In ALL patients receiving L-ASP therapy, the use of fibrinogen concentrates may increase the risk of thrombosis and should be restricted to rare patients with hypofibrinogenemia-induced hemorrhage. Patients developed VTE despite extensive AT supplementation which advocates for additional prophylactic measures. While this large descriptive study was not powered to demonstrate the efficacy of these prophylactic measures, it provides important insight to guide future trial design. NCT00327678.

Objectives We previously reported the prognostic value of serum ferritin in younger patients with intermediate-risk acute myeloid leukemia (AML). The aims of this study were to confirm this finding in a larger cohort regardless of age and prognostic subgroups, to explore the expression and functional role of ferritin in AML cells as well as the regulation of serum ferritin levels in AML patients. Patients/materials/methods Serum ferritin levels at diagnosis were collected in a cohort of 525 patients treated by intensive chemotherapy. In silico, in vitro, and in vivo analyses were conducted to assess the pattern of expression and functional role of FTH1 and FTL in AML. Results We confirmed the independent prognostic value of serum ferritin. In transcriptomic databases, FTH1 and FTL were overexpressed in AML and leukemic stem cells compared to normal hematopoietic stem cells. The gene signature designed from AML patients overexpressing FTH1 revealed a significant enrichment in genes of the immune and inflammatory response including Nf-KB pathway, oxidative stress, or iron pathways. This gene signature was enriched in cytarabine-resistant AML cells in a patient-derived xenograft model. FTH1 protein was also overexpressed in patient's samples and correlated with the in vitro cytotoxic activity of cytarabine. Lastly, we demonstrated that chemotherapy induced an inflammatory response including a significant increase in serum ferritin levels between day 1 and 8 of induction chemotherapy that was blocked by dexamethasone. Conclusion Ferritin is deregulated in most AML patients likely through inflammation, associated with chemoresistance, and could represent a new therapeutic target.

On behalf of the GRAALL group, the Czech Republic ALL group, the Finland ALL group and the EWALL group. Introduction. Treatment of older patients (pts) with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) remains an unmet medical need. Inotuzumab ozogamicin (INO), an anti-CD22 antibody conjugated to calicheamicin, is approved for the treatment of relapsed/refractory BCP-ALL in adults, sinusoidal obstruction syndrome (SOS) being the major adverse event associated with INO. A previous first line study conducted by the MDACC in pts 60 years or older successfully used INO in combination with a lower intensity version of the hyper-CVAD (mini-hyper-CVD). Due to the occurrence of SOS, the total doses were fixed at 1.3 mg/m² for cycle 1 followed by 3 cycles at 1 mg/m² (Kantarjian H et al. Lancet Oncol, 2018). Here, we aimed to assess the activity and safety of fractionated INO at a reduced dosage in combination with low-intensity chemotherapy as frontline therapy for older pts with CD22+ Philadelphia chromosome-negative (Ph-neg) BCP-ALL. Methods. EWALL-INO is a single arm prospective phase 2 multicentric study conducted in European centers belonging to the EWALL group. Eligibility criteria were pts aged 55y or older, performance status ≤2, and newly diagnosed CD22+ (20% or more of positive blast cells) Ph-neg BCP-ALL without central nervous system involvement. After a prephase including 5 days (D) of dexamethasone (DEX) 10mg per D and a single intrathecal injection (IT), the induction regimen was begun and split in 2 parts. Induction part I (Induc1) consisted of one triple IT, vincristine (VCR) 2 mg (1 mg over 70y) D1 D8 D15 D22 and DEX 20 mg D1D2 D8D9 D15D16 D22D23 combined with 3 injections of INO (0.8 mg/m² D1, 0.5 mg/m² D8 and D15). Induction part II (Induc2) was offered to pts in CR or CRp (CR with platelets < 100 G/l) after Induc1 or as salvage therapy. Induc2 consisted of DEX 20mg D1D8, cyclophosphamide (CY) 300 mg/m² D1 to D3, one triple IT D2 and 2 injections of INO (0.5 mg/m² D1 and D8). Pts in CR/CRp were programmed to receive 6 blocks of consolidation (Ara-C 1.5g/m²/12h adapted to renal clearance D1D2 and DEX 10mg/12h D1D2, cycles 1 and 4; Methotrexate (MTX) 1.5 g/m² over 24h D1, VCR 1 or 2 mg D1, one triple IT D2 and 6-mercaptopurin (6-MP) D1 to D7, cycles 2 and 5; CY 500 mg/m² D1D2, VP16 75 mg/m² D1D2, one triple IT D2 and MTX 25 mg/m² D1, cycles 3 and 6) followed by a POMP maintenance (VCR, 6-MP, MTX, DEX) during 18 months. Allograft was allowed after at least 3 blocks of consolidation at the discretion of the investigators. The evaluable population was pts who received at least 1 dose of INO. Analyses were by modified intention to treat and performed JUN 28, 2021. All pts gave informed consent. The study is registered at ClinicalTrials.gov under the NCT number: NCT03249870. Results. Between DEC 29, 2017 and JUN 22, 2021, 115 pts (out of 130 planned pts) were enrolled including 6 pts with screen failure. The first 90 eligible pts (up to MAR 1, 2021) were considered for this analysis to obtain a minimum of 4 months follow-up. Median age was 69y (range 55-84) and median follow-up for alive pts was 1.18 years (range 0.3-3.5). At time of analysis, 90 and 88 pts had started induc1 and induc2, respectively. Treatment related mortality was 2.2% (2/90) and CR/CRp rate was 85.5% (77/90, 6 CRp) after induc1. Three cases relapsed between induc1 and induc2 and 5 pts were salvaged by induc2 allowing to a CR/CRp rate of 87.7% (79/90, 8 CRp) after induc2. One pts died from refractory disease during induc2. One, 2, 3 4 and 5 injections of INO were administered to 2 (2.2%), 2(2.2%), 11 (12.2%), 2 (2.2%) and 73 pts (81.1%) respectively. Only 6 pts were allografted. One-year OS was estimated to be 78.5% (95%CI 68-85.9) and median OS was not reached. One-year relapse free survival was 74.5% (95CI 63.5-82.6) (Figure 1). Grade 3-4 liver toxicity was observed in 8 pts (8.8%) during the study including 3 pts (3.3%) developing SOS, 2 related to INO during induc1 and one occurred after transplant. Twenty-nine pts died during the follow-up, 16 from relapses (overall incidence 18%) and 13 from adverse events (overall incidence 14.4%), including one COVID19 fatal infection during consolidation. Conclusion. Fractionated inotuzumab ozogamicin at reduced doses (0.8/0.5/0.5/0.5 mg/m²) combined with low-intensity chemotherapy is a very active and well tolerated frontline therapy for older patients with CD22+ Ph-neg BCP-ALL. Figure 1 Figure 1. Disclosures Doubek: Janssen-Cilag, AbbVie, AstraZeneca, Amgen, Gilead, Novartis: Honoraria, Research Funding. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. Raffoux: ABBVIE: Consultancy; PFIZER: Consultancy; CELGENE/BMS: Consultancy; ASTELLAS: Consultancy. Boissel: CELGENE: Honoraria; Servier: Consultancy, Honoraria; Incyte: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; PFIZER: Consultancy, Honoraria; JAZZ Pharma: Honoraria, Research Funding; SANOFI: Honoraria. 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. Rousselot: Incyte, Pfizer: Consultancy, Research Funding. OffLabel Disclosure: Inotuzumab ozogamicin as first line therapy in newly diagnosed CD22+ Philadelphia chromosome-negative B-cell precursor acute lymphoblastic leukemia

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 IG/TR-based minimal residual disease (MRD) is a faithful marker of response to therapy and the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). In adults with Philadelphia chromosome-positive (Ph+) ALL, MRD is commonly monitored by BCR-ABL1 transcript quantification, although its prognostic significance has not been compared to IG/TR MRD to date. Recently, it has been shown that BCR-ABL1 rearrangement may be found and persist in non-lymphoblastic cells in some patients. In the prospective GRAAPH-2014 trial, using a dual IG/TR and BCR-ABL1 MRD monitoring, we aimed to study the biological and clinical significance of persistent BCR-ABL1 clonal hematopoiesis (CH) in adults with de novo Ph+ ALL. Patients and Methods The study comprised 156 adults with de novo Ph+ ALL randomized in the GRAAPH-2014 trial. Bone marrow (BM) and peripheral blood (PB) follow-up (FU) samples were collected after each treatment cycle and before hematopoietic stem cell transplantation (HSCT). MRD monitoring was performed by quantification of both BCR-ABL1 transcripts and IG/TCR clonal rearrangements on all available samples and MRD quantification of genomic BCR-ABL1 breakpoint fusion was also performed for 37 patients. MRD results were considered discordant if more than one log10 difference or positivity/negativity discordance on the same FU sample was evidenced. Cell fractions from 14 peripheral blood mononuclear cells (PBMC) samples (T-cells, B-cells and monocytes) were FACS-sorted and evaluated for BCR-ABL1 expression. Achievement of major molecular response (MMR) defined as Results Quantification of BCR-ABL1 transcripts and IG/TR MRD levels on 876 samples from 156 patients (456 BM and 542 PB) identified 54 out of 142 (38%) evaluable patients with consistently discordant MRD results in at least 3 different timepoints, suggesting the persistence of non-lymphoblastic BCR-ABL1-positive cells in these patients and BCR-ABL1 CH. Possible bias related to variable BCR-ABL1 expression was ruled out by genomic BCR-ABL1 quantification on 263 FU samples (r s=0.89, p We then evaluated the clinical significance of BCR-ABL1 CH. Unexpectedly, CH+ patients had a significant lower cumulative incidence of relapse (CIR) (panel A, hazard ratio (HR) 0.37, 95% CI [0.15-0.90], p=0.03). However, this lower CIR did not translate into longer disease-free survival (DFS) (panel B, HR=0.85, 95% CI [0.44-1.63], p=0.63). Since an imbalance in alloSCT was observed between CH+ and CH- patients, we tested if the observed difference in CIR may be related to different alloSCT outcomes. When censoring patients at alloSCT, the difference in CIR was indeed no longer significant (subhazard ratio (SHR) 0.48, 95% CI [0.16-1.43], p=0.19). More interestingly, the benefit of alloSCT was restricted to CH- patients. Using alloSCT as a time-dependent variable, DFS was indeed improved by alloSCT in CH- (SHR 0.40, 95% CI [0.17-0.91], p=0.03, panel C) but not in CH+ patients (SHR 1.12, 95%CI [0.32-3.87], p=0.86, panel D) despite a non-significant interaction between CH status and alloSCT. Conclusion More than one third of adults with de novo Ph+ ALL displays persistent measurable BCR-ABL1 signal during therapy, likely related to BCR-ABL1 CH. Strikingly, this condition is not associated with a higher risk of relapse nor with poorer overall outcomes in the GRAAPH-2014 trial. Moreover, our results suggest that patients with BCR-ABL1 CH may not be good candidates for alloSCT. By contrast, IG/TR MRD may allow to identify patients with the higher risk of relapse. These results highlight the need for implementation of IG/TR MRD in adult Ph+ ALL to guide therapeutic decisions. Figure 1 Figure 1. Disclosures 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. Straetmans: Alexion: Membership on an entity's Board of Directors or advisory committees. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. 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: SANOFI: Honoraria; CELGENE: Honoraria; Servier: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; PFIZER: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Incyte: Honoraria; Novartis: Consultancy, Honoraria, Research Funding; JAZZ Pharma: Honoraria, Research Funding.

Hyperleukocytic AML (HL-AML) is characterised by a high risk of early death and poor prognosis. We previously reported the impact of adding dexamethasone (DEX) to intensive chemotherapy in this situation (Bertoli et al, Haematologica 2018). The aim of this study was to give a comprehensive description of HL-AML at the molecular level and to investigate interactions between molecular lesions and DEX treatment. In the earlier study which included 160 patients (pts) (18 - 75 years old) with WBC > 100 x 10 9/L or > 50 x 10 9/L with leukostasis symptoms, multivariate analyses had shown that DEX treatment was significantly associated with better DFS, EFS and OS (Bertoli S, Haematologica 2018). In this pre-midostaurin registration patient cohort (2004-2015), no pt received a FLT3 inhibitor. Diagnostic samples for NGS analyses were available for 154 pts (96.3% of the initial cohort), 59 pts who received DEX with 3+7 induction chemotherapy and 95 pts who did not. The presence of FLT3-ITD was tested as described (Larochelle O, Oncotarget 2011). CEBPA screening was performed by Sanger sequencing (Pabst T, Nat Genet 2001). Extended DNA resequencing was performed using an Illumina NextSeq500 and Sureselect target enrichment system (Agilent, Santa Clara, CA), targeted on the complete coding regions of 79 genes commonly mutated in myeloid malignancies. The cytogenetic risk was favorable, intermediate or adverse in 15 (9.7%), 121 (78.6%) and 18 (11.7%) pts. A total of 616 mutations were identified with an average of 4 mutations/pt (0 to 10 mutations/pt). Only one pt with inv(16) had no mutation detected. The most frequently mutated genes were FLT3 (62%), NPM1 (53%), DNMT3A (34%), TET2 (23%), NRAS (21%), IDH2 (12%), WT1 (11%), PTPN11 (10%), RUNX1 (10%), KRAS (9%) and IDH1 (9%). Of the 71 pts (46%) with FLT3-ITD mutations, 32 (45.1%) had an allelic ratio > 0.5. Mutations in the RAS pathway were detected in 67 pts (44%), including NRAS (n=32, 21%), PTPN11 (n=15, 10%), KRAS (n=14, 9%) and NF1 (n=6, 4%). Overall, a large majority of pts had mutations in signaling genes (n=131, 85.1%). Drug-actionable mutations such as FLT3 (n=96), IDH2 (n=17), IDH1 (n=14), KIT (n=11), TP53 (n=4) or JAK2 (n=1) were detected in 113 patients (73.4%). In patients with FLT3 mutations (n=96), 12 had co-mutations in IDH1 and 12 pts had co-mutations in IDH2. The prognostic impact of the AML genomic classification (Papaemmanuil E, NEJM 2018), NPM1/FLT3-ITD/DNMT3A status, functional gene categories (Bullinger L, JCO 2017) ELN 2017 classification and individual genes was assessed. AML with inv(16)/CBFB-MYH11, CEBPA mutations, NPM1 mutations and myeloid transcription factor gene fusions or mutations were significantly and independently associated with better OS whereas the chromatin-modifying gene subset, NPM1/FLT3-ITD/DNMT3A triple mutations, ELN 2017-adverse risk and DNMT3A mutations were associated with poorer OS. NPM1/FLT3-ITD/DNMT3A triple mutations were observed in 25 pts (16%), 23 of whom died. Compared to this triple mutated subset, lower HRs were found in double mutant NPM1mut/FLT3-ITD (HR, 0.43; 95%CI: 0.19-0.97; P=0.041) or NPM1mut/DNMT3Amut (HR, 0.47; 95% CI: 0.21-1.07; P=0.074). The prognostic impact of each individual gene was assessed using the LASSO statistical method. CBFB-MYH11 (HR, 0.10; 95% CI: 0.02-0.43; P=0.002), CEBPA (HR, 0.22; 95% CI: 0.09-0.53; P=0.001), NPM1 (HR, 0.33; 95% CI: 0.19-0.58; P Median DFS (13.6 months vs 66.3, P=0.002), EFS (11.3 vs 39.4, P=0.002) and OS (18.3 vs not reached, P=0.006) were significantly better in pts who received DEX. In multivariate analyses, no significant interaction between DEX and classifications or gene mutations was found, indicating that the effect of DEX did not differ significantly between the various genetic subsets. This may be due to insufficient numbers or DEX may have broader effects on biological phenomena such as inflammation. Since more than 80% of pts have mutations in signaling genes, inhibition of signaling pathways could improve prognosis of HL-AML. The impact of midostaurin will be interesting to analyse in this setting. Inhibition of the RAS pathway could also be a valuable avenue. Figure 1 Figure 1. Disclosures Bertoli: Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Tavitian: Novartis: Consultancy. Vergez: Pierre Fabre Laboratory: Research Funding; Roche: Research Funding. Huguet: Novartis: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Celgene: Other: Advisor; BMS: Other: Advisor; Amgen: Other: Advisor; Pfizer: Other: Advisor. Delabesse: Novartis: Consultancy; Astellas: Consultancy. Recher: Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria; Janssen: Honoraria; Jazz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MaatPharma: Research Funding; Macrogenics: 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, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: dexamethasone in hyperleukocytic AML.

Few recent studies from registries have reported an improvement in overall survival of younger patients with acute myeloid leukemia (AML). However, reasons for this improvement are not defined. We analyzed the therapeutic course and outcome of 976 patients treated by intensive chemotherapy between 2000 and 2014. The number of patients receiving allogeneic stem cell transplantation in first or second response significantly increased over time whereas autologous transplantation was progressively abandoned. In the 513 younger patients, there were no differences in first complete response, induction failure, incidence of relapse, or non-relapse mortality over time. The period of time was significantly associated with a better overall survival especially in 2010–2014. The 2010–2014 period effect was still significant in multivariate analysis and was independent of allogeneic stem cell transplantation. In the 463 older patients, there was a significant interaction between the period and leukocytosis in multivariate analysis meaning that the 2010–2014 period had only an impact in patients with white blood cell count >50 giga/L for response and overall survival. Progresses have been made in each phase of the therapeutic course of younger AML patients resulting in survival improvement. In older patients, the outcome of hyperleukocytic patients has significantly improved in 2010–2014.

Describing the prognosis of sub-groups of acute myeloid leukemia (AML) patients treated in real world with current therapies is becoming increasingly relevant to estimate the benefit that new targeted drugs will bring in the field. This is particularly the case when novel drugs are registered on the basis of non-randomized studies. IDH2 inhibitors have recently emerged as promising drugs in patients with IDH2R140 or IDH2R172 mutations. Enasidenib, a first-in-class IDH2 inhibitor, has been approved following promising results of a phase 1-2 clinical trial in relapsed or refractory AML patients with IDH2 mutations. In this study, we described the characteristics, treatments and outcome of 75 IDH2 mutated patients both at diagnosis and relapse or refractory disease. Among the 33 relapsed/refractory AML patients with either IDH2R140 or IDH2R172, 28 (84.8%) patients received salvage therapy and 14 achieved a complete response (50%). Median duration of response was 15.2 months. Median, 1-y, 3-y and 5-y OS were 15.1 months (IQR, 4.6-37.7), 53.1% (95% CI, 33.2-69.5), 29.2% (95% CI, 12.6-48.1) and 24.4% (95% CI, 9.3-43.1), respectively. In responding patients, median OS was 37.7 months and 1-y, 3-y and 5-y OS was 85.7%, 57.1% and 47.6%, respectively. In non-responding patients, median OS was 5.0 months (IQR, 4.5-8.6) and 1-y and 3-y OS was 17.9% and 0%, respectively. Thus, a substantial number of R/R AML patients with IDH2 mutations can be salvaged by current treatments and benefit from prolonged survival. It is expected that novel targeted agents such as enasidenib will further improve efficacy and safety in the next future.

The prognostic implications of DNMT3A genotype in T-cell acute lymphoblastic leukemia are incompletely understood. We performed comprehensive genetic and clinico-biological analyses of T-cell acute lymphoblastic leukemia patients with DNMT3A mutations treated during the GRAALL-2003 and -2005 studies. Eighteen of 198 cases (9.1%) had DNMT3A alterations. Two patients also had DNMT3A mutations in non-leukemic cell DNA, providing the first potential evidence of age-related clonal hematopoiesis in T-cell acute lymphoblastic leukemia. DNMT3A mutation was associated with older age (median 43.9 years vs. 29.4 years, P

Introduction. AML standard intensive induction chemotherapy ("3+7" or equivalent) combined with wide spectrum antibiotics can dramatically alter the composition of the gut microbiota, leading to dysbiosis which is characterized by loss of microbial diversity. Such dysbiosis status can promote a pathological condition involving uncontrolled local immune responses, systemic inflammation and increased incidence of adverse events. The development of FMT-based drugs to restore microbial communities could offer novel therapeutic possibilities to reduce such adverse events and potentially improve outcomes in AML. We therefore conducted this single arm prospective phase I/II multicenter trial (NCT02928523) to evaluate the use of a FMT-based drug in association with AML induction treatment to restore the gut microbiota diversity. Patients and methods. A total of 62 consecutive patients aged between 24 and 69 years old with a diagnosis of de novo AML were screened in 7 French sites. At time of admission and AML diagnosis (Step 1=S1), patients' faeces were collected, rigorously screened, prepared following a standardized process, and stored at -80°C until later administration. The drug was administered as an enema after hematopoietic recovery (S2) and before consolidation chemotherapy (Conso). The primary endpoint was the recovery of at least 70% of microbiota diversity (based on the Simpson index) after drug administration and the reduction of multidrug resistant bacteria carriage. Blood and feces samples were collected at S1, S2, and around 10 days post-FMT before Conso (S3). Microbiome diversity restoration was assessed by metagenomics analysis through Illumina HiSeq shotgun sequencing. Antibiotic resistance gene carriage (ARGC, also known as resistome) was evaluated through mapping of readouts on the MEGARES database. Secondary objectives included safety and analysis of host response with assessment of blood and fecal markers by ELISA and Luminex. Results. Overall, 25 patients were actually treated with FMT, and 20 were included in the per-protocol population. Induction Chemotherapy (IC) induced a dramatic shift in microbial communities, with a significant 42.3% decrease of mean α-diversity Simpson index between S1 and S2 at species level (0.85 to 0.50; p No serious adverse events (SAE) were observed within 30 days after FMT and all post FMT SAEs were not related to the FMT procedure. Moreover, FMT did not induce any local or systemic inflammatory reaction as measured by fecal and blood markers (fecal neopterin and IgA; plasmatic CRP, IL-6 and sCD14). Interestingly, restoration of the microbiome diversity was associated with a significant reduction of CRP and fecal neopterin levels, suggesting a potential anti-inflammatory impact of FMT. Overall, FMT was well tolerated and had an excellent safety profile. The one-year overall survival estimate in the whole cohort was 84% (4 deaths among 25, none of which were related to FMT: 2 multiple organ failures, 1 heart attack and 1 grade IV resistant GVHD). The median time to death from the second FMT was 182.5 days (113-225 days). Conclusions. This is the first prospective trial testing the safety and efficacy of FMT in AML patients receiving intensive induction chemotherapy. The trial achieved its primary endpoint and established the capacity of FMT to restore a diverse microbiome with high levels of similarity to baseline, as well as reducing ARGC and intestinal inflammation. A controlled randomized trial with repeated FMT administrations is currently planned to further evaluate the impact of FMT on clinical outcomes and long-term survival. (This trial was funded by MaaT Pharma whose product was tested in this protocol). Disclosures Mohty: MaaT Pharma: Consultancy, Honoraria. Doré:MaaT Pharma: Consultancy, Honoraria.

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.

International audience; no abstract

Patients with chronic myeloid leukemia treated with breakpoint cluster region-Abelson tyrosine kinase inhibitors are likely to survive in excess of 20 years after diagnosis. New challenges appear as we consider life after the disease, including professional challenges and the social reintegration of patients. The purpose of this study was to determine the impact of chronic myeloid leukemia on employment within 2 years after diagnosis. This prospective, observational study included patients diagnosed with chronic myeloid leukemia and treated with a tyrosine kinase inhibitor. Two populations were defined as patients who reported modifications in their professional activity during the study (Acti-Pro+) and patients who did not report a modification (Acti-Pro−). Cancer survivors received a self-assessment questionnaire. The primary endpoint was to determine the professional status of patients. One hundred patients completed the questionnaire. Sixty-six patients out of 100 reported professional activity within 2 years after their diagnosis. During the 2 years after the diagnosis, 65.2% (95% confidence interval (CI), 53.7–76.7) of patients faced modifications in their professional activity due to chronic myeloid leukemia or adverse effects of drug treatments (group Acti-Pro+); in contrast, 34.8% of patients did not report any impact on their occupational activity (group Acti-Pro−). Among modifications to work organization, a change in the number of working hours was the most represented. Other modifications comprised changes in status or work pace. A majority of chronic myeloid leukemia patients face professional consequences of their disease and treatments. Our findings suggest that adverse drug reactions are a major factor affecting the occurrence of work modifications in this context.

We assessed the influence of obesity on the characteristics and prognosis of acute myeloid leukemia (AML). Indeed, safety of intensive chemotherapy and outcome of obese AML patients in a real-life setting are poorly described, and chemotherapy dosing remains challenging. We included 619 consecutive genetically-defined cases of AML treated with intensive chemotherapy between 2004 and 2012. In this cohort, 93 patients (15%) were classified in the obese category according to WHO classification; 59% of them received capped doses of chemotherapy because of a body surface area above 2 m(2) . Obese patients were older and presented more often with cardiovascular comorbidities. Although obese patients had more frequently de novo AML, main characteristics of AML including white blood cell count, karyotype and mutations were well-balanced between obese and non-obese patients. After induction chemotherapy, early death and complete remission rates were similar. Overall (OS), event-free (EFS) and disease-free (DFS) survival were not significantly different compared to non-obese patients. However, in the European LeukemiaNet (ELN) favorable subgroup, obese patients had lower median OS, EFS and DFS than non-obese patients (18.4, 16.8 and 17.2 vs. 43.6, 31.8 and 29.7 months, respectively) and obesity showed a significant impact on OS (OR 2.54; P = 0.02) in multivariate models. Although we did not find any significant impact of obesity on outcome in the whole series, this study suggests that special efforts for chemotherapy dose optimization are needed in the ELN favorable subgroup since dose capping may be deleterious.

Central nervous system (CNS) thrombotic events are a well-known complication of acute lymphoblastic leukemia (ALL) induction therapy, especially with treatments including l-asparaginase (l-ASP). Data on risk factors and clinical evolution is still lacking in adult patients. We report on the clinical evolution of 22 CNS venous thrombosis cases occurring in 708 adults treated for ALL or lymphoblastic lymphoma (LL) with the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-induction protocol, which included eight L-ASP (6,000 IU/m2) infusions. The prevalence of CNS thrombosis was 3.1%. CNS thrombosis occurred after a median of 18 days (range: 11–31) when patients had received a median of three l-ASP injections (range: 2–7). Patients with CNS thrombosis exhibited a median antithrombin (AT) nadir of 47.5% (range: 36–67%) at Day 17 (range: D3–D28), and 95% of them exhibited AT levels lower than 60%. There were no evident increase in hereditary thrombotic risk factors prevalence, and thrombosis occurred despite heparin prophylaxis which was performed in 90% of patients. Acquired AT deficiency was frequently detected in patients with l-ASP-based therapy, and patients with CNS thrombosis received AT prophylaxis (45%) less frequently than patients without CNS thrombosis (83%), P = 0.0002). CNS thrombosis was lethal in 5% of patients, while 20% had persistent sequelae. One patient received all planned l-ASP infusions without recurrence of CNS thrombotic whereas l-ASP injections were discontinued in 20 patients during the management of thrombosis without a significant impact on overall survival (P = 0.4). Am. J. Hematol. 90:986–991, 2015. © 2015 Wiley Periodicals, Inc

Optimal treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN), a rare entity of dismal prognosis previously described as CD4+/CD56+ hematodermic malignancies, is not defined. We report five cases of relapsed BPDCN treated with bendamustine hydrochloride, a well-tolerated bifunctional drug acting as an alkylating and antimetabolite agent. All patients were above the age of 50 years and in advanced disease (early first relapse in two, subsequent relapse in three; multi-organ involvement in four; previous intensive chemotherapy in five; and stem cell transplantation in four). Four patients were evaluable for response. Two failed therapy, one died from tumor lysis syndrome after rapid blast clearance from blood, and one reached and maintained complete remission for 7 months. Bendamustine should be further evaluated in BPDCN. Copyright © 2015 John Wiley & Sons, Ltd.

PURPOSE: The GRASPALL/GRAALL-SA2-2008 Phase II trial evaluated the safety and efficacy of L-asparaginase encapsulated within erythrocytes (GRASPA®) in patients ≥ 55 years with Philadelphia chromosome-negative acute lymphoblastic leukemia. FINDINGS: Thirty patients received escalating doses of GRASPA® on Day 3 and 6 of induction Phases 1 and 2. The primary efficacy endpoint was asparagine depletion \textless 2 µmol/L for at least 7 days. This was reached in 85 and 71% of patients with 100 and 150 IU/kg respectively but not with 50 IU/kg. Grade 3/4 infection, hypertransaminasemia, hyperbilirubinemia and deep vein thrombosis occurred in 77, 20, 7, and 7% of patients, respectively. No allergic reaction or clinical pancreatitis was observed despite 17% of Grade 3/4 lipase elevation. Anti-asparaginase antibodies were detected in 50% of patients and related to a reduction in the duration of asparagine depletion during induction Phase 2 without decrease of encapsulated L-asparaginase activity. Complete remission rate was 70%. With a median follow-up of 42 months, median overall survival was 15.8 and 9.7 months, in the 100 and 150 IU/kg cohorts respectively. CONCLUSIONS: The addition of GRASPA®, especially at the 100 IU/kg dose level, is feasible in elderly patients without excessive toxicity and associated with durable asparagine depletion. (clinicaltrials.gov identifier NCT01523782)

Summary Background Prognosis of patients with relapsed or refractory acute lymphoblastic leukaemia is poor and new treatments are needed. We aimed to assess the feasibility, tolerability, dosimetry, and efficacy of yttrium-90-labelled anti-CD22 epratuzumab tetraxetan ( 90 Y-DOTA-epratuzumab) radioimmunotherapy in refractory or relapsed CD22-positive B-cell acute lymphoblastic leukaemia in a standard 3 + 3 phase 1 study. Methods Adults (≥18 years) with relapsed or refractory B-cell acute lymphoblastic leukaemia (with CD22 expression on at least 70% of blast cells) were enrolled at six centres in France. Patients received one cycle of 90 Y-DOTA-epratuzumab on days 1 and 8 (give or take 2 days) successively at one of four dose levels: 2·5 mCi/m 2 (92·5 MBq/m 2 ; level 1), 5·0 mCi/m 2 (185 MBq/m 2 ; level 2), 7·5 mCi/m 2 (277·5 MBq/m 2 ; level 3), and 10·0 mCi/m 2 (370 MBq/m 2 ; level 4). The primary objective was to identify the maximum tolerated dose of 90 Y-DOTA-epratuzumab. We assessed safety during infusions and regularly after radioimmunotherapy over a 6-month period. Analyses included only patients who received radioimmunotherapy. The trial is closed to inclusion and is registered at ClinicalTrials.gov, NCT01354457. Findings Between Aug 25, 2011, and June 11, 2014, 17 patients (median age 62 years; range 27–77) were treated (five at level 1, three at level 2, three at level 3, and six at level 4). Radioimmunotherapy infusion was overall well tolerated. One dose-limiting toxic effect (aplasia lasting 8 weeks) occurred at level 4, but the maximum tolerated dose was not reached. The most common grade 3–4 adverse events were pancytopenia (one patient at level 2, one at level 3, and six at level 4) and infections (three at level 1, one at level 2, and five at level 4). Interpretation 90 Y-DOTA-epratuzumab radioimmunotherapy is well tolerated. We recommend the dose of 2 × 10·0 mCi/m 2 1 week apart per cycle for phase 2 studies. Funding Immunomedics and Direction de la Recherche Clinique of Nantes.

International audience; Patients with acute myeloid leukemia and a high white blood cell count are at increased risk of early death and relapse. Because mediators of inflammation contribute to leukostasis and chemoresistance, dexamethasone added to chemotherapy could improve outcomes. This retrospective study evaluated the impact of adding or not adding dexamethasone to chemotherapy in a cohort of 160 patients with at least 50×109 white blood cells. In silico studies, primary samples, leukemic cell lines, and xenograft mouse models were used to explore the antileukemic activity of dexamethasone. There was no difference with respect to induction death rate, response, and infections between the 60 patients in the dexamethasone group and the 100 patients in the no dexamethasone group. Multivariate analysis showed that dexamethasone was significantly associated with improved relapse incidence (adjusted sub-HR: 0.30; 95% CI: 0.14-0.62; P=0.001), disease-free survival (adjusted HR: 0.50; 95% CI: 0.29-0.84; P=0.010), event-free survival (adjusted HR: 0.35; 95% CI: 0.21-0.58; P

Despite persistence of leukemic stem cells, patients with chronic myeloid leukemia who achieve and maintain deep molecular responses may successfully stop the tyrosine kinase inhibitor imatinib. However, questions remain unanswered regarding the biological basis of molecular relapse after imatinib cessation. In IMMUNOSTIM, we monitored 51 patients from the French Stop IMatinib trial for peripheral blood T cells and natural killer cells. Molecular relapse-free survival at 24 months was 45.1% (95% CI: 31.44%-58.75%). At the time of imatinib discontinuation, non-relapsing patients had significantly higher numbers of natural killer cells of the cytotoxic CD56dim subset than had relapsing patients, while CD56bright natural killer cells, T cells and their subsets did not differ significantly. Furthermore, the CD56dim natural killer-cell count was an independent prognostic factor of molecular-relapse free survival in a multivariate analysis. However, expression of natural killer-cell activating receptors, BCR-ABL1+ leukemia cell line K562-specific degranulation and cytokine-induced interferon-gamma secretion were decreased in non-relapsing and relapsing patients as compared with healthy individuals. After imatinib cessation, the natural killer-cell count increased significantly and stayed higher in non-relapsing patients than in relapsing patients, while receptor expression and functional properties remained unchanged. Altogether, our results suggest that natural killer cells may play a role in controlling leukemia-initiating cells at the origin of relapse after imatinib cessation, provided that these cells are numerous enough to compensate for their functional defects. Further research will decipher mechanisms underlying functional differences between natural killer cells from patients and healthy individuals and evaluate the potential interest of immunostimulatory approaches in tyrosine kinase inhibitor discontinuation strategies. (ClinicalTrial.gov Identifier NCT00478985).

The treatment of older patients with acute lymphoblastic leukemia (ALL) still represents an unmet medical need. Here we report the results of a chemoimmunotherapy approach combining vincristine/dexamethasone and epratuzumab, a humanized monoclonal therapeutic antibody against CD22, in patients over

SUMMARY: The ENESTnd trial is a Phase III, randomized, open-label, multicenter trial, in which 846 patients with newly diagnosed chromosome Philadelphia-positive chronic-phase chronic myeloid leukemia were randomly assigned in a 1:1:1 ratio between three arms of treatment: imatinib mesylate 400 mg once daily, nilotinib 300 mg twice daily (b.i.d.), nilotinib 400 mg b.i.d. Nilotinib appeared superior to imatinib in terms of complete cytogenetic response at 12 months (77 vs 87 vs 85%; p < 0.001); major molecular response at 12 months (primary end point; BCR–ABL1 on an International Scale < 0.1%: 22 vs 44 vs 43%; p < 0.001); deep response at 4 years (BCR–ABL1IS< 0.0032%: 23 vs 40 vs 37%; p < 0.0001). Less progression to advanced phases at 4 years (0.7 vs 1.1 vs 4.2% on core treatment) converted into a slight advantage in terms of overall survival at 4 years for the nilotinib 400 mg b.i.d. arm in Sokal intermediate- and high-risk patients. Tolerance and quality of life were in favor of nilotinib, with the noteworthy exception of cardiovascular events (1.5 vs 6.4vs 8.7% at 4 years). This trial led to the approval of nilotinib 300 mg b.i.d. as front-line therapy of chronic-phase chronic myeloid leukemia in 2010.

Introduction. Cases series of patients with FIP1L1-PDGFRA (F/P)-associated chronic eosinophilic leukemia (F/P+ CEL) are scarce and of small sample-size. Low-dose imatinib mesylate (IM) is highly effective in this setting. Although successful treatment discontinuation has been reported, approximately 40% of the patients subsequently relapse. To date, no predictor of relapse after IM discontinuation has yet been evidenced. Methods. We conducted a French multicentric retrospective of patients diagnosed with F/P+ CEL between 2003-2019. Weight loss was defined as a 10% weight loss over the course of the disease's history. Complete (CHR) and partial (PHR) hematological responses were defined as a normalization of the absolute eosinophil count (AEC) and as a reduction in peripheral blood eosinophilia by at least 50% from baseline, respectively. Relapses were defined as the recurrence of eosinophilia, with or without evidence of F/P-gene transcript, but without any other explanation. Complete molecular response (CMR) was defined as a negative RT-PCR and/or RQ-PCR assay for F/P rearrangement. A backward stepwise logistic regression model was used to identify factors associated with relapse after IM discontinuation. Results. One hundred and fifty F/P+ CEL patients (145 males; mean (SD) age at diagnosis: 49 (+/-12 years) were included, among which 26 (17%) did not report any symptom. The main involved organs were the spleen (n=65, 43%), skin (n=47, 31%), heart (n=27, 18%), lungs (n=36, 24%), central nervous system (n=14, 9%), and bones/joints (n=8, 5%). Four (2,6%) patients showed features of vasculitis, involving the skin (n=2) and the CNS (n=2). The mean peak AEC was 10.3 G/L (+/-6 G/l). Besides eosinophilia, the most frequent associated complete blood count (CBC) abnormalities were thrombocytopenia (n=43, 28%), anemia (n=37, 24%), hyperleukocytosis (n=33, 22%) and monocytosis (n=25, 16%). Forty-seven (31%) patients had normal CBC besides eosinophilia. Bone marrow karyotype was normal in 91% (when tested, n=94). Serum vitamin B12 and tryptase (mean: 2386 (+/-1435) pmol/L and 34 (+/-20) µg/L) levels were elevated in 74 (94%) and 44 (79%) of patients respectively, whereas CRP and IgE levels were elevated in 31 (26%) and 12 (14%) each. None of the 37 (25%) patients that received first-line glucocorticoid therapy achieved CHR. All but 3 patients received IM (daily starting dose: 100 (n= 102; 72%), 200 (n=13; 9%) or 400 mg (n=20; 14%)), of whom 100% and 99% achieved CHR and CMR (when tested: n=84), respectively. The mean follow-up (FU) was 80 (+/- 56) months, with overall survival at 1, 5 and 10 years of 99%, 95% and 84% (reaching 100%, 98% and 89% in the 147 IMB-treated patients) respectively. Overall, 8 (5%) patients died during FU, including untreated patients with acute myeloblastic leukemia transformation (n=2) and a single patient with massive cerebral infarction. Eight patients relapsed during IM tapering, all of which were successfully treated when higher doses of IM were resumed. After a median [IQR] of 44 [27-72] months of IM treatment, 46 (32%) patients eventually discontinued IM, amongst whom 19 (41%) relapsed after a median of 10[4-23] months (42% of relapses defined by PCR). In multivariate analysis, weight loss (HR: 5,02 95%CI[1,9 - 28,04]; p =0,004), the time between onset of eosinophilia and IM initiation (HR 1,02 [1,00 - 1,03]; 0,01) and duration of IM treatment prior to discontinuation (HR: 0,97 [0,95-0,99]; p=0,01) were independent factors of relapse (Table 1). Conclusion. This large cohort further confirms that F/P+ CEL almost exclusively affects male patients, with spleen, skin, heart and lung involvements being the most frequent. While glucocorticoids never lead to the normalization of CBC parameters, IM is highly effective and treated patients carry an excellent prognosis. After IM discontinuation, although 60% of patients maintain CHR overtime, 40% subsequently relapse, with weight loss, time between onset of eosinophilia and IM initiation and duration of IM treatment prior to discontinuation being significant but moderate independent factors of relapse. Disclosures Nicolini: Incyte Biosciences: Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Sun Pharma Ltd: Consultancy. Tavitian:Novartis: Membership on an entity's Board of Directors or advisory committees. Huguet:Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria; Incyte Biosciences: Honoraria; Amgen: Honoraria; Servier: Honoraria; Jazz Pharmaceuticals: Honoraria. Jardin:Servier: Honoraria; janssen: Honoraria; celgene: Honoraria; roche: Honoraria; amgen: Honoraria.

Ponatinib is a third generation tyrosine kinase inhibitor (TKI) indicated in the treatment of CML-chronic phase (CP), accelerated phase (AP) and blast phase (BP) as well as in patients with the gatekeeper T315I mutation. TOPASE is the real life observatory initiated in France with the participation of 40 CML centers. We report here the interim results of the first 46 patients included in the study as of July 2019, which represents one of the largest real-life Ponatinib study to date in CML. Methods and Aims: CML Patients (Pts) > 18 years old, with any stage of disease treated with Ponatinib for a period of less than 6 months or prospectively, were included in the study since February 2018 (ambispective study). The principal aims were the evaluation of efficacy (haematological, cytogenetic and molecular responses), overall survival as well as the safety profile of the use of Ponatinib. After a period of 2 years of inclusion, 2 years of follow-up will be performed until 2022. The study will include 150 patients. Results: 48% of pts were female and 52% males and the median age was 57 +/-18 years. 87% of pts were in CP, 8.7% in AP and 4.3% in BP. The Sokal score was high (34.8% of Pts) intermediate (19.6% pts ) and low (28.3 % pts), not available in 17.4 %. The initiating dose was 15mg in 19 pts, 30mg in 16 pts and 45 mg in 11 pts. All patients with AP/BP except one, were treated with 45 mg/d. Previous therapies were 2 lines (44.4% of pts), 3 lines (26.7% pts), 1 line (17.8% of pts), 4 lines (6.7% of pts), and 5 lines (2.2% of pts) of TKI. The majority of pts had previously Dasatinib (77%) and Imatinib (70%) whereas 43% received Nilotinib and 31% Bosutinib. The last TKI administered prior to inclusion was Dasatinib (40.9% of pts) , Bosutinib (25% of pts) Nilotinib (18.2% of pts) , Imatinib (11.4% of pts) , Ponatinib (2.3% of pts) and ABL001 (2.3% of pts). There was no significant dose-initiation difference with regard to the previous TKI used. The main reason for the initiation of Ponatinib was failure and poor response to previous therapies (63% of pts) followed by intolerance (28.3% of pts). An ABL kinase mutation was detected in 11 patients during their TKI therapy. In 4 pts, the mutation was a T315I and in these pts the last TKI therapy was Nilotinib (n=2), Dasatinib ( n= 1) and Bosutinib ( n= 1). In 7 other patients, previous mutations detected were mostly in p-loop, with previous therapies including Dasatinib, Nilotinib, Imatinib and Bosutinib. One patient previously treated with Dasatinib, Nilotinib and Ponatinib (last therapy) had a F317L mutation, and two pts treated previously with 2 lines (Imatinib, Dasatinib) and 3 lines (Imatinib, Dasatinib, Nilotinib) had E255V/C1135 and F359C / E450K mutations, respectively. At the time of inclusion, the cardiovascular (CV) history of pts (n=46) included high blood pressure (HBP) (35% of pts) or other CV history (26.9%) including peripheral vascular disorders and ischemic heart disease. In the majority of pts with HBP, the initiating dose of Ponatinib was 15 mg/d ( 41%). Other significant medical disorders included diabetes ( 21.7% of pts ) and dyslipidemia ( 8.7% of pts). Results of the efficacy were evaluated at +3 Months (M3) and at +6 months (M6). M3 analyses were available on 18 pts (Figure 1) and M3+M6 analyses on 14 pts. At the entry of the study, the status of the 18 evaluable pts at M3 was as follows: no CHR (n=8), CHR (n=2), no CCyR ( n= 1) CCyR (n= 4), MMR (n=2), MR5 (n=1). At M3, CHR was obtained in 6/8 pts and 4 out of 6 attaining in the same time MMR and 1/6 reaching MR 4.5. For the remaining 10 pts, MMR was obtained in 5/10, and deep molecular responses in 4/10. At M6, out of 14 pts available for molecular analyses, 6 were in MMR, and 3 were in deep molecular responses. 3 pts had no response to Ponatinib. Analysis of responses in individual pts showed that in 8 pts unresponsive to previous therapies 2 had MMR and 1 MR 4. In 10 pts in CHR or absence of CyR, deep molecular responses were obtained in 5/10 pts. Overall, global improvement of responses was obtained in 55.6% at M3 and 60% in M6. At the time of the interim analysis no significant AE were noted for the 46 pts available for analysis. Conclusion: Ponatinib in real life situation is a highly efficient therapy in TKI-resistant and intolerant CML pts. Overall improvement was obtained in 60% of pts with early molecular responses, despite 2 or more previous TKI therapies in 70% of pts. The updated molecular results will be presented concerning M3, M6 and M9 timepoints. Funding : Incyte Biosciences, France Figure 1 Disclosures Guerci: INCYTE: Consultancy, Honoraria. Rousselot:Pfizer: Research Funding; Incyte: Research Funding. Huguet:Servier: Honoraria; Jazz Pharmaceuticals: Honoraria; Amgen: Honoraria; Incyte Biosciences: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Novartis: Honoraria. Coiteux:Pfizer: Honoraria; BMS: Honoraria; Novartis: Consultancy, Honoraria; Incyte: Consultancy, Honoraria. Berger:Incyte: Consultancy, Honoraria. Etienne:Novartis: Consultancy, Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau. Turhan:novartis: Honoraria, Research Funding; Incyte: Consultancy, Honoraria.

NPM1 mutations are frequent in acute myeloid leukemia (AML) and define a distinct entity according to the 2016 WHO classification. NPM1 mutations are generally associated with chemosensitivity and a favorable prognosis. However, outcome may vary according to co-mutational events, and still approximately 40% of patients relapse after achieving complete response. Wild-type NPM1 is mainly located in the nucleolus where it plays a key role in the regulation of ribosome biogenesis, protein synthesis and tumor suppression through TP53 activation. Mutated NPM1 loses its predominant nucleolar location and accumulates in cytoplasm contributing to leukemogenesis (Falini B, Blood 2011). Moreover, this mutational event leads to haploinsufficiency and cytoplasmic retention of wild type NPM1 creating a vulnerability to nucleolar stress. Indeed, complete responses have been observed in NPM1-mutated AML patients with dactinomycin, a nucleolar stress-inducing drug (Falini B, NEJM 2015). Here, we report our experience of off-label dactinomycin in untreated or relapsed/ refractory NPM1-mutated AML. Inclusion criteria for this retrospective study were: age ≥ 18 years-old, AML with NPM1 mutation, relapsed or refractory disease as well as treatment-naive patients unfit for intensive chemotherapy. Patients should also have completed one cycle of dactinomycin 12.5 µg/kg/day for 5 days every 28 days. From September 2015 to February 2019, 26 patients received dactinomycin. Median age was 62.5y, WBC count was > 50 giga/L in 8 patients (31%), 13 patients (50%) had FLT3-ITD mutation whereas 10 (38%) and 11 (42%) patients were classified as favorable or intermediate-I according to the ELN-2010 classification. There were 7 (27%) relapses post-allogeneic transplantation. Median number of dactinomycin cycle was 1 (1-8) and 7 patients (27%) received more than 3 cycles. Sorafenib was added in 6 patients with associated FLT3-ITD mutations whereas 2 others patients received ATRA in combination with dactinomycin. Dactinomycin was administered in different situations: front-line treatment in 4 unfit patients (16%); morphologic (n=16, 62%) or molecular relapses (n=4, 16%) following intensive chemotherapy, refractory disease (n=1, 13%) or post remission therapy in second complete response (CR) following salvage chemotherapy (n=1, 13%). Three out of 17 patients (18%) in morphologic relapse or refractory to chemotherapy reached complete remission after the first cycle of dactinomycin. The duration of response was 4 and 6 months in 2 patients whereas the third patient is still in CR 3 years after dactinomycin. One out of 4 patients in molecular relapses achieved a complete molecular remission with dactinomycin. None of the 4 patients unfit for intensive chemotherapy responded to dactinomycin as front-line therapy. The only patient treated in post-CR2 with dactinomycin achieved a complete molecular remission before allogeneic transplantation. Overall, 5 patients (19%) appeared to benefit from dactinomycin treatment. Grade 3-4 adverse events were thrombocytopenia (n=11, 42%), neutropenia (n=11, 42%), GI toxicity (n=6, 23%), mucositis (n=5, 19%), lung infection (n=5, 19%) and skin rash (n=2, 7.6%). Dactinomycin is an inexpensive and easily available drug that may induce significant responses in AML patients with NPM1 mutations with an acceptable safety profile. Prospective and controlled clinical trials are mandatory to clearly define the role of this agent in AML with NPM1 mutations. Disclosures Tavitian: Novartis: Membership on an entity's Board of Directors or advisory committees. Bertoli:Sanofi: Honoraria. Huguet:Incyte Biosciences: Honoraria; Servier: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Jazz Pharmaceuticals: Honoraria; Novartis: Honoraria. Bories:Abbvie: Consultancy. Recher:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Macrogenics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: NPM1 mutations are frequent in acute myeloid leukemia (AML) and define a distinct entity according to the 2016 WHO classification. Wild-type NPM1 is mainly located in the nucleolus where it plays a key role in the regulation of ribosome biogenesis, protein synthesis and tumor suppression through TP53 activation. Mutated NPM1 loses its predominant nucleolar location and accumulates in cytoplasm contributing to leukemogenesis (Falini B, Blood 2011). Moreover, this mutational event leads to haploinsufficiency and cytoplasmic retention of wild type NPM1 creating a vulnerability to nucleolar stress. Indeed, complete responses have been observed in NPM1-mutated AML patients with dactinomycin, a nucleolar stress-inducing drug (Falini B, NEJM 2015).

Introduction The acquisition of ABL1 Kinase Domain (KD) mutations represent the most frequent resistance mechanism in CP-CML patients (pts) treated with tyrosine kinase inhibitors (TKI). Currently, the standard assay relies on a poorly sensitive technique, Sanger Sequencing (SS). Thus, the detection of these mutations using SS might be too late to trigger a timely treatment change. In a national phase III academic trial (PETALs, EudraCT 2013-004974-82), we evaluated prospectively the value of a more sensitive technique, Next Generation Sequencing (NGS) to detect KD ABL1 mutations in newly diagnosed CP-CML patients randomized to get nilotinib 600 mg/d for 6 years ± Pegylated-IFN-α2a (Peg-IFN) 45 μg/wk for 2 years in combination. Methods Newly diagnosed CP CML pts ≤65 years were randomized 1:1 to get NIL 300 mg BID alone (M0 to M48, arm A) vs Peg-IFN alone for 30 days (M-1→M0) 30 mg/wk as priming, prior to NIL 300 mg BID + Peg-IFN 30 μg/wk 2 weeks, upgraded to 45 μg/wk thereafter, for up to 2 y (M0 to M24, arm B) followed by NIL alone for 4 more years unless pts enter a treatment-free remission phase. In addition to KD mutational analysis performed by SS as per protocol, patients also had KD mutational analysis performed by NGS at M3, M6, M12 and 6-monthly thereafter until achievement of a stable MMR, regardless of response. NGS assay was performed as previously described (Kizilors et al. Lancet Haematol 2019). Results Two hundred pts were randomized (99 in A, 101 in B), of which 96 patients (51/99 in A, 45/101 in B, p=0.399) underwent a KD mutational analysis performed by NGS as part of this study. The remaining 104 patients are currently being screened and the full dataset will be presented. Among the 96 patients tested, there was no difference in the distribution between the 2 arms with respect to gender, age [median 45 years (18-66)] or risk factors distribution (p=0.862 and 0.328 for Sokal and ELTS respectively in patients tested at 3 months). The median follow-up of this cohort is 45.0 (33.2-58.7) months. By 12 months, 11 patients [8/51 (11.8%) in A, 3/45 (6.6%) in B] had developed a KD mutation. After only 3 months of TKI therapy, 3 patients were found mutated (Y253H 2 pts, T315I 1 pt), of whom 2 pts were only detected using NGS. At M6, a KD mutation was found in 8 pts [A: 7 patients, B: 1 pt, (p= 0.055), of which 6/8 were not detected by SS, due to either low level Variant Allele frequency (VAF, n=5) or low level BCR-ABL transcript levels (n=1). Y253H mutations were found in 4 pts, T315I in 2 pts and E255K in 1 pt. Consecutively to KD mutation identification, 6/8 patients lost their response and were withdrawn from study (1 pt with a Y253H detected at M3 progressed to advanced phase), while 1 pt lost MMR at last follow-up and another pt with a mutation sensitive to nilotinib achieved MMR. KD mutations were detected while pts were in optimal response at M6 [BCR-ABL Conclusions This is the first prospective trial to demonstrate that NGS can detect low level KD mutations in CP CML patients treated with first line 2GTKI±Peg-IFN after only 3 to 6 months on therapy before these become detectable by SS and despite achieving an optimal response in BCR-ABL transcript level reduction (according to ELN 2013). The proportion of patients who develop KD mutations by 12 months on upfront 2GTKI should not be underestimated, as their outcome is poor. NGS may trigger early clinical intervention and prevent progression in this group, although a prospective trial is needed in this regard. Finally, the proportion of KD incidence in pts who receive Peg-IFN in addition to nilotinib might be lower compared to those treated with nilotinib alone. Final updated results will be presented. Figure Disclosures de Lavallade: Novartis: Honoraria, Speakers Bureau; Incyte biosciences: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau. Jackson:Incyte biosciences: Honoraria, Research Funding, Speakers Bureau. Kizilors:Incyte biosciences: Research Funding. Etienne:BMS: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Huguet:Jazz Pharmaceuticals: Honoraria; Servier: Honoraria; Amgen: Honoraria. Guerci-Bresler:Pfizer: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Incyte biosciences: Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau. Rea:BMS: Honoraria; Incyte Biosciences: Honoraria; 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. Mahon:Novartis: Consultancy, Honoraria, Speakers Bureau; BMS: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau. Dulucq:BMS: Honoraria, Speakers Bureau; Incyte Biosciences: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Nicolini:Incyte Biosciences: Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Sun Pharma Ltd: Consultancy. OffLabel Disclosure: Pegylated Interferon alpha 2 a is not licensed in this indication

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.