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Thalidomide analogues exert their therapeutic effects by binding to the CRL4CRBN E3 ubiquitin ligase, promoting ubiquitination and subsequent proteasomal degradation of specific protein substrates. Drug-induced degradation of IKZF1 and IKZF3 in B-cell malignancies demonstrates the clinical utility of targeting disease-relevant transcription factors for degradation. Here, we found that avadomide (CC-122) induces CRBN-dependent ubiquitination and proteasomal degradation of ZMYM2 (ZNF198), a transcription factor involved in balanced chromosomal rearrangements with FGFR1 and FLT3 in aggressive forms of hematologic malignancies. The minimal drug-responsive element of ZMYM2 is a zinc-chelating MYM domain and is contained in the N-terminal portion of ZMYM2 that is universally included in the derived fusion proteins. We demonstrate that avadomide has the ability to induce proteasomal degradation of ZMYM2–FGFR1 and ZMYM2–FLT3 chimeric oncoproteins, both in vitro and in vivo. Our findings suggest that patients with hematologic malignancies harboring these ZMYM2 fusion proteins may benefit from avadomide treatment.Significance:We extend the potential clinical scope of thalidomide analogues by the identification of a novel avadomide-dependent CRL4CRBN substrate, ZMYM2. Avadomide induces ubiquitination and degradation of ZMYM2–FGFR1 and ZMYM2–FLT3, two chimeric oncoproteins involved in hematologic malignancies, providing a proof of concept for drug-induced degradation of transcription factor fusion proteins by thalidomide analogues.

Supplementary Table 1. Proteomic data

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Several fusion genes such as BCR::ABL1, FIP1L1::PDGFRA, and PML::RARA are now efficiently targeted by specific therapies in patients with leukemia. Although these therapies have significantly improved patient outcomes, leukemia relapse and progression remain clinical concerns. Most myeloid next-generation sequencing (NGS) panels do not detect or quantify these fusions. It therefore remains difficult to decipher the clonal architecture and dynamics of myeloid malignancy patients, although these factors can affect clinical decisions and provide pathophysiologic insights. An asymmetric capture sequencing strategy (aCAP-Seq) and a bioinformatics algorithm (HmnFusion) were developed to detect and quantify MBCR::ABL1, μBCR::ABL1, PML::RARA, and FIP1L1::PDGFRA fusion genes in an NGS panel targeting 41 genes. One-hundred nineteen DNA samples derived from 106 patients were analyzed by conventional methods at diagnosis or on follow-up and were sequenced with this NGS myeloid panel. The specificity and sensitivity of fusion detection by aCAP-Seq were 100% and 98.1%, respectively, with a limit of detection estimated at 0.1%. Fusion quantifications were linear from 0.1% to 50%. Breakpoint locations and sequences identified by NGS were concordant with results obtained by Sanger sequencing. Finally, this new sensitive and cost-efficient NGS method allowed integrated analysis of resistant chronic myeloid leukemia patients and thus will be of interest to elucidate the mutational landscape and clonal architecture of myeloid malignancies driven by these fusion genes at diagnosis, relapse, or progression.

Since the development of tyrosine kinase inhibitors (TKIs) targeting BCR/ABL1 and significantly improved outcomes on long-term disease-free survival in Philadelphia chromosome–positive (Ph+) acute ...

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

T-cell acute lymphoblastic leukemias (T-ALL) represent 15% of pediatric and 25% of adult ALL. Since they have a particularly poor outcome in relapsed/refractory cases, identifying prognosis factors at diagnosis is crucial to adapting treatment for high-risk patients. Unlike acute myeloid leukemia and BCP ALL, chromosomal rearrangements leading to chimeric fusion-proteins with strong prognosis impact are sparsely reported in T-ALL. To address this issue an RT-MPLA assay was applied to a consecutive series of 522 adult and pediatric T-ALLs and identified a fusion transcript in 20% of cases. PICALM-MLLT10 (4%, n = 23), NUP214-ABL1 (3%, n = 19) and SET-NUP214 (3%, n = 18) were the most frequent. The clinico-biological characteristics linked to fusion transcripts in a subset of 235 patients (138 adults in the GRAALL2003/05 trials and 97 children from the FRALLE2000 trial) were analyzed to identify their prognosis impact. Patients with HOXA trans-deregulated T-ALLs with MLLT10, KMT2A and SET fusion transcripts (17%, 39/235) had a worse prognosis with a 5-year EFS of 35.7% vs 63.7% (HR = 1.63; p = 0.04) and a trend for a higher cumulative incidence of relapse (5-year CIR = 45.7% vs 25.2%, HR = 1.6; p = 0.11). Fusion transcripts status in T-ALL can be robustly identified by RT-MLPA, facilitating risk adapted treatment strategies for high-risk patients.

Primary effusion lymphoma (PEL) is associated with human herpesvirus 8 and frequently with Epstein-Barr virus (EBV). We report here a single-center series of 19 human immunodeficiency virus-associated PELs, including 14 EBV+ and 5 EBV- PELs. The objectives were to describe the clinicopathologic features of PELs, with a focus on programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) expression, to search for genetic alterations by targeted deep sequencing analysis, and to compare the features between EBV+ and EBV- cases. All the patients were male, and the median age at diagnosis was 47 years old (interquartile range: 40 to 56 y). Reflecting the terminal B-cell differentiation, immunophenotypic profiles showed low expression levels of B-cell markers, including CD19 (0/19), CD20 (1/19), CD79a (0/19), PAX5 (1/19), BOB1 (3/19), and OCT2 (4/19), contrasting with a common expression of CD38 (10/19), CD138 (7/19), and IRF4/MUM1 (18/19). We observed a frequent aberrant expression of T-cell markers, especially CD3 (10/19), and less frequently CD2 (2/19), CD4 (3/19), CD5 (1/19), and CD8 (0/19). Only 2 cases were PD-L1 positive on tumor cells and none PD-1 positive. With respect to immune cells, 3 samples tested positive for PD-L1 and 5 for PD-1. Our 36-gene lymphopanel revealed 7 distinct variants in 5/10 PELs, with either a single or 2 mutations per sample: B2M (n=2), CD58 (n=1), EP300 (n=1), TNFAIP3 (n=1), ARID1A (n=1), and TP53 (n=1). Finally, we did not observe any major clinical, pathologic, or immunohistochemical differences between EBV+ and EBV- PELs and the outcome was similar (2-y overall survival probability of 61.9% [95% confidence interval, 31.2-82.1] vs. 60.0% [95% confidence interval, 12.6-88.2], respectively, P=0.62).

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).

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.

Thalidomide analogues exert their therapeutic effects by binding to the CRL4CRBN E3 ubiquitin ligase, promoting ubiquitination and subsequent proteasomal degradation of specific protein substrates. Drug-induced degradation of IKZF1 and IKZF3 in B-cell malignancies demonstrates the clinical utility of targeting disease-relevant transcription factors for degradation. Here, we found that avadomide (CC-122) induces CRBN-dependent ubiquitination and proteasomal degradation of ZMYM2 (ZNF198), a transcription factor involved in balanced chromosomal rearrangements with FGFR1 and FLT3 in aggressive forms of hematologic malignancies. The minimal drug-responsive element of ZMYM2 is a zinc-chelating MYM domain and is contained in the N-terminal portion of ZMYM2 that is universally included in the derived fusion proteins. We demonstrate that avadomide has the ability to induce proteasomal degradation of ZMYM2–FGFR1 and ZMYM2–FLT3 chimeric oncoproteins, both in vitro and in vivo. Our findings suggest that patients with hematologic malignancies harboring these ZMYM2 fusion proteins may benefit from avadomide treatment. Significance: We extend the potential clinical scope of thalidomide analogues by the identification of a novel avadomide-dependent CRL4CRBN substrate, ZMYM2. Avadomide induces ubiquitination and degradation of ZMYM2–FGFR1 and ZMYM2–FLT3, two chimeric oncoproteins involved in hematologic malignancies, providing a proof of concept for drug-induced degradation of transcription factor fusion proteins by thalidomide analogues.

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.

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

Additional file 1. Supplemental Table 1: Custom capture Nextera XT gene panel. Supplemental Table 2: IDH1 and IDH2 mutations identified in 1085 patients with T-ALL. Supplemental Table 3: Chemotherapy in the FRALLE 2000 standard risk group T1 and high risk T2.

International audience; Molecular tests have become an indispensable tool for the diagnosis and prognosis of hematological malignancies and are subject to accreditation according to the International Standard ISO 15189. National standardization of these techniques is essential to ensure that patients throughout France benefit from the same care. We report here on the experience of the GBMHM (Groupe des Biologistes Moléculaires des Hémopathies Malignes). By organizing External Evaluation of Quality (EEQ) programs and training meetings, the GBMHM has contributed to improvement and standardization of molecular tests in 64 French laboratories. A retrospective analysis of the quality-control results of 11 national campaigns spanning 10 years was performed for the 3 most frequently prescribed tests: BCR-ABL1, JAK2 V617F, and lymphoid clonality. For each test, particular attention was placed on comparing methodologies and their evolution throughout the period. The establishment of the BCR-ABL1, JAK2 V617F, and lymphoid clonality EEQ programs and the associated training meetings have initiated a process of collective standardization concerning the methods of implementation (JAK2 V617F) and the interpretation and formulation of results (lymphoid clonality). In addition, it resulted in objective improvement in technical performance (BCR-ABL1). Our evaluation of the impact of these EEQ programs demonstrates that it is possible to obtain reproducible values across different laboratories in France by applying national recommendations. To our knowledge, this is the first publication that evaluates the impact of a national quality assurance program on improving molecular results in hematology.

Additional file 2. Figure S1: Lollipop plots indicating the observed mutations for IDH1 and IDH2 in the present series confront with Cosmic-reported mutations for AML and AITL. Figure S2: Lollipop plots indicating the observed mutations for IDH1 and IDH2 affecting patients included in FRALLE and GRAALL protocol. Figure S3: Variant Allele Frequency (VAF) of individual IDH1 and IDH2 mutations observed in 1085 T-ALL. Figure S4: OS and CIR according to the IDH1 or IDH2Mut status in the two subgroups (FRALLE and GRALL 03/05). Figure S5: General design of FRALLE 2000 T guidelines.

TO THE EDITOR: T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) are aggressive neoplasms that result from the proliferation of T-lymphoid progenitors blocked at thymic stages of differentiation. They account for 15% and 25% of pediatric and adult ALLs, respectively. T-ALL/T-LBL are associated with a wide range of acquired genetic abnormalities that contribute to developmental arrest and abnormal proliferation. Although intensive treatment protocols have markedly improved the outcomes of children with T-ALL, cure rates remain below 60% for adults and 85% for children. The prognosis is particularly poor in relapsing patients, highlighting an urgent need for risk stratification factors at diagnosis.[...]

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of BCR-ABL1 transcript as a result of reciprocal translocation between chromosome 9 and 22. The most common transcripts subtypes are e13a2 (b2a2) and e14a2 (b3a2). The prognostic impact of the type of BCR-ABL1 transcript has been the subject of controversies over time. In the imatinib era, several studies have suggested a deeper and faster response in patients expressing e14a2. However, the impact on response after first line therapy with a second-generation tyrosine kinase inhibitor, nilotinib, is unknown. We retrospectively evaluated 118 patients newly diagnosed with chronic phase CML and treated frontline with nilotinib inside or outside clinical trial in five French centers. Only patients expressing e14a2 or e13a2 transcripts alone were analyzed. At baseline, 55.3% expressed e14a2, 44.7% expressed e13a2. The median age was 51 years and median follow-up was 49 months. Relative risks of CML at diagnosis were similar according to the ELTS score (p = .87). Complete hematological response and complete cytogenetic response rates were similar among groups. Patients expressing e14a2 transcripts compared to e13a2 transcripts had deeper and faster molecular responses, when considering MMR (100% vs 84.1%, p = .007) with a median time of 6.7 and 17.1 months or MR4.5 (100% vs 59.9%, p = .005) with a median time of 39.7 and 70.9 months, respectively. A sustained treatment free remission was observed in 10/10 patients with e14a2 versus 1/3 with e13a2 transcript (p = .04). In conclusion, even treated with nilotinib first line, patients with chronic phase CML expressing BCR-ABL1 e13a2 transcript have a lower rate of deep molecular responses.

Treatment-free remission (TFR) is an opportunity for patients with chronic myeloid leukemia (CML). Reported cumulative incidence curves of molecular recurrence (MRec) arbor a 2-phase shape with mainly early events, but also some late events (late MRec [LMRec]). Having discontinued our first patient in 2004, we have access to a prolonged follow-up, enabling us to characterize these late events. Over 15 years, 128 patients from our institution were registered in the Stop Imatinib (STIM; A Study for Tyrosine Kinase Inhibitors Discontinuation [A-STIM]) trial. MRec was defined by the loss of major molecular response (BCR-ABL1IS >0.1%). At the first TFR attempt, patients had been taking a tyrosine kinase inhibitor for a median of 7.1 years and in BCR-ABL1IS ≤0.01% (MR4) for a median of 4 years. The median follow-up of patients in TFR was 6.5 years. The TFR rate was estimated to be 45.6% after 7 years. For 9/65 (14%) patients experiencing MRec, recurrence occurred after 2 years in TFR (median, 3.6 years). The residual rate of MRec after 2 years was estimated to be 18%. The probability of remaining in TFR was 65.4% for patients having experienced fluctuations of their minimal residual disease (MRD) (at least 2 consecutive measurements BCR-ABL1IS >0.0032% or loss of MR4), whereas it was 100% for those with stable MRD (P = .003). After 2 years in TFR, we observed an 18% residual rate of LMRec. These late events represent 14% of all MRec and occur in patients with fluctuating MRD measurements. A long-term molecular follow-up therefore remains mandatory for CML patients in TFR. The A-STIM study was registered at www.clinicaltrials.gov as #NCT02897245.

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

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

Introduction Les leucemies a grands lymphocytes granuleux (LGL) font partie des syndromes lymphoproliferatifs T (SLPT) matures, maladies clonales rares dont le diagnostic repose sur une signature phenotypique particuliere. L’association de deux SLPT est rare. Nous rapportons le premier cas de LGL chez un patient suivi pour un syndrome pre-Sezary aux caracteristiques phenotypiques atypiques. Materiel et methodes Un homme de 77 ans suivi pour une gammapathie monoclonale etait adresse en dermatologie pour une erythrodermie prurigineuse associee a un ectropion bilateral, une ichtyose et une keratodermie palmoplantaire. On ne palpait aucune adenopathie et le scanner montrait un nodule pulmonaire isole (adenocarcinome pT1aN0M0 traite chirurgicalement). Le phenotypage lymphocytaire (PLy) revelait une population lymphoide TCD3+ suspecte CD4+CD7-CD26-TCRαβ CD158k- representant 34 % des lymphocytes totaux. L’histologie cutanee compatible avec une localisation d’un lymphome T epidermotrope (CD4/CD8 > 10) et la presence d’un clone T sanguin important identique au clone T cutane faisaient porter le diagnostic de syndrome pre-Sezary (stade IIIB T4N0B1). Debute en 2016 et arrete en 2019, un traitement par bexarotene entrainait une remission complete. Hospitalise en 2020 pour asthenie et bicytopenie (anemie, neutropenie) associees a une splenomegalie sans erythrodermie, le PLy retrouvait une population CD8+ a 3277/mm3 (80,9 %) dont 86 % CD158k+ majoritairement TCRαβ(98,5 %) CD26-(75 %) et CD57+(CD3+CD8+CD57+ 79,1 % soit 2592/mm3). Il existait un clone T circulant distinct de 2016. L’etude next generation sequencing (NGS) confirmait le diagnostic de T-LGL par la presence de mutations caracteristiques STAT3 (Asp661Val et Asp661Tyr) et une mutation TET2 (Phe1287Ser). Une surveillance simple etait recommandee. Discussion Notre malade presentait un syndrome pre-Sezary atypique par l’absence d’expression de KIR3DL2 et la reponse complete rapide et durable induite par le bexarotene. Il s’agit du 1er cas de LGL chez un patient suivi pour un syndrome pre-Sezary. Les CTCL et les LGL partagent des voies de signalisations pathogeniques telles que IL15/IL15R. Le syndrome de Sezary, quasi exclusivement CD3+CD4+, exprime dans 90 % des cas le marqueur CD158k (KIR3DL2). La LGL est une proliferation monoclonale de lymphocytes de phenotype CD3+CD8+ dans plus de 80 % des cas ou CD3- CD56+ (NK) plus rarement CD4+. L’expression de KIR3DL2 par les LGL n’a jamais ete rapportee. Conclusion La survenue d’une double population clonale CD4 puis CD8 peut faire suspecter l’apparition au sein d’un progeniteur T d’une mutation commune telle que sur la voie JAK/STAT deja retrouvee dans ces maladies. L’expression de KIR3DL2 par les cellules de LGL merite d’etre etudiee sur un plus grand nombre de cas et pourrait ouvrir la voie a un traitement par l’anticorps monoclonal anti-KIR3DL2, le lacutamab.

Introduction Le diagnostic precoce de lymphome T cutane n’est pas toujours aise et repose sur un faisceau d’arguments cliniques, biologiques, histologiques et moleculaires. Le sequencage haut debit du TCR-beta permet par la reconnaissance de sequences CDR3 specifiques l’identification et la quantification de chaque clone T present dans un echantillon donne. Il existe encore peu d’etudes a ce sujet avec des resultats discordants et aucun critere diagnostic valide. Notre etude avait comme but de determiner pour cette technique des seuils optimaux pour les valeurs suivantes : frequence du clone T majoritaire dans la peau rapportee a l’echantillon total (TCF) et ratio entre la frequence du premier et du deuxieme clone T (RPF), avec comme objectif de developper de nouveaux algorithmes pour le diagnostic de lymphome T cutane. Materiel et methodes Nous avons analyse retrospectivement les donnees obtenues par le sequencage haut debit du TCR-beta dans des echantillons de biopsies cutanees realisees chez 144 patients entre 2013 et 2020. Le diagnostic de lymphome T cutane etait base sur des criteres internationaux valides. Nous avons inclus 101 echantillons de patients ayant un diagnostic de lymphome T confirme dont 47 MF stade I-IIA, 1 stade IIB, 4 stade III, 35 syndromes de Sezary, 8 lymphomes T agressifs (PTCL NOS ou CD8+) et 6 lymphoproliferations CD30+ (3 papuloses lymphomatoides et 3 lymphomes anaplasiques a grandes cellules). En complement 43 echantillons provenant de patients avec des pathologies inflammatoires etaient inclus. Les performances de la technique ont ete etudiees a l’aide de courbes ROC. Resultats Les meilleures performances diagnostiques etaient obtenues pour le TCF avec une AUC de 0,957 versus 0,929 pour le RPF. Les valeurs de TCF et RPF pour chaque categorie ont ete modelisees. Avec des seuils de TCF de 5 % et 25 %,la specificite pour le diagnostic etait de 95 % et 100 %, et la sensibilite de 89 % et 50 %. Il existait une correlation significative entre le TCF et l’importance de l’atteinte sanguine chez les patients SS (cellules TCD4 + CD26−, r = 0,59, p = 0,0008 ; T CD4 + CD7−, r = 0,45, p = 0,01 ; T CD4 + CD158k+, r = 0,4, p = 0,03) Discussion Le TCF obtenu par HTS-TRB est un critere robuste pour le diagnostic de lymphome T cutane et particulierement pour celui de MF, avec une sp de 95 % et une se de 89 % pour un seuil de 5 %. Une telle specificite permettrait un diagnostic precoce de lymphome T cutane dans des cas difficiles. Ces resultats sont meilleurs que ceux obtenus a l’aide de la PCR classique sur gel du TCR gamma qui sont entaches de nombreux faux negatifs et faux positifs. Des etudes multicentriques prospectives seraient necessaires pour la definition de criteres valides internationaux pour l’usage de cette technique dans le diagnostic de lymphome T cutane.

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

Aims: The onset of blast crisis (BC) in initially chronic phase (CP) CML patients that entered treatment-free remission (TFR) after TKI is an exceptional event, however, there is emerging evidence that this may occur in such patients (pts), although the pathogenesis remains unclear to date. Methods: Anonymous clinical case retrospective data collection from patients' datafiles, after written agreement of living patients, centralisation of available frozen nucleic acid collection from diagnosis and from blast crisis and reanalysis by Next-Generation Sequencing of samples (ASXL1, ASXL2, BCOR, CALR, CBL, CEBP alpha , CSF3R, DNMT3A, EP300, ETNK1, ETV6, EZH2, FLT3, GATA2, IDH1, IDH2 JAK2, KIT, , KRAS,MPL, NPM1, NRAS, PHF6, PTPN11 , RAD2, RUNX1, SETBP1, SF3B1, SH2B3, SMC1A, SMC3, SRSF2, STAG1, STAG2, TET2, TP53, U2AF1, WT1 and ZRSR2 genes analysed) on Illumina platform. CNV analysis were performed using VisCAp or in-house pipelines and/or by Multiplex Ligation Dependant Probe Amplification (MLPA). ABL1 tyrosine kinase domain mutations were screened by NGS on cDNA or directly on DNA. BCR-ABL1 transcripts are expressed in % (IS) with at least 32,000 copies of ABL1 as control. All patients discontinued their TKI after 2 years of MR4.5 and a TKI was resumed in case of MMR loss. Results: Along 15-year experience of TFR in our country and ≥ ~800 patients experiencing a TKI cessation attempt, informations from 4 (~0.5%) TFR CML patients entering BC have been collected. All patients harboured Major BCR transcripts. The chronic phase characteristics are mentioned in Table 1. All these long-lasting CP CML pts were ELTS risk score low, and 1 was harbouring ACA at diagnosis. One pt was mutated for ASXL2 and 2 mutations for EP300, found again at BC. Three pts had IFN-a prior to imatinib for all. Three out of 4 lost their MMR after a first cessation attempt at 12, 10 and 3 months after cessation. Pt #1 experienced a 2 nd cessation attempt 52 months after re-initiation of TKIs and entered lymphoid BC 6 months after a second resumption of TKI for a 2 nd MMR loss. The BC characteristics are mentioned in Table 2. Three out of 4 BC were lymphoid, one had ACA different from those at CP diagnosis. Two pts explored had multiple mutations in Runx1, U2AF1, EP300 and ASXL2 genes, not present at CP diagnosis, in addition to multiple ABL1 mutations in 2 out of 4 pts (2 T315I, 3 P-Loop mutations). All pts underwent chemotherapy + various TKI leading to complete remission (CR) in all and 3 out of 4 pts could be allotransplanted in CR, one relapsed shortly after transplant, and a second one 34 months after transplant. Overall 3 pts are alive with 1 in controlled relapse. Conclusions: The onset of BC after TFR for sustained deep molecular response remains an exceptional event and is probably not induced by this therapeutic procedure. These 4 cases underline the need for a sustained long-lasting molecular follow-up of pts in TFR, although the majority of these BC seem sudden. Figure 1 Figure 1. Disclosures Bauduer: Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Rea: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Nicolini: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Research Funding; Sun Pharma Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kartos Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte Biosciences: Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; BMS: Honoraria.

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.

Clinical trials have formally demonstrated that in chronic myeloid leukemia (CML), patients treated with tyrosine kinase inhibitors (TKI) who achieved and maintained deep molecular responses could discontinue their treatment after several years without facing overt signs of disease relapse in approximately 50% of the cases. In patients with a molecular relapse, prompt re-introduction of TKI therapy was able to rapidly restore deep molecular responses. The concept of a lifelong therapy with TKI has thus been challenged and treatment-free remission (TFR) strategies will soon integrate clinical practice, providing that safe recommendations will be established. In this article, we give an update on TKI discontinuation studies in CML and we also provide an overview of upcoming TFR clinical and biological challenges.

Purpose This study assessed the prognostic impact of postinduction NPM1-mutated ( NPM1m) minimal residual disease (MRD) in young adult patients (age, 18 to 60 years) with acute myeloid leukemia, and addressed the question of whether NPM1m MRD may be used as a predictive factor of allogeneic stem cell transplantation (ASCT) benefit. Patients and Methods Among 229 patients with NPM1m who were treated in the Acute Leukemia French Association 0702 (ALFA-0702) trial, MRD evaluation was available in 152 patients in first remission. Patients with nonfavorable AML according to the European LeukemiaNet (ELN) classification were eligible for ASCT in first remission. Results After induction therapy, patients who did not achieve a 4-log reduction in NPM1m peripheral blood-MRD (PB-MRD) had a higher cumulative incidence of relapse (subhazard ratio [SHR], 5.83; P < .001) and a shorter overall survival (OS; hazard ratio [HR], 10.99; P < .001). In multivariable analysis, an abnormal karyotype, the presence of FLT3-internal tandem duplication (ITD), and a < 4-log reduction in PB-MRD were significantly associated with a higher relapse incidence and shorter OS. In the subset of patients with FLT3-ITD, only age, white blood cell count, and < 4-log reduction in PB-MRD, but not FLT3-ITD allelic ratio, remained of significant prognostic value. In these patients with nonfavorable AML according to European LeukemiaNet, disease-free survival and OS were significantly improved by ASCT in those with a < 4-log reduction in PB-MRD. This benefit was not observed in those with a > 4-log reduction in PB-MRD, with a significant interaction between ASCT effect and PB-MRD response ( P = .024 and .027 for disease-free survival and OS, respectively). Conclusion Our study supports the strong prognostic significance of early NPM1m PB-MRD, independent of the cytogenetic and molecular context. Moreover, NPM1m PB-MRD may be used as a predictive factor for ASCT indication.

Introduction :Since the introduction of tyrosine kinase inhibitors (TKIs) the prognosis of Philadelphia positive (Ph+) diseases like chronic myeloid leukemia (CML) dramatically improved (Sasaki K, Lancet Haematol 2015). Nonetheless, myeloid blastic crisis of CML (MBC-CML) and Ph+ acute myeloid leukemia (AML) represent a clinical challenge due to their rarity, the absence of a standard therapy and mutations. Methods :We collected clinical data of patients treated in Paris in 5 different hospitals with confirmed diagnosis in patients with CML successively transformed in MBC-CML, and in patients with MBC-CML straight away or Ph+ AML. We performed descriptive analysis as well as analysis on overall survival (OS) and event-free survival (EFS). Results :We found 64 patients (24 F/40 M) treated since 2001 to present days. 35/64 patients had an history of CML before MBC of which 30 were diagnosed in chronic phase (Sokal risk: low 3 pts, intermediate 8 pts, high 4 pts, NA 15 pts) and 5 in accelerated phase according to ELN classification. Lines of treatment before MBC for these 35 patients were principally TKIs, IFN, hydroxyurea and homoarringtonine: 11 pts experienced only 1 line of treatment, 15 pts 2 lines, 5 pts 3 lines, 1 pt 4 lines and 3 pts 5 lines. Best response before MBC was complete hematological remission (CHR) for 14 pts, complete cytogenetic remission (CCyR) for 7 pts, molecular remission for 6 pts (4 pts MR3, 1 pt MR4, 1 pt CMR TKI free), whereas 8 pts never gained any response. 21/64 pts were in MBC at diagnosis and 8/64 pts were classified as Ph+ AML. At diagnosis of MBC/AML median age was 49 years old (11-73). 12/64 pts had an extramedullary/central nervous system (CNS) involvement of which 2 pts presented a solitary CNS disease and 3 patients had lesions compatible with myeloid sarcomas without marrow blasts. 46/64 pts (72%) received a classical induction therapy (mostly cytarabine + anthracycline combination) combined in 40 pts with a TKI (15 pts Imatinib, 13 pts Dasatinib, 2 Nilotinib and 10 Ponatinib). 11/64 pts (17%) started Azacytidine (1 pt in combination with Imatinib, 2 pts with Nilotinib, 6 pts with Dasatinib, 1 pt with Ponatinib and 1 pt with Venetoclax). 2/64 pts (3%) received Dasatinib monotherapy. 1/64 pt (2%) received ATRA+ATO+Dasatinib combination. 4/64 pts (6%) received only best supportive care. At first revaluation after therapy 47 pts (78%) were in CR/CRi, 9 pts (15%) were refractory, 2 pts (3%) died during induction, 1 pt (2%) induction therapy is ongoing, in 1 pt (2%) lost to follow up. Most patients who obtained CR/CRi after induction continued with consolidations, mostly high-dose Cytarabine associated with a TKI. 41 pts (68%) were transplanted (40 alloHSCT, 1 autoHSCT), 38 pts in first CR (CR1), 1 pt in second CR (CR2) and 2 pts in progressive disease. Notably, 1 pt who had only Dasatinib monotherapy without any form of chemotherapy nor allotransplant is still alive and in second chronic phase after more than two years of follow up. Median follow up for patients who received an active treatment was 23 months. Median OS was 44 months and median EFS was 29 months (figure 1). The only factor whose impact was significant for both OS and EFS in our cohort was transplant (p At last follow up, 30 pts (47%) are still alive (29 in CR, 1 pt with active refractory disease), 30 pts (47%) died, 4 pts (6%) are lost to follow up. Causes of death were progression of disease for 18 pts, sepsis for 7 pts, GVHD for 3 pts, ischemic stroke for 1 pt, cardiovascular complications for 1 pt. Conclusion :We showed here a multicentric experience about an unselected cohort of patients with MBC CML and Ph+ AML who received different treatments according to age, comorbidities, performance status, TKI availability. Survival of this cohort was mostly linked to the possibility to achieve CR and to perform an allotransplant. Already published experiences showed a generical dismal prognosis with median OS which doesn't exceed 1-2 years (16 months, Deau B, Leukemia Research 2011 ; 12 months, Palandri F, Haematologica 2008 ; 6.4 months, Fruehauf S, Cancer 2007) whereas in our real life cohort median OS was longer. For fit and potentially « transplantable » patients, combination with classic chemotherapy plus a TKI seems reasonable and associated with good outcomes in terms of OS and EFS. Disclosures Rousselot: Incyte:Consultancy, Research Funding;Pfizer:Consultancy, Research Funding;Bristol-Myers Squibb:Consultancy;Novartis:Consultancy;Takeda:Consultancy.Itzykson:Jazz Pharmaceuticals:Honoraria, Membership on an entity's Board of Directors or advisory committees;Daiichi Sankyo:Honoraria;BMS (Celgene):Honoraria;Sanofi:Honoraria;Astellas:Honoraria;Oncoethix (now Merck):Research Funding;Novartis:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Janssen:Research Funding;Stemline:Membership on an entity's Board of Directors or advisory committees;Karyopharm:Membership on an entity's Board of Directors or advisory committees;Otsuka Pharma:Membership on an entity's Board of Directors or advisory committees;Amgen:Membership on an entity's Board of Directors or advisory committees;Abbvie:Honoraria.Cayuela:Incyte:Speakers Bureau;Novartis:Speakers Bureau.Rea:BMS:Membership on an entity's Board of Directors or advisory committees;Novartis:Honoraria, Membership on an entity's Board of Directors or advisory committees;Pfizer: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.

Nilotinib (NIL) 600 mg daily has demonstrated its superiority over Imatinib 400 mg daily in terms of response and incidence of deep molecular response in the front-line chronic phase (CP) CML setting. In this observational study we have retrospectively analyzed the outcome of in- and out-study 202 patients (pts) treated in this setting with NIL 600 mg front-line, in "real-life" conditions. All pts with newly diagnosed adult CP-CML receiving NIL 300 mg BID alone front-line between 10/2007 and 06/2020, were eligible for this study. Data were retrospectively collected according to the current French regulations with pts' information. All pts were assessed and followed according to ELN recommendations 2003, 2006, and 2009 along treatment and to the recommendations from the French group of CML (D. Rea et al., Cancer 2018) in case of TFR. In this regard, a TKI was resumed if loss of MMR. All BCR-ABL1 assessments were performed in the 3 reference laboratories, standardised and expressed in % (IS) with ≥32,000 copies of ABL1 as control. The primary endpoints were the rate of molecular responses in the long-term and the (vascular) safety of Nilotinib. Secondary endpoints were the kinetics of molecular response, survival and safety of Nilotinib. Survival (OS, PFS & EFS) was defined according to ELN (J. Guilhot et al. Blood 2012). Two hundred and two patients were reported with 44% females and 56% males with a median age at diagnosis of 50.4 (17.5-83) years, and 26% of them had cardiovascular risk factors at onset (tobacco abuse 11%, hypercholesterolemia 9.3%, diabetes 1.45%, none with past history of cardiovascular events [CVE]). ELTS scores were high in 14%, intermediate in 31% and low in 55% of pts. Twenty-four (12%) pts harboured additional chromosomal abnormalities at diagnosis. The median follow-up after NIL initiation was 61.5 (1-147.5) months. At last follow-up 113 pts (55%) are not on NIL anymore for toxicities, TFR or resistance reasons. Twenty-eight (14%) pts present an arterial event on NIL (18% PAOD, 14% angina pectoralis, 7% myocardial infarction, 14% stroke, 47% others such as atrial fibrillation, cardiomyopathy...), that occurred after a median of 26 (0.6-98.5) months on NIL. Forty-six (22.5%) pts reached TFR criteria and stopped NIL after a median of 58.5 (27-126) months. The cumulative incidence (CI) rates of MMR at 1, 2 and 5 years were 64 (57-71)%, 79.4 (75.45-83.35)% and 95 (92-98.5)% respectively. For MR4, those were 35.5 (29-42)%, 60 (52-67)% and 82 (74.5-89)% respectively; and for MR4.5, were 14 (9-19)%, 31 (24-28)% and 62 (54-70.5)% respectively. The CI of sustained MR4.5 (i. e. patients eligible for TFR: MR4.5 ≥2 years) was observed in 30 (23-37)% at 3 years, 45.5 (36-55)% at 5 years and 52.5 (41.5-64)% at 6 years (Figure). The CI of patients entering TFR was 16.75 (10.5-23)% at 5 years and 51.94 (37.31-66.57)% at 10 years with a survival without MMR loss of 70.7 (58- 86)% at 1 year and 65.26 (50.6-84)% at 5 years. Nine (4.5%) pts progressed towards accelerated phase (4 pts) or BC (2 lymphoid, 3 myeloid) responsible for 5 deaths at latest follow-up. Among NIL resistant patients screened, 15 were harbouring ABL1 mutations (5 Y253H, 3 E255K, 3 T315I, 1 M244V, 1 G250E, 1 F359V, 1 V299L). Overall, 10 patients died (5 from CML, 5 from unrelated causes). The probability of OS was 95.75 [95%CI: 92.9-98.7]% at 2 years and 94.8 [91.5-98.3]% at 5 years, for PFS it was 94.92 [91.7-98.2]% at 2 years and 89.5 [84.7-94.6]% at 5 years, and EFS it was 78 [72.3-84]% at 2 years and 60.25 [53.3-68.1]% at 5 years. Regarding sustained MR4.5, univariate analysis showed that female gender (HR=2.46 [1.50-4.02], p NIL first-line efficiently limits progression of newly diagnosed CP-CML patients and provides high rates of sustained MR4.5, allowing TFR in a substantial proportion of pts. However, the onset of arterial occlusive events, especially in the elderly is a matter of concern in the choice of this compound at treatment initiation. Disclosures Nicolini: Incyte: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Sun Pharma Ltd: Consultancy. Cony-Makhoul:BMS: Speakers Bureau; Incyte Biosciences: Speakers Bureau; Pfizer: Consultancy; Novartis: Consultancy; BMS: Consultancy. Dulucq:Incyte: Speakers Bureau; Novartis: Speakers Bureau. Cayuela:Novartis: Speakers Bureau; Incyte: Speakers Bureau. Rea:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: 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. Mahon:ARIAD: Honoraria; Pfizer: Honoraria; Novartis Pharma: Honoraria, Research Funding; BMS: Honoraria. Etienne:Pfizer: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau.

Introduction Le lymphome T cutane anaplasique a grandes cellules est un lymphome T cutane (LTC) de bon pronostic avec expression de CD30 par plus de 75 % des cellules. Les lymphomes T cutanes primitifs qui ne correspondent a aucune des categories definies par la classification Organisation mondiale de la sante/European Organization for Research and Treatment of Cancer (OMS/EORTC) sont classes comme lymphome T peripherique non classable (pcPTCL-NOS). Materiel et methodes Nous presentons deux cas cliniques avec un diagnostic initial de pcPTCL-NOS avec peu ou pas d’expression de CD30 initiale qui echappaient apres la premiere ligne de traitement et rechutaient sous forme de lymphomes cutanes CD30+ avec une atteinte systemique. Observations Cas 1 : un patient de 79 ans presentait une plaque ulceree du prepuce. L’histologie montrait une infiltration dense de lymphocytes atypiques de taille moyenne sans epidermotropisme. Les cellules tumorales exprimaient CD3, CD8, granzyme B et 10 % etaient CD30+, ce qui permettait de porter le diagnostic de pcPTCL-NOS. Le patient etait en reponse complete apres radiotherapie. Il rechutait 4 ans plus tard sous forme de lesions cutanees et systemiques. L’examen anatomopathologique montrait un aspect de lymphome anaplasique a grandes cellules, avec une infiltration lymphocytaire dense, dont 80 % des cellules etaient CD30+. Les traitements par doxorubicine liposomale pegylee et brentuximab vedotin permettaient d’obtenir une reponse complete, mais le patient rechutait a nouveau. Une analyse des recepteurs T des lymphocytes par hightroughput sequencing retrouvait un clone T identique au diagnostic initial et au moment de la rechute dans les biopsies cutanees. Cas 2 : un patient de 71 ans se presentait avec des symptomes B et des ulcerations du genou droit. La biopsie montrait une infiltration dermique par des lymphocytes de taille moyenne, CD3+ CD5-, CD7-, granzyme B+, CD4+/− et CD8+/−, sans expression de CD30. La tomographie a emission de positons–tomodensitometrie (TEP-TDM) etait strictement normale, le diagnostic de pcPTCL-NOS etait retenu. Quelques mois apres la polychimiotherapie, le patient rechutait avec une atteinte systemique et des ulcerations cutanees. La biopsie montrait un aspect de lymphome T anaplasique CD30+. Discussion L’heterogeneite de l’expression du CD30 chez un meme patient et dans la meme biopsie a deja ete rapportee. Ces observations demontrent la plasticite d’un meme clone T qui peut realiser des tableaux anatomocliniques differents ce qui peut avoir des consequences therapeutiques, en particulier concernant les possibilites de traitement par un anticorps anti-CD30. Conclusion Il est toujours utile de faire plusieurs biopsies initiales et au cours de l’evolution devant des lymphomes cutanes de classement et de traitement difficiles.