Search

There are few data regarding the association of autoimmune and inflammatory diseases (AID) with Philadelphia negative myeloproliferative neoplasms (MPN). In this retrospective study, we describe the prevalence, clinical and biological features and outcome of AID association in MPN. A total of 1541 MPN patients were included, encompassing 95 (6%) patients with AID. Female patients were predominant within the AID group (65% versus 54%, p=0.03). A total of 103 AID diagnoses were reported in 95 patients, including 48 organ-specific AID, 13 inflammatory arthritis, 9 connective tissue diseases, 9 dermatosis, 6 systemic vasculitis and 18 unclassified AID. The prevalence of TET2 mutations was higher in the AID cohort (32% versus 22%), although not statistically significant (p=0.08). In subgroup analysis of patients with myelofibrosis, TET2 mutations were more prevalent in AID group (p=0.025). The prevalence of driver and other additional mutations did not differ between the 2 groups. The association with AID did not impact overall survival (p=0.67), transformation-free survival (p=0.37) or secondary myelofibrosis-free survival (p=0.91). Our data suggest that the prevalence of AID is similar in MPN patients to that of the general population. TET2 mutations are highly prevalent in MPN patients with AID potentially suggesting a shared physiopathology.

Resume Contexte Le Centre d’investigations cliniques de l’Hopital Saint-Louis (CIC-1427) est une structure dediee qui accueille des patients inclus dans des essais cliniques essentiellement de phases precoces (premiere administration chez l’homme, phases I et II). Ces patients sont accueillis dans des locaux autorises et valides par l’Agence regionale de sante (ARS). En mars 2020, face a la pandemie de la COVID-19 et aux mesures de confinement national de la population decidees, par le gouvernement francais, le CIC-1427 a du adapter rapidement ses procedures de fonctionnement pour assurer la securite des patients et de son personnel. Objectif Assurer une prise en charge optimale des patients inclus dans les essais cliniques de phases precoces, tout en respectant les bonnes pratiques cliniques (BPC) et les bonnes pratiques professionnelles des CIC (BPP des CIC), les exigences des promoteurs de chaque protocole, la securite des patients et du personnel multidisciplinaire (infirmiers, aide-soignants [AS], assistants de recherche clinique [ARC], coordonnateur d’etudes cliniques [CEC]), chefs de projets, cadre de sante et medecins investigateurs), dans le contexte de la crise sanitaire liee a la COVID-19. Methodes et resultats De par son activite, necessitant des tâches en presentiel, chaque personnel de l’equipe specialisee en recherche clinique du CIC-1427 a du adapter son activite quotidienne aux contraintes de la crise sanitaire. De nouvelles procedures specifiques ont ete rapidement elaborees, pour faire face a la pandemie. La plupart des visites medicales sur site ont ete remplacees par des teleconsultations avec bilans biologiques dans les laboratoires de proximite, les « remote monitoring » ont remplace les visites de monitoring sur site, les traitements ont ete envoyes au domicile de chaque patient via des coursiers apres accord des CPP (Comite de protection des personnes) de chaque protocole. Les visites indispensables ont pu etre maintenues sur site grâce a l’implication sans faille de notre equipe soignante et sous condition de mise en place d’un protocole sanitaire adapte. Conclusion Grâce a l’implication de l’ensemble de notre equipe de recherche multidisciplinaire, et malgre les difficultes rencontrees, chaque patient a pu beneficier d’un suivi personnalise et poursuivre son traitement protocolaire. Les procedures mises en place ont egalement permis la collecte d’un maximum de donnees de securite et d’efficacite pour les promoteurs des essais cliniques et le respect des bonnes pratiques reglementaires. L’ensemble de ces mesures prises dans le contexte de l’urgence sanitaire, lors de la premiere vague epidemique, ont permis d’aborder plus sereinement la suite de l’epidemie.

Contexte Le Centre d’investigations cliniques de l’Hôpital Saint-Louis (CIC-1427) est une structure dédiée qui accueille des patients inclus dans des essais cliniques essentiellement de phases précoces (première administration chez l’homme, phases I et II). Ces patients sont accueillis dans des locaux autorisés et validés par l’Agence régionale de santé (ARS). En mars 2020, face à la pandémie de la COVID-19 et aux mesures de confinement national de la population décidées, par le gouvernement français, le CIC-1427 a dû adapter rapidement ses procédures de fonctionnement pour assurer la sécurité des patients et de son personnel. Objectif Assurer une prise en charge optimale des patients inclus dans les essais cliniques de phases précoces, tout en respectant les bonnes pratiques cliniques (BPC) et les bonnes pratiques professionnelles des CIC (BPP des CIC), les exigences des promoteurs de chaque protocole, la sécurité des patients et du personnel multidisciplinaire (infirmiers, aide-soignants [AS], assistants de recherche clinique [ARC], coordonnateur d’études cliniques [CEC]), chefs de projets, cadre de santé et médecins investigateurs), dans le contexte de la crise sanitaire liée à la COVID-19. Méthodes et résultats De par son activité, nécessitant des tâches en présentiel, chaque personnel de l’équipe spécialisée en recherche clinique du CIC-1427 a dû adapter son activité quotidienne aux contraintes de la crise sanitaire. De nouvelles procédures spécifiques ont été rapidement élaborées, pour faire face à la pandémie. La plupart des visites médicales sur site ont été remplacées par des téléconsultations avec bilans biologiques dans les laboratoires de proximité, les « remote monitoring » ont remplacé les visites de monitoring sur site, les traitements ont été envoyés au domicile de chaque patient via des coursiers après accord des CPP (Comité de protection des personnes) de chaque protocole. Les visites indispensables ont pu être maintenues sur site grâce à l’implication sans faille de notre équipe soignante et sous condition de mise en place d’un protocole sanitaire adapté. Conclusion Grâce à l’implication de l’ensemble de notre équipe de recherche multidisciplinaire, et malgré les difficultés rencontrées, chaque patient a pu bénéficier d’un suivi personnalisé et poursuivre son traitement protocolaire. Les procédures mises en place ont également permis la collecte d’un maximum de données de sécurité et d’efficacité pour les promoteurs des essais cliniques et le respect des bonnes pratiques réglementaires. L’ensemble de ces mesures prises dans le contexte de l’urgence sanitaire, lors de la première vague épidémique, ont permis d’aborder plus sereinement la suite de l’épidémie.

Introduction: Although myeloproliferative neoplasms (MPN) are driven by three mutually exclusive driver mutations (JAK2, CALR and MPL), targeted deep sequencing studies identified multiple additional somatic mutations potentially impacting MPN evolution. Presence of a high molecular risk (HMR: ASXL1, EZH2, SRSF2 and IDH1/2) or a TP53 mutations has been associated with adverse prognosis. However, to date, the effect of clonal evolution (CEv) on MPN patients' outcome has not been evaluated, as most of the studies assessed mutational-based prognosis stratification from single baseline molecular genotyping. The objective of our study was to describe the clinical and molecular characteristics of patients with CEv in a large cohort of MPN patients and analyze its impact on patients' outcome. Methods: A total of 1538 consecutive patients were diagnosed with MPN according to WHO criteria and followed in our hospital between January 2011 and January 2021. From this large retrospective cohort, we included in this study 446 patients who had at least 2 molecular analyses during the chronic phase of MPN, performed at diagnosis and/or during follow-up using next generation sequencing (NGS), targeting a panel of 36 genes involved in myeloid malignancies. Significant variants were retained with a sensitivity of 1%. CEv was defined as the acquisition of a new additional non-driver mutation between baseline and subsequent NGS evaluation. Statistical analyses were performed using the STATA software (STATA 17.0 for Mac Corporation, College Station, TX). Results: The median age at MPN diagnosis in our whole cohort was 51 years [IQR 41 - 60]. Our cohort included 167 (37%), 205 (46%) and 64 (14%) patients with polycythemia vera, essential thrombocythemia and primary myelofibrosis (MF) respectively. With a median interval of 1.6 years [IQR 1.0 - 2.8] between the first and the second NGS analysis in the whole cohort, CEv occurred in 128 patients (29%). Patients with CEv were significantly older compared to patients without CEv (n=318) (p=0.03). MPN diagnosis, the type of driver mutation and complete blood counts at MPN diagnosis did not differ between the 2 groups. Eighty-one (63%) and 198 (62%) patients with or without CEv respectively had at least one additional non-driver mutation at baseline NGS (p=0.59), while the rate of HMR (n=25 (20%) versus n=79 (25%)) or TP53 (n=7 (5%) versus n=20 (6%)) mutations at baseline NGS did not differ between the 2 groups. Thirty six out of 128 (28%) of patients with CEv had more than 1 acquired mutation. Most recurrently acquired mutations involved the epigenetic regulators TET2 and DNMT3A that were mutated in respectively 33% and 25% of patients with CEv (Figure 1A). Moreover, 38% of CEv patients acquired HMR (ASXL1 (14%), EZH2 (6%), SRSF2 (3%), IDH1/2 (2%)) or TP53 (13%) mutations. After a median follow up of 10.8 years [IQR 6.6 - 17.2] in the whole cohort representing a total of 5635 patient years, 32 (7%) patients died, and 11 (2.5%) and 11 (2.5%) patients with at least 2 NGS performed during MPN chronic phase transformed respectively into secondary MF or myelodysplastic syndrome / acute myeloid leukemia (MDS/AML). Interestingly, CEv (HR 11.27, 95%CI [5.09; 24.96], p Conclusion: Our study on a large retrospective clinically and biologically annotated real-life cohort of MPN patients with long-term follow up shows that CEv independently adversely impacts OS, MDS/AML and secondary MF free survivals. CEv occurred in a clinically relevant proportion of MPN patients (28%) and was associated with patients' age. Acquired mutations mainly involved epigenetic regulators, HMR and TP53 genes. These results suggest that serial molecular monitoring using NGS could be routinely implemented in MPN patients follow up, to assess more accurately disease evolution and potentially update therapeutic management. Figure 1 Figure 1. Disclosures Raffoux: PFIZER: Consultancy; CELGENE/BMS: Consultancy; ABBVIE: Consultancy; ASTELLAS: Consultancy. Kiladjian: Novartis: Membership on an entity's Board of Directors or advisory committees; Taiho Oncology, Inc.: Research Funding; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees; PharmaEssentia: Other: Personal fees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Benajiba: Gilead: Research Funding; Pfizer: Research Funding.

Introduction: Auto-immune and Inflammatory Diseases (AID) have been associated with myeloproliferative neoplasms (MPN) in a large population-based study (Kristinsson et al. Haematologica 2010). In myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML), epigenetic regulators TET2 and IDH1/2 were more frequently mutated in patients with AID, suggesting potentially common pathogenesis pathways (Zhao et al. Leukemia 2021). However, in the context of MPN, AID specific features remain poorly characterized, and no study has reported to date the mutational landscape of MPN patients with AID. The objectives of our study were to describe the clinical and molecular characteristics of MPN patients with associated AID and evaluate its impact on patient's outcome. Methods: A total of 1541 patients were diagnosed with MPN according to WHO criteria between January 2011 and January 2021 in our center, of whom 998 had a molecular analysis by next generation sequencing (NGS) targeting a panel of 36 genes involved in MPN, performed at diagnosis and/or during follow-up. AID diagnosis was based on international criteria, and all cases have been reviewed by internal medicine experts. Patients with AID induced by interferon-alpha treatment were not included. Results: The median age of our whole cohort was 51.3 years IQR[40.4-63.2]. Our cohort included 522 (34%), 709 (46%) and 229 (15%) diagnosis of polycythemia vera (PV), essential thrombocytemia (ET) and primary myelofibrosis (MF) respectively. A total of 100 patients (6.6%) had AID and were compared to the remaining 1441 MPN patients without AID. There were more females (66 (66%) versus 769 (53%), p=0.019) within the AID group compared to non-AID patients. MPN subtype, driver mutation, complete blood counts at diagnosis did not differ between the two groups. Occurrence of thrombosis and hemorrhage episodes did not vary either (44 (44%) versus 564 (39%), p=0.356). AID diagnosis was prior to MPN in 34% of cases, concomitant in 12% and posterior in 31% of cases. AID diagnosis included 45 (45%) organ-specific AID (mainly autoimmune thyroiditis, n=34), 13 (13%) inflammatory arthritis, 9 (9%) connective tissue diseases, 8 (8%) inflammatory dermatosis, 7 (7%) systemic vasculitis and 18 (18%) unclassified AID (Figure 1A). The AID fulfilled the required classification criteria in 70 (70%) cases, while complete criteria were not reached in 30 (30%) cases. The median interval of time between MPN diagnosis and NGS was 7.2 years IQR[2.1-13.3] in the whole cohort. Among patients with available molecular analysis, 44 (62%) and 571 (62%) patients had at least one additional non-driver mutated gene in the AID and control groups respectively. Interestingly, TET2 mutations were more frequent in MPN patients with AID (24 (34%) versus 205 (22%), OR=1.84 95%CI[1.08-3.07], p=0.028, Fig 1B). The prevalence of TET2 mutations did not significantly differ between the AID categories. When focusing on IDH1/2 mutations, as they act on the same biological epigenetic pathway as TET2, IDH1/2 mutations were more frequent in the AID cohort although not statistically significant (4 (6%) versus 27 (3%), OR=2.02 95%CI[0.74-5.51], p=0.27). No other mutations including other epigenetic factors, splicing regulators, transcription factors or high molecular risk mutations, were significantly associated with AID. After a median follow up of 8.3 years IQR[3.7-14.3] in the whole cohort, 10 (10%) and 122 (8%) patients died in the AID and control groups respectively. The presence of AID did not impact overall survival (p=0.82), secondary myelofibrosis free (p=0.98) or MDS/AML transformation free (p=0.53) survivals. Conclusion Our study reports on a large retrospective clinically and molecularly annotated cohort the prevalence of AID in MPN patients (6.6%). This prevalence did not differ from that of the general population. Interestingly, our data emphasize a high prevalence of TET2 mutations in patients with both AID and MPN, compared to MPN patients without AID. Although other studies are warranted to better define the causal relationship between MPN and AID, our results may suggest a common pathophysiology as it has been proposed in MDS patients, based on shared genetic susceptibilities with mutations in TET2 that could occur within early hematopoietic progenitors and give rise to both the inflammatory phenotype and myeloid malignancy. DE and LPZ contributed equally to this work. Figure 1 Figure 1. Disclosures Fenaux: Celgene/BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Ades: Novartis: Honoraria; Takeda: Honoraria; Abbvie: Honoraria; JAZZ: Honoraria; Celgene: Honoraria, Research Funding. Raffoux: PFIZER: Consultancy; CELGENE/BMS: Consultancy; ABBVIE: Consultancy; ASTELLAS: Consultancy. Kiladjian: Incyte Corporation: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Taiho Oncology, Inc.: Research Funding; PharmaEssentia: Other: Personal fees. Benajiba: Pfizer: Research Funding; Gilead: Research Funding.

Background: Although patients with MPN may achieve complete hematological remission (CHR) with cytoreductive therapy (CRT), lifelong treatment represents a major burden for these chronically ill patients. IFN has emerged as a major MPN therapy thought to positively alter the natural history of MPN and appears to be the only drug that can provide long-term CHR after discontinuation in some patients (Hasselbalch HC et al., Seminars in Immunopathology, 2019). In this study, we aimed to identify clinical and molecular factors associated with long-term CHR after IFN treatment discontinuation and to compare clinical outcome of patients who discontinued therapy, to patients who continued IFN treatment despite achieving a CHR. Methods: All MPN patients followed between January 2000 and May 2020 in our institution who received at least 3 months of IFN were included. Logistic regression analysis was performed to identify variables associated with long-term CHR after discontinuation. Cumulative incidence of relapse was calculated from time of IFN discontinuation, considering death without relapse as a competitive event. Overall survival (OS) and thrombotic/hemorrhagic events free survival (EFS) curves were estimated using the Kaplan-Meier method and compared by cause-specific hazard Cox models. Results: 381 patients treated with IFN were included in the study. Median age at MPN diagnosis was 44 years [interquartile range: 33-54]. 171 had polycythemia vera (PV), 169 essential thrombocythemia (ET) and 34 primary myelofibrosis (PMF). JAK2V617F was the most frequent driver mutation (78.8% of patients), while CALR and MPL were mutated in 15.5%, and 2.9% of patients respectively. Median driver variant allele frequency (VAF) at time of IFN therapy initiation was 34% [12; 51]. Reasons to start IFN included age younger than 50 years in 44.9%, intolerance/resistance to previous therapies in 17.8% or pregnancy in 1.8% patients. CHR was achieved with IFN in 77.2% of patients. After a median follow-up of 72.4 months [28.4; 119.7] from IFN initiation, 131 patients were still on IFN treatment, while 250 patients had discontinued therapy. No significant difference was observed between continued and discontinued IFN patients in terms of MPN subtype, initial clinical, biological or molecular characteristics. Reasons for discontinuation were toxicity in 128 (50.4%), prolonged hematological CHR in 76 (29.9%), failure in 16 (6.3%) and other in 30 (11.8%) patients. At time of IFN discontinuation, 170 (66.9%) patients were in CHR and the median driver mutation VAF was 12% [3; 35]. Of note, IFN was re-introduced in 61 patients who lost CHR with a second CHR rate of 83.6%, arguing for the absence of development of IFN resistance in post-discontinuation relapses. In multivariate logistic regression analysis, stopping for prolonged CHR (OR 3.52, 95%CI [1.18; 10.56], p=0.024) was associated with a higher CHR without CRT rate, while VAF ≥ 10% at time of IFN discontinuation (OR 0.26, 95%CI [0.1; 0.65], p=0.004) was associated with lower long-term CHR without CRT. Accordingly, VAF ≥ 10% at time of IFN discontinuation (HR 3.06 [1.59; 5.90], p=0.001) was independently associated with a higher cumulative incidence of relapse after IFN discontinuation (Figure A). Driver VAF at IFN discontinuation time was available for 117 patients. 53 patients (45.3%) had a driver VAF < 10% at IFN discontinuation. Finally, we compared discontinued IFN patients who stopped IFN for CHR (n=76) to patients who obtained CHR and are still on IFN therapy (n=116). Hematological transformation could not be evaluated due to very low incidence of events: 2 patients from each group progressed to myelofibrosis while leukemic progression was only observed in 1 patient. Importantly, OS (HR 0.23, 95%CI [0.5; 1.14], p=0.07) and EFS (HR 0.53, 95%CI [0.19; 1.45], p=0.217) were not significantly different between patients who discontinued and those who continued IFN. Conclusion: Overall, our study demonstrates that IFN discontinuation represents a safe strategy in MPN patients who achieved CHR, and particularly in patients with a driver VAF lower than 10% at time of discontinuation. Importantly, relapsed patients did not develop IFN resistance. Our data contributes to set the frame for future clinical trials evaluating the possibility of IFN treatment holidays in good responding MPN patients. Disclosures Benajiba: Gilead Foundation: Research Funding. Kiladjian:Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees.

Introduction: Ruxolitinib (RUX) is a JAK 1/2 inhibitor approved for the treatment of intermediate and high-risk primary or secondary MF. In addition to the intrinsic immune system modulation in MF patients, JAK inhibition exerts an immunosuppressive effect that may increase the risk of infections (Heine A et al., Blood, 2013). We aimed to investigate the association between treatment with RUX and infectious complications in a large monocentric cohort of MF patients. Methods: We performed a retrospective study including all patients diagnosed with primary, post-polycythemia vera or post-essential thrombocythemia MF in our MPN clinic between January 2011 and April 2020. Patients were considered RUX treated when exposed to treatment for at least two consecutive months. Clinical and biological characteristics at time of MF diagnosis and follow-up were collected from medical charts and electronic medical records. We used logistic regression models to identify specific infection subtypes associated with RUX treatment. Univariate and multivariate analysis assessing the impact of categorical and continuous variables on infectious events cumulative incidence were performed using Cox models. Results: 213 MF patients were included in the study. 114 (51.1%) patients were treated with RUX while 99 didn't receive RUX. Overall 102 patients exhibited a total of 231 infectious episodes. To search for factors associated with occurrence of infectious events, we evaluated the characteristics of MF, potential clinical and biological immune suppression factors (immunosuppressive treatment, prior non-MPN cancer, diabetes, hepatic/renal failure, neutropenia, lymphopenia, hypo-gammaglobulinemia, complement deficiency, prior history of infection), use of infection prophylaxis and RUX treatment using Cox models. In this cohort of MF patients, we found that RUX treatment (HR 5.91, 95%CI[3.48; 10.04], p 2 (HR 4.91, 95%CI[2.62; 9.21], p 41 (22.2%) and 16 (34.0%) infections were of grade 3-4, 61 (33.1%) and 19 (40.4%) required hospitalization, while 8 (4.3%) and 2 (4.2%) resulted in patients' death, in RUX treated and RUX naïve patients, respectively (all non-significantly different). Bacterial infections represented 48.0%, viral infections 16.0% and fungal infections 4.8% of the total infectious events. The most frequently infected sites were lungs/respiratory tract (28.1%) and skin/soft tissue (24.2%). RUX treatment was significantly associated with recurrence of HSV-1/2 or VZV (OR 7.57, 95%CI[1.01-57.30], p=0.050), and skin/soft tissue infections including the above herpetic recurrences (OR 3.33, 95%CI[1.13-9.78], p=0.029). 17 (14.9%) patients presented with HSV/VZV recurrence in the RUX treated group compared to 1 (1.0%) in non-treated patients (Figure B). We then thought to evaluate the impact of potential infections risk factors in RUX treated patients at time of treatment initiation in order to inform clinicians' therapeutic decision and follow-up guidance. For this analysis, we evaluated the characteristics of MF, potential clinical and biological immune suppression factors, treatment lines prior to RUX, dose and cumulative exposition to RUX. No clinical or biological factor was significantly associated with the overall risk of infectious events. However, hypo-gammaglobulinemia at time of RUX initiation was independently associated with HSV and/or VZV recurrence (HR 4.57, 95%CI[1.29-16.16], p=0.018). The higher rate of infections in RUX treated patients was associated with a not statistically significant trend towards shorter OS (HR 1.97, 95%CI[0.98; 3.94], p=0.055). Conclusion: This retrospective study shows an association between the occurrence of infectious complications and Ruxolitinib treatment in MF patients, and in particular, a higher incidence of HSV/VZV recurrence and skin/soft tissue infection. Patients with hypo-gammaglobulinemia at time of RUX initiation were at higher risk of HSV/VZV recurrence, suggesting that protein electrophoresis should be performed prior to treatment initiation and primary antiviral prophylaxis proposed to patients with hypo-gammaglobulinemia. Disclosures Rea: 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; Novartis: 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. Kiladjian:AbbVie: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Benajiba:Gilead Foundation: Research Funding.

Introduction: MPN are a heterogeneous group of chronic hematological malignancies often resulting from a combination of a driver gene mutation (JAK2, MPL or CALR) and a variety of somatic mutations harboring diverse prognosis values. A subset of MPN patients carry somatic mutations in the hematopoietic transcription factor NFE2 (nuclear factor erythroid 2) resulting in a functionally enhanced truncated form of NFE2 (Jutzi JS et al., JEM, 2013). Moreover, epigenetically induced overexpression of NFE2 has recently been reported in the majority of MPN patients (Peeken JC et al., Blood, 2018). In transgenic murine models, NFE2 overexpression results in an MPN phenotype (thrombocytosis, leukocytosis, EPO-independent colony formation, characteristic bone marrow histology and expansion of stem and progenitor compartments) and has recently been shown to predispose to the acquisition of additional genetic abnormalities and subsequent leukemic transformation (Kaufmann KB et al., JEM, 2012) (Jutzi JS et al., Blood, 2019). However, clinical impact of NFE2 mutations in MPN patients remains unknown. The aim of this study was to evaluate the phenotypic characteristics and prognostic impact of NFE2 somatic mutations in a large mono-centric cohort of MPN patients. Methods: A total of 1243 consecutive patients were diagnosed with MPN according to WHO criteria and followed in our hospital between January 2011 and May 2020. This study included 707 of them in whom a next-generation sequencing (NGS) molecular analysis targeting 36 myeloid genes was performed at diagnosis and/or during follow-up. Clinical and biological characteristics at time of diagnosis and follow-up were collected from medical charts and electronic medical records. Statistical analyses were performed using the STATA software (STATA 15.0 Corporation, College Station, TX). Results: In our cohort, 411 patients presented with polycythemia vera (PV), 577 with essential thrombocythemia (ET), 184 with primary or pre-fibrotic myelofibrosis (PMF), 59 with unclassified MPN and 12 with MDS/MPN. Median age at diagnosis was 51 years [40-63]. 73.1% patients had a JAK2V617F mutation, 14.1% a CALR mutation and 3.3% a MPL mutation. Overall, 64 (9.05%) patients harbored a NFE2 mutation with a variant allelic frequency (VAF) ≥ 0.5% and 36 had a VAF ≥ 5%, the latest were considered as NFE2 mutated for the rest of the study as VAF Conclusion: In this retrospective study we show that presence of NFE2 mutations with a VAF ≥5% is independently associated with an increased risk of leukemic transformation and shorter overall survival. These findings are in line with recently reported animal models and suggest that NFE2 mutations screening should be routinely performed in MPN patients. Disclosures Rea: Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Kiladjian:AOP Orphan: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Benajiba:Gilead Foundation: Research Funding.

Introduction: Next generation sequencing (NGS) studies identified additional somatic mutations impacting disease evolution and prognosis in MPN. SF3B1, a component of the U2 small nuclear ribonucleoprotein splicing complex, is frequently mutated in myelodysplastic syndromes where it has been proposed to define a new entity (Malcovati et. al. Blood 2020). In MPN, SF3B1 is mutated in approximately 10% of patients with primary myelofibrosis (PMF) and 3-5% with polycytemia vera or essential thrombocytemia (ET). Recent reports suggested that spliceosome mutations may adversely affect myelofibrosis free survival (MFS) in ET (Tefferi et. al. Br J Haematol. 2020). The main objective of this study was to evaluate the impact of the concomitant presence of driver (JAK2, MPLor CALR) and SF3B1 clonal or sub-clonal mutations on MPN phenotype and evolution in a large single center cohort of MPN patients. Methods: A total of 1243 consecutive patients were diagnosed with MPN according to WHO criteria between January 2011 and May 2020 in our center, of whom 707 had molecular analysis by NGS targeting a panel of 36 myeloid genes performed at diagnosis and/or during follow-up. Significant variants were retained with a sensitivity of 0.5%. Patients were grouped according to variant allele frequencies (VAF) determined by NGS as "driver" SF3B1mutated patients when driver and SF3B1 mutations VAF were similar (double mutated clone), and as "non-driver" SF3B1 mutants when SF3B1VAF was lower than that of the driver mutation, suggestive of a sub-clone. 4 patients with SF3B1 mutations but no driver mutation were excluded. We then compared the characteristics and outcomes of 3 groups of patients according to their SF3B1 mutational status: wild type (WT), driver and non-driver SF3B1 mutations. Results: A total of 39/703 (5.6%) patients had SF3B1 mutations, of whom 11/39 (28.2%) and 28/39 (71.8%) harbored driver and non-driver SF3B1mutations, respectively. Driver SF3B1 mutations were associated with PMF (OR 6.1, 95%CI [1.1; 33.6], p= 0.039) and MPN unclassified (OR 15.6,95%CI [1.1; 116.5], p= 0.007) subtypes, presence of immature myeloid cells ≥ 2% (OR 9.3, CI [2.6; 32.8], p= 0.001) and peripheral blasts ≥ 1% (OR 5.0,95%CI [1.0; 24.7], p= 0.047) at diagnosis (Figure A). Other variables were not significantly different between patients with driver, non-driver and WT SF3B1, including age, driver mutation type, MPN-related symptoms, cytogenetics and high molecular risk mutations (ASXL1, EZH2, SRSF2, IDH1/2or U2AF1). There was no significant difference in the response to therapy: complete hematological response was seen in 5/11 (45.5%), 10/28 (35.7%) and 327/664 (49.3%) of patients with driver, non-driver and WT SF3B1 respectively. After a median follow-up of 103.7 months IQR [47.2; 175.6], evolution to myelofibrosis occurred in 5/7 (71.4%), 6/20 (30.0%) and 99/564 (17.6%) of patients with driver, non-driver and WT SF3B1 respectively. Interestingly, driver SF3B1 but not non-driver SF3B1 mutational status adversely impacted MFS (OR 7.56,95%CI[2.95; 19.38], p Conclusion: This study in a large cohort of MPN patients highlights for the first time to our knowledge the adverse impact on MFS of SF3B1 and MPN-driver co-mutated clones. In contrast, presence of an SF3B1 mutation at sub-clonal level didn't increase the risk of MF development. In line with our findings, a recent study reported an association between rapid progression to myelofibrosis and SF3B1 mutations in patients with age-related clonal hematopoiesis (Bartels et al. Leukemia 2020). Further studies are warranted to confirm our results on independent cohorts and to investigate the mechanisms of bone marrow fibrosis development in patients with SF3B1 and MPN-drivermutations. Disclosures Rea: Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Kiladjian:BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Benajiba:Gilead Foundation: Research Funding.

To evaluate the association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC).The patients were evaluated by ultrasonography-guided fine needle aspiration cytology. Typical cytopathological aspects and/or classical histopathological findings were taken into consideration in the diagnosis of HT, and only histopathological results were considered in the diagnosis of PTC.Among 1,049 patients with multi- or uninodular goiter (903 women and 146 men), 173 (16.5%) had cytopathological features of thyroiditis. Thirty-three (67.4%) out of the 49 operated patients had PTC, 9 (27.3%) of them with histopathological features of HT. Five (31.3%) out of the 16 patients with non-malignant disease also had HT. In the groups with HT, PTC, and PCT+HT, the female prevalence rate was 100%, 91.6%, and 77.8%, respectively. Mean age was 41.5, 43.3, and 48.5 years, respectively. No association was observed between the two diseases in the present study where HT occurred in 31.1% of the benign cases and in 27.3% of malignant cases (p = 0.8).In spite of the absence of association between HT and PCT, the possibility of malignancy in HT should always be considered because of the coexistence of the two diseases already reported in the literature.Avaliar a associação entre tireoidite de Hashimoto (TH) e carcinoma papilífero da tireoide (CPT).Pacientes foram avaliados por punção aspirativa guiada pela ultrassonografia. Para TH consideraram-se aspectos característicos da citopatologia e/ou achados histopatológicos clássicos. O diagnóstico de CPT foi considerado apenas pela histopatologia.De 1.049 pacientes portadores de bócios uni-multinodulares (903 femininos e 146 masculinos), 173 (16,5%) tinham quadro citopatológico de tireoidite. Dos 49 pacientes operados, 33 (67,4%) revelaram CPT, dos quais 9 (27,3%) tinham a glândula com quadro histopatológico de TH. Dos 16 pacientes sem malignidade, 5 (31,3%) exibiam também TH. Nos grupos TH, CPT e CPT+TH, a proporção de acometimento do gênero feminino foi, respectivamente, 100%, 91,6% e 77,8%. A distribuição da média da idade (anos) nos três grupos foi 41,5, 43,3 e 48,5. Não houve associação entre as duas doenças, neste estudo, em que a TH esteve presente em 31,3% dos casos benignos e em 27,3% dos casos malignos (Não houve associação entre TH e CPT, mas a possibilidade de malignidade em TH deve ser sempre lembrada em razão da concomitância das duas doenças, já revelada na literatura.