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PURPOSE Hydroxyurea (HY) is a reference treatment of advanced myeloproliferative neoplasms. We conducted a randomized phase III trial comparing decitabine (DAC) and HY in advanced myeloproliferative chronic myelomonocytic leukemias (CMML). PATIENTS AND METHODS Newly diagnosed myeloproliferative CMML patients with advanced disease were randomly assigned 1:1 to intravenous DAC (20 mg/m2/d days 1-5) or HY (1-4 g/d) in 28-day cycles. The primary end point was event-free survival (EFS), events being death and acute myelomonocytic leukemia (AML) transformation or progression. RESULTS One-hundred seventy patients received DAC (n = 84) or HY (n = 86). Median age was 72 and 74 years, and median WBC count 32.5 × 109/L and 31.2 × 109/L in the DAC and HY arms, respectively. Thirty-three percent of DAC and 31% of HY patients had CMML-2. Patients received a median of five DAC and six HY cycles. With a median follow-up of 17.5 months, median EFS was 12.1 months in the DAC arm and 10.3 months in the HY arm (hazard ratio [HR], 0.83; 95% CI, 0.59 to 1.16; P = .27). There was no significant interaction between treatment effect and blast or platelet count, anemia, CMML Prognostic Scoring System, Groupe Francophone des Myelodysplasies, or CMML Prognostic Scoring System–mol risk. Fifty-three (63%) DAC patients achieved a response compared with 30 (35%) HY patients ( P = .0004). Median duration of response was similar in both arms (DAC, 16.3 months; HY, 17.4 months; P = .90). Median overall survival was 18.4 months in the DAC arm and 21.9 months in the HY arm ( P = .67). Compared with HY, DAC significantly reduced the risk of CMML progression or transformation to acute myelomonocytic leukemia (cause-specific HR, 0.62; 95% CI, 0.41 to 0.94; P = .005) at the expense of death without progression or transformation (cause-specific HR, 1.55; 95% CI, 0.82 to 2.9; P = .04). CONCLUSION Compared with HY, frontline treatment with DAC did not improve EFS in patients with advanced myeloproliferative CMML (ClinicalTrials.gov identifier: NCT02214407 ).

Waffle chart (%) of patients addressed for cytopenia exploration after OC exposed to a PARPi treatment from cytopenia diagnosis (A) and cytopenia diagnosis based on NGS results (B). Dot plots (C) showing the median WBC, hemoglobin, and platelet counts from patients referred for cytopenia exploration after OC exposed to a PARPi treatment according to t-MN diagnosis (“t-MN”) or not (“Cytopenia”).

Blood smear and bone marrow aspiration of patient referred for cytopenia post PARPi.

Commutation plot visualizing the mutated genes in t-MN after OC according to PARPi treatment.

Univariate analysis for overall survival from t-MN diagnosis of patients from the national cohort.

Flow chart of the study displaying the three cohorts.

TP53 mutations characteristics among t-MN PARPi national cohort.

Univariate analysis for overall survival from t-MN diagnosis of patients diagnosed with t-MN after OC according to PARPi exposure.

Purpose:To provide insights into the diagnosis and management of therapy-related myeloid neoplasms (t-MN) following PARP inhibitors (PARPi).Experimental Design:In a French cancer center, we identified and described the profiles of 13 t-MN diagnosed among 37 patients with ovarian cancer referred to hematology consultation for cytopenia under PARPi. Next, we described these 13 t-MN post-PARPi among 37 t-MN post ovarian cancer according to PARPi exposure. Finally, we described 69 t-MN post-PARPi in a national cohort.Results:From 2016 to 2021, cumulative incidence of t-MN was 3.5% (13/373) among patients with ovarian cancer treated with PARPi. At time of hematologic consultation, patients with t-MN had a longer PARPi exposure (9 vs. 3 months, P = 0.01), lower platelet count (74 vs. 173 G/L, P = 0.0005), and more cytopenias (2 vs. 1, P = 0.0005). Compared with t-MN not exposed to PARPi, patients with t-MN-PARPi had more BRCA1/2 germline mutation (61.5% vs. 0%, P = 0.03) but similar overall survival (OS). In the national cohort, most t-MN post-PARPi had a complex karyotype (61%) associated with a high rate of TP53 mutation (71%). Median OS was 9.6 months (interquartile range, 4–14.6). In multivariate analysis, a longer time between end of PARPi and t-MN (HR, 1.046; P = 0.02), olaparib compared with other PARPi (HR, 5.82; P = 0.003) and acute myeloid leukemia (HR, 2.485; P = 0.01) were associated with shorter OS.Conclusions:In a large series, we described a high incidence of t-MN post-PARPi associated with unfavorable cytogenetic and molecular abnormalities leading to poor OS. Early detection is crucial, particularly in cases of delayed cytopenia.

MDS-RS patients are characterized by chronic anemia and a low risk of Acute Myeloid Leukemia (AML) progression and they generally become Red Blood Cell (RBC) transfusion dependent (TD).We performed a retrospective "real-life" observational study of 6 months in 100 MDS-RS TD patients, recruited in 12 French centers, to describe transfusion characteristics, and evaluate the frequency and causes of hospitalizations, health costs, and morbidity, associated with transfusion dependency, in a French population of RBC transfusion-dependent MDS-RS patients.79% of the patients had high transfusion burden (HTB) and 21% low transfusion burden (LTB). HTB patients had a longer disease duration (6 vs. 3.7 years, p = 0.0078), more frequent iron chelation (82% vs. 50%, p = 0.0052) and higher serum ferritin (p = 0.03). During the 6-month study period, 22% of the patients required inpatient hospitalization, 36% of them for symptomatic anemia requiring emergency RBC transfusion. The 6-month median transfusion costs, including the cost of the day care facility, transportation to and from the hospital, iron chelation, and lab tests, was 16,188€/patient.MDS-RS represents the archetypal type of chronically transfused lower-risk MDS. Most of those patients have a high transfusion burden and thus frequently need visits to the hospital's day care facility, and frequent hospitalizations, with an overall high median treatment cost. Those costs should be compared with costs of new treatments potentially able to avoid RBC transfusion dependence and to reduce the complications of chronic anemia in MDS-RS patients.

Mouse models of chronic myeloid malignancies suggest that targeting mature cells of the malignant clone disrupts feedback loops that promote disease expansion. Here, we show that in chronic myelomonocytic leukemia (CMML), monocytes that accumulate in the peripheral blood show a decreased propensity to die by apoptosis. BH3 profiling demonstrates their addiction to myeloid cell leukemia-1 (MCL1), which can be targeted with the small molecule inhibitor S63845. RNA sequencing and DNA methylation pattern analysis both point to the implication of the mitogen-activated protein kinase (MAPK) pathway in the resistance of CMML monocytes to death and reveal an autocrine pathway in which the secreted cytokine-like protein 1 (CYTL1) promotes extracellular signal-regulated kinase (ERK) activation through C-C chemokine receptor type 2 (CCR2). Combined MAPK and MCL1 inhibition restores apoptosis of monocytes from patients with CMML and reduces the expansion of patient-derived xenografts in mice. These results show that the combined inhibition of MCL1 and MAPK is a promising approach to slow down CMML progression by inducing leukemic monocyte apoptosis.

Purpose: To provide insights into the diagnosis and management of therapy-related myeloid neoplasms (t-MN) following PARP inhibitors (PARPi). Experimental Design: In a French cancer center, we identified and described the profiles of 13 t-MN diagnosed among 37 patients with ovarian cancer referred to hematology consultation for cytopenia under PARPi. Next, we described these 13 t-MN post-PARPi among 37 t-MN post ovarian cancer according to PARPi exposure. Finally, we described 69 t-MN post-PARPi in a national cohort. Results: From 2016 to 2021, cumulative incidence of t-MN was 3.5% (13/373) among patients with ovarian cancer treated with PARPi. At time of hematologic consultation, patients with t-MN had a longer PARPi exposure (9 vs. 3 months, P = 0.01), lower platelet count (74 vs. 173 G/L, P = 0.0005), and more cytopenias (2 vs. 1, P = 0.0005). Compared with t-MN not exposed to PARPi, patients with t-MN-PARPi had more BRCA1/2 germline mutation (61.5% vs. 0%, P = 0.03) but similar overall survival (OS). In the national cohort, most t-MN post-PARPi had a complex karyotype (61%) associated with a high rate of TP53 mutation (71%). Median OS was 9.6 months (interquartile range, 4–14.6). In multivariate analysis, a longer time between end of PARPi and t-MN (HR, 1.046; P = 0.02), olaparib compared with other PARPi (HR, 5.82; P = 0.003) and acute myeloid leukemia (HR, 2.485; P = 0.01) were associated with shorter OS. Conclusions: In a large series, we described a high incidence of t-MN post-PARPi associated with unfavorable cytogenetic and molecular abnormalities leading to poor OS. Early detection is crucial, particularly in cases of delayed cytopenia.

International audience; Acute and chronic renal failures are very common after allogeneic HSCT. These complications have a real impact on mortality and morbidity of transplant recipients. Within the framework of the ninth workshops of practice harmonization of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) held in Lille in September 2018, various causes and mechanisms of renal failure, diagnostic work-up, treatment and recommendations to limit renal failure after transplantation are reviewed. Recommendations to adjust medications to avoid renal failure are also proposed in this article.

Resume Les complications stomatologiques de l’allogreffe de cellules souches hematopoietiques (CSH) sont frequentes et tres inconfortables pour les patients. La reaction du greffon contre l’hote represente la principale complication. Les infections, les troubles du gout et les risques carcinologiques constituent les autres effets secondaires de la procedure. Differents traitements locaux sont utilises mais restent imparfaits. Dans le cadre de la dixieme edition des ateliers d’harmonisation des pratiques en allogreffe, organises par la Societe francophone de greffe de moelle et de therapie cellulaire (SFGM-TC) a Lille, en septembre 2019, la demarche diagnostique et les traitements des complications orales apres allogreffe de CSH ont ete revus apres analyse des resultats des etudes publiees.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive leukemia for which we developed a nationwide network to collect data from new cases diagnosed in France. In a retrospective, observational study of 86 patients (2000-2013), we described clinical and biological data focusing on morphologies and immunophenotype. We found expression of markers associated with plasmacytoid dendritic cell origin (HLA-DRhigh, CD303+, CD304+, and cTCL1+) plus CD4 and CD56 and frequent expression of isolated markers from the myeloid, B-, and T-lymphoid lineages, whereas specific markers (myeloperoxidase, CD14, cCD3, CD19, and cCD22) were not expressed. Fifty-one percent of cytogenetic abnormalities impact chromosomes 13, 12, 9, and 15. Myelemia was associated with an adverse prognosis. We categorized chemotherapeutic regimens into 5 groups: acute myeloid leukemia (AML)–like, acute lymphoid leukemia (ALL)–like, lymphoma (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP])–like, high-dose methotrexate with asparaginase (Aspa-MTX) chemotherapies, and not otherwise specified (NOS) treatments. Thirty patients received allogeneic hematopoietic cell transplantation (allo-HCT), and 4 patients received autologous hematopoietic cell transplantation. There was no difference in survival between patients receiving AML-like, ALL-like, or Aspa-MTX regimens; survival was longer in patients who received AML-like, ALL-like, or Aspa-MTX regimens than in those who received CHOP-like regimens or NOS. Eleven patients are in persistent complete remission after allo-HCT with a median survival of 49 months vs 8 for other patients. Our series confirms a high response rate with a lower toxicity profile with the Aspa-MTX regimen, offering the best chance of access to hematopoietic cell transplantation and a possible cure.

Background Acute myeloid leukemia mainly affects adult patients. Complete remission for patients younger than 60 years, who are candidates for standard induction therapy, is achieved in 60%-80% of cases. However, the prognosis is still poor for older patients, who are unfit for intensive chemotherapy, and only a few therapies are available. Hypomethylating agents, such as decitabine, are approved for such patients. The current dosing regimen consists of one administration per day, for 5 days, each 4 weeks. Methods Here, we present the synthesis of a decitabine prodrug, combined with its encapsulation into a lipid-based nanocapsule formulation. Decitabine (C12)2 was synthetized, then loaded into nanocapsules. Its stability in phosphate buffer ans human plasma was checked. Its activity was evaluated by Cell proliferation assays and cell-cycle analysis on human erythroleukemia cells. Then its pharmacokinetics was determined on a rat model. Results Decitabine (C12)2 was obtained with a yield of 50%. Drug loading into nanocarriers of 27.45±0.05 nm was 5.8±0.5 mg/mL. The stability of decitabine was improved and its activity on leukemia cells was not altered. Finally, pharmacokinetics studies showed a prolonged mean residence time of the drug. Conclusion Decitabine (C12)2 as a prodrug showed high encapsulation efficiency, a good stability in plasma with no impact on its activity on leukemia cells and improved pharmacokinetics.

International audience; Objectives: Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukaemia (CMML) are associated with systemic inflammatory and autoimmune diseases (SIADs) in 10-30% of cases. The aims of this study were (i) to evaluate the prevalence of venous thromboembolism VTE in patients presenting with both MDS/CMML and SIADs, (ii) to describe risk factors associated with thrombosis, and (iii) to analyse the impact of VTE on overall survival and transformation to acute myeloid leukaemia in comparison to patients with MDS/CMML-associated SIADs without VTE.Methods: This retrospective multicentre case-control study was conducted among patients with MDS/CMML and dysimmune disorders and featured in the French retrospective database of the French Network of Dysimmune Disorders Associated with Hemopathies (MINHEMON), diagnosed with MDS/CMML and dysimmune disorders.Results: During a median follow-up of 16 months (5-48) VTE occurred in 35 patients (21.6 %) whereas 127 patients did not. Among those with VTE, 8 patients (22.9%) experienced two or more VTE. Common prothrombotic risk factors were not significantly different in patients with or without VTE. CMML was more frequent in patients without VTE (37 % vs. 14.3%, p=0.01), whereas myelodysplasic/myeloproliferative neoplasm (MDS/MPN) was higher in VTE patients (20 % vs. 5.5 %, p=0.01). In a multivariate analysis, only MDS/CMML progression at the time of VTE (odds ratio 28.82, 95 % CI (5.52-530.70) was significantly associated with VTE. When treated with an anticoagulation therapy, bleeding occurred in 19.4% of cases (6/31). Overall survival was not significantly different between patients with and without VTE (p=0.68). Leukaemia-free survival between groups was not significantly different (p=0.83).Conclusions: VTE is a common complication in MDS/CMML-associated SIADSs with an increased risk of bleeding when treated by anticoagulants. In the MDS/CMML subgroup, SIADS flares and MDS/CMML progression seem to be prothrombotic risk factors.

The benefit of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with acute myeloid leukemia (AML) aged >60 years remains a matter of debate, notably when performed in first complete remission (CR1). To clarify this issue, the French Innovative Leukemia Organization (FILO) performed a 10-year real-world time-dependent analysis. The study enrolled patients between 60 and 70 years of age with AML in CR1 after intensive chemotherapy with intermediate (IR) or unfavorable (UR) risk according to the European LeukemiaNet (ELN) 2010 classification. The impact of allo-HSCT was analyzed through three models: (1) time-dependent Cox; (2) multistate for dynamic prediction; and (3) super landmark. The study enrolled 369 (73%) IR and 138 (27%) UR patients with AML, 203 of whom received an allo-HSCT. Classical multivariate analysis showed that allo-HSCT significantly improved relapse-free survival (RFS; hazard ratio [HR] [95% confidence interval (CI)], 0.47 [0.35-0.62]; P < .001) and overall survival (OS; HR [95% CI], 0.56 [0.42-0.76]; P < .001), independently of the ELN risk group. With the multistate model, the predicted 5-year probability for IR and UR patients to remain in CR1 without allo-HSCT was 8% and 1%, respectively. Dynamic predictions confirmed that patients without allo-HSCT continue to relapse over time. Finally, the super landmark model showed that allo-HSCT significantly improved RFS (HR [95% CI], 0.47 [0.36-0.62]; P < .001) and OS (HR [95% CI], 0.54 [0.40-0.72]; P < .001). allo-HSCT in CR1 is reported here as significantly improving the outcome of fit older patients with AML. Long-term RFS without allo-HSCT is very low (

PURPOSE Patients with lower-risk (LR) myelodysplastic syndromes (MDS) who are RBC transfusion dependent and have experienced relapse after or are refractory to erythropoiesis-stimulating agent (ESA) have limited treatment options. High telomerase activity and human telomerase reverse-transcription expression in clonal hematopoietic cells have been reported in patients with MDS. Imetelstat, a first-in-class competitive inhibitor of telomerase enzymatic activity, targets cells with active telomerase. We report efficacy, safety, and biomarker data for patients with LR MDS who are RBC transfusion dependent and who were relapsed/refractory to ESAs. PATIENTS AND METHODS In this two-part phase II/III study (MDS3001), the primary end point was 8-week RBC transfusion independence (TI) rate, with key secondary end points of 24-week RBC TI rate, TI duration, and hematologic improvement-erythroid. RESULTS Data from the phase II part of the study are reported. Of 57 patients enrolled and treated (overall population), 38 were non-del(5q) and hypomethylating agent and lenalidomide naïve (subset population). The 8- and 24-week RBC TI rates in the overall population were 37% and 23%, respectively, with a median TI duration of 65 weeks. In the subset population, 8- and 24-week RBC TI rates were 42% and 29%, respectively, with a median TI duration of 86 weeks. Eight-week TI rate was observed across all subgroups evaluated. Cytogenetic and mutational data revealed a reduction of the malignant clones, suggesting disease modification activity. The most common adverse events were cytopenias, typically reversible within 4 weeks. CONCLUSION Imetelstat treatment results in a meaningful, durable TI rate across a broad range of heavily transfused patients with LR MDS who are ineligible for or relapsed/refractory to ESAs. Biomarker analyses indicated effects on the mutant malignant clone.

Background: Allo HSCT is a potentially curative treatment in MDS which, in higher risk (IPSS high and int 2) MDS demonstrated an overall survival (OS) advantage over conventional treatment (especially HMAs) in retrospective (Koreth et al., JCO 2013) and prospective (Robin et al. leukemia 2015) studies. Retrospective studies, on the other hand, suggested no OS advantage for allo HSCT in lower risk MDS (IPSS low and int 1), except possibly in the "poorest" lower risk MDS subsets, as classified by the WPSS (Alessandrino et al. AMJH 2013) However, about 25% of lower risk MDS patients are reclassified as higher risk by the R-IPSS and a proportion of other lower risk MDS can also harbor some higher risk features that compromise their outcome. MDS-ALLO-RISK trial (clinicaltrial.gov NCT02757989), was designed to assess outcome of lower risk MDS patients with some high-risk features after HLA-matched donor HSCT. Method: The primary objective of this study was to demonstrate an OS improvement in lower risk MDS patients with some high risk features with a donor compared with those without a donor (with a 3 year OS of 70% versus 40%, respectively) . Inclusion criteria were: IPSS low or int1 MDS with at least one of the following characteristics: 1) R-IPSS intermediate or higher 2) RBC transfusion dependent anemia and failure to two or more treatments (including EPO, Lenalidomide or HMA ); 3) platelets < 20 G/L requiring transfusions 4) ANC < 0.5 G/L with severe infection 5) no contra indication to allo HSCT 6) age Results: 79 patients were included, 64 in group A and 15 in group B. Median age was 62.4 (IQR: 58-65) years in group A and 66 (IQR: 60.5-68) years in group B. Patients in group A were more frequently males (73 vs 40%, p=0.029), WHO was CMML in 8 (10%), MDS-SLD in 5 (8%), MDS-MLD in 9 (11%), MDS-EB1 in 41 (52%), MDS-RS in 12 (15%), unclassified in 4 (6%) without significant differences between the two groups. IPSS /IPSS-R was similar in both groups: IPSS low in 10% (11% in group A and 7% in group B) and Int-1 in 90%. IPSS-R: very low risk (6% vs 0%); low risk (25% vs 27%); intermediate (50% vs 47%); high (19% vs 27%); no very high risk. Among the 64 patients with a donor, 58 (92%) received HSCT, 2 died before HSCT; 2 had progressive disease and 2 are planned for HSCT. Transplanted patients received reduced intensity conditioning regimen with busulfan 6.4mg/kg, fludarabine 150mg/m2 and ATG (rabbit antithymocyte globulin therapy, grafalon®) 30mg/kg and cyclosporine-mycophenolate mofetil as GVHD prophylaxis. In group A, 21/64 had died, including 13 died from a non-relapse cause. In group B, 4/15 patients had died, 3 from MDS progression and one from CNS bleeding. Three-year OS was 60% (95%CI: 46.9-76.8) in group A and 64.2% (41.3-99.6) in group B (p=NS). At the time of analysis, 20 and 5 patients had progressed/relapsed in group A and B respectively. with a cumulative incidence of relapse/progression (from inclusion) of 27.4% (IC95%: 15;39.8) in group A and 41.7% (IC95%:9.2;74.2) in group B (p=0.71). Among the 58 transplanted patients, 11 (19%) died without disease progression, including one death from a solid tumor. 3 years non-relapse mortality in transplanted patients was 23.4% (IC95%:9.7;37). 3 years Incidence of grade 2 to 4 acute GVHD was 40.8% and 3 years chronic GVHD was 24.9%. Conclusion: In this, to our knowledge, first prospective study in IPSS lower risk patients with some unfavorable clinical or biological features, HLA identical donor (sibling or 10/10 unrelated) HSCT yielded a 3-year OS of 60%. Non relapse mortality was however 23%, and OS somewhat lower than expected (70% at 3 years) and similar to that observed in patients without a donor. Long-term follow-up is needed to better define subgroups of IPSS lower risk MDS that may benefit from allo HSCT. Disclosures Sebert: Abbvie: Consultancy; BMS: Consultancy. Cluzeau: Pfizer: Other: travel, accommodations, expenses; Astellas: Speakers Bureau; Amgen: Speakers Bureau; Agios: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Speakers Bureau; Roche: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Speakers Bureau; Takeda: Other: travel, accommodations, expenses; Jazz Pharma: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau. Loschi: AbbVie: Ended employment in the past 24 months, Honoraria; CELGENE/BMS: Honoraria; Gilead: Ended employment in the past 24 months, Honoraria; Novartis: Ended employment in the past 24 months, Honoraria; Servier: Ended employment in the past 24 months, Honoraria; MSD: Honoraria. Huynh: Jazz Pharmaceuticals: Honoraria. Ades: ABBVIE: Honoraria; NOVARTIS: Honoraria; CELGENE/BMS: Honoraria; CELGENE: Research Funding; JAZZ: Honoraria, Research Funding; TAKEDA: Honoraria. Fenaux: JAZZ: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Robin: NEOVII MEDAC NOVARTIS: Research Funding.

Background and aims: intensive chemotherapy (IC) has been used since the early 90's in the treatment of higher risk MDS, yielding 40 to 50% complete response (CR) but prolonged myelosuppression and 10 to 30% early deaths. IC is also recommended before allogeneic (allo) SCT when marrow blasts are increased (De Witte et al, Blood, 2017). CPX-351, a liposomal combination of cytarabine and daunorubicin, proved greater efficacy than classical IC with 3+7 in secondary-AML, including in patients with 20-30% marrow blasts and those who subsequently received allo SCT (Lancet et al, Lancet Haematol, 2021). We evaluated response to CPX-351 in a group of untreated higher risk MDS patients, most of whom were candidates for allo SCT. Methods: This prospective study, involving 12 GFM centers, included int-2 or high IPSS MDS, previously untreated with HMA or chemotherapy, and aged Results: 31 patients were included between July 2020 and January 2021. Median age was 62 years (range 31-69); WHO classification: 26 MDS-EB2, 5 CMML-2; IPSS: int-2: 84%, high: 16%; R-IPSS: intermediate: 29%, high: 55%, very high: 16%; karyotype: 2 very good, 22 good, 3 intermediate, 2 poor, 2 very poor. 27 patients received one induction cycle and 4 (in stable disease (SD) after the first cycle), a second induction cycle. Response rates, eventually evaluated a median of 53 days (range 28-112) from onset of induction, were with ELN 2017 criteria: CR: 52%, CRi: 13%, MLFS: 23%, SD: 13% and with IWG 2006 criteria : CR: 23%, mCR: 45%, mCR + HI-P: 6%, mCR + HI-P + HI-N: 6%, mCR + HI-N: 3%, PR: 3%, SD: 13%. Minimal residual disease assessment by NGS and flow cytometry will be presented at the meeting. 24/27 patients with baseline marrow blasts >10%, reached 20G/L and >50G/L were: 16 (range 0-55) days and 28 (range 8-51), respectively and to ANC >1G/L: 26 (range 2-60) days. Only one patient had grade ≥ 3 mucositis and 4 had grade ≥ 2 alopecia during induction treatment. No patient died during induction treatment or required management in the intensive care unit. With a median follow-up of 201 days (range 102-350), 22 of the 30 patients initially considered for allo SCT received transplant after no (10 pts), 1 (9 pts), 2 or 3 (3 pts) consolidation cycles and 5 are planned for allo SCT. Reasons for not being transplanted were, investigators' choice (n=1), relapse (1), no donor (1) and invasive fungal infection (n=1). None of the 4 non transplanted patients received consolidation cycles. Reasons for not receiving consolidation cycles were persistent cytopenia (n=5), cardiac toxicity (n=2), failure to achieve CR or PR (n=2). At the time of analysis (June 2021), 4 patients had relapsed, after 3 to 6 months of response. Conclusions : CPX-351 is effective in higher risk MDS/CMML, especially to achieve blast clearance, and as a bridge to allo SCT. Figure 1: waterfall plot according to IWG 2006 and ELN 2017 criteria Figure 1 Figure 1. Disclosures Fenaux: Novartis: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria; Takeda: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. OffLabel Disclosure: CPX-351 use off-label for myelodysplastic syndroms in a prospective trial

Background : ENA is a selective inhibitor of IDH2 approved in the US for the treatment of patients with relapsed/refractory IDH2 mutated AML. Little is known on its efficacy in patients with IDH2m myelodysplastic syndromes. Here we report the preliminary results of a Phase 2 study evaluating the safety and efficacy of ENA in three different cohorts of MDS : Higher risk MDS having failed HMA (cohort A, n=29), untreated higher risk MDS without life threatening cytopenias (ie ANC < 500/mm3 or any recent severe infections and/or platelets below 30,000/mm3 and any bleeding symptom, cohort B, with the addition of AZA in non-Responders after 3 cycles, n=29) and lower risk MDS having failed ESA (cohort C, n=10). (ClinicalTrials.gov NCT03744390). Methods : Subjects enrolled in cohort A, B or C received continuous 28-day cycles of ENA - 100 mg PO QD. In cohort B, Azacitidine (75 mg/m2/d x 7 days, SC) was added to Enasidenib after 3 cycles, only in the absence of IWG 2006 response (absence of CR, PR or HI). The primary endpoint was Overall hematological response (including CR, PR,stable disease with HI according to IWG 2006). All patients who achieved CR, PR or HI were considered as responders and could continue treatment until loss of response. Secondary endpoints of the trial included safety,duration of response, EFS, Overall survival and translational project evaluating the role of biomarkers on response.We report interim results in the first 26 pts enrolled. Resul t s : At data cut off (6/15/2021), 45 pts were enrolled, including 26 who were evaluable for the primary endpoint. 11, 9 and 6 were enrolled in cohort A, B and C respectively. Median age was 75.5 years and 34.6% were female. WHO was MDS-MLD, MDS-RS-SLD, MDS-RS-MLD, MDS-EB1, MDS-EB2, CMML and AML (with 20-30% blast) in 1, 2, 3,4, 10, 2 and 4 pts, respectively. IPSS was low, intermediate 1, int 2 and high in 1, 7, 13, 5 resp. IPSS-R was low,intermediate, high and very high in 4, 8, 11, 3 resp. At data cut off, 10 pts were still on treatment. Most common reasons for discontinuing ENA were Treatment failure (7.7%), disease progression (23.1%), adverse events (7.7%) and death (3.8%). Three patients experienced a differentiation syndrome (1 in cohort A and 2 in cohort B) that resolved without sequelae. Other most common grade 3-4 AEs were nausea/diarrhea (n=4) and thrombocytopenia (n=5). Overall best response rate (ORR including CR, PR, and HI) was achieved in 11 pts (42 %), including 6 CR (55%), 2 PR (18%), 2 mCR with HI (18%), 1 Stable disease with HI (9%). ORR was achieved in 3 (27 %), 5 (56 %) and 3 (50%)in cohort A, B and C respectively. In cohort B, AZA wad added to ENA in 3 patients who were primarily resistant to ENA. Among them, 2/3 patients subsequently achieved a response. Moreover, CR was seen in 2, 1 and 3 in cohort A, B and C respectively. The 6 months response rate was 29.5 % [6 ;59], 53.1 % [11.7 ;83] and 50 % [7.7 ;82.9] in cohort A, B and C respectively. At the time of analysis, all responses but 2 were sustained. Responses were lower (p=0.27) among the 23 pts with IDH2 R140 (30.4%) as compared to the 3 with IDH2 R172 mutation (66.7%). With a median follow up of 8.6 months, the median OS was 17.3 months (figure 1). Six patients died during follow-up, including 4/11 in cohort A, 1/9 in cohort B and 1/6 in cohort C. The 6 months death rate observed was 8.2 % [0 ;18.4] and the 1-year OS was 55.4%, 100% and 80% in cohorts A, B and C, respectively. Four patients evolved to AML (2 and 2 in cohort A and B) with a 1y risk of AML of 19.3%. Conclusion : Results from the first 26 patients included in this study show that ENA has no limiting toxicity in patients with MDS and that it can provide responses in 42% of patients. These responses appear to be encouraging, especially in first-line (low and high risk) patients. An update of this study will be presented. Figure 1 Figure 1. Disclosures Ades: JAZZ: Honoraria; Novartis: Honoraria; Abbvie: Honoraria; Takeda: Honoraria; Celgene: Honoraria, Research Funding. Sebert: BMS: Consultancy; Abbvie: Consultancy. Stamatoulas Bastard: Pfizer: Other: Travel Support; Celgene: Membership on an entity's Board of Directors or advisory committees. Laribi: Novartis: Other: Personal Fees, Research Funding; AstraZeneca: Other: Personal Fees; BeiGene: Other: Personal Fees; Takeda: Other: Personal Fees, Research Funding; Jansen: Research Funding; Le Mans Hospital: Research Funding; IQONE: Other: Personal Fees; AbbVie: Other: Personal Fees, Research Funding; Astellas Phama, Inc.: Other: Personal Fees. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Platzbecker: AbbVie: Honoraria; Takeda: Honoraria; Celgene/BMS: Honoraria; Janssen: Honoraria; Geron: Honoraria; Novartis: Honoraria. Fenaux: Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. OffLabel Disclosure: enasidenib is not approved for MDS

Background: Ivosidenib (IVO) is an oral, targeted, small-molecule inhibitor of mutant IDH1 approved in the US for adult patients with unfit or relapse/refractory AML with IDH1 mutation. Little is known on its efficacy in patients with IDH1 mutated MDS. Here we report interim results of a Phase 2 study evaluating safety and efficacy of IVO in three different cohorts of MDS patients: Higher risk MDS having failed azacytidine (AZA) (cohort A, n=29), untreated higher risk MDS without life threatening cytopenias (ie ANC < 500/mm3 or any recent severe infections and/or platelets below 30,000/mm3 and any bleeding symptom,) as a first line treatment (cohort B, with the addition of AZA in non-Responders after 3 cycles, n=29) and lower risk MDS having failed EPO (cohort C, n=10). (ClinicalTrials.gov NCT03503409). Methods: Subjects enrolled in cohort A, B or C received continuous 28-day cycles of IVO - 500 mg orally QD. In cohort B, AZA (75 mg/m2/d x 7 days, SC) was added to IVO after 3 cycles, only in the absence of IWG 2006 response (absence of CR, PR or HI). The primary endpoint was overall hematological response rate (ORR) at 3 and 6 months (including CR, PR, stable disease with HI according to IWG 2006). All responders allowed to continue treatment until loss of response. Secondary endpoints included safety, duration of response, EFS, overall survival and translational project evaluating the role of biomarkers on response. We report the preliminary results on the first 26 pts enrolled. Results: At data cut off (6/15/2021), 32 patients had been enrolled, including 26 who were evaluable for the primary endpoint. 13, 11 and 2 were enrolled in cohort A, B and C respectively. Median age was 76 years and 50% were female. WHO was MDS-MLD, MDS-EB1, MDS-EB2, CMML and low blast count AML in 2, 2, 12, 1 and 9 patients respectively. IPSS-R was low, intermediate, high and very high in 2, 6, 5 and 13 resp. IDH1 mutation was p.R132C in 15 patients, p.R132H in 7, p.R132G/S in 3 and not specified in 1. The ORR was 69% (18 patients) including 12 CR (46%), 1 PR and 5 HI. Most patients achieved response after 3 cycles (17/18). Response was achieved in 7 (54%), 10 (91%) and 1 (50%) in cohort A, B and C respectively. Moreover, CR was achieved in 3, 8 and 1 in cohort A, B and C respectively. In cohort B, AZA was added to IVO in one patient after 3 cycles, without additional response. With a median follow up of 9.1 months, the median duration of response of the 18 responders was 7.4 months, 9 of them lost their response, and two had died without loss of response (from bleeding and after HSCT, respectively). IPSS-R was the only prognostic factor of response after 6 cycles. At data cut off, 12 patients had progressed (9 in cohort A, 2 in cohort B and 1 in cohort C) and 11 (42%, 10 in cohort A and 1 in cohort C) patients had died, mostly of relapse/progression (n=5/11), infection in 1, suicide in 1, hemorrhage in 1 and other unrelated causes in 3. Median overall survival was 14 months in the whole cohort, 7.7 and not reached in cohort A and B resp. The most common treatment-related serious adverse event (SAE) was differentiation syndrome (4/5), one died and three resolved without sequelae. One patient had febrile neutropenia related to IVO, resolved without sequelae. Conclusion: IVO was well tolerated in MDS patients with significant responses in all the cohorts. With a response rate of 91%, IVO was particularly effective in treatment naïve higher risk MDS patients with IDH1 mutations (cohort B). These encouraging preliminary results have to be confirm in more patients. The IDIOME study is still ongoing, and molecular monitoring results of IDH1 mutations will be presented. Disclosures Sebert: BMS: Consultancy; Abbvie: Consultancy. Cluzeau: Abbvie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Speakers Bureau; Agios: Honoraria; Amgen: Speakers Bureau; Takeda: Other: travel, accommodations, expenses; Astellas: Speakers Bureau; Jazz Pharma: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Other: travel, accommodations, expenses. Stamatoulas Bastard: Pfizer: Other: Travel Support; Celgene: Membership on an entity's Board of Directors or advisory committees. Fenaux: Abbvie: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Ades: Abbvie: Honoraria; Takeda: Honoraria; Novartis: Honoraria; JAZZ: Honoraria; Celgene: Honoraria, Research Funding.

Introduction: Imetelstat is a first-in-class telomerase inhibitor that targets cells with high telomerase activity and human telomerase reverse transcriptase (hTERT) expression, characteristics observed in MDS patients (pts) across all disease stages. IMerge (MDS3001, NCT02598661) is a Phase 2/3 global study of imetelstat for red blood cell (RBC) transfusion dependent (TD) pts with non-del 5q LR-MDS ESA-R/R, who have limited treatment options. The results from the Phase 2 part indicated that imetelstat achieved durable transfusion independence (TI) with a manageable safety profile. Among 38 pts with median follow-up of 24 months, ≥8-week (w), ≥24-w, ≥1-year (y) TI rates were 42%, 32% and 29%, respectively (Steensma JCO 2020, Platzbecker ASH 2020). Aims: To assess the correlation between imetelstat's on-target activity with clinical benefits and safety data as of 10-May 2021 in the Phase 2 part of IMerge. Methods: Peripheral blood samples pre and after 1 and 2 cycles of imetelstat administration were collected to analyze hTERT level by Taqman RT-PCR assay. ≥50% hTERT reduction by imetelstat was considered optimal pharmacodynamic (PD) effect. Correlation analyses between the optimal PD and efficacy, including TI rates ≥8-w, ≥24-w, and ≥1-y, duration of the longest TI, and OS, as well as hematological and liver function lab parameters were performed. Results: hTERT analyses on 35/38 pts with matched pre- and post-1 to 2 cycles of treatment samples available demonstrated on-target activity/optimal PD effect of imetelstat in 54.3% (19/35) of pts. Pts who achieved optimal PD had significantly higher rates of TI compared to pts who did not achieve optimal PD: 63.2% (12/19) vs 25% (4/16) had ≥8-w TI (p=0.0411); 57.9% (11/19) vs 12.5% (2/16) had ≥24-w TI (p=0.0125); and 52.6% (10/19) vs 6.3% (1/16) had ≥1-y TI (p=0.0125) (Fig A). Pts who achieved optimal PD effect had a greater reduction in transfusions (both absolute change in transfusion units and % of change in transfusion burden) in the best 8-week interval compared to pts who did not. In addition, pts who achieved optimal PD had a significantly longer median TI duration (68.4 w, 95% CI 4.9, 92.4) compared to those who did not (5.5 w, 95% CI 2.3, 6.6) with a hazard ratio of 0.364 (95% CI 0.167, 0.794, log-rank p value=0.0087, Fig B). Furthermore, median OS was 57.0 months (95% CI 34.6, -) in pts who achieved optimal PD vs 40.7 months (95% CI 26.9, -) in pts who did not, and the 4-year OS rate was 58.4% vs 31.0%, respectively, although not statistically significant. Pts who achieved optimal PD also had lower rates of Grade 3+neutropenia (52.6%), thrombocytopenia (57.9%), or liver function elevations (5.3%) compared to pts who did not achieve optimal PD (68.8%, 68.8% and 18.8%, respectively), although the differences were not statistically significant. Conclusion: Optimal PD effect of imetelstat treatment was demonstrated by ≥50% hTERT reduction. A significant correlation was observed between optimal PD effect of imetelstat and durable TI and improved 4-year OS rate, effectively linking imetelstat activity to clinical efficacy. Additionally, pts who achieved an optimal PD effect by imetelstat treatment did not have higher rates of cytopenias or liver enzyme elevations compared to pts without optimal PD effect. Enrollment is ongoing for the Phase 3 part of IMerge, a randomized (2:1) double-blind, placebo-controlled trial to compare efficacy of imetelstat vs. placebo. Figure 1 Figure 1. Disclosures Santini: Menarini: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Geron: Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Fenaux: JAZZ: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Raza: Celgene Inc: Research Funding, Speakers Bureau; Novartis: Speakers Bureau; Genoptix: Speakers Bureau; Kura Oncology: Research Funding; Janssen R&D: Research Funding; Syros Pharmaceuticals: Research Funding; Onconova Therapeutics: Research Funding, Speakers Bureau. Germing: Bristol-Myers Squibb: Honoraria, Other: advisory activity, Research Funding; Janssen: Honoraria; Jazz Pharmaceuticals: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria. Font: CELGENE-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodations, expenses; GILEAD: Membership on an entity's Board of Directors or advisory committees; Menarini: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses, Speakers Bureau; Abbvie: Other: Travel, accomodations, expenses. Diez-Campelo: BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Patnaik: Kura Oncology: Research Funding; Stemline Therapeutics: Membership on an entity's Board of Directors or advisory committees; Stemline Therapeutics: Membership on an entity's Board of Directors or advisory committees. Sherman: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Berry: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Feller: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Dougherty: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Sun: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Wan: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Rizo: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Huang: Geron Corp: Current Employment, Current equity holder in publicly-traded company. Platzbecker: Takeda: Honoraria; AbbVie: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Geron: Honoraria; Celgene/BMS: Honoraria. OffLabel Disclosure: Imetelstat, a first-in-class telomerase inhibitor, is under clinical development but not approved for treatment of MDS

Because of the persistently high rates of relapse of patients with high-risk acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) following allogeneic hematopoietic stem cell transplantation (allo-HSCT), post-transplantation maintenance therapy has been proposed. We previously initiated a Phase II trial in which epigenetic therapy was combined with immunotherapy in an attempt to reduce disease relapse. In that study, low-dose azacitidine (AZA) and escalating doses of donor lymphocyte infusion (DLI) were given as post-allo-HSCT maintenance treatment. In the present study, we retrospectively analyze a larger cohort of patients receiving post-transplantation maintenance therapy and provide updates on some patients of the earlier study. The objectives of the present study were to analyze the cumulative incidence of relapse (CIR), overall survival (OS), and progression-free survival (PFS) and the incidence of acute and chronic graft-versus-host disease (GVHD) of patients with high-risk AML or MDS receiving post-transplantation maintenance treatment with AZA with or without DLI. We retrospectively analyzed 77 patients (54 with AML, 23 with MDS) considered at high risk based on either their genomic or clinical status at transplantation. Following allogeneic transplantation, they received at least 1 cycle of prophylactic or preemptive low-dose AZA with or without escalating doses of DLI to prevent disease relapse. Almost one-half of the patients (47%) were able to receive the full 12 cycles of scheduled AZA, and a majority (79%) received at least 1 DLI. With a median follow-up of 24 months, 19 patients (25%; 16 with AML, 3 with MDS) relapsed, at a median of 9.8 months (range, 4 to 58.6 months), giving a 22% CIR at 24 months. OS and PFS at 24 months were 70.8% and 68.3%, respectively. The cumulative incidences of grade II-IV acute GVHD and chronic GVHD were 27.4% and 45%, respectively. Only a minority of patients (11%) required delayed administration of AZA. These findings confirm that AZA-DLI maintenance is both tolerable and effective in reducing the risk of post-transplantation relapse.

International audience; Background. Admission of allogeneic stem cell transplantation (SCT) recipients to the intensive care unit (ICU) remains controversial , especially when graft-versus-host disease (GVHD) is present. Methods. We performed a retrospective study to assess prognostic factors of survival in all allogeneic SCT recipients admitted to the ICU between 2002 and 2013 in our center which has flexible admission criteria, especially regarding GVHD. Results. Of 349 patients who underwent allogeneic SCT during the study period, 92 patients (26%) were admitted to the ICU. Intensive care unit and hospital discharge rates were 66% and 46%, respectively , whereas 1 year survival was 24%. Acute GVHD, either grade III to IV (30 patients, 33%) or refractory (12 patients, 13%) had a nonsignificant impact on hospital mortality (odds ratio [OR], 2.1; P = 0.1; OR, 5, P = 0.05, respectively). Fifty percent of patients required invasive mechanical ventilation, 30% required vasopressors, 17% required renal replacement therapy, and 28% had liver impairment (bilirubin >34 μmol/L), each of these parameters defining organ failure. Mortality was closely associated with the number of organ failures as hospital discharge rates were 69%, 50%, 42%, and 0% among patients with 0 (26 patients), 1 (26 patients), 2 (26 patients), and 3 to 4 (14 patients) organ failures, respectively (OR, 2.7; 95% confidence interval, 1.6-4.6; P < 0.001 according to the number of organ failures). Conclusions. Early mortality of allogeneic SCT recipients admitted to the ICU is especially influenced by the number of organ failures and therefore patients with 0 to 2 organ failures should be considered if required. Refractory GVHD affects survival but not within the confined ICU admission.

Context: Thrombocytopenia ( Methods: In this a phase I/II, open-label, single arm, multicenter study, key inclusion criteria were: WHO 2008 defined HMA-naive CMML, PLT < 50 x109/L, marrow blasts ≤ 5%, IPSS low/int-1 in MD-CMML, and in MP-CMML no or only 1 severity criteria (Hb < 10 g/dL, ANC > 16 x109/L, abnormal karyotype, extramedullary disease), spleen size < 16 cm. ELT was started at 100mg/d (amended to 50 mg/d) with escalating dose up to 300mg/d for at least 12 weeks. Primary endpoint was Platelet Response (HI-P) at 12 weeks, according to IWG 2006 criteria. Responders could continue ELT until protocol-defined progression, loss of response or toxicity. Results: Between August 2014 and September 2018, 30 pts (median age 77.5 years; M/F 22/8) including 21 MD-CMML and 9 MP-CMML were enrolled. 19 pts had CMML-0 and 11 pts CMML-1 with median PLT count of 32 x109/L (IQR 21-43 x109/L). 12 pts were PLT transfusion dependent (PLT-TD). In the 28 pts sequenced, TET2 mutation (mut) was found in 26 pts, RUNX1mut in 16 pts, SRSF2mut in 11 pts, ASXL1mut in 9 pts, signaling mut in 10 pts and PHF6mut in 5 pts. Median ELT dose at 12 weeks was 150 mg/d (IQR 100-262.5 mg/d). At 12 weeks, 14 pts (46.7%) achieved HI-P (95%CI 28 ; 66%) including 10 MD-CMML and 4 MP-CMML irrespective of PLT-TD status (p=0.46). Responders and non-responders mutational profile was comparable except that none of the 5 PHF6mut pts responded (p=0.06). Responders received ELT for a median of 33 weeks (IQR 17.3-49.5 weeks) with one responder still on therapy at 24 months. Median duration of response was 3.4 months (95%CI: 1.7-11.6 months). Loss of response were due to PLT decrease (11 pts) or transfusion (5 pts) and disease progression (3 pts). At 12 weeks, bleeding symptoms (all grades) were present in 3 (38%) non-responders and 4 (29%) responders. Clinical and biological grade≥ 3 adverse events (AE) were reported in 15 pts each. Before 12 weeks, 24 clinical and 16 biological AE occurred in 7 and 10 pts resp. Toxicity was cardiovascular, pulmonary or gastro intestinal in 2 pts each resp., hepatic and musculo-skeletal in 1 pt each and others in 3 pts. Biological toxicity was hepatic in 4 pts, electrolytic in 4 pts and others in 3 pts. Five pts discontinued ELT due to persistent drug related toxicity. No therapy-related deaths were reported. With a median follow-up of 17 months, 14 pts progressed (including 4 AML transformations) and 17 died. The12-month cumulative incidence of AML was 7% (95%CI: 1-21%). No factors were associated with risk of transformation in univariate analysis (neither WBC nor molecular mutational profile). Two-years OS and PFS were 47% (95%CI: 31-71%) and 28% (95%CI: 15-52%) respectively. Splice mutations were associated with better PFS in univariate analysis (HR=0.29, (95%CI: 0.11-0.76%); p=0.012). In the 21 CMML pts with PLT < 50 x109/L and ≤5% BM blasts from our previous CMML cohort (Itzykson JCO 2013) who were not exposed to ELT, the 12-month estimates cumulative incidence of AML was 10% (95%CI: 0-23%). Comparison with a larger historical cohort not exposed to ELT is ongoing. Conclusion: In CMML patients with severe thrombocytopenia and no marrow blast excess, treatment with ELT is safe and induces frequent but mostly transient responses without increasing the risk of CMML progression. ELT could thus help manage a situation at risk of bleeding such as a scheduled surgical procedure. Phase III studies may be useful to confirm the role of ELT in CMML patients with thrombocytopenia. Disclosures Rabian: Novartis: Honoraria; Jazz Pharmaceuticals: Honoraria. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Braun:Daiichi Sankyo: Honoraria; Servier: Research Funding. Ades:jazz: Membership on an entity's Board of Directors or advisory committees, Research Funding; novartis: Research Funding; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Celgene/BMS: Research Funding. Solary:Janssen: Research Funding. Itzykson:Oncoethix (now Merck): Research Funding; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Otsuka Pharma: Membership on an entity's Board of Directors or advisory committees; BMS (Celgene): Honoraria; Janssen: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria; Sanofi: Honoraria; Amgen: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Honoraria; Abbvie: Honoraria; Stemline: Membership on an entity's Board of Directors or advisory committees.

Context. The perhaps only CMML-specific Randomized Clinical Trial (RCT) established hydroxyurea (HY) as the main treatment (Tx) for advanced proliferative CMML (Wattel Blood 1996). In Europe, the only hypomethylating agent (HMA) approved in CMML is AZA in non proliferative CMML-2. Phase 2 trials reported the activity of decitabine (DAC) in advanced proliferative CMML (Braun Blood 2011, Santini Leukemia 2018). We performed a RCT of DAC (±HY during the first 3 cycles) vs HY alone in those pts. Methods. The DACOTA trial (EudraCT 2014-000200-10) accrued pts with previously untreated (or < 6 weeks of HY), proliferative (WBC ≥ 13x109/L) CMML with advanced disease defined per Wattel et al as presence of extramedullary disease or ≥2 criteria among: BM blasts ≥5%, abnormal karyotype (except -Y), ANC ≥ 16x109/L, Hb < 10 g/dL, platelets < 100 x109/L or splenomegaly > 5 cm below costal margin. Pts were randomized 1:1 to DAC (20 mg/m2/d IV 5d/28d) or HY (1g/d, adjusted on WBC, 28d cycles) and treated until death, AML transformation or progression. The primary endpoint was EFS, events being death, transformation to AML, progression of myeloproliferation after 3+ cycles or progression of blasts and cytopenias after 6+ cycles. Response was assessed with IWG 2006 criteria modified to account for improvement of myeloproliferation, after central morphology review. Intent-to-treat analyses were done considering missing responses as failures. Results. From Oct 2014 to Sep 2019, 217 pts from 47 centers were screened and 170 randomized (84 DAC and 86 HY), including 12 pts (6 DAC and 6 HY) who never started Tx. Median age was 73 years (IQR 68-78). WHO was CMML-NA/1/2 in 2, 114 and 54 pts, respectively (resp). Median WBC 34.9 x109/L (IQR 22.9-55.7). Cytogenetic risk (Such Haematologica 2011) was fav 69%, int 12%, adv 18% NA 1%. Mutations in TET2, SRSF2, ASXL1 and signaling genes (CBL, JAK2, FLT3, KIT, NRAS, KRAS and CSF3R) were present in 64%, 51%, 62% and 57% resp. 72 pts had received HY for a median 27 days prior to randomization. Aside from older age in the HY arm (median 74 vs 71.5y in the DAC arm), there was no imbalance between Tx arms. DAC and HY pts received a median of 5 (IQR 3-12) and 6 (IQR 3-14) cycles, resp. As of 15th June 2020, 5 and 10 DAC and HY pts were still on Tx. Reasons for Tx cessation in the DAC arm were death (n=19), AML transformation (n=16), progression (n=9) , hematological toxicity (n=13) or other (n=21). Reasons for Tx cessation in the HY arm were death (n=14), AML transformation (n=13), progression (n=18), hematological toxicity (n=6) or other (n=20). 126 and 85 pts received 3 and 6 cycles, resp. In the ITT population, ORR at 3 cycles was 56% (7CR, 25 mCR±HI, 15 SD+HI) and 30% (0 CR, 8 mCR±HI, 18 SD+HI) in the DAC and HY arms, resp (p=0.0011) and ORR at 6 cycles was 32% (6 CR, 9 mCR±HI, 12 SD+HI) and 17% (2 CR, 4 mCR±HI, 9 SD+HI) in the DAC and HY arms, resp (p=0.033). Median response duration was 15.9 vs 18.2 months (mos) in the DAC and HY arm, resp (p=0.81). Infection and hemorrhage occurred at least once in 49% and 31% of pts, resp. 55% of DAC pts and 38% of HY pts required hospitalization at least once (p=0.05). Non-heme ≥ grade 2 AEs occurred in 79% and 63% of DAC and HY arms, resp (p=0.03). Grade ≥3 cardiac AEs occurred in 13 DAC and 4 HY pts, resp. With a median follow-up of 13.9 mos, median EFS was 12.6 vs 10.3 mos in the DAC and HY arms, resp (reference DAC arm, HR= 1.14 CI95 0.8-1.64, p= 0.46). Median AML-free survival (AMLFS) was 13.6 and 15.8 mos in the DAC and HY arms resp (p=0.86). Median OS was 18.4 and 23.1 mos in the DAC and HY arms, resp (p=0.72). Considering death and AML transformation as competing risks there was no significant difference in cumulative incidence of AML (p=0.1) or death without transformation (p=0.06) between arms. 30 pts from the HY arm received an HMA (DAC n= 13, AZA n= 16, both=1) after study exit. Censoring at HMA onset in the HY arm, median OS was 18.4 vs 30.4 in the DAC and HY arm, resp (p=0.15). 13 pts were transplanted (DAC n= 10, HY n= 3). There was no interaction between Tx arm and CMML-0/1 vs -2, platelets ≥ vs 0.05). Conclusion. RCTs are feasible in advanced proliferative CMML, which remains an unmet medical need. In these pts, DAC did not provide an overall or event-free survival advantage over HY. HY remains a valid option in advanced proliferative CMML. However, one third of HY pts subsequently received an HMA and more DAC pts achieved a response and were bridged to HSCT. Figure Disclosures Itzykson: Abbvie: Honoraria; Daiichi Sankyo: Honoraria; Otsuka Pharma: Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria; Sanofi: Honoraria; BMS (Celgene): Honoraria; Janssen: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Stemline: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncoethix (now Merck): Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Santini:BMS, J&J, Novartis: Honoraria; Acceleron, BMS, Menarini, Novartis: Consultancy; Takeda, Pfizer: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding. Lionel:Abbvie: Consultancy; Takeda: Consultancy; Celgene/BMS: Consultancy, Research Funding; Novartis: Consultancy; Jazz: Consultancy, Research Funding. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Giagounidis:AMGEN: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Luebbert:Janssen: Research Funding. Park:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Other: Travel expenses. Stamatoulas Bastard:Pfizer: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene: Honoraria; Takeda: Consultancy. Solary:Janssen: Research Funding. Platzbecker:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria; Amgen: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Geron: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Fenaux:Novartis: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Jazz: Honoraria, Research Funding. OffLabel Disclosure: Decitabine for CMML with WBC > 13 x109/L.

Introduction Citrulline, a non-essential amino acid produced exclusively by enterocytes in the small intestine and involved in the synthesis of L-arginine, is not metabolized by the liver. Therefore citrulline serum concentration is highly correlated with functional enterocyte mass, and decreases with digestive toxicity induced by conditioning therapy (radiotherapy and/or chemotherapy) for hematopoietic stem cell transplantation (HSCT) . Acute Graft-versus-host disease (GvHD), one of the major complications of HSCT, is correlated to conditioning-induced gut barrier damage and may be predicted by pre-transplant serum citrulline level (Rashidi, BBMT 2018). It could be interesting to know whether citrulline kinetics could also represent a biomarker for conditioning toxicity, non-relapse mortality (NRM), and GvHD. The aim of this study is thus to define group-based trajectory modeling, to identify clusters of individual serum citrulline kinetics in the early phase of allogeneic HCST, and to test whether these unsupervised trajectories were correlated with these early complications. Materials and Methods Serum citrulline was quantified by liquid chromatography in blood samples collected from consecutive patients who received an allogeneic HSCT in our institution between July 2014 and November 2019. These samples were drawn at different time-points: pre-transplant (D-7, D-3); day of transplant (D0), and post-transplant (D7, D15, D21). Distinct trajectories were identified for serum citrulline by using the semiparametric mixture model described by Nagin (Nagin, Stat Methods Med Res 2018). Results Among 161 patients (pts) included in the study, with a median age of 53 years (17-72), 98 pts (60.9%) received a reduced-intensity conditioning (RIC), 36 pts (22.4%) reduced-toxicity conditioning (RTC), 18 pts (11.1 %) sequential conditioning, and 9 pts (5.6%) myeloablative conditioning (MAC). Donor were identical sibling (22%), matched unrelated donor (52%) and haploidentical sibling (25%). Graft source was peripheral blood mononuclear cells in 144 pts (89.4%) and bone marrow in 17 pts (10.6%) respectively. HCT-CI score was low, intermediate and high-risk in 38%, 32%, and 30% of pts respectively. Disease-Risk Index (DRI) was low/intermediate in 111 pts (69%) and high/very-high in 50 pts (31%). With a median follow up of 29.1 month, 3-year overall survival (OS), disease-free survival (DFS), and NRM rates were 64.5%, 58.3%, and 18.9%, respectively. The median number of citrulline samples per patient was 7 [3-16]. Median citrulline concentrations before conditioning and at D-3, D0, D7 and D15 were statistically different during RIC, RTC, MAC, and sequential conditioning (p In the whole cohort, 3 citrulline trajectories were determined in an unsupervised method. Patients belonging to these 3 trajectories were different according to intensity of conditioning received with lower citrulline trajectories during MAC and sequential conditioning (p After restricting the analysis to pts who received RIC conditioning (n=98), higher pre-HSCT citrulline concentrations were associated with a lower NRM (p=0.042). Unsupervised analysis in this setting individualized 4 clusters of individual trajectories (figure 1), that did neither distinguish age (p=0.28), DRI (p=0.87), HCT-CI score (p=0.81) nor the incidence of acute (p=0.6) or chronic (p=0.4) GvHD. However, the lowest citrulline trajectory contained significantly more haploidentical transplantations (p=0.004) and less pts who received antithymocyte globulin for GvHD prophylaxis (p=0.005). Interestingly in this RIC cohort, cumulative incidence of NRM at 12 months was 23%, 21%, 8%, and 0% respectively according to the 4 citrulline trajectories (figure 2). Conclusion In patients receiving allogeneic HSCT, the variation of serum citrulline concentrations depends on the intensity of the conditioning regimen. In patients who received RIC conditioning, lower plasma citrulline trajectories are associated with higher NRM. In this setting, citrulline may be an attractive biomarker for predicting conditioning toxicity and NRM. Disclosures Hunault: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Diachi: Membership on an entity's Board of Directors or advisory committees; Jansen: Honoraria; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria.

Introduction: Pre-transplant comorbidities, which may impact the success of allogeneic stem cell transplantation (AlloSCT) can be appreciated through 3 different scoring systems. The Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) allows to predict non-relapse mortality (NRM) and survival (Sorror, Blood 2005). Its prognostic value was further augmented by the addition of donor age (< vs ≥40 yo) (Comorbidity/Age index, C/AI, Sorror, JCO 2014) then of pre-transplant ferritin (< or >2500 µg/L) and albumin (3.5g/dL) serum levels as well as platelet count (< vs >100 109/L) (Augmented Comorbidity/Age index, AC/AI, Elsawy, BBMT 2019). The performance of these 3 scores has not been evaluated in haploASCT using post-transplant cyclophosphamide (PTCY), a procedure in constant expansion worldwide. Material and Methods: We studied retrospectively the impact on non-relapse mortality (NRM), overall (OS) and disease-free (DFS) survival of the 3 comorbidity scores on a cohort of 223 patients (pts) having received a haploSCT with PTCY. All pts had pre-transplant ferritin and albumin levels and platelet counts available. These parameters were evaluated at the time of the pre-transplant check-up or just before conditioning (median from transplant: 20 days, range: 4-49). Results: Pts were recruited in 4 French centers (Nantes n=127; Angers n=45; Besançon n=29, Brest n=22). They had received haploSCT between October 2013 and January 2020. There were 136 males and 87 females with a median age of 55 yo (16-71, >40 years n=172). The majority of pts had a myeloid disease (n=157) and received a reduced intensity regimen (n=161, myeloablative n=30; sequential n=32). Respectively, 132 and 91 pts had low/intermediate and high/very-high Disease-Risk Index (DRI). All pts received PTCY, cyclosporine and mycophenolate mofetyl as graft versus host disease (GVHD) prophylaxis. Donors had a median age of 40.8 years (19.4-71.7). Median HCT-CI, C/AI and AC/AI scores were 2 (0-8), 3 (0-9) and 3 (0-11), respectively. The HCT-CI score was 5 in 110, 83 and 30 pts, respectively, while the AC/AI score was With a median follow-up for alive patients of 35.6 months (6-77), 3-year OS, DFS and NRM were 47.8+3%, 46+3% and 29.4+6%, respectively. In univariate analysis, better 3-year OS and DFS were associated with lymphoid diseases (OS: 60.4+6% vs 42.3+4%, p=0.02; DFS: 56.2+6% vs 41.6+4%, p=0.04), low/intermediate DRI (OS: 59.1+4% vs 30.1+7%, p3.5g/dL 50.1+4%, p=0.03; 3.5g/dL 47.4+3%, p=0.05). OS and DFS were not impacted by ferritin levels, platelet count, recipient age, gender, nor any of the 3 comorbidity scores. A lower 3-year NRM was observed in younger pts ( In multivariate analysis, each comorbidity score was compared to DRI, donor and patient age, type of disease and pre-transplant albumin levels. DRI and donor age remained associated with OS and DFS. This was also the case for recipient age, except when considering a high C/AI index score. Finally, an older age of recipients and donors remained associated with higher NRM. Conclusion: HCT-CI, C/AI and AC/AI do not to predict survivals nor NRM in haploSCT with PTCY, suggesting that pre-transplant comorbidities should not be a contra-indication to this procedure. As donor age is the only factor predicting survivals and NRM in this series, while multiple donors are generally available in the haploSCT setting, the selection of a younger donor should be the rule whenever possible for all patients. Disclosures Hunault: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Diachi: Membership on an entity's Board of Directors or advisory committees; Jansen: Honoraria; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Deconinck:ImmunoGen: Consultancy, Research Funding; Stemline: Consultancy. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Le Gouill:Loxo Oncology at Lilly: Consultancy; Roche Genentech, Janssen-Cilag and Abbvie, Celgene, Jazz pharmaceutical, Gilead-kite, Loxo, Daiichi-Sankyo and Servier: Honoraria. Chevallier:Incyte Corporation: Honoraria.

Background: Most IPSS low and int1 (lower) risk MDS patients with isolated del(5q) develop RBC TD or need treatment for symptomatic anemia early after diagnosis (median time to transfusion/treatment of 20 months, López Cadenas et al abstract 3180 ASH, 2016). Lenalidomide (LEN) is a reference treatment in MDS-del(5q) but approved in many countries only when RBC-TD occurs. LEN directly targets the del(5q) clone improving anemia and quality of life. Limited data also suggest a role of LEN in non-TD patients with del(5q) (Oliva et al Cancer Med 2015), but no randomized trial has assessed the efficacy and tolerance of early LEN treatment in this MDS subset. Material: The Sintra-Rev clinical trial is a phase III European multicenter study in low-risk MDS-del(5q) patients with anemia (Hb Results: Main clinical characteristics of the 61 patients (ITT population) included (Feb-2010 to Feb-2018) are summarized in Table 1: 82% females, median age 72 years (range 37-89), median time since diagnosis 3.6 months, median Hb at inclusion 9.8 g/dL (7.1 - 11.7) g/dL and 93% patients had isolated del(5q). Four patients were excluded due either to screening failure (1 pat) or failure to complete at least 12w of treatment (3 pat). Fifty-seven patients were included in the ITT evaluable population for efficacy and 59 for safety (2 patients did not receive any drug). Median time on treatment was 66 weeks (3-121), 95w in the LEN arm and 42w in the placebo arm (p=0.392). Forty-seven percent patients in the LEN arm successfully completed the study compared to 33% in the placebo arm. After a median follow up of 25.6 months (Q1 16-Q3 39), median OS was not achieved. Among the 57 patients evaluable for efficacy, median time to TD was 75.7 mo for the LEN patients and 25.9 mo for the placebo arm (HR 2.703, 95CI1.162-6.286, p=0.021, figure 1). HI-E response was observed in 72.5% of LEN patients compared to 0% in the placebo arm (p Fifty-eight patients developed at least one adverse event (AE) during the trial (no differences between the LEN and placebo arm), related to the drug 86.8% in the LEN and 33.3% in the placebo arm, respectively (p Conclusions: In this interim analysis we confirm that low dose LEN (5 mg) in anemic non-TD low risk MDS del(5q) patients prolongs the period of time to TD (75.7 mo vs 25.9 mo), improves Hb levels (72.5% of ER) and induces clonal responses (70% complete CyR), ie potentially more responses than in historical series of MDS del(5q) treated with LEN at time of TD, with a manageable safety profile, and no increased progression rate. Longer follow up will be required to assess the effect of early treatment with LEN, and particularly the effect of the early reduction of the del(5q) clone size, on long-term outcomes. Disclosures Hernandez-Rivas: Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Rovi: Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Sanz:LaHoffman Roche Ltd.: Membership on an entity's Board of Directors or advisory committees; Abbvie Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Takeda Pharmaceutical Ltd.: Membership on an entity's Board of Directors or advisory committees; Helsinn: Membership on an entity's Board of Directors or advisory committees. Giagounidis:AMGEN: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Platzbecker:BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Geron: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Götze:Celgene: Research Funding. Fenaux:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Jazz: Honoraria, Research Funding. Diez-Campelo:Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. OffLabel Disclosure: LEN IN ANEMIC BUT NOT TD PATIENTS WITH LOW RISK MDS AND DEL(5Q)

Background: MDS-RS are associated with a low risk of Acute Myeloid Leukemia (AML) progression and prolonged survival in most cases, but recurring anemia whose treatments, including Erythropoiesis Stimulating Agent (ESA), Lenalidomide, hypomethylating agents (HMAs), Luspatercept, and experimental drugs generally have transient effect and/or are not widely available. MDS-RS patients thus eventually have regular Red Blood Cells (RBC) transfusion dependency (TD) associated with mean low hemoglobin levels, and chronic anemia responsible for reduced quality of life, cardiovascular complications, and iron overload with organ dysfunction. We performed a retrospective observational study to describe transfusion characteristics and costs, along with clinical events, in a French population of RBC TD MDS-RS patients. Methods: Adult RBC-TD patients with MDS-RS from 12 hematology departments of the GFM were included. The number of RBC concentrates transfused was assessed over the last 6 months (during which no other treatment than transfusions was received), and patients categorized in low transfusion burden (LTB: 3 to 7 RBC/16 weeks) and high transfusion burden (HTB: ≥8 RBC concentrates /16 weeks). Data about iron chelation, full time hospitalization (differing from day care facility stays for programmed transfusions), causes of hospitalization, treatment of anemia before inclusion and transfusion costs was collected. Results: 100 patients MDS-RS were included, with a median time from diagnosis of 5 years (1 to 21 years). Median age was 78 years (57 to 99). Patients had received a median of 2 lines of treatment (including an ESA in 97% of them). 21% had LTB and 79% HTB. HTB patients had a longer disease duration, more frequent iron chelation (82% versus 50% in LTB patients, p=0.0052) and higher serum ferritin at inclusion (median 1958 µg/l versus 1176 µg/l, p=0.03). During the 6-month study period, 22% of the patients required full time hospitalization (in addition to day care facility for transfusions), including 25% of patients with HTB and 15% with LTB, and 43% during overall disease follow-up. Causes of full time hospitalization (figure) were symptomatic anemia (41%), general condition degradation (5%) or cardiac disease (8%), to both of which anemia potentially contributed, infection (23%), bleeding (8%), pulmonary (2%), 13% for other reasons. 15 HTB patients versus 1 LTB patient were hospitalized for symptomatic anemia. The 6-months average transfusion costs, including cost of the day care facility for RBC transfusion, transportation to and from the hospital, lab tests and iron chelation were $21459/patient, excluding costs of full-time hospitalization for complications. The average cost in HTB and LTB patients was $22829 and $7586/patient, respectively. Conclusion: Most MDS-RS patients currently become RBC-TD, often during several years, and most have high transfusion burden. The average cost of RBC transfusions and iron chelation was $21459/ 6 months. During this short observation time, 22% of the patients required full time hospitalization, due to complications of anemia in at least 50% of the cases, which also increased costs (comparison with rates of hospitalization in an age and sex matched general population will be presented). Poor quality of life associated with chronic anemia should also be taken into account in those RBC-TD patients. Widely available treatments, capable of avoiding RBC transfusion dependence and improving mean hemoglobin levels, are required in those MDS-RS patients. Disclosures Cony-Makhoul: BMS: Speakers Bureau; Incyte Biosciences: Speakers Bureau; BMS: Consultancy; Novartis: Consultancy; Pfizer: Consultancy. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Cluzeau:Celgene: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Menarini: Consultancy; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Stamatoulas Bastard:Takeda: Consultancy; Pfizer: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene: Honoraria. Fenaux:Jazz: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Park:Pfizer: Other: Travel expenses; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees.

The efficacy of azacitidine in patients with anemia and with lower-risk myelodysplastic syndromes, if relapsing after or resistant to erythropoietic stimulating agents, and the benefit of combining these agents to azacitidine in this setting are not well known. We prospectively compared the outcomes of patients, all of them having the characteristics of this subset of lower-risk myelodysplastic syndrome, if randomly treated with azacitidine alone or azacitidine combined with epoetin-β. High-resolution cytogenetics and gene mutation analysis were performed at entry. The primary study endpoint was the achievement of red blood cell transfusion independence after six cycles. Ninety-eight patients were randomised (49 in each arm). Median age was 72 years. In an intention to treat analysis, transfusion independence was obtained after 6 cycles in 16.3% versus 14.3% of patients in the azacitidine and azacitidine plus epoetin-β arms, respectively (P=1.00). Overall erythroid response rate (minor and major responses according to IWG 2000 criteria) was 34.7% vs. 24.5% in the azacitidine and azacitidine plus epoetin-β arms, respectively (P=0.38). Mutations of the SF3B1 gene were the only ones associated with a significant erythroid response, 29/59 (49%) versus 6/27 (22%) in SF3B1 mutated and unmutated patients, respectively, P=0.02. Detection of at least one “epigenetic mutation” and of an abnormal single nucleotide polymorphism array profile were the only factors associated with significantly poorer overall survival by multivariate analysis. The transfusion independence rate observed with azacitidine in this lower-risk population, but resistant to erythropoietic stimulating agents, was lower than expected, with no observed benefit of added epoetin, (clinicaltrials.gov identifier: 01015352).

Background: Current treatment options for red blood cell (RBC) transfusion-dependent (TD) patients with lower risk (LR) myelodysplastic syndromes (MDS) relapsed after or refractory to erythropoiesis-stimulating agents (ESAs) have limited efficacy and durability; new approaches are needed. Imetelstat is a 13-mer lipid-conjugated oligonucleotide that targets the RNA template of human telomerase and is a competitive inhibitor of telomerase enzymatic activity (Asai et al, Cancer Res 2003; Herbert et al, Oncogene 2005). Preclinical, in vivo xenograft models (Dikmen et al, Cancer Res 2005; Hochreiter et al, Clin Cancer Res 2006) and preliminary clinical data from a pilot study (Tefferi et al, Blood Cancer J 2016) supported initiation of a study in TD LR MDS patients. The Phase 2 part of IMerge demonstrated an 8-week RBC transfusion independence (RBC-TI) rate of 42%, 24-week RBC-TI rate of 32%, with median duration of TI being 88 weeks. The responses were seen across different subtypes of LR MDS (Platzbecker et al, EHA 2020, S183). No new safety signal was identified. These results support the Phase 3 part of the trial. Methods: IMerge is two-part, Phase 2/3 study (ClinicalTrials.gov: NCT02598661). The Phase 2 portion of the study described above is closed for enrolment. The Phase 3 portion of the study is open for enrollment of adult patients with International Prognostic Scoring System (IPSS) low or intermediate-1 risk, non-del(5q) MDS, who are TD, are relapsed after or refractory to ESAs, and have not received treatment with lenalidomide or hypomethylating agents. The study is a randomized (2:1) double-blind, placebo-controlled trial to compare efficacy of imetelstat vs. placebo that will enroll approximately 170 patients and will be conducted at approximately 130 centers in North America, Europe, Asia and Middle East. Imetelstat will be administered as 2-hour IV infusion every 4 weeks at 7.5 mg/kg. The primary endpoint of the study is to assess the rate of RBC-TI lasting ≥8 weeks. Secondary endpoints include safety, rate of RBC-TI ≥24 weeks, time to RBC-TI start, RBC-TI duration, rate of hematologic improvement-erythroid (HI-E), the amount and relative change in RBC transfusions, rate of complete response or partial response, overall survival, progression of MDS, pharmacokinetics, and effect of treatment on quality of life. Biomarkers relevant to the mechanism of action of imetelstat will be assessed to demonstrate target inhibition and their association with clinical responses. Cytogenetics and mutation analyses will be performed to evaluate the impact of imetelstat on reduction/depletion of malignant clones leading to disease modification. Disclosures Platzbecker: AbbVie: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Geron: Consultancy, Honoraria; Amgen: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Fenaux:Abbvie: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Jazz: Honoraria, Research Funding. Steensma:CRISPR: Current equity holder in publicly-traded company; Aprea Therapeutics: Research Funding; Takeda: Consultancy; BMS/Celgene: Consultancy; Onconova: Consultancy; Arena: Current equity holder in publicly-traded company; H3 Biosciences: Research Funding; Astex Pharmaceuticals, Otsuka: Consultancy; Arrowhead Pharmaceuticals: Current equity holder in publicly-traded company. Font:Abbvie: Other: Travel, accommodations, expenses; Menarini: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees. Diez-Campelo:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Thepot:astellas: Honoraria; novartis: Honoraria; sanofi: Honoraria; celgene: Honoraria. Jang:Bristol Myers Squibb: Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Research Funding. Sherman:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Dougherty:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Sun:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Huang:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Wan:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Rizo:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Berry:Geron Corp: Current Employment, Current equity holder in publicly-traded company. Feller:Geron Corp: Current Employment, Current equity holder in private company. Santini:Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria; Acceleron: Consultancy; Takeda: Consultancy, Honoraria; Menarini: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria; Johnson & Johnson: Honoraria.

Acute Myeloid Leukemia (AML) and myelodysplasia (MDS) with chromosome 3q abnormalities have a dismal outcome either untreated or with conventional treatments. Azacitidine (AZA) is now considered as the standard of care in high-risk MDS and oligoblastic AML patients. The objective of this study was to evaluate the impact of azacitine treatment in this cytogenetic subgroup. We report here a multicentre retrospective study of 157 patients treated with AZA for AML/MDS with chromosome 3q abnormalities and 27 patients with isolated EVI-1 overexpression. Median age was 65 years, 40 patients (25%) had inv(3)(q21q26.2) or t(3;3)(q21;q26.2), 36 patients (23%) had other balanced 3q26 rearrangements, 8 patients (5%) had balanced 3q21 rearrangements and 73 patients (46%) had other 3q abnormalities. The overall response rate was 50% (29% CR). Median overall survival was 10.6 months. By multivariate analysis, patients with lower bone marrow blast counts, higher platelet counts, non-complex cytogenetics, and absence of prior treatment with intensive chemotherapy had a better outcome. 27 patients were allo-transplanted and achieved a 21-month median OS. Balanced 3q21 translocations were associated with a better response rate and overall survival. Outcome of patients with isolated EVI-1 overexpression was comparable to that of patients with chromosome 3q lesions. Thus, AML/MDS patients with 3q abnormalities appear to be a heterogeneous group in their response to AZA, and AZA may represent a suitable option in particular as a bridge to allogeneic transplantation.

Les syndromes myelodysplasiques (SMD) sont des affections clonales des cellules souches pluripotentes, caracterisees par une hematopoiese inefficace, responsable de cytopenies sanguines qui contrastent avec une moelle generalement riche. De plus, les SMD evoluent frequemment en leucemie aigue myeloide (LAM) et constituent les plus frequents des etats preleucemiques de l’adulte.Les SMD predominent chez le sujet âge, avec une mediane d’âge au diagnostic de l’ordre de 70 [...]

Survival after azacitidine (AZA) failure in higher-risk myelodysplastic syndromes (MDS) is poor and new treatment options are needed. Erlotinib, an oral inhibitor of the epidermal-growth-factor-receptor (EGFR), has shown in preclinical models some efficacy in higher risk MDS and acute myeloid leukemia (AML). In this phase I/II trial, 30 patients received 100 mg/day ( n = 5) or 150 mg/day ( n = 25) of Erlotinib orally after primary or secondary resistance to AZA treatment. Eighteen MDS and 12 AML patients were treated. This outpatient treatment was well tolerated with limited grade III–IV extra hematological toxicities (skin ( n = 1), and diarrhea ( n = 3). Response was observed in 6 patients (20%) including 1 complete remission (CR), 1 marrow CR and 4 hematological improvement (2 erythroid and 2 on platelets). Median duration of response was 5 months. Erlotinib appears to induce a significant number of responses in higher risk MDS/AML having failed AZA treatment. Given the good safety profile of Erlotinib, its combination with other drugs could be tested in the future in MDS and AML.

Limited data are available on azacitidine (AZA) treatment and its prognostic factors in acute myeloid leukemia (AML). One hundred and forty-nine previously untreated AML patients considered ineligible for intensive chemotherapy received AZA in a compassionate patient-named program. AML diagnosis was de novo, post-myelodysplastic syndromes (MDS), post-MPN, and therapy-related AML in 51, 55, 13, and 30 patients, respectively. Median age was 74 years, median white blood cell count (WBC) was 3.2 × 10⁹ /L and 58% of the patients had ≥ 30% marrow blasts. Cytogenetics was adverse in 60 patients. Patients received AZA for a median of five cycles (range 1-31). Response rate (including complete remission/CR with incomplete recovery/partial remission) was 27.5% after a median of three cycles (initial response), and 33% at any time (best response). Only adverse cytogenetics predicted poorer response. Median overall survival (OS) was 9.4 months. Two-year OS was 51% in responders and 10% in non-responders (P 15 × 10⁹ /L and ECOG-PS ≥ 2 predicted poorer OS, while age and marrow blast percentage had no impact. Using MDS IWG 2006 response criteria, among patients with stable disease, those with hematological improvement had no significant survival benefit in a 7 months landmark analysis. Outcomes observed in this high-risk AML population treated with AZA deserve comparison with those of patients treated intensively in prospective studies.