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Symptoms of anaemia due to clinically significant extravascular haemolysis can affect patients with paroxysmal nocturnal haemoglobinuria (PNH) treated with C5 inhibitors (ravulizumab or eculizumab). The aim of this study was to assess the efficacy and safety of danicopan (ALXN2040), an investigational, first-in-class, oral complement factor D inhibitor, as add-on therapy to ravulizumab or eculizumab in patients with PNH and clinically significant extravascular haemolysis.

The main objective of this study was to compare the long-term health-related quality of life of patients with acute promyelocytic leukemia (APL) treated with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) vs ATRA plus standard chemotherapy. Patients previously enrolled in the randomized controlled trial APL0406 were considered eligible for this follow-up study. The following patient-reported outcome measures were used: the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core30 (EORTC QLQ-C30), the EORTC Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy 20 (QLQ-CIPN20), and the Short Form Health Survey 36 (SF-36). The prevalence of late comorbidities and health problems was also assessed. The clinical significance of differences was evaluated based on predefined thresholds. A total of 161 of 232 potentially eligible patients were analyzed, of whom 83 were treated with ATRA-ATO and 78 were treated with ATRA chemotherapy. The median time since diagnosis of the study sample was 8 years. The 2 largest clinically meaningful differences in the EORTC QLQ-C30 were observed for role functioning (Δ = 8.4; 95% confidence interval [CI], 0.5 to 16.3) and dyspnea (Δ = −8.5; 95% CI, −16.4 to −0.7), favoring patients treated with ATRA-ATO. With regard to the SF-36 results, a clinically relevant better physical component score (Δ = 4.6; 95% CI, 1.3 to 7.8) was observed in patients treated with ATRA-ATO, but this was not the case for the mental component score. The 2 groups showed similar profiles in the scores of the EORTC QLQ-CIPN20 scales and in the prevalence of late comorbidities. Overall, our findings suggest that the greater and more sustained antileukemic efficacy of ATRA-ATO is also associated with better long-term patient-reported outcomes than ATRA chemotherapy. This study was registered at www.clinicaltrials.gov as #NCT03096496.

The main objective of this study was to compare the long-term health-related quality of life of patients with acute promyelocytic leukemia (APL) treated with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) vs ATRA plus standard chemotherapy. Patients previously enrolled in the randomized controlled trial APL0406 were considered eligible for this follow-up study. The following patient-reported outcome measures were used: the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core30 (EORTC QLQ-C30), the EORTC Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy 20 (QLQ-CIPN20), and the Short Form Health Survey 36 (SF-36). The prevalence of late comorbidities and health problems was also assessed. The clinical significance of differences was evaluated based on predefined thresholds. A total of 161 of 232 potentially eligible patients were analyzed, of whom 83 were treated with ATRA-ATO and 78 were treated with ATRA chemotherapy. The median time since diagnosis of the study sample was 8 years. The 2 largest clinically meaningful differences in the EORTC QLQ-C30 were observed for role functioning (Δ = 8.4; 95% confidence interval [CI], 0.5 to 16.3) and dyspnea (Δ = −8.5; 95% CI, −16.4 to −0.7), favoring patients treated with ATRA-ATO. With regard to the SF-36 results, a clinically relevant better physical component score (Δ = 4.6; 95% CI, 1.3 to 7.8) was observed in patients treated with ATRA-ATO, but this was not the case for the mental component score. The 2 groups showed similar profiles in the scores of the EORTC QLQ-CIPN20 scales and in the prevalence of late comorbidities. Overall, our findings suggest that the greater and more sustained antileukemic efficacy of ATRA-ATO is also associated with better long-term patient-reported outcomes than ATRA chemotherapy. This study was registered at www.clinicaltrials.govas #NCT03096496.

In chronic myeloid leukemia (CML) patients, tyrosine kinase inhibitors (TKIs) may select for drug-resistant BCR-ABL1 kinase domain (KD) mutants. Although Sanger sequencing (SS) is considered the gold standard for BCR-ABL1KD mutation screening, next-generation sequencing (NGS) has recently been assessed in retrospective studies. We conducted a prospective, multicenter study (NEXT-in-CML) to assess the frequency and clinical relevance of low-level mutations and the feasibility, cost, and turnaround times of NGS-based BCR-ABL1mutation screening in a routine setting. A series of 236 consecutive CML patients with failure (n = 124) or warning (n = 112) response to TKI therapy were analyzed in parallel by SS and NGS in 1 of 4 reference laboratories. Fifty-one patients (22 failure, 29 warning) who were negative for mutations by SS had low-level mutations detectable by NGS. Moreover, 29 (27 failure, 2 warning) of 60 patients who were positive for mutations by SS showed additional low-level mutations. Thus, mutations undetectable by SS were identified in 80 out of 236 patients (34%), of whom 42 (18% of the total) had low-level mutations somehow relevant for clinical decision making. Prospective monitoring of mutation kinetics demonstrated that TKI-resistant low-level mutations are invariably selected if the patients are not switched to another TKI or if they are switched to a inappropriate TKI or TKI dose. The NEXT-in-CML study provides for the first time robust demonstration of the clinical relevance of low-level mutations, supporting the incorporation of NGS-based BCR-ABL1 KD mutation screening results in the clinical decision algorithms.

In chronic myeloid leukemia (CML) patients, tyrosine kinase inhibitors (TKIs) may select for drug-resistant BCR-ABL1 kinase domain (KD) mutants. Although Sanger sequencing (SS) is considered the gold standard for BCR-ABL1 KD mutation screening, next-generation sequencing (NGS) has recently been assessed in retrospective studies. We conducted a prospective, multicenter study (NEXT-in-CML) to assess the frequency and clinical relevance of low-level mutations and the feasibility, cost, and turnaround times of NGS-based BCR-ABL1 mutation screening in a routine setting. A series of 236 consecutive CML patients with failure (n = 124) or warning (n = 112) response to TKI therapy were analyzed in parallel by SS and NGS in 1 of 4 reference laboratories. Fifty-one patients (22 failure, 29 warning) who were negative for mutations by SS had low-level mutations detectable by NGS. Moreover, 29 (27 failure, 2 warning) of 60 patients who were positive for mutations by SS showed additional low-level mutations. Thus, mutations undetectable by SS were identified in 80 out of 236 patients (34%), of whom 42 (18% of the total) had low-level mutations somehow relevant for clinical decision making. Prospective monitoring of mutation kinetics demonstrated that TKI-resistant low-level mutations are invariably selected if the patients are not switched to another TKI or if they are switched to a inappropriate TKI or TKI dose. The NEXT-in-CML study provides for the first time robust demonstration of the clinical relevance of low-level mutations, supporting the incorporation of NGS-based BCR-ABL1 KD mutation screening results in the clinical decision algorithms.

Drs Roeth and Kulasekararaj contributed equally as authors.

The clinical outcome, response to treatment, and occurrence of acute complications were retrospectively investigated in 308 primary autoimmune hemolytic anemia (AIHA) cases and correlated with serological characteristics and severity of anemia at onset. Patients had been followed up for a median of 33 months (range 12-372); 60% were warm AIHA, 27% cold hemagglutinin disease, 8% mixed, and 5% atypical (mostly direct antiglobulin test negative). The latter 2 categories more frequently showed a severe onset (hemoglobin [Hb] levels ≤6 g/dL) along with reticulocytopenia. The majority of warm AIHA patients received first-line steroid therapy only, whereas patients with mixed and atypical forms were more frequently treated with 2 or more therapy lines, including splenectomy, immunosuppressants, and rituximab. The cumulative incidence of relapse was increased in more severe cases (hazard ratio 3.08; 95% confidence interval, 1.44-6.57 for Hb ≤6 g/dL; P< .001). Thrombotic events were associated with Hb levels ≤6 g/dL at onset, intravascular hemolysis, and previous splenectomy. Predictors of a fatal outcome were severe infections, particularly in splenectomized cases, acute renal failure, Evans syndrome, and multitreatment (4 or more lines). The identification of severe and potentially fatal AIHA in a largely heterogeneous disease requires particular experienced attention by clinicians.

The clinical outcome, response to treatment, and occurrence of acute complications were retrospectively investigated in 308 primary autoimmune hemolytic anemia (AIHA) cases and correlated with serological characteristics and severity of anemia at onset. Patients had been followed up for a median of 33 months (range 12-372); 60% were warm AIHA, 27% cold hemagglutinin disease, 8% mixed, and 5% atypical (mostly direct antiglobulin test negative). The latter 2 categories more frequently showed a severe onset (hemoglobin [Hb] levels ≤6 g/dL) along with reticulocytopenia. The majority of warm AIHA patients received first-line steroid therapy only, whereas patients with mixed and atypical forms were more frequently treated with 2 or more therapy lines, including splenectomy, immunosuppressants, and rituximab. The cumulative incidence of relapse was increased in more severe cases (hazard ratio 3.08; 95% confidence interval, 1.44-6.57 for Hb ≤6 g/dL; P < .001). Thrombotic events were associated with Hb levels ≤6 g/dL at onset, intravascular hemolysis, and previous splenectomy. Predictors of a fatal outcome were severe infections, particularly in splenectomized cases, acute renal failure, Evans syndrome, and multitreatment (4 or more lines). The identification of severe and potentially fatal AIHA in a largely heterogeneous disease requires particular experienced attention by clinicians.

This prospective study investigated the efficacy, safety, and response duration of low-dose rituximab (100 mg fixed dose for 4 weekly infusions) together with a short course of steroids as first- or second-line therapy in 23 patients with primary autoimmune hemolytic anemia (AIHA). The overall response was 82.6% at month +2, and subsequently stabilized to ∼ 90% at months +6 and +12; the response was better in warm autoimmune hemolytic anemia (WAIHA; overall response, 100% at all time points) than in cold hemagglutinin disease (CHD; average, 60%); the relapse-free survival was 100% for WAIHA at +6 and +12 months versus 89% and 59% in CHD, respectively, and the estimated relapse-free survival at 2 years was 81% and 40% for the warm and cold forms, respectively. The risk of relapse was higher in CHD and in patients with a longer interval between diagnosis and enrollment. Steroid administration was reduced both as cumulative dose (∼ 50%) and duration compared with the patient's past history. Treatment was well tolerated and no adverse events or infections were recorded; retreatment was also effective. The clinical response was correlated with amelioration biologic markers such as cytokine production (IFN-γ, IL-12, TNF-α, and IL-17), suggesting that low-dose rituximab exerts an immunomodulating activity. This study is registered at www.clinicaltrials.govas NCT01345708.

This prospective study investigated the efficacy, safety, and response duration of low-dose rituximab (100 mg fixed dose for 4 weekly infusions) together with a short course of steroids as first- or second-line therapy in 23 patients with primary autoimmune hemolytic anemia (AIHA). The overall response was 82.6% at month +2, and subsequently stabilized to ∼ 90% at months +6 and +12; the response was better in warm autoimmune hemolytic anemia (WAIHA; overall response, 100% at all time points) than in cold hemagglutinin disease (CHD; average, 60%); the relapse-free survival was 100% for WAIHA at +6 and +12 months versus 89% and 59% in CHD, respectively, and the estimated relapse-free survival at 2 years was 81% and 40% for the warm and cold forms, respectively. The risk of relapse was higher in CHD and in patients with a longer interval between diagnosis and enrollment. Steroid administration was reduced both as cumulative dose (∼ 50%) and duration compared with the patient's past history. Treatment was well tolerated and no adverse events or infections were recorded; retreatment was also effective. The clinical response was correlated with amelioration biologic markers such as cytokine production (IFN-γ, IL-12, TNF-α, and IL-17), suggesting that low-dose rituximab exerts an immunomodulating activity. This study is registered at www.clinicaltrials.gov as NCT01345708.

All-trans-retinoic acid (ATRA) has greatly modified the prognosis of acute promyelocytic leukemia; however, the role of maintenance in patients in molecular complete remission after consolidation treatment is still debated. From July 1993 to May 2000, 807 genetically proven newly diagnosed acute promyelocytic leukemia patients received ATRA plus idarubicin as induction, followed by 3 intensive consolidation courses. Thereafter, patients reverse-transcribed polymerase chain reaction–negative for the PML-RARA fusion gene were randomized into 4 arms: oral 6-mercaptopurine and intramuscular methotrexate (arm 1); ATRA alone (arm 2); 3 months of arm1 alternating to 15 days of arm 2 (arm 3); and no further therapy (arm 4). Starting from February 1997, randomization was limited to ATRA-containing arms only (arms 2 and 3). Complete remission was achieved in 761 of 807 (94.3%) patients, and 681 completed the consolidation program. Of these, 664 (97.5%) were evaluated for the PML-RARA fusion gene, and 586 of 646 (90.7%) who tested reverse-transcribed polymerase chain reaction–negative were randomized to maintenance. The event-free survival estimate at 12 years was 68.9% (95% confidence interval, 66.4%-71.4%), and no differences in disease-free survival at 12 years were observed among the maintenance arms.

All-trans-retinoic acid (ATRA) has greatly modified the prognosis of acute promyelocytic leukemia; however, the role of maintenance in patients in molecular complete remission after consolidation treatment is still debated. From July 1993 to May 2000, 807 genetically proven newly diagnosed acute promyelocytic leukemia patients received ATRA plus idarubicin as induction, followed by 3 intensive consolidation courses. Thereafter, patients reverse-transcribed polymerase chain reaction–negative for the PML-RARAfusion gene were randomized into 4 arms: oral 6-mercaptopurine and intramuscular methotrexate (arm 1); ATRA alone (arm 2); 3 months of arm1 alternating to 15 days of arm 2 (arm 3); and no further therapy (arm 4). Starting from February 1997, randomization was limited to ATRA-containing arms only (arms 2 and 3). Complete remission was achieved in 761 of 807 (94.3%) patients, and 681 completed the consolidation program. Of these, 664 (97.5%) were evaluated for the PML-RARA fusion gene, and 586 of 646 (90.7%) who tested reverse-transcribed polymerase chain reaction–negative were randomized to maintenance. The event-free survival estimate at 12 years was 68.9% (95% confidence interval, 66.4%-71.4%), and no differences in disease-free survival at 12 years were observed among the maintenance arms.

After the identification of discrete relapse-risk categories in patients with acute promyelocytic leukemia (APL) receiving all-transretinoic and idarubicin (AIDA)–like therapies, the Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) designed a protocol for newly diagnosed APL (AIDA-2000) in which postremission treatment was risk-adapted. Patients with low/intermediate risk received remission at 3 anthracycline-based consolidation courses, whereas high-risk patients received the same schedule as in the previous, non–risk-adapted AIDA-0493 trial including cytarabine. In addition, all patients in the AIDA-2000 received all-transretinoic acid (ATRA) for 15 days during each consolidation. After induction, 600 of 636 (94.3%) and 420 of 445 (94.4%) patients achieved complete remission in the AIDA-0493 and AIDA-2000, respectively. The 6-year overall survival and cumulative incidence of relapse (CIR) rates were 78.1% versus 87.4% (P= .001) and 27.7% versus 10.7% (P< .0001). Significantly lower CIR rates for patients in the AIDA-2000 were most evident in the high-risk group (49.7% vs 9.3%, respectively, P< .0001). Our data confirm that anthracycline-based consolidation is at least equally effective as cytarabine-containing regimens for low-/intermediate-risk patients and suggest that a risk-adapted strategy including ATRA for consolidation improves outcome in newly diagnosed APL. Furthermore, our results highlight the role of cytarabine coupled to anthracyclines and ATRA during consolidation in the high-risk group. This trial was registered at www.clinicaltrials.govas #NCT 001064570.

After the identification of discrete relapse-risk categories in patients with acute promyelocytic leukemia (APL) receiving all-trans retinoic and idarubicin (AIDA)–like therapies, the Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) designed a protocol for newly diagnosed APL (AIDA-2000) in which postremission treatment was risk-adapted. Patients with low/intermediate risk received remission at 3 anthracycline-based consolidation courses, whereas high-risk patients received the same schedule as in the previous, non–risk-adapted AIDA-0493 trial including cytarabine. In addition, all patients in the AIDA-2000 received all-trans retinoic acid (ATRA) for 15 days during each consolidation. After induction, 600 of 636 (94.3%) and 420 of 445 (94.4%) patients achieved complete remission in the AIDA-0493 and AIDA-2000, respectively. The 6-year overall survival and cumulative incidence of relapse (CIR) rates were 78.1% versus 87.4% (P = .001) and 27.7% versus 10.7% (P < .0001). Significantly lower CIR rates for patients in the AIDA-2000 were most evident in the high-risk group (49.7% vs 9.3%, respectively, P < .0001). Our data confirm that anthracycline-based consolidation is at least equally effective as cytarabine-containing regimens for low-/intermediate-risk patients and suggest that a risk-adapted strategy including ATRA for consolidation improves outcome in newly diagnosed APL. Furthermore, our results highlight the role of cytarabine coupled to anthracyclines and ATRA during consolidation in the high-risk group. This trial was registered at www.clinicaltrials.gov as #NCT 001064570.

Clinical risk classification is inaccurate in predicting relapse in adult patients with acute lymphoblastic leukemia, sometimes resulting in patients receiving inappropriate chemotherapy or stem cell transplantation (SCT). We studied minimal residual disease (MRD) as a predictive factor for recurrence and as a decisional tool for postconsolidation maintenance (in MRDneg) or SCT (in MRDpos). MRD was tested at weeks 10, 16, and 22 using real-time quantitative polymerase chain reaction with 1 or more sensitive probes. Only patients with t(9;22) or t(4;11) were immediately eligible for allogeneic SCT. Of 280 registered patients (236 in remission), 34 underwent an early SCT, 60 suffered from relapse or severe toxicity, and 142 were evaluable for MRD at the end of consolidation. Of these, 58 were MRDneg, 54 MRDpos, and 30 were not assessable. Five-year overall survival/disease-free survival rates were 0.75/0.72 in the MRDneggroup compared with 0.33/0.14 in MRDpos(P= .001), regardless of the clinical risk class. MRD was the most significant risk factor for relapse (hazard ratio, 5.22). MRD results at weeks 16 to 22 correlated strongly with the earlier time point (P= .001) using a level of 10−4or higher to define persistent disease. MRD analysis during early postremission therapy improves risk definitions and bolsters risk-oriented strategies. ClinicalTrials.gov identifier: NCT00358072.

Clinical risk classification is inaccurate in predicting relapse in adult patients with acute lymphoblastic leukemia, sometimes resulting in patients receiving inappropriate chemotherapy or stem cell transplantation (SCT). We studied minimal residual disease (MRD) as a predictive factor for recurrence and as a decisional tool for postconsolidation maintenance (in MRDneg) or SCT (in MRDpos). MRD was tested at weeks 10, 16, and 22 using real-time quantitative polymerase chain reaction with 1 or more sensitive probes. Only patients with t(9;22) or t(4;11) were immediately eligible for allogeneic SCT. Of 280 registered patients (236 in remission), 34 underwent an early SCT, 60 suffered from relapse or severe toxicity, and 142 were evaluable for MRD at the end of consolidation. Of these, 58 were MRDneg, 54 MRDpos, and 30 were not assessable. Five-year overall survival/disease-free survival rates were 0.75/0.72 in the MRDneg group compared with 0.33/0.14 in MRDpos (P = .001), regardless of the clinical risk class. MRD was the most significant risk factor for relapse (hazard ratio, 5.22). MRD results at weeks 16 to 22 correlated strongly with the earlier time point (P = .001) using a level of 10−4 or higher to define persistent disease. MRD analysis during early postremission therapy improves risk definitions and bolsters risk-oriented strategies. ClinicalTrials.gov identifier: NCT00358072.

In paroxysmal nocturnal hemoglobinuria (PNH) hemolytic anemia is due mainly to deficiency of the complement regulator CD59 on the surface of red blood cells (RBCs). Eculizumab, an antibody that targets complement fraction 5 (C5), has proven highly effective in abolishing complement-mediated intravascular hemolysis in PNH; however, the hematologic benefit varies considerably among patients. In the aim to understand the basis for this variable response, we have investigated by flow cytometry the binding of complement fraction 3 (C3) on RBCs from PNH patients before and during eculizumab treatment. There was no evidence of C3 on RBCs of untreated PNH patients; by contrast, in all patients on eculizumab (n = 41) a substantial fraction of RBCs had C3 bound on their surface, and this was entirely restricted to RBCs with the PNH phenotype (CD59−). The proportion of C3+RBCs correlated significantly with the reticulocyte count and with the hematologic response to eculizumab. In 3 patients in whom 51Cr labeling of RBCs was carried out while on eculizumab, we have demonstrated reduced RBC half-life in vivo, with excess 51Cr uptake in spleen and in liver. Binding of C3 by PNH RBCs may constitute an additional disease mechanism in PNH, strongly enhanced by eculizumab treatment and producing a variable degree of extravascular hemolysis.

In paroxysmal nocturnal hemoglobinuria (PNH) hemolytic anemia is due mainly to deficiency of the complement regulator CD59 on the surface of red blood cells (RBCs). Eculizumab, an antibody that targets complement fraction 5 (C5), has proven highly effective in abolishing complement-mediated intravascular hemolysis in PNH; however, the hematologic benefit varies considerably among patients. In the aim to understand the basis for this variable response, we have investigated by flow cytometry the binding of complement fraction 3 (C3) on RBCs from PNH patients before and during eculizumab treatment. There was no evidence of C3 on RBCs of untreated PNH patients; by contrast, in all patients on eculizumab (n = 41) a substantial fraction of RBCs had C3 bound on their surface, and this was entirely restricted to RBCs with the PNH phenotype (CD59−). The proportion of C3+ RBCs correlated significantly with the reticulocyte count and with the hematologic response to eculizumab. In 3 patients in whom 51Cr labeling of RBCs was carried out while on eculizumab, we have demonstrated reduced RBC half-life in vivo, with excess 51Cr uptake in spleen and in liver. Binding of C3 by PNH RBCs may constitute an additional disease mechanism in PNH, strongly enhanced by eculizumab treatment and producing a variable degree of extravascular hemolysis.

Goldberg: Celgene: Consultancy; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Aptose: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Research Funding; Aprea: Research Funding; AROG: Research Funding; Celularity: Research Funding; Dava Oncology: Honoraria; Pfizer: Research Funding. Geyer:Amgen: Research Funding. Pardee:Rafael Pharmaceuticals: Consultancy; AbbVie: Consultancy; Genentech, Inc.: Consultancy; BMS: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Research Funding; Rafael: Research Funding; Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Pharmacyclics: Speakers Bureau. Grunwald:Cardinal Health: Consultancy; Amgen: Consultancy; Amgen: Consultancy; Agios: Consultancy; Merck: Consultancy; Merck: Consultancy; Abbvie: Consultancy; Agios: Consultancy; Daiichi Sankyo: Consultancy; Agios: Consultancy; Abbvie: Consultancy; Abbvie: Consultancy; Trovagene: Consultancy; Daiichi Sankyo: Consultancy; Incyte: Consultancy, Research Funding; Celgene: Consultancy; Incyte: Consultancy, Research Funding; Astellas: Consultancy; Astellas: Consultancy; Astellas: Consultancy; Genentech/Roche: Research Funding; Premier: Consultancy; Premier: Consultancy; Janssen: Research Funding; Genentech/Roche: Research Funding; Genentech/Roche: Research Funding; Forma Therapeutics: Research Funding; Merck: Research Funding; Janssen: Research Funding; Forma Therapeutics: Research Funding; Forma Therapeutics: Research Funding; Trovagene: Consultancy; Premier: Consultancy; Merck: Consultancy; Daiichi Sankyo: Consultancy; Trovagene: Consultancy; Incyte: Consultancy, Research Funding; Pfizer: Consultancy; Celgene: Consultancy; Celgene: Consultancy; Cardinal Health: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Pfizer: Consultancy; Cardinal Health: Consultancy. Wang:Arog Pharmaceuticals: Current Employment. Pathan:Arog Pharmaceuticals: Current Employment. Messahel:AROG Pharmaceuticals: Current Employment.

Background:Gilteritinib monotherapy provides a CR/CRh rate of 34% and a median event-free survival of 2.3 months in relapsed FLT3 mutant AML. Many AML patients (pts) who relapse after gilteritinib still express mutant FLT3 receptor and could potentially respond to FLT3 inhibition. Crenolanib is a type I, pan-FLT3 inhibitor which can be given as monotherapy or combined at full doses with standard salvage chemotherapy.

COVID-19 pandemic has raised several concerns regarding patients with hematologic and immune-mediated diseases. It can be assumed that Paroxysmal nocturnal hemoglobinuria (PNH), both classic hemolytic and associated with aplastic anemia, particularly on treatment with complement inhibitors, may be more susceptible and have higher morbidity and mortality rates from COVID-19 than the general population. Italy has been heavily affected from the COVID-19 outbreak with the peak of contagions at the end of March 2020. As of July, 23 2020 the cumulative incidence of COVID-19 in Italy was 0.4% (1 case every 246 residents) (ranging from 0.06% - 1/1621- in Calabria to 0.9% - 1/106 - in Lombardy). We conducted a survey on 126 patients with PNH (77 females/49 males, median age 48 years, range 19-86) among 7 reference Italian centers in order to evaluate the occurrence and clinical characteristics of COVID-19 infection from the outbreak until the time of writing. According to International PNH Interest Group (IPIG) classification, 95 patients suffered from classic hemolytic PNH, 24 had associated bone marrow failures (aplastic anemia or myelodysplastic syndrome), and 7 had subclinical PNH (clone size <10%). Sixty-nine cases were on complement fraction 5 (C5) inhibition (72 eculizumab and 19 ravulizumab). Comorbidities were present in 33 patients, including arterial hypertension (N=14), ischemic cardiomyopathy (N=3), atrial fibrillation (N=2), diabetes mellitus (N=2), breast cancer (N=3), colon cancer (N=1), prostate cancer (N=1), Crohn disease (N=1), and Hashimoto thyroiditis (N=1). During the observation period, only one patient (55 years female), from Milan, Lombardy, not on C5-inhibitor was diagnosed with COVID-19 infection (positive swab, ageusia, and mild fever for few days). No hemolytic flare occurred, nor hospital admission was required. She received azithromycin and low molecular heparin. Other 6 patients, all on C5-inhibitors, experienced fever (N=5) and cough (N=2), and/or dysgeusia (N=1), of whom 2 experienced breakthrough hemolysis (BTH), but swabs and CT scans (N=2) were negative. At variance, 6 patients (4 on eculizumab and 2 on ravulizumab) experienced BTH without COVID-19 symptoms. Interestingly, a young male patient on eculizumab, working as medical doctor in a COVID-19 ward, did not contract the infection. In conclusion, this survey suggests that PNH subjects, either on complement inhibition or not, are not at significantly higher risk of COVID-19 infection as compared with the general population. As a matter of fact, the basic protective measures against COVID-19 have always been advised to PNH patients particularly during treatment and were presumably carefully followed during the pandemic. On the other hand, immune activation and inflammation are thought to play an important role in the clinical severity of COVID-19 pneumonia. Complement inhibition, which is under investigation in COVID-19 disease, seems at least not disadvantageous in PNH.

The anti-CD33 antibody calicheamicinconjugate gemtuzumab ozogamicin (GO) was used to treat 16 patients with acute promyelocytic leukemia (APL) who had relapsed at the molecular level. Of these patients, 8 were experiencing a first, 5 a second, 2 a third, and 1 a fourth relapse. GO was administered at 6 mg/m2 for 2 doses, and patients achieving a new molecular remission (MR) (ie, negativity of the reverse transcriptase–polymerase chain reaction [RT-PCR] test for PML/RARα) received a third dose. MR was obtained in 9 (91%) of 11 patients tested after 2 doses and in 13 (100%) of 13 patients tested after the third dose. Of the 3 remaining patients, 1 achieved MR after one GO administration and received no further therapy owing to hepatic toxicity, and 2 showed disease progression during treatment. Quantitative RT-PCR studies showed that responding patients experienced a dramatic decline (at least 2 logs) of the PML/RARα transcript after the first GO dose. Of 14 responders, 7 remained in sustained MR for a median of 15 months (range, 7-31 months) while 7 experienced relapse at 3 to 15 months. GO was administered again in 2 patients with relapse, and both obtained a new MR. These data indicate that GO is highly effective as a single treatment for patients with molecularly relapsed APL including those with very advanced disease.

The anti-CD33 antibody calicheamicinconjugate gemtuzumab ozogamicin (GO) was used to treat 16 patients with acute promyelocytic leukemia (APL) who had relapsed at the molecular level. Of these patients, 8 were experiencing a first, 5 a second, 2 a third, and 1 a fourth relapse. GO was administered at 6 mg/m2for 2 doses, and patients achieving a new molecular remission (MR) (ie, negativity of the reverse transcriptase–polymerase chain reaction [RT-PCR] test for PML/RARα) received a third dose. MR was obtained in 9 (91%) of 11 patients tested after 2 doses and in 13 (100%) of 13 patients tested after the third dose. Of the 3 remaining patients, 1 achieved MR after one GO administration and received no further therapy owing to hepatic toxicity, and 2 showed disease progression during treatment. Quantitative RT-PCR studies showed that responding patients experienced a dramatic decline (at least 2 logs) of the PML/RARα transcript after the first GO dose. Of 14 responders, 7 remained in sustained MR for a median of 15 months (range, 7-31 months) while 7 experienced relapse at 3 to 15 months. GO was administered again in 2 patients with relapse, and both obtained a new MR. These data indicate that GO is highly effective as a single treatment for patients with molecularly relapsed APL including those with very advanced disease.

Shortly before the all-trans retinoic acid (ATRA) era, the GIMEMA cooperative group initiated a randomized study comparing idarubicin (IDA) alone with IDA plus arabinosylcytosine (Ara-C) as induction treatment in patients with newly diagnosed hypergranular acute promyelocytic leukemia (APL). Of the 257 patients evaluable for induction treatment, 131 were randomized to receive IDA alone (arm A) and 126 to receive IDA + Ara-C (arm B). Treatment in arm A consisted of 10 mg/m2 IDA daily for 6 consecutive days, whereas in arm B it consisted of 12 mg/m2 IDA daily for 4 days combined with 200 mg/m2 Ara-C daily in continuous infusion for 7 days. Once in complete remission (CR), patients received 3 consolidation courses of standard chemotherapy, and those still in CR at the end of the consolidation were randomized to receive or not receive 1 mg/kg 6-mercaptopurine daily and intramuscular injections of 0.25 mg/kg methotrexate weekly for 2 years. Overall, 100 (76.3%) patients in arm A and 84 (66.6%) patients in arm B achieved CR (P = NS). Event-free survival (EFS) rates were 35% and 23% for patients in arm A and arm B, respectively (P = .0352). Multivariate analysis revealed that EFS was favorably influenced by induction treatment with IDA alone (P = .0352) and unfavorably influenced by white blood cell (WBC) counts greater than 3000/μL (P = .0001) and increasing age (P = .0251). These results indicate that anthracycline monochemotherapy with IDA favorably influences the EFS of patients with newly diagnosed hypergranular APL.

Shortly before the all-transretinoic acid (ATRA) era, the GIMEMA cooperative group initiated a randomized study comparing idarubicin (IDA) alone with IDA plus arabinosylcytosine (Ara-C) as induction treatment in patients with newly diagnosed hypergranular acute promyelocytic leukemia (APL). Of the 257 patients evaluable for induction treatment, 131 were randomized to receive IDA alone (arm A) and 126 to receive IDA + Ara-C (arm B). Treatment in arm A consisted of 10 mg/m2IDA daily for 6 consecutive days, whereas in arm B it consisted of 12 mg/m2IDA daily for 4 days combined with 200 mg/m2Ara-C daily in continuous infusion for 7 days. Once in complete remission (CR), patients received 3 consolidation courses of standard chemotherapy, and those still in CR at the end of the consolidation were randomized to receive or not receive 1 mg/kg 6-mercaptopurine daily and intramuscular injections of 0.25 mg/kg methotrexate weekly for 2 years. Overall, 100 (76.3%) patients in arm A and 84 (66.6%) patients in arm B achieved CR (P= NS). Event-free survival (EFS) rates were 35% and 23% for patients in arm A and arm B, respectively (P= .0352). Multivariate analysis revealed that EFS was favorably influenced by induction treatment with IDA alone (P= .0352) and unfavorably influenced by white blood cell (WBC) counts greater than 3000/μL (P= .0001) and increasing age (P= .0251). These results indicate that anthracycline monochemotherapy with IDA favorably influences the EFS of patients with newly diagnosed hypergranular APL.

We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P < .003), higher median age (P < .05), and worse performance status (P < .005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor α (PML/RARα) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-trans retinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.

We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P< .003), higher median age (P< .05), and worse performance status (P< .005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor α (PML/RARα) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-transretinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.

SARS-CoV-2 infection and vaccination have raised concerns in paroxysmal nocturnal hemoglobinuria (PNH). In fact, PNH patients carry an increased infectious risk secondary to complement inhibition treatment or associated bone marrow failure (BMF), and may therefore benefit from preventive strategies such as vaccinations. On the contrary, vaccines can be numbered among inflammatory complement amplifiers (e.g., infections, traumas, surgery), potentially triggering a disease exacerbation. In PNH patients on complement inhibitors, this phenomenon has been defined pharmacodynamic breakthrough hemolysis (BTH). Based on isolated reports of BTH following SARS-CoV-2 vaccines, we conducted a survey among 5 Italian reference centers to evaluate complications and BTH occurrence in PNH patients who completed the SARS-CoV-2 vaccination schedule from January, 2 2021 until the time of writing. Adverse events, hematologic and hemolytic parameters were recorded within 7-10 days before and after each dose of vaccine. A total of 67 patients (females/males 43/24, median age 47.6 years, range 21-90.5) were eligible for the analysis. According to the International PNH Interest Group classification, 45 patients suffered from hemolytic PNH, 20 from PNH in the context of BMF syndromes (aplastic anemia or myelodysplastic syndrome), and 2 from subclinical PNH. Fifty-five subjects (82%) were on regular complement inhibition therapy, i.e., eculizumab (N=35), ravulizumab (N=13), subcutaneous anti-C5 (N=3), anti-factor B (N=2) and ravulizumab + anti-factor D combination (N=2). Vaccines (Comirnaty/Pfizer-BioNTech N=53, mRNA-1273/Moderna N=12, and ChAdOx1 nCov-19/AstraZeneca N=2) were complessively well-tolerated, with 3 non-hematologic adverse events after the first dose (2 fever and 1 exercise-induced tachycardia, grade 1 according to CTCAE v5.0) and 2 after the second one (fever, accompanied by vomit in one patient, grade 1). During the observation period, 3 BTH and 1 hemolytic exacerbation were recorded (5.9% of patients), as detailed in Table 1. The most severe episode occurred in a young woman (Patient 3) on subcutaneous ravulizumab who experienced a hemoglobin (Hb) drop >2 g/dL, marked clinical signs of intravascular hemolysis and lactate dehydrogenase (LDH) increase >1.5 x upper limit of normal (ULN) from baseline, which is considered a clinical BTH according to the criteria proposed by the Severe Aplastic Anemia Working Party of the European group for Bone Marrow Transplantation. The patient required hospitalization for additional treatment with recombinant erythropoietin and anti-thombotic/bacterial prophylaxis. The second more severe BTH was registered in a male patient (Patient 1) on oral anti-factor B who experienced a Hb drop >2 g/dL without an overt hemolytic flare, and required hospitalization for intravenous antibiotic therapy (concomitant urinary tract infection). The remaining two patients experienced a subclinical BTH (Patient 2) and a hemolytic flare (Patient 4, not on complement inhibition). On the whole, a median delta variation from usual values of Hb and LDH of -25% (range -26+3%) and +80% (+18+105%) were observed, respectively. Of note, 3 episodes occurred after the second dose of vaccine, generally within 24-48 hours. Anti-complement drugs were not modified/discontinued in any of the 3 patients on regular treatment. Patients not experiencing BTH (94.1%) showed stable hematologic parameters after the first dose (Hb/LDH median delta variations from baseline -1%/+1%, range -14+12%/-32+40%) and the second dose of vaccine (Hb/LDH median delta variations from baseline +1%/0%, range -18+47%/-76+41%). Of note, 4 patients with a previous SARS-CoV-2 infection completed the vaccination without any complication/PNH exacerbation.

Fattizzo: Novartis: Speakers Bureau; Kira: Speakers Bureau; Alexion: Speakers Bureau; Annexon: Consultancy; Momenta: Honoraria, Speakers Bureau; Apellis: Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Bianchi: Agios pharmaceutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Sica: Jazz Pharma: Consultancy; Alexion: Consultancy. Barcellini: Novartis: Other: Invited speaker, Research Funding; Agios: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees, Other: Invited speaker, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees.

The consistency in time of responses to separate desmopressin (DDAVP) infusions in patients with von Willebrand's disease (vWD) and mild or moderate hemophilia A has been the subject of limited investigation. We report here the results of a clinical study undertaken to test the consistency of responses to repeated DDAVP administrations in 22 patients with vWD and 10 with mild or moderate hemophilia A (time interval between first and last infusion ranging from 1 to 77 months; median, 13 months). In patients with vWD, 80% of cases showed a departure of less than 20% from the average VIII:C peak level calculated after the two infusions. A similarly consistent pattern was observed for bleeding times recorded 30 minutes after each infusion. In patients with hemophilia A, some infused on more than two instances, the departure from the average VIII:C peak level was less than 20% in nearly 70% of cases. A good within-family consistency was also demonstrated by analyzing data obtained from seven kindreds with vWD and two with hemophilia A. In conclusion, our study suggests that the pattern of responsiveness observed after a DDAVP test-infusion can be reliably used to decide the future clinical management of the individual patient and that a similar pattern of response is usually observed within the same kindred.

Semenzato: Abbvie: Honoraria; Roche: Honoraria; Takeda: Honoraria. Pizzolo:janssen: Speakers Bureau; Abbvie: Speakers Bureau. Krampera:Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees.

Le Coutre: Incyte: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Speakers Bureau. Elena:Novartis: Consultancy; Pfizer: Consultancy. Assouline:Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria. Stagno:Incyte: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; BMS: Honoraria. Iurlo:Novartis: Other: Speaker Honoraria; Incyte: Other: Speaker Honoraria; Pfizer: Other: Speaker Honoraria. Kim:Novartis: Research Funding; BMS: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Il-Yang co.: Research Funding. Fava:Pfizer: Honoraria; Novartis: Honoraria; Incyte: Honoraria; BMS: Honoraria. Gambacorti-Passerini:Bristol-Meyers Squibb: Consultancy; Pfizer: Honoraria, Research Funding.

Introduction.

le Coutre: Pfizer: Honoraria; Incyte: Honoraria; BMS: Honoraria; Novartis: Honoraria. Abruzzese:BMS: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Ariad: Consultancy. Assouline:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding. Kim:Pfizer: Research Funding; BMS: Research Funding; Ilyang: Research Funding; Novartis: Research Funding. Gambacorti-Passerini:Pfizer: Consultancy, Honoraria, Research Funding; BMS: Consultancy.

Soverini: Novartis: Consultancy; Incyte Biosciences: Consultancy; Bristol Myers Squibb: Consultancy. Pagano:Pfizer: Speakers Bureau; Gilead: Speakers Bureau; Basilea: Speakers Bureau; Merck: Speakers Bureau; Janssen: Speakers Bureau. Gugliotta:Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Incyte: Honoraria; Novartis: Honoraria. Castagnetti:Incyte: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Angelucci:Roche Italy: Other: Local (national) advisory board; Novartis: Honoraria, Other: Chair Steering Comiittee TELESTO Protocol; Celgene: Honoraria, Other: Chair DMC; Jazz Pharmaceuticals Italy: Other: Local ( national) advisory board; Vertex Pharmaceuticals Incorporated (MA) and CRISPR CAS9 Therapeutics AG (CH): Other: Chair DMC. Martinelli:Abbvie: Consultancy; Ariad/Incyte: Consultancy; Janssen: Consultancy; Novartis: Speakers Bureau; Jazz Pharmaceuticals: Consultancy; Roche: Consultancy; Pfizer: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Amgen: Consultancy. Cavo:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Next-Generation Sequencing (NGS)-based BCR-ABL1 kinase domain (KD) mutation screening has been shown to enable greater accuracy and sensitivity and straightforward identification of compound mutants (CM) as compared to Sanger sequencing (seq). However, the prevalence of CMs has never been assessed in prospective studies, and although in vitrodata suggest that many of them may be challenging for all tyrosine kinase inhibitors (TKIs) including ponatinib, attempts to correlate such data with in vivoresponses have never been made. To address these issues, we have reviewed the results of routine NGS-based BCR-ABL1 KD mutation screening performed over the past 3 years.

Introduction.It is known that imatinib can be safely discontinued in patients (pts) with Chronic Myeloid Leukemia (CML) with minimal residual disease. Here we report an update of the Imatinib Suspension And Validation (ISAV) study at 79 months (mts) from study initiation to provide long term follow up data.

Introduction.Imatinib discontinuation in Chronic Myeloid Leukemia (CML) patients (pts) with minimal residual disease is a procedure that allows a treatment free remission in approximately 50% of them. However long term follow-up data are generally missing Here we report an update of the Imatinib Suspension And Validation (ISAV) study at 62 months (mts) of follow-up (FUP).

Introduction:Patients with APL typically present with a life-threatening thrombo-hemorrhagic syndrome (THS), due to the consumption of coagulation factors and platelets, secondary to clotting activation. Presently, all- transretinoic acid (ATRA) has greatly improved the management of APL, but has not significantly changed the rate of early hemorrhagic deaths and may actually promote thrombosis.Characterizing the coagulopathy and identifying predictive markers of bleeding/clotting complications remain critical issues. Aim: In newly diagnosed APL patients, in the first month after diagnosis, we wanted prospectively to: 1. register thrombo/hemorrhagic events; 2. evaluate, the profiles of circulating hypercoagulation markers and the molecular expression of Tissue Factor (TF), before and during ATRA therapy; and 3. verify whether changes in the biomarker profiles correlate with the occurrence of thrombo-hemorragic events. Methods: Sixty consecutive APL patients receiving ATRA+Idarubicin for remission induction (GIMEMA protocol AIDA2000) were enrolled from January 2005 to March 2017. Blood samples from a subgroup of 30 patients (F/M= 11/19) were obtained at the onset (T0), and on days 7, 14 and 28 (T7, T14, T28) of remission induction therapy. Plasma levels of activated factor VII-antithrombin complex (FVIIa-AT), thrombin-antithrombin complex (TAT), and D-dimer were measured by ELISA; TF mRNA levels in peripheral blood mononuclear cells (PBMC) was evaluated in 16 APL patients by real time-polymerase chain reaction. Results: At enrolment (T0), before starting ATRA, 13.3% of APL patients presented with early major hemorrhages, including 3 (5%) fatal intracranial bleeding and 5 (8.3%) non-fatal major bleeding (i.e. gengivorrhagia, gastrointestinal bleeding, epistaxis, menorrhagia). At T0, the prevalence of thrombosis in the total group of 60 APL patients was 6.6%, including 1 fatal pulmonary embolism (PE), 2 non-fatal venous thrombosis (1 PE, 1 lower limb deep vein thrombosis [DVT]), and 1 non-fatal arterial thrombosis (acute myocardial infarction [AMI]). During ATRA therapy, 8.3% of APL patients developed major bleeding: including 2 fatal intracranial hemorrhage after 3 days of ATRA treatment and 3 non-fatal major bleeding (i.e. gengivorrhagia, epistaxis, menorrhagia) after 7, 10 and 17 days of ATRA. Two more patients developed non-fatal thrombosis (i.e. 1 AMI and 1 DVT) after 9 and 20 days of ATRA treatment, respectively. The laboratory sub-study of 30 subjects showed that, at T0, before starting therapy, the plasma levels of FVIIa-AT, TAT and D-dimer were significantly higher in APL patients compared to controls (p<0.05). During induction therapy with ATRA, the levels of TAT and D-dimer significantly (p<0.05) and progressively decreased at T7 and T14, reaching the lowest value at 28 days. Differently, FVIIa-AT levels were unchanged at T7 and T14, and dropped significantly only at T28 (p<0.05 vs T0). In addition, in APL PBMC from 16 patients, the levels of TF mRNA, initially elevated compared to healthy control PBMC (p<0.05), during induction therapy were significantly decreased by 68% and 90%, at T7 and T28, respectively. In these 16 APL patients, a statistically significant correlation (p<0.05) was found between decrease in TF mRNA and FVIIa-AT levels during ATRA therapy. Of the 30 patients included in the laboratory sub-study, 3 had non-fatal thrombosis at diagnosis, no major hemorrhages were recorded. The predictive value of THS of thrombotic markers could not be calculated. Conclusions: Our data show a significant rate (31%) of severe (fatal and non-fatal) thrombo/hemorrhagic events in our cohort of APL patients in the first 3 weeks of diagnosis, with 4 fatal events (6.6%) occurring early, before starting ATRA. Laboratory data show for the first time that, while TAT and D-dimer confirm to be sensitive to ATRA downregulation, differently FVIIa-AT levels persist at high level over time, showing the perseverance of TF-dependent clotting activation. Future large prospective clinical trials should include FVIIa-AT to evaluate persistent clotting activation during ATRA.

Introduction:Decitabine has been recently approved in Europe for treatment of AML patients (pts) aged more than 65 years and unfit to receive standard chemotherapy. However data on its efficacy and tolerability derive mainly from clinical trials performed in selected pts. Herein we report on a population based series of AML pts treated with decitabine and registered in observational prospective studies.