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Ph-negative myeloproliferative neoplasms (MPN) are rare oncohematological diseases characterized by long duration and indolence. World epidemiological data on these diseases considerably vary depending on geographical area and time frame of the study. The breakthrough in the understanding of MPN pathogenesis, observed in the early 2000s, enabled to elaborate approaches to differential diagnosis and treatment of Ph-negative MPNs as well as to improve their prognosis. Although these approaches are specified in the Russian clinical guidelines, physicians still face challenges in their implementation in practice. The present review provides a detailed description and analysis of literature data on epidemiology, pathogenesis, and principles of Ph-negative MPN diagnosis and treatment. It also describes the situation in Saint Petersburg as an example of existing challenges in management of patients with Ph-negative MPNs in Russia and offers potential solutions.

Classical Ph-negative myeloproliferative neoplasms (MPN) constitute a group of diseases including polycythemia vera, essential thrombocythemia, and primary myelofibrosis. Over the past decade, the approaches to understanding of MPN pathogenesis and therapy have considerably changed. At the same time, etiological factors and pathophysiological mechanisms of disease progress are being thoroughly studied. The improvement of diagnosis methods and new approaches to therapy can reduce complications and mortality risks. The review outlines the current diagnosis methods, such as the molecular genetic one, and provides prognostic scores. Different methods of conservative therapy are assessed. Special attention is paid to quality of life measurement and targeted treatment of patients.

The development of National clinical guidelines on diagnosis and treatment of Ph-negative myeloproliferative neoplasms comes in response to the need to standardize the approach to diagnosis and treatment. The availability of clinical guidelines can facilitate the choice of adequate treatment strategy, provides practicing physicians with exhaustive and up-to-date information on advantages and shortcomings of different treatment methods as well as lets health professionals better assess expected extents of treatment required by patients. In 2013 a working group was formed to develop and formulate clinical guidelines on the treatment of myeloproliferative neoplasms. These guidelines were first published in 2014, afterwards they were revised and republished. The dynamic development of current hematology presupposes constant updating of knowledge and implementation of new diagnosis and treatment methods in clinical practice. In this context clinical guidelines present a dynamic document to be continuously amended, expanded, and updated in accordance with scientific findings and new requirements of specialists who deal directly with this category of patients. The present edition is an upgraded version of clinical guidelines with updated information on the unification of constitutional symptoms assessment using MPN-SAF TSS questionnaire (MPN10), on applying prognostic scales in primary myelofibrosis, assessing therapy efficacy in myeloproliferative neoplasms, revising indications for prescription, on dose correction, and discontinuation of targeted drugs (ruxolitinib). The guidelines are intended for oncologists, hematologists, healthcare executives, and medical students.

The aim of this paper was to present evaluation and synthesis of data derived from a survey of Russian patients and physicians, performed as a part of the international Landmark study for the emerging market countries designed to specify problems and areas of concern in management of patients with chronic Ph-negative myeloproliferative neoplasms (MPN). The online survey forms were filled by 40 adult patients with Ph(-) MPNs (PV, 42.5%; MF, 37.5%; ET, 20%) and 30 physicians with sufficient experience in the Ph(-) MPNs treatment. As a part of this survey, patients and physicians answered questions related to perception of the disease symptoms and their impact on quality of life, daily activities and work productivity of patients, as well as their attitude to main treatment goals and various aspects of the patient-physician communication. The results revealed a number of differences between patient and physician perception of the disease and treatment, thus complementing the data of the Landmark Survey in other countries. It was shown that the patients with different variants of Ph(-) MPNs encounter sufficient disease-related difficulties in everyday life, impaired quality of life and reduced work productivity. Lack of coincidence revealed between the physician and patient assessment of the disease burden and treatment indicates the need for new ways of improving quality of clinical care provided to this category of patients. Further research in this area would be an important step towards implementation

Background: Mutations in the JAK2, CALR, and MPL genes are key factors of the classical Ph-negative CMPD pathogenesis with demonstrated diagnostic and prognostic value. The aim of this research was to study the prevalence of JAK2, CALR, and MPL mutations in patients with CMPD and healthy individuals in the Republic of Sakha (Yakutia) (RS(Y)). Methods and Results: The study included patients with previously confirmed diagnoses of PV (n=15), ET (n=16), and PMF (n=11) and 68 people with peripheral blood changes, suspected to have CMPD. The control group included 184 healthy volunteers. All patients and participants in the control group were genotyped according to the following SNPs: the JAK2 rs77375493 SNP, the CALR rs765476509 SNP, the CALR rs1450785140 SNP, the MPL rs121913616 SNP, and the MPL rs121913615. The prevalence of the JAK2V617F mutation among PV patients in the RS(Y) was 90.9%. Patients with ET in 61.3% of cases were carriers of the JAK2V617F mutation, in 6.4% of CALR mutations, and in 3.2% of the MPLW515L mutations. In PMF patients, the JAK2V617F mutation was detected in 64.7% of cases, and the Type 1 CALR mutation was detected in 17.6% of cases. Carriage of the JAK2V617F mutation was revealed in 1.1% of healthy individuals and in 4.4% of individuals with initial signs of a myeloproliferative process. Conclusion: Early molecular genetic testing will improve the timely diagnosis of CMPD and possibly reduce the number of complications.

Aim. To study the structure of Ph-negative myeloproliferative diseases (Ph- MPD) and to identify morphological markers for diagnosing masked polycythemia vera (PV). Materials & Methods. Bone marrow core biopsy samples from the database of pathology department of National Research Center for Hematology within the period from January 2014 to June 2017 provided the basis for analyzing the diagnosed Ph- MPD cases. The trial included the bone marrow core biopsy samples of the patients treated and fol-lowed-up not only at the National Research Center for Hematology but also at other medical centers in the Russian Federation in the context of clinical, laboratory and molecular data. Results. In 1611 Ph- MPD patients PV prevailed corresponding to 40.6 % of all cases. In the PV group the masked form was diagnosed in 29 % of patients. Primary myelofibrosis (PMF) was diagnosed in 26.6 % of all patients including 10 % of cases with pre-fibrosis/early stage. The 3d most frequent disorder was essential thrombocythemia (ET) which corresponded to 16 %. JAK2 driver mutation was identified in all 654 PV patients. In 4 cases out of them exon 12 mutation was detected. A similar mutation was found out in PMF (53 %) and ET (60 %). In 36 % of PMF patients and 27 % of ET patients CALR mutation was detected. MPL mutation was identified in 4 % of PMF cases and was not discovered in ET. Triple negative patients were identified in 7 % of PMF and 13 % of ET cases. The designation of “myeloproliferative disease unclassifiable” can be applied to 16.8 % of cases. The trial deals with morphological criteria for diagnosing masked PV during examination of bone marrow core biopsy samples. In 30 % of patients with masked PV (according to the 2017 WHO classification) and splenomegaly (> 14 cm) portal vein thrombosis was identified. Conclusion. In the Ph- MPD group PV diagnosis prevailed (40.6 %). The histological analysis of bone marrow core biopsy samples of the patients with the masked PV accounting for 29 % of all PV cases, revealed morphological features typical of overt PV. Histological analysis of bone marrow is a reliable method for diagnosing overt and masked PV. Among morphological characteristics of the bone marrow of patients with masked PV and portal vein thrombosis special attention should be paid to the MF-1 grade of reticulin fibrosis (29 % of cases) and loose clusters of megakaryocytes (71.4 %).

The prognostic significance of Wilms’ tumor gene 1 (WT1) expression at diagnosis in adults with B cell precursor acute lymphoblastic leukemia (BCP-ALL) remains poorly understood. A total of 257 adults with Ph-negative BCP-ALL who were consecutively diagnosed and received at least 1 course of induction therapy at our institute were retrospectively analyzed. The WT1 expression patterns were significantly different among the molecularly and cytogenetically defined groups (E2A-PBX1, TEL-AML1, and MLL rearrangements; high hyperdiploidy and B-other). By considering the WT1 expression pattern and the relapse status, 2 cutoff values, 1.8% and 7.2%, were arbitrarily selected to place patients into WT1-low, WT1-inter, and WT1-high groups. In the B-other patients who achieved complete remission (CR), WT1-low and WT1-high patients had similar 3-year relapse-free survival (RFS), disease-free survival (DFS), and overall survival (OS) rates, which were all significantly lower than those of WT1-inter patients. The combined WT1-low/high expression group (n = 132) had significantly lower 3-year RFS, DFS, and OS rates compared with the WT1-inter group (n = 63) of B-other patients (RFS and DFS all P

Aim. To assess the rate of WT1 gene overexpression and its clinical value in Ph-negative myeloproliferative disorders (MPD). Materials & Methods. The trial included 72 patents with Ph-negative MPD. Among them there were patients with primary myelofibrosis (MF; n = 32), post-polycythemia vera MF (n = 7), polycythemia vera (PV; n = 17), and essential thrombocythemia (ET; n = 16) with median age of 57 years (range 19-78 years). Median (range) time from diagnosis to the date of evaluating WT1 expression in PV, ET, and MF was 9.4 (0-309), 14.4 (0-55), and 21.4 months (0-271 months), respectively. WT1 expression in terms of WT1 copies/104 ABL copies was measured by quantitative PCR. Results. WT1 gene overexpression is revealed solely in patients with MF (in 34/39; 87 %). In PV/ET no WT1 gene overexpression was observed. Median WT1 expression in MF was 230/104 ABL copies (range 42.2-9,316.45/104 ABL copies). Sensitivity and specificity of WT1 gene overexpression in MF with respect to PV/ET were 87 % and 100 %, respectively. A distinct correlation was identified between WT1 gene expression level and spleen size, duration of the disease, blast cell count, and DIPSS risk group. WT1 gene expression level could be correlated neither with age and sex, nor with MF mutation status and leucocyte, thrombocyte, and haemoglobin levels. Conclusion It appears that due to a high specificity and sensitivity of WT1 gene expression in MF it can be used as a marker for differential diagnosis of Ph-negative MPD. A correlation between WT1 gene expression and tumor mass in MF cannot be excluded. It is advisable to analyze the dynamics of WT1 expression level to predict the efficacy of current targeted therapy.

Background. Cerebrovascular disorders continue to be among the most common and socially significant worldwide. Among multiple reasons for circulatory disturbances special importance is attached to hemorheology and hemostasis disorders occurring also in patients with Ph-negative myeloproliferative diseases (MPD). Aim. To investigate typical characteristics of the course of cerebrovascular disorders in patients with Ph-negative MPD. Materials & Methods. The trial included 169 adult patients with neurological diseases. Among them the main group consisted of 104 patients aged 34 to 55 years (median 48.5 years) with Ph-negative MPD diagnosed at the National Research Center for Hematology. The control group consisted of 65 patients aged 51 to 58 years (median 55.5 years) with cerebrovascular diseases without concomitant hematological pathology. Results. The incidence of acute ischemic strokes was 26.2 % in polycythemia vera (PV), 20.5 % in essential thrombocythe-mia (ET), and 8.7 % in primary myelofibrosis (PMF). Conclusion. An acute ischemic stroke with a concurrent thrombotic occlusion of one of the major head arteries is a criterion for ruling out Ph-negative MPD. To identify cerebral lesions in patients with Ph-negative MPD (PV, ET, PMF) MRI of the brain is recommended.

Objectives: Detectable minimal residual disease (MRD) after therapy for acute lymphoblastic leukemia (ALL) is the strongest predictor of hematologic relapse. This study evaluated outcomes of patients with B-cell precursor ALL with MRD of ≥10−4 Methods: Study population was from ALL study groups in Europe managed in national study protocols 2000–2014. MRD was measured by polymerase chain reaction or flow cytometry. Patients were age ≥15 years at initial ALL diagnosis. Patients were excluded if exposed to blinatumomab within 18 months of baseline or prior alloHSCT. Results: Of 272 patients in CR1, baseline MRD was ≥10−1, 10−2 to −1, 10−3 to −2, and 10−4 to −3 in 15 (6%), 71 (26%), 109 (40%), and 77 (28%) patients, respectively. Median duration of complete remission (DoR) was 18.5 months (95% confidence interval [CI], 11.9–27.2), median relapse-free survival (RFS) was 12.4 months (95% CI, 10.0–19.0) and median overall survival (OS) was 32.5 months (95% CI, 23.6–48.0). Lower baseline MRD level (P ≤ .0003) and white blood cell count P ≤ .0053) were strong predictors for better RFS and DoR. Allogeneic hematopoietic stem cell transplantation (alloHSCT) was associated with longer RFS (hazard ratio [HR], 0.59; 95% CI, 0.41–0.84) and DoR (HR, 0.43; 95% CI, 0.29–0.64); the association with OS was not significant (HR, 0.72; 95% CI, 0.50–1.05). Discussion: In conclusion, RFS, DoR, and OS are relatively short in patients with MRD-positive ALL, particularly at higher MRD levels. AlloHSCT may improve survival but has limitations. Alternative approaches are needed to improve outcomes in MRD-positive ALL.

Background: The ischemic cerebrovascular disease (ICVD) is major thrombotic complication of Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (Ph-negative MPNs) which included essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF) leading to high disability and mortality rates. However, risk factors attributable to ICVD in Ph-negative MPNs patients are still not understood. This study aimed to identify risk factors for ICVD in Ph-negative MPNs. Methods: Patients with Ph-negative MPNs were divided into ICVD and non-ICVD groups. The demographic, biochemical, genetic parameters (JAK2V617F and CALR mutations) were assessed. The association between these factors and ICVD was assessed using logistic regression analysis.Results: One hundred eighty five Ph-negative MPNs patients (82 ET, 78 PV, and 25 PMF) were recruited，and 57 (30.8%) had ICVD which was higher than recently published data. The higher prevalence of hypertension(59.6% vs 32.0%), smoking(22.8% vs 6.3%), drinking(22.8% vs 6.3%), JAK2V617F mutation(78.9% vs 63.3%), the percentage of neutrophils( 78.76% vs 71.73%)， the lower prevalence of CALR mutation(3.2% vs 22.2%) and the percentage of basophils(0.82% vs 1.40%) were found in the ICVD group comparing with the non-ICVD group. The frequency of ICVD events was significantly higher in patients with JAK2V617F mutation than in those without (35.7% and 20.3%, P=0.034). Multivariate logistic regression analysis showed that hypertension (OR=2.464, 95%CI 1.218-4.983, p=0.012) and smoking (OR=5.426, 95%CI 1.919-15.340, p=0.001) were significantly positively associated with ICVD events. For ET patients, both smoking (OR=4.414, 95%CI 1.079-15.685, p=0.038) and increased percentage of neutrophils (OR=1.080, 95%CI 1.019-1.144, p=0.009) were independently associated with ICVD incidence. Hypertension (OR=4.647, 95%CI 1.215-17.781, p=0.025), smoking (OR=6.065, 95%CI 1.083-33.951, p=0.040), and increased percentage of lymphocytes (OR=1.039, 95%CI 1.002-1.078, p=0.039) were all positively correlated with ICVD risk in PV patients. Conclusions: Our data suggest that hypertension, smoking, higher percentage of neutrophils and lymphocytes rather than JAK2V617F and CALR mutations may be associated with an elevated risk of ICVD in Ph-negative MPNs patients, although the relative role of each factor may vary in the individual subgroup. Additional studies of large patient cohorts will be essential to validate these findings.

Thrombosis is a serious and extremely dangerous disease that has a negative impact on the quality and longevity. Antiphospholipid syndrome (APS) is a pathology characterized by recurring venous, arterial, microvasculature thrombosis, pregnancy pathology with loss of the fetus and the synthesis of antiphospholipid antibodies. A high risk of thrombotic complications is also observed in patients with myeloproliferative neoplasms (MPN). This article presents a description of three clinical cases of Ph - negative myeloproliferative diseases, occurring in conjunction with APS. In all cases, recurrent thrombosis allowed to suspect the presence of two diseases - MPN and APS.Тромбоз является тяжелым и крайне опасным заболеванием, которое оказывает негативное влияние на качество и продолжительность жизни. Антифосфолипидный синдром (АФС) характеризуется повторяющимися тромбозами венозного, артериального, микроциркуляторного русла, патологией беременности с потерей плода и синтезом антифосфолипидных антител. Высокий риск тромботических осложнений также наблюдается у больных миелопролиферативными заболеваниями (МПЗ). Представлено описание трех клинических случаев Ph-негативных МПЗ, протекающих совместно с АФС. Во всех случаях рецидивирующие тромбозы позволили заподозрить наличие двух заболеваний - МПЗ и АФС.

Исследование проведено с целью оценки влияния клинико-лабораторных показателей и мутации JAK2V617F на частоту развития тромботических осложнений среди пациентов с классическими Ph-негативными хроническими миелопролиферативными заболеваниями. Мутация JAK2V617F выявлена у больных истинной полицитемией, эссенциальной тромбоцитемией и первичным миелофиброзом. Тромботические осложнения достоверно чаще наблюдались у носителей мутации JAK2V617F и больных, имеющих сердечно-сосудистые факторы риска., The study was conducted with aim to assess the effect of clinical and laboratory parameters and JAK2V617F mutation on the incidence of thrombotic complications in patients with classical Ph-negative chronic myeloproliferative diseases. JAK2V617F mutation was detected in patients with polycythemia vera, essential thrombocythemia and patients with primary myelofibrosis. Thrombotic complications were significantly more often observed in carriers of the JAK2V617F mutation and in patients with cardiovascular risk factors., Якутский медицинский журнал, Выпуск 1 (69) 2020

The addition of tyrosine kinase inhibitors to conventional chemotherapy has improved outcomes for pediatric patients with Philadelphia chromosome-positive (Ph) acute lymphoblastic leukemia (ALL). However, the rate of relapse is still higher compared with many other types of pediatric ALL, with many possible mechanisms for resistance. We describe an 8-year-old boy with Ph ALL relapsing with ALL without the Ph following treatment with dasatinib as a part of Children's Oncology Group trial AALL1122. This emphasizes the polyclonal nature of ALL at diagnosis and indicates that the BCR-ABL fusion oncogene is not always an essential "driver" mutation.

Background. The classic Ph-negative myeloproliferative neoplasms (MPN) are a group of clonal haematopoietic disorders, including polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF), whose shared and diverse phenotypic signatures are caused by a dysregulated JAK/STAT signal transduction because of acquired somatic mutations. It has been demonstrated that autoimmune diseases and MPN can be associated (Kristinsson et al., Haematologica. 2010 Jul;95(7):1216-20.), suggesting a common background of immune dysregulation (Barosi, Curr Hematol Malig Rep. 2014 Dec;9(4):331-9). SARS-CoV-2 infection displays extreme inter-individual clinical variability, ranging from silent infection to lethal disease. It has been described that at least 10% of patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia have neutralizing autoantibodies (AAbs) against type I IFNs, that precede SARS-CoV-2 infection (Bastard et al., Science. 2020 Oct 23;370(6515):eabd4585). In this study we searched for AAbs against type I IFNs in a cohort of MPN patients to evaluate the prevalence of these AAbs in the MPN population and to check for clinical correlations, including severity of COVID-19. Methods. Plasma samples from consecutively referred MPN patients were prospectively collected between November 2020 and June 2021 and frozen at -30°C immediately after collection. Levels of AAbs against type I IFN subtypes including IFNs alpha, beta and omega were measured using the enzyme-linked immunosorbent assay (ELISA) and a neutralization assay, as previously reported (Bastard et al., Science. 2020 Oct 23;370(6515):eabd4585; Moreews et al., Sci Immunol. 2021 May 25;6(59):eabh1516). Results. We included a total of 219 MPN patients (101 ET, 76 PV, 36 MF and 6 MPN unclassificable). Neutralizing AAbs to type I IFNs were detected in 29 patients (13.2%, 95%CI: 9.1% - 18.5%). Comparing patients with and without AAbs we observed a significant difference in terms of distribution of MPN diagnosis (P = 0.029) and driver mutations (P = 0.019), while we did not observe a difference in terms of age, sex, and treatment (Table 1). Overall, 29 patients (13%) got SARS-CoV-2 infection and 8 of them (28%) required hospitalization due to severe COVID-19. AAbs against type I IFNs were detected in 4 of the 29 SARS-CoV-2 infected patients. A higher rate of hospitalization for severe COVID-19 was observed in patients with AAbs to type I IFNs (2 of 4 patients, 50%) compared to those without these AAbs (6 of 25 patients, 24%), although the difference did not reach a statistical significance (P = 0.300). Conclusions. In this study, we detected a prevalence of AAbs against type I IFNs which is much higher in our MPN cohort (13%) than in the general population (2-3%). We also found a correlation between the presence of AAbs to type I IFNs and both the hematological diagnosis and the driver mutation. Despite a comparable prevalence of SARS-CoV-2 infection between MPN patients with or without AAbs to type I IFNs, we observed a different rate of hospitalization due to severe COVID-19 which is almost twice in those with AAbs against type I IFNs compared to those without these AAbs. However, this difference did not reach a statistical significance, probably because of the low number of SARS-CoV-2 infection in the subgroup of patients with AAbs against type I IFNs. Thus, further studies to analyse the prevalence of AAbs against type I IFNs in patients with MPN, their association with other forms of auto-immunity and severe COVID-19 are warranted. Figure 1 Figure 1. Disclosures Arcaini: Gilead Sciences: Research Funding; Bayer, Celgene, Gilead Sciences, Roche, Sandoz, Janssen-Cilag, VERASTEM: Consultancy; Celgene, Roche, Janssen-Cilag, Gilead: Other: Travel expenses; Celgene: Speakers Bureau. Rumi: Novartis, Abbvie: Consultancy.

Introduction Pediatric inspired regimens can achieve good outcomes in adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) by delivering intense non-myelosuppressive chemotherapy and are considered standard. Experience with the implementation of these regimens outside of academic centers in high-income countries is limited. Furthermore, Mexican patients (with "hispanic ethnicity") have increased risk for relapse and treatment related complications. Objectives Primary objective: to determine 2-year overall survival (OS) and event-free survival (EFS). Secondary objectives: to determine the impacts of treatment abandonment and measurable residual disease (MRD) on outcomes, and to compare treatment costs with a widely used standard regimen in the United States. Patients and Methods Consecutive patients 16-45 years diagnosed with Ph-negative B-cell acute lymphoblastic leukemia after 2016 were included. The salient features of our modified-BFM regimen include the use mitoxantrone, E. coli L-asparaginase, without systemic cytarabine or high dose methotrexate designed to be delivered entirely in an outpatient basis for maximum affordability (Table 1), given that we treat an uninsured population that must cover their own treatment costs out of pocket. Genetic risk assessment was limited to BCR/ABL. Thereafter, relapse risk assessment was based exclusively on "next generation" flow cytometry measurable residual disease (MRD) after consolidation, with a planned allogeneic transplant for MRD-positive patients (≥0.001%). Treatment abandonment was defined as a missed ≥14-day period during intensive treatment or ≥1 month during maintenance. Statistical analysis was performed as intent-to-treat. Lastly, drugs included in our protocol were compared to those of CALGB 10403 with current local pricing in USD. Results Ninety-one AYAs have been treated, 47 women and 44 men, with a median age of 21 years (range, 15-45), mostly with a good functional capacity and no comorbidities (ECOG≤2: 92.1%; HCT-Ci 0-1: 97.8%); 43.8% of patients had ≥30x10 9/L white blood cells at diagnosis and 31.7% had grade ≥1 obesity. Notable grade ≥3 adverse events during induction were infections/neutropenic fever (35.6%),hepatotoxicity (11%) and thrombosis/bleeding (8.1%) with 44.3% eventually requiring hospitalization. Induction related mortality was 11%. Only n=3 were refractory to induction and the remainder assessed achieved complete remission (n=63; 95.5%) with a median follow-up of 15 months (range, 0.9-50.1). N=29 received induction and consolidation entirely on an outpatient basis, ulterior hospitalizations during therapy were rare. Treatment abandonment was common (n=24; 26.4%) usually during induction (n=8; 32%) or consolidation (n=12; 48%) and mostly related to unaffordability. For the same reason, transfers to social security healthcare systems were also frequent (n=19; 20.9%). Most patients assessed were MRD negative (n=38; 74.5%) Early relapse incidence was 32.9%; 44.4% in MRD-positive and 27.5% in MRD-negative patients (p=0.43). OS at 24 months was 61.5% (95% CI 47-73%) and EFS 49.8% (95% CI 37-62%) with excellent outcomes for MRD-negative patients (Figure 1, Panels A and B). Treatment abandonment and MRD positivity were the only independent predictors of mortality in a multivariate analysis (HR 7.8 [95% CI 2.8-21.9] and HR 4.5 [95% CI 1.4-14], respectively). Lastly, the total cumulative price for medications included in our regimen was calculated at $16,750 vs. $36,061 USD in CALGB 10403, representing a cost reduction of 53.5%. Conclusions The treatment of Hispanic ALL patients with our regimen has shown promising outcomes at a reduced cost for patients. Genetic risk assessment, induction mortality, treatment abandonment and lack of access to novel therapies for MRD positive patients remain the main barriers for improving outcomes further. Figure 1 Figure 1. Disclosures Gomez-De Leon: Novartis: Honoraria; ASH: Research Funding; Sanofi: Honoraria; Abbvie: Honoraria. González López: JANSSEN: Honoraria; AMGEN: Honoraria. Gomez-Almaguer: Roche: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Bristol-Myers-Squibb: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau.

Background: Children with Acute Lymphoblastic Leukemia (ALL) in Low Middle income countries(LMIC) face major challenges including treatment abandonment and poor overall survival (OS) and event-free survival (EFS).The preliminary data and results of outcome of Pediatric ALL from our pediatric hematology-oncology center which follows BFM based ALLtreatment protocol has been published in 2015 in ASH forum.Due to non availability of Polymerase chain reaction (PCR)based Minimal residual disease(MRD)analysis, we use multiparametric flowcytometry (FCM) based MRD analysis for remission assessment and risk stratification in our patients. Within resource constraints, we present evidence that outcomes comparable with that seen in high income (HIC)and upper middle income countries(UMIC) can be achieved with a post remission therapy guided by a risk stratification incorporating FCM MRD. Methods: Following IRB approval,an ambidirectional cohort study was performed using clinical information and outcomes of all patients aged 1to 14 years treated for newly diagnosed B- or T-ALL between January 1,2015 and December 31, 2020. AIEOP BFM ALL 2009 protocol with modifications was followed as the institutional protocol in all patients.The treatment algorithm is mentioned in Figure 1. Patients who underwent multiparametric FCM MRD analysis at the end of Induction IA and whose 6 months follow up details were available were included in the analysis. Patients with Ph positive ALL and those who died during Induction IA were excluded. FCM MRD analysis was performed after Induction IA on Day 33.MRD level above 0.01% was considered positive.MRD assessment was repeated following Induction IB on Day 74 in patients who had MRD positivity on Day 33. At the end of Induction IB patients were risk stratified into High risk(HR) and non High risk(Non HR).HR features included Hypodiploidy( Results: Median follow-up time was 33.5(4-102) months . Study had 102(n=102) consecutive Ph negative patients who underwent induction therapy. Six patients (5.88%) died during induction IA;96(n=96) children who continued treatment were included in further analysis. The mean age at diagnosis was 6(1-14) years .Forty seven (48.95%)patients were male..B-ALL n=84(87.5%) and T ALL n=12.(12.5%). Four patients(4.16%) had CNS disease at diagnosis. Three children (3.13%) had high risk cytogenetics.Ten children (10.42%)in the cohort had poor prednisolone response. Five patients(5.20%) didnot achieve morphological remission on Day33. Fifteen (15.63%) patients were risk stratified as HR during IA. Four more (4.16%) were reallocated to HR in view of persistent MRD positivity after Induction IB. At median follow-up, the OS was 95.35%±2.65(95% CI 90.16-100.54) and the EFS 94.48%±2.74 (95% CI, 89.11%-99.84%).Female gender predicted better EFS (p=0.042).The EFS of patients without CNS disease at presentation was significantly better(93.5% Vs 23.2% p=0.000). The EFS at median follow up of patients in re HR cohort was 64.19% Vs 97.81% in non HR (p=0.010). EFS by risk stratification is shown in Figure II. Conclusion:Our study suggests that FCM MRD can be successfully incorporated into the treatment algorithm in a resource limited setting. With FCM MRD were able to identify an additional subset of HR patients who otherwise would have been stratified into non HR group. In a prospective cohort , FCM MRD could be tested at an earlier time point in IA induction to facilitate identification of early drug responsive patients with lowest risk of relapse. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

INTRODUCTION: Hispanic patients with acute lymphoblastic leukemia (ALL) are historically known to have poor outcomes compared to non-Hispanic patients. Our institution, LAC-USC (LA County Hospital/University of Southern California) has shown a complete remission rate of 96% with use of pegasparagase at 2000 IU/m2 using the USC ALL regimen (based on CCG-1882) for patients aged 17-55 years with a 7-year OS of 51% reported in 2014. The modified USC ALL regimen now uses a single dose of cytarabine rather than fractionated doses and uses a single dose 3g/m 2 methotrexate compared to 1g/m 2 (2.5g/m 2 if T-cell) D1, 15 in original USC ALL regimen to improve compliance, while consolidation was increased to six cycles allowing for PEG holidays to improve toxicity (Table 1). Since our institution takes care of a large population of Hispanic patients with ALL, we now report outcomes in Hispanic and Non-Hispanic patients using the modified USC ALL regimen in the era of novel agents like blinatumomab and inotuzumab. METHODS : This retrospective, single institution chart review included adults >18 years old with newly diagnosed Ph-negative ALL (2016-2020). Primary objectives were 3-year over-all survival (OS), event-free survival (EFS), disease-free survival (DFS). Secondary objectives were complete remission/complete remission with incomplete recovery (CR/CRi), minimal residual disease (MRD) by flow cytometry, descriptive statistics of patients who were stratified into Hispanic and non-Hispanic cohorts and evaluated using Fisher's exact test. OS, DFS, EFS were reported through Kaplan Meier curves and Log-rank tests. Two-sided p-value ≤0.05 was significant. RESULTS: 121 Ph-negative patients were reviewed. 87 were Hispanic patients (HP) and 34 non Hispanic patients (NHP). Median ages were 39 and 35 years (p=0.51) and median BMI were 29 and 26.9 kg/m 2 (p=0.42), respectively. There were about equal males and females in HP while NHP had 70.6% males compared to 29.4% females (p=0.076). Both HP and NHP were mainly of the Ph-negative ALL subtype, 50.6% vs 47.1%, followed by Ph-like, 25.4% vs 20.6%, respectively (p=0.884). Majority of the population were unfavorable risk by NCCN karyotypic risk stratification, 55.9% in HP compared to 56.0% in NHP (p=0.99). Over-all, no significant difference between baseline characteristics in both cohorts. After induction 1: CR/CRi was 85.9% in HP and 73.4% in NHP (p=0.09). MRD negativity by flow cytometry in HP was 41.4% compared to 26.4% in NHP (p=0.13). After induction 2: 83% of HP were in CR/CRi compared to 80% in NHP (p=0.99) and MRD negativity by flow was 35.6% in HP compared to 32.4% in NHP (p=0.73). Blinatumomab was given in 33.3% of HP and 32.3% of NHP (p=0.92) while only 5.7% of HP and 2.9% of NHP received inotuzumab (p=0.99). 34.5% of HP underwent allogenic hematopoietic stem cell transplant (allo-HSCT) versus 26.5% in NHP (p=0.40). 3-year OS was 92.2% in HP versus 67.4% in NHP (p=0.004). 3-year DFS was 92.8% in HP versus 60.7% in NHP (p=0.003). 3-year EFS was 54.1% in HP versus 32.3% in NHP (p=0.02) (Table 2). Rate of relapse for HP and NHP were 23.4% vs 29.4% (p=0.74) while rate of mortality for HP and NHP were 7.5% vs 28% (p=0.015), respectively. No clear difference in grade 3/4 PEG toxicities were found in HP and NHP except more hypertriglyceridemia in HP (p=0.019). CONCLUSIONS: We present comparison of outcomes in Hispanic and non-Hispanic patients using our modified USC ALL pediatric-based regimen in an era of novel agents. Our data shows significantly better outcomes in Hispanic patients compared to non-Hispanic patients [OS (92.2% vs 67.4%, p=0.004), DFS (92.8% vs 60.7%, p=0.003) and EFS (54.1% vs 32.3%, p=0.02)]. This study demonstrates that given equal access to care (eg. receiving blinatumomab, allo-HSCT), outcomes in HP with Ph-negative ALL are not worse, but rather superior to those in NHP. Utilization of novel immunotherapy like blinatumomab in the salvage setting to achieve deeper molecular response and increased utilization of haploidentical allo-HSCT have likely contributed to reducing ethnic disparities in Hispanic ALL patients. Future studies are needed to validate these findings with larger patient populations. Figure 1 Figure 1. Disclosures Chaudhary: Oncotartis: Consultancy; Pancella: Consultancy; Moderna: Current equity holder in publicly-traded company; Celldex: Current equity holder in publicly-traded company; TCR2: Current equity holder in publicly-traded company; Allogene: Current equity holder in publicly-traded company; Athelas: Consultancy, Current holder of stock options in a privately-held company; Angeles Therapeutics: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties: Cell therapy . Douer: Jazz: Consultancy; Amgen: Consultancy, Speakers Bureau; Adaptive: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Speakers Bureau; Servier: Consultancy, Speakers Bureau. Yaghmour: Takeda: Consultancy, Speakers Bureau; Astellas: Speakers Bureau; Alexion: Speakers Bureau; BMS: Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Jazz: Speakers Bureau.

Background: ALL in adults is considered a heterogeneous disease with poor prognosis. However, adolescents and young adults (AYA) display intermediate characteristics as compared with children. Risk groups and response predictors are essential to guide the treatment. Aims: The aim of this report was to evaluate the experience of Ph-negative ALL in AYA patients (pts) treated with the pediatric Argentine type-BFM protocol, assessing predictors of response in terms of overall survival (OS) and event-free survival (EFS). Methods: We performed a retrospective multicenter analysis of AYA pts diagnosed between 2013 to 2021, from 16 Argentine institutions who were treated following the pediatric Argentine type-BFM protocol. Response to prednisone (PR) at day(d) 8 ( Results: One hundred and seventy-three patients similarly distributed among private and public institutions were analyzed. The median (Md) age was 22 years (15-40) with a male predominance (66%). At diagnosis, 23% presented central nervous system (CNS) involvement, 79.5% B and 20.5% T immunophenotype, 29% CD20 positive, 16% adverse cytogenetic/molecular findings and 29% no data. Ph-like screening was not routinely performed assessed only in 13% revealing two CRLF2 and one PDGFRB rearrangements. Twenty-one (12%) of pts underwent allogeneic bone marrow transplantation (Allo-HSCT) at 1 st line, 20 with MRD negative and 1 MRD positive at the time of the procedure.Of 171 pts, 155 (91%) achieved MCR, 12 (7%) were refractory, 3 (2%) died prior/during induction and 1 (0.6%) patient dropped out of treatment; 144 (84%) achieved negative MRD, 22 (13%) positive MRD and 5 (3%) were not evaluated. The Md to reach CR and MRD (-) was 33d (IQR 31-42) and 35d (IQR 32-73), respectively. With a Md follow-up of 16 months (1-79), 52 pts (30%) relapsed and 68 pts (39%) died. Early deaths at 3 months occurred in 8 (5%) pts, 5 related to treatment and 3 to disease. The Md OS and EFS were 58 and 34 months, respectively. Prognostic predictors analyzed were sex, white blood counts (WBC) at diagnosis (limit of 30 x10 -9/L), age (limit of 30 years), CNS involvement, cytogenetic/molecular findings, PR at d8, MRD in bone marrow (BM) at d15, 33 and 78. In the univariate analysis, response at d8, MRD at d15, 33 and 78 were useful to predict both OS and EFS, adding age and WBC in terms of OS. Similar results were obtained when patients who underwent Allo-HSCT were censored at the time of the procedure. (Table). In the multivariate analysis, positive MRD at d33 and d78 (and WBC in OS) maintained their independent adverse prognostic impact in relation to OS and EFS. Allo-HSCT showed benefits in pts with MRD >0.1% at d33 and >0.01% at d78 in terms of OS (d33: NR vs. 11 m, p =0.048, HR 0.3, 95%CI [0.1-0.9]; d78: NR vs. 8 m, p =0.009, HR 0.4, 95%CI [0.2-0.8]) and EFS (d33: NR vs. 6 m, p =0.022, HR 0.2, 95%CI [0.1-0.8]; d78: NR vs. 5 m, p =0.003, 0.1 HR, 95%CI [0.02-0.5]). The adverse risk of positive MRD at day 33 and 78 in terms of OS and EFS was overcome when pts were transplanted. Summary/Conclusion: The results show that positive MRD at d33 and 78 independently impacted on OS and EFS in our series and that Allo-HSCT overcame their adverse risk. Our data confirms the relevance of using pediatric protocols in AYA. On the other hand, the importance of prognostic tools in order to improve the outcome of AYA patients, reinforcing their inclusion in current guidelines. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

INTRODUCTION: The use of pediatric inspired regimens in adolescent young adults and adults has improved outcomes in acute lymphoblastic leukemia (ALL). CALGB 10403 was prospectively tested in patients 17-39 years, showing a 3-year event free survival of 59%. In 2007, our institution reported outcomes after incorporating peg-asparaginase (PEG) dosed at 2000mg/m 2 in induction for patients aged 17- 55 years. This regimen was well tolerated and resulted in a complete remission (CR) rate of 96%. In 2014, we reported experience with the use of multiple doses of PEG (CCG-1882) for newly diagnosed ALL adult patients, with a 7-year overall survival (OS) of 51%. Since our last report, the USC ALL regimen consisting of 2 induction phases, has been further modified with a goal of maintaining good outcomes, and improving compliance and toxicities. Fractionated doses of cytarabine were changed to a single dose, the methotrexate dose of 1g/m 2 (2.5 g/m 2 if T-cell) given D1,15 of intensification phases was changed to 3g/m 2 (B and T cell) given in single doses, and consolidation was increased to six cycles allowing for PEG holidays (Table 1). Moreover, the approval and incorporation of novel agents such as blinatumomab and inotuzumab also changed outcomes in ALL. Therefore, this study reports an update of outcomes since further modification of the USC ALL pediatric-based regimen in the era of novel agents. METHODS: This is a retrospective review which included adults aged >18 with newly diagnosed Philadelphia negative ALL between 2016 and 2020 treated at USC/Norris Cancer Center and Los Angeles County Hospital (LAC). Primary objectives were over-all survival (OS), event-free survival (EFS), disease-free survival (DFS) at 3 years, and secondary outcomes were complete remission/complete remission with incomplete recovery (CR/CRi) rates and minimal residual disease (MRD) by flow cytometry. OS, DFS, EFS were reported through Kaplan Meier curves and Log-rank tests. Two-sided p value ≤0.05 was significant. RESULTS: 121 patients with Ph-negative ALL were identified (49.6% Ph-negative B-ALL, 24% Ph-like B-ALL, 0.8% B cell lymphoblastic leukemia (LBL), 9.1% T cell ALL, 4.1% T cell LBL, 4.1% early T-cell, 5.8% mixed phenotype acute leukemia (MPAL). Median age at diagnosis was 38.5 years and maximum age of patient to receive pegasparagase during induction 1 was 63 years. 71.9% Hispanic, 15.7% white, 9.9% Asian, 2.5% African American. 57.9% males, 42.1% females. 3.4% were favorable, 4.2% intermediate, 54.6% unfavorable and 37.8% unknown by karyotypic risk stratification. Median BMI was 28.9 kg/m 2.54.6% had hepatic steatosis either on history or imaging and 5.1% had CNS disease pre-induction. Post-induction 1, 81.4% of patients achieved CR/CRi and 50% MRD negative. Post induction 2, 82.2% achieved CR/CRi, 67.7% MRD flow negative. Post-consolidation 1, 90.9% were MRD flow negative. 33.1% subsequently received blinatumomab for MRD positive disease, 5% given inotuzumab for relapsed disease, 32.2% underwent allogenic hematopoietic stem cell transplant (allo-HSCT). Median number of pegasparagase doses received during treatment was 2, rate of relapse and mortality was 27.3% and 13% respectively. Median OS and DFS were not reached but median EFS was 35 months. 3-year OS was 85.3%, when stratified according to MRD post induction 2; 3-year OS was 91.7% for MRD positive patients and 91.2% for MRD negative patients (p=0.55). 3-year DFS was 83.2%; 88.2% for MRD positive patients and 97.4% for MRD negative patients (p=0.22). 3-year EFS was 47.3%; 51.3% for MRD positive patients and 50.6% for MRD negative patients (p=0.49) (Tables 2-3). Use of pegasparagase resulted in grade 3/4 toxicities including hypersensitivity (4.1%), transaminitis (21.5%), pancreatitis (5.4%), hypertriglyceridemia (49.5%), hypofibrinogenemia (45.5%), hyperbilirubinemia (21.5%) and thrombosis (16.5%). CONCLUSIONS: Pediatric-based modified USC ALL induction regimen led to a high 3-year OS (85.3%), DFS (83.2%) and EFS (47.3%) with predictable toxicity and compares favorably with original USC ALL regimen, CALGB 10407, GRAALL 2005 and USC/MSKCC regimen. Interestingly, MRD positivity after induction 2 did not adversely affect OS, DFS or EFS, which is likely due to incorporation of blinatumomab and inotuzumab. These agents could have allowed for deeper remissions allowing Ph-negative patients with residual disease to receive allo-HSCT. Figure 1 Figure 1. Disclosures Chaudhary: Oncotartis: Consultancy; Pancella: Consultancy; Moderna: Current equity holder in publicly-traded company; Celldex: Current equity holder in publicly-traded company; TCR2: Current equity holder in publicly-traded company; Allogene: Current equity holder in publicly-traded company; Athelas: Consultancy, Current holder of stock options in a privately-held company; Angeles Therapeutics: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties: Cell therapy . Douer: Servier: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Adaptive: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Speakers Bureau; Jazz: Consultancy. Yaghmour: Novartis: Consultancy, Speakers Bureau; BMS: Speakers Bureau; Alexion: Speakers Bureau; Astellas: Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Jazz: Speakers Bureau; Agios: Consultancy, Speakers Bureau.

Background: Relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LL) remain a therapeutic challenge, especially in elderly patients(pts) or those with T-cell immunophenotype. Inhibition of apoptosis is an increasingly recognized mechanism for resistance to conventional chemotherapy. Recently, the oral bcl-2 inhibitor venetoclax (VEN) has shown remarkable activity in a variety of hematologic malignancies. Preclinical data in both B- and T-ALL suggests synergy of VEN with vincristine(VCR). Liposomal VCR (L-VCR) is FDA approved for relapsed ALL having progressed following 2 or more antileukemia therapies. We designed a phase I/II trial (EA9152) of the combination of L-VCR and VEN for pts with r/r B-or T-cell ALL or LL. Here, we report for the first time the safety and efficacy outcomes of the phase I portion of this trial (NCT03504644). Methods: This open-label phase I/II study enrolled pts age>=18 with ALL or LL who were R/R to multiagent chemotherapy. Subjects could have received prior VCR or VEN . In a standard 3 + 3 dose escalation design, subjects were given a two week lead-in phase of single agent VEN in the following schedule: dose level 1 - 20, 50, 100, 200 mg on days 1, 2, 3, 4 and 400 mg on days 5 ‒ 42; dose level 2 - 50, 100, 200, 400 mg on days 1, 2, 3, 4 and 600 mg on days 5 ‒ 42; and dose level 3 ‒ 100, 200, 400, 600 mg on days 1, 2, 3, 4 and 800 mg on days 5 ‒ 42. Weekly L-VCR 2.25mg/m 2 IV was started on D15 of cycle 1, and starting day 1 for subsequent cycles (cycle 2+ = 28 days). For cycle 2 and beyond, VEN 400mg, 600mg, or 800mg based on dose level was given starting on day 1 of the cycle. Primary objective of the phase I portion was to determine the maximum tolerated dose (MTD) of VEN in combination with L-VCR. Secondary objectives included determining preliminary response rates. Results: EA9152 was activated on April 26, 2018 and the phase I portion closed to accrual on March 2, 2021. Among the 18 pts in dose escalation (Table 1), the median age was 42 years (22-77). The majority of pts were male (56%), white (80%), and with a performance status (PS) of 1 (78%). Among 13 pts with disease diagnosis reported, 9 had ALL and 4 had LL. Seventeen of 18 (94%) reported previous chemotherapy, two of which had previous stem cell transplant. Median treatment cycles received is 1 (range 1-11). One patient, having received 11 cycles, remains on study at the time of data analysis. Grade >=3 treatment-related adverse events were reported in 89% of treated pts, with neutrophil count decreased (67%), white blood cell decreased (56%), and anemia (50%) as the most common. One pt experienced grade 3 tumor lysis syndrome. Twelve pts were considered evaluable for MTD determination. Six pts were considered not evaluable for toxicity analysis on account of withdraw of consent for treatment (n=4) or rapid disease progression (n=2). Two pts (2 of 3) at dose level 3 experienced DLTs, one each of hypokalemia and heart failure. Therefore, the MTD of the combination was determined to be dose level 2 - VEN 50, 100, 200, 400 mg on days 1, 2, 3, 4 and 600 mg on days 5 ‒ 42 and for subsequent cycles, with L-VCR 2.25mg/m2 IV weekly. In regards to best overall responses observed (Table 2) 4 of 18 pts (22%) achieved complete response (CR), 4 patients (22%) had stable disease, and 7 (39%) had progressive disease. Two patients in CR were found to be measurable residual disease (MRD) negative as well. Conclusions: In the phase 1 portion of this study, the combination of VEN and L-VCR was found to be safe for patients with ALL and LL. The MTD of the combination was found to be VEN 600mg daily with encouraging preliminary efficacy seen including MRD negative responses. The phase 2 portion of this trial is actively enrolling with VEN 600mg daily starting C1D1. Figure 1 Figure 1. Disclosures Palmisiano: Takeda: Consultancy; Genentech: Research Funding; Foundation One: Consultancy; AbbVie: Consultancy, Research Funding. Claxton: Astellas: Other: Clinical Trial; Novartis: Research Funding; Astex: Research Funding; Cyclacel: Research Funding; Daiichi Sankyo: Research Funding; Incyte: Research Funding. Park: BMS: Consultancy; Amgen: Consultancy; Autolus: Consultancy; Novartis: Consultancy; Minerva: Consultancy; PrecisionBio: Consultancy; Curocel: Consultancy; Artiva: Consultancy; Kite Pharma: Consultancy; Kura Oncology: Consultancy; Affyimmune: Consultancy; Servier: Consultancy; Innate Pharma: Consultancy; Intellia: Consultancy. Podoltsev: Novartis: Honoraria; Incyte: Honoraria; Celgene: Honoraria; Pfizer: Honoraria; Blueprint Medicines: Honoraria; Bristol-Myers Squib: Honoraria; PharmaEssentia: Honoraria; CTI BioPharma: Honoraria. Atallah: Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Research Funding; BMS: Honoraria, Speakers Bureau; Takeda: Consultancy, Research Funding; Abbvie: Consultancy, Speakers Bureau; Amgen: Consultancy. Dinner: Kite/Gilead: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Webster: AmGen: Consultancy; Pfizer: Consultancy. Luger: Syros: Honoraria; Agios: Honoraria; Daiichi Sankyo: Honoraria; Jazz Pharmaceuticals: Honoraria; Brystol Myers Squibb: Honoraria; Acceleron: Honoraria; Astellas: Honoraria; Pfizer: Honoraria; Onconova: Research Funding; Celgene: Research Funding; Biosight: Research Funding; Hoffman LaRoche: Research Funding; Kura: Research Funding. Litzow: AbbVie: Research Funding; Astellas: Research Funding; Amgen: Research Funding; Actinium: Research Funding; Pluristem: Research Funding; Jazz: Other: Advisory Board; Omeros: Other: Advisory Board; Biosight: Other: Data monitoring committee. OffLabel Disclosure: Venetoclax, a BCL-2 inihibitor, is not FDA-approved for use in ALL.

Context: TPMTandNUDT15polymorphisms are involved in the toxicity and therapeutic efficacy of thiopurine drugs (6-mercaptopurine (6-MP)). The frequencies of polymorphisms of these genes are different across diverse populations. The role ofTPMTandNUDT15genes in adult patients (pts) with Ph-negative acute lymphoblastic leukemia (ALL) in Russia is still unclear. Objective:Evaluation of frequency and significance ofTPMTandNUDT15polymorphisms in the cohort of adult Ph-negative ALL pts treated by the RALL-2016 protocol. Design and Patients:Since April 2017 till July 2020 56 adult Ph-negative ALL patients treated by RALL-2016 protocol were included in the research ofTPMTandNUDT15polymorphisms. Median age was 32 у (range, 18-54), m/f: 39 (70%) / 17 (30%). B-ALL/LBL were diagnosed in 26 (46,4%) pts, T-ALL- in 26 (46,4%) and MPAL- in 4 (7,2%). Genomic DNA was extracted from peripheral blood samples of given pts. Genetic polymorphisms inNUDT15(*2, *3)and TPMT(*2, *3A, *3B, *3C)genes were detected using the allele-specific RT-PCR. The dose of 6-MP was calculated only for 54 pts from 56 (one of these pts stopped the therapy and another received the 1 st phase of induction by RALL-2016 without 6-MP). According to the RALL-2016 protocol 6-MP dose correction imply: if the level leukocytes Results:From 54 pts CR rate was 87 % (n=47) and resistance - 13% (n=7). One patient died in CR. The frequency ofTPMTandNUDT15polymorphisms in study group was 17,8 % (n=10): 6 (23%) of 26 pts with B-ALL, 3 (11,5 %) of 26 pts -T-ALL and 1 (25%) of 4 pts - MPAL. In our cohort these polymorphisms were found significantly more frequently in pts with B-ALL (p Conclusions:In our study the frequency ofTPMTandNUDT15polymorphisms in adult pts with Ph-negative ALL was 17,8%. The statistical analysis showed that polymorphisms of these genes were detected more frequently in pts with В-ALL. Only one patient withTPMT*2had significant toxicity on the therapy of 6-MP and died in CR. However, we don't know whether this is due to deficient 6-MP metabolism. We didn't find a correlation between the 6-MP toxicity and the polymorphisms in our pts. There is a tendency that OS within 2-years in pts withoutTPMTandNUDT15polymorphisms is better than in the group of pts with them. But our cohorts are small and require further study. Keywords:acute lymphoblastic leukemia, toxicity, 6-mercaptopurine,TPMT,NUDT15 Disclosures No relevant conflicts of interest to declare.

Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by excessive proliferation of myeloid lineages. Accurate classification and appropriate management of MPNs requires integration of clinical, morphological and genetic findings. Despite major advances in understanding the molecular and genetic basis, morphological assessment of the bone marrow trephine (BMT) remains paramount in differentiating between MPN subtypes and reactive conditions. However, morphological assessment is heavily constrained by a reliance on subjective, qualitative and poorly reproducible criteria. To address this, we have developed a machine-learning strategy for the automated identification and quantitative analysis of megakaryocyte morphology using clinical BMT samples. Using a sample cohort of recently diagnosed or established ET (n = 48) and reactive control cases (n = 42) we demonstrated a high predictive accuracy (AUC = 0.95) of automated tissue ET diagnosis based upon these specific megakaryocyte phenotypes. These separate morphological phenotypes showed evidence of specific genotype associations, which offers promise that an automated cell phenotyping approach may be of clinical diagnostic utility as an adjunct to standard genetic and molecular tests. This has great potential to assist in the routine assessment of newly diagnosed or suspected MPN patients and those undergoing treatment / clinical follow-up. The extraction of quantitative morphological data from BMT sections will also have value in the assessment of new therapeutic strategies directed towards the bone marrow microenvironment and can provide clinicians and researchers with objective, quantitative data without significant demands upon current routine specimen workflows.

В статье представлен обзор литературы, где описываются современные представления о молекулярной биологии хронических миелопролиферативных заболеваний., The paper presents a review, which demonstrates current understanding of the molecular biology of chronic myeloproliferative diseases., №1(65) (2019)

We report the data on 15 women who presented with Ph-negative acute lymphoblastic leukemia (ALL) between Jan 2009 until Dec 2016 and who were treated on the prospective multicenter RALL-2009 clinical trial. A comparison of their outcome was made with 129 non-pregnant females who entered the study and were treated by the same schedule. 10-years OS for pregnant and non-pregnant women was 58.6 % (29.6 %-85.0 %) and 43.3 % (32.1 %-58.8 %), DFS was 46 % (15.2 %-78.8 %) and 51 % (39.7 %-64.6 %); probability of relapse was 49 % (16.6 %-83.3 %) and 40.3 % (27.3 %-53.4 %), respectively. Twelve born during the study children are well and alive with a median age 5 years 2 months (2 years - 9 years). Though small, our study has shown some specific features of ALL diagnosed during pregnancy (more T-cell ALL, higher initial WBC, later responses) and has shown that the long-term outcome of women with ALL treated while pregnant is equivalent to female control patients treated on the same protocol.

Acute lymphoblastic leukemia (ALL) among older adults continues to be associated with a dismal prognosis. Novel effective immunotherapies and targeted agents are expected to address unmet needs in adult ALL. This review has summarized recent evidence to determine whether these approaches can lead to the decreased use of chemotherapy among older adults with ALL and result in improved outcomes.

Philadelphia (Ph) chromosome is a cytogenetic hallmark of chronic myeloid leukemia (CML). Most patients with CML harbor either the e13a2 or e14a2 BCR-ABL fusion product, while a small subset of the cases expresses e1a2 or e19a2 transcripts. We report a patient with chronic myelomonocytic leukemia (CMML), initially Ph chromosome negative at presentation, with rapid disease progression to acute myeloid leukemia (AML) and appearance of Ph chromosome and BCR-ABL e6a2, a very uncommon fusion transcript. The AML was refractory to treatment with subsequent emergence and dominance of a Ph negative leukemic clone. The patient expired shortly after disease progression.

7524 Background: Philadelphia-like Acute B-ALL(PHL) are Ph negative B-ALL(PHN) with molecular signatures that mirrors Ph + B ALL. Studies have shown worse prognosis in this subtype of leukemias, but few have reported outcomes with incorporation of novel agents. Our study seeks to describe clinical and molecular profile of a single center experience. Methods: This is a retrospective study of patients treated for PHL in community referral center in central valley of California from 1/2009 to 12/2019. Of the initial 71 patients, 34 met the inclusion and exclusion criteria. 16 of the 34 patients who had Next Generation Sequencing (NGS) by Foundation Medicine (14) or NeoGenomics (2). Data for 34 PHN and 8 with PHL patients were analyzed. Results: There are no differences in mean ages (36.7 x 36) and gender between the PHN and PHL subgroup. There is over representation of Hispanics in both groups (63% x 65%) with slightly male predominance in PHL group (62%). This ratio is slightly higher than reported by 2010 census of 46%. The BMI 38.4(27.5-48.4) vs. 29.1(26.6-39.1), mean WBC (71 vs. 58), bone marrow CD20+ by flow cytometry (90% vs. 63%) and abnormal cytogenetics (50% vs.15%) are all higher in PHL compared to PHN group. The prevalence rate of PHL signature in 16 tested patients is 8(50%). CRLF2 like subtype accounted for 6/8(75%), with 1 each of ABL-like and JAK-Stat subtype. All patients harbored multiple other mutational abnormalities in addition to those associated with Ph-like genetic signatures (Table). The median number of mutations was 4.55(3-7). The distribution of the 20 other mutation is as shown in table. 6 patients had morphological remission after induction chemotherapy of HyperCVAD (37%) and CALGB 10403 (25%) with measurable MRD in 5 of the patients. 7 patients were exposed to novel therapy; Blinatumomab; 2nd line (6 patients), Cart T cell; 3rd line (2 patients), Inotuzumab; 3rd line (3 patients) and ASCT; (3 Patients post second- or third-line remission). 2 patients died at the time of data cut off, 1 from infection and other from refractory leukemia. Conclusions: Our data shows high incidence of PHL signatures in the cohort. The mutational heterogeneity between and within patients, may represent sub-clonal population vs. passenger and hence poor clinical outcomes. [Table: see text]

Background Data on outcome of allogeneic transplantation (HSCT) from mismatched unrelated donors (MMUD) (≤6/8) in leukemic patients (pts) are limited. Methods We assess HSCT results in pts with AML/ALL in CR transplanted between 2000 and 2017 from ≤6/8 MMUD (2-4 HLA mismatches at the allelic level at loci A, B, C and DR) reported to the EBMT. Results A total of 465 pts were allocated, AML-320 and ALL-145. Median age was 50.2 years (range, 18-71.8) and 34.8 years (range, 18.2-62.9); 54% and 64% were males, respectively. Median F/U was 63 and 75 months, respectively. 69% and 66% were in CR1, while 31% and 34% were in CR2. 40% of AML pts had intermediate risk cytogenetics, 10% poor risk and 5% good risk (missing 45%),respectively. 37% of ALL pts were Ph positive, 22% Ph negative and 18% T ALL (17% B ALL with no Ph data,6% missing data). The number of HLA mismatches (HLAMM) was 6/8 - in 82% and 85%,5/8- in 11.5% and 12% and 3-4 in 6% and 3% of AML and ALL pts, respectively. 85% of AML pts and 77% of ALL pts received PBSC graft. Conditioning regimen was myeloablative in the majority of pts (89% of AML and 61% of ALL pts). 82% and 77% underwent in vivo TCD, respectively. GVHD prophylaxis was CSA/MTX in 51% and 67% and CSA/MMF in 21% and 10% of AML and ALL pts, respectively. Engraftment was achieved in 97% and 95% of pts, respectively. The incidence of acute (a) GVHD grade (Gr) II-IV and Gr III-IV was 34% and 41% and 14% and 21% for AML and ALL pts, respectively. Total and extensive chronic(c) GVHD rates at 2y were 38% and 38% and 23% and 14%, respectively. The main causes of death were disease recurrence (37% in both), GVHD (29% and 22%) and infections (22% and 26%).The 2 and 5y outcomes in the entire population were: RI-28% and 33%, NRM-28% and 30%; LFS-44% and 37%, OS- 50% and 41% and GRFS- 33% and 27%, respectively. More than 2 HLA mismatches were associated with a higher incidence of aGVHD Gr II-IV (29% vs 15%, respectively).In MVA, RI was lower for ALL vs AML HR (95% CI) 0.60, p=0.02. Disease status (CR2 vs CR1) was poor prognostic factor for RI, LFS and OS. Age was prognostic factor for NRM, LFS and OS. HLA mismatch at locus DR was poor prognostic factor, giving increased NRM: HR (95% CI) 1.68, p=0.02, and lower LFS: HR (95% CI), 1.42, p=0.03and OS HR (95% CI) 1.46, p=0.03and higher GVHD Gr II-IV HR (95% CI) 1.48, p=0.048. Results of MVA in AML pts in CR1 were similar. GVHD prophylaxis CSA/MMF in comparison to CSA/MTX resulted in higher NRM HR (95% CI) 2.2,p= 0.005 and lower GRFS HR (95% CI) 1.58, p=0.02.Notably, in 154 pts with AML in CR1 transplanted from ≤6/8 UD with T cell depletion c mismatches was associated with higher incidence of cGVHD HR (95% CI) 2.52, p=0.002. Summary and Conclusions HSCT from ≤6/8 MMUD transplantation can provide 40% 5y OS, 37% LFS and GRFS of 27% in leukemic pts. DR mismatch is a poor prognostic factor. cGVHD incidence at 5y is 41% with 21% being severe and is associated in AML pts with HLA C mismatches. CSA and MTX is the preferred GVHD prophylaxis.

Philadelphia-negative myeloproliferative neoplasms (MPNs) are a diverse group of diseases whose common feature is the presence of V617F mutation of the JAK2 gene. In the era of novel therapeutic strategies in MPNs, such as JAK-inhibitor therapy, there is a growing need for establishing high sensitive quantitative methods, which can be useful not only at diagnosis but also for monitoring therapeutic outcomes, such as minimal residual disease (MRD). In this study, we compared the qPCR and ddPCR methods and their clinical utility for diagnosis, prognostication, and treatment monitoring of MPNs with JAK2 V617F mutation in 63 MPN patients of which 6 were subjected to ruxolitinib treatment. We show a high conformance between the two methods (correlation coefficient r = 0.998 (p

OBJECTIVE To establish which of hematological parameters have discriminatory ability for forecast the development of thromboses in spontaneous and radiation associated Ph negative myeloproliferative neoplasms (MPN). MATERIALS AND METHODS It was analyzed hematological parameters of 85 patients with polycythemia vera (PV), 43 - essential thrombocythemia (ET) and 40 - primary myelofibrosis (PMF). The main group consisted of patients (PV = 18, ET = 6, PMF = 18) which were exposed to ionizing radiation due to the Chornobyl accident, and control - patients (PV = 67, ET = 37, PMF = 22) without affecting emergency radiation in history. RESULTS It was determined, that in spontaneous PV predictive for the thromboses development value of the hema tocrit and the leukocytes is > 55 % and > 13.2 · 109/l respectively, and the total cholesterol is > 5.7 mmol/l. The effi ciency such factor as the "hematocrit > 55 %" (area under the curve - AUC = 0.67; p = 0.023) and the "leukocytes > 13.2 · 109/l "(AUC = 0.66; p = 0.011) is average for the predicting of thromboses, and the "total cholesterol > 5.7 mmol / l" (AUC = 0.92; p 10.0 · 109/l respectively, and it character ized by very good (AUC = 0.84; p = 0.0002 and AUC = 0.72, p = 0.019, respectively) predictive power. In the main and in the control group of PV patients was determined the same AUC for application the "hematocrit> 55 %" (p = 0.800) and the "leukocytes > 13.2 · 109/l" (p = 0.831) in the thromboses prediction, but it was calculated dif ferent AUC for the "platelets 10.0 · 109 / l" (p = 0.509), so it can be used at spontaneous and radiation related ET.

Optimal post-remission therapy for adolescents and young adults (AYAs, 16-39 years) with Ph-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1) is not well established. We hypothesized that post-remission therapy with a pediatric-inspired regimen would yield superior outcomes to myeloablative allogeneic HCT for AYA patients with Ph- ALL in CR1. We compared overall survival (OS), disease-free survival (DFS), relapse, and non-relapse mortality (NRM) for patients receiving post-remission therapy on CALGB 10403 to a contemporary matched AYA cohort undergoing myeloablative allogeneic HCT in CR1 reported to the CIBMTR (Table). The allogeneic HCT cohort consisted of patients 16-39 years of age with Ph- ALL in CR1 undergoing myeloablative transplant from a matched sibling/relative or unrelated donor using peripheral blood or bone marrow stem cells between 11/2002 and 8/2012 in the United States. Patients receiving post-remission therapy with pediatric-inspired chemotherapy had superior OS (P Figure. Allogeneic HCT (HCT) vs. CALGB 10403 pediatric-inspired chemotherapy (chemo) after CR1: Adjusted (left-truncated) overall survival, disease-free survival, cumulative incidence of relapse, and cumulative incidence of non-relapse mortality. Disclosures Wieduwilt: Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen, Leadiant, Merck, Servier: Research Funding; Reata Pharmaceuticals: Equity Ownership. Stock:Astellas: Membership on an entity's Board of Directors or advisory committees; Research to Practice: Honoraria; Kite, a Gilead Company: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Daiichi: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; UpToDate: Honoraria. Advani:Macrogenics: Research Funding; Abbvie: Research Funding; Pfizer: Honoraria, Research Funding; Amgen: Research Funding; Kite Pharmaceuticals: Consultancy; Glycomimetics: Consultancy, Research Funding. Luger:Ariad: Research Funding; Biosight: Research Funding; Celgene: Research Funding; Cyslacel: Research Funding; Daichi Sankyo: Honoraria; Genetech: Research Funding; Jazz: Honoraria; Kura: Research Funding; Onconova: Research Funding; Pfizer: Honoraria; Seattle Genetics: Research Funding; Agios: Honoraria. Larson:Novartis: Honoraria, Other: Contracts for clinical trials; Agios: Consultancy; Celgene: Consultancy. Tallman:Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biosight: Research Funding; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Research Funding; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kebriaei:Kite: Honoraria; Jazz: Consultancy; Amgen: Research Funding; Pfizer: Honoraria. Weisdorf:Pharmacyclics: Consultancy; Incyte: Research Funding; Fate Therapeutics: Consultancy.

Introduction RALL-2009 study (NCT01193933) has demonstrated that non-intensive but non-interruptive treatment with fewer allo-HSCT is rather effective in adult Ph-negative ALL pts aged 18-55 yy, producing more than 50% OS at 8-years [Parovichnikova, EHA E836, 2017]. In this study we have shown that only age, initial WBC >30*109/l and t(4;11) became the factors of poor prognosis for BCP-ALL and none of the factors - for T-ALL. MRD was not measured in this study. Since Dec 2016 we started a new RALL-2016 (NCT03462095) protocol based on the same principle but modified according to the conclusions drawn from RALL-2009. Aim. To evaluate the first interim results of MRD monitoring and 1-year probability of relapse regarding MRD status in Ph-negative ALL treated by RALL-2016 protocol. Materials and patients. Taking in consideration the major pitfalls of RALL-2009 (high CR rate, early CNS relapses in T-ALL, selection bias for autologous HSCT in T-cell ALL, absence of MRD testing) a new study was developed. One day high-dose MTX block and one-day high-dose ARA-C block are eliminated and substituted by 2 months of non-intensive and non-interruptive treatment, L-asparaginase is scheduled for 1 year of treatment instead of 2,5 y, 15 intrathecal injections are increased up to 21 during consolidation phase, CR T-ALL patients are brought to randomization after the informed consent: auto-HSCT vs no auto-HSCT, - with further similar maintenance. All primary bone marrow samples are collected and tested for cytogenetic and molecular markers, all included pts are MRD monitored by flow cytometry in a centralized lab at 3-time points (days +70,+133,+190). Since Dec2016 till July 2018, 86 adult Ph-negative ALL pts from 11 centers (10 regions of Russia) were included in theRALL-2016 protocol: median age 33 y (18-54), m/f 54/32, BCP-ALL was diagnosed in 48 (56%), T-ALL/LBL - in 35 (40,5%), biphenotypic ALL -3 (3,5%). Results. CR rate in 76 available for the analysis patients was 80% (n=61), induction death occurred in 12% (n=9) and refractory ALL was registered in 8% (n=6). There were no deaths in CR so far. 2 allo-HSCT were performed (1 MUD and 1 haplo) for BCP-ALL with MRD persistence and T-ALL associated with Nijmegen breakage syndrome, respectively. 26 T-ALL patients after CR achievement were randomized for chemo (n=13) or for auto-HSCT (n=13). Up to now 7 of randomized T-ALL patients were transplanted at a median of 6 mo of CR. OS for the whole cohort constituted 68% at 18 months, relapse probability - 8,7%. MRD at the 1st time point (+70 day) was measured in 54 pts, at the 2nd time point (+133 day) - in 43 pts and at the 3rd time point (+190 day) - in 36 pts. MRD-positivity was detected in 15 pts (28%) at day+70 (BCP-ALL=11 out of 32 pts, T-ALL=4 out of 22), at day +133 - in 8 pts (19%) (BCP-ALL=7 out of 30 pts, T-ALL=1 out of 13), at day +190 - in 2 pts (5%) (both BCP-ALL). MRD clearance was much better in T-ALL patients, as it was demonstrated by other studies earlier [Bruggemen, Goekbuget]. But we have to mention that regardless our non-intensive approach, the portion of MRD-positive patients was similar at the same time points as in the other studies applying highly intensive protocol. We did not reveal any differences in early (within 1-year) relapse probability according to MRD status, though we have to assume that the study is small and the period of follow is too short. Conclusion Our data demonstrate that non-intensive but non-interruptive approach is as effective as more intensive protocols providing very similar MRD clearance in Ph-negative ALL. MRD is declining better in T-ALL patients comparing to BCP-ALL. And no correspondence was noticed between the MRD-positivity and relapse probability at the 18 mo of follow-up. Figure. Figure. Disclosures Kulikov: Russian Foundation for Basic Research grant 18-015-00399 A: Research Funding.

A retrospective analysis of evidence of platelet clumping, an in vitro phenomenon in blood samples anticoagulated by EDTA, was performed in 49 patients with myeloproliferative diseases other than chronic myeloid leukaemia. Evidence of platelet clumping was provided by the H6000 picture, which in the presence of platelet aggregates yields a characteristic “whisk” in a defined region. Out of the 49 patients, 17 (35%) had evidence of platelet clumping which, however, occurred in an unpredictable manner from time to time. Platelet clumping thus provides a confounding factor when automated platelet counts are used to monitor effects of cytotoxic treatment in this type of disorders. In a prospective study, it was shown that the problem can be overcome by optimizing the hospital routine to secure minimum delay between sampling and analysis.

To highlight the role of azacytidine (AZA) in patients with myeloproliferative neoplasms developing blast phase (MPN-BP), we evaluated retrospectively 19 patients [M/F 15/4, median age 71.3 years, interquartile range (IQR) 64.5-77.7] reported in the database of our cooperative group. Median time from diagnosis to BP evolution was 52.7 months (IQR 11.2-181.8). All patients were treated with AZA at the standard dosage of 75 mg/m(2). Two patients died early after 5-AZA initiation from pulmonary fungal infection and respiratory failure respectively, 4 patients had a disease progression, 4 patients a stable disease, 3 patients had an hematological improvement, 1 patient a partial response and 5 pts (26.3%) a complete response (CR) after 4, 4, 4, 5, and 12 months. The median cumulative survival from BP evolution was 9.9 months (95%CI 6.6-13.1): the comparison with an historical cohort of 72 patients with MPN-BP treated with approaches other than AZA (median cumulative survival 3.1 months, 95%CI 1.1-5.0) showed a significant advantage for patients treated with AZA (p=0.02). Our data confirm the relative efficacy and safety of AZA in this group of patients with otherwise dismal prognosis, underlining the possible achievement of long-lasting responses in a sizeable portion of them.

Development of acute myeloid leukemia with NPM1 mutation, in Ph-negative clone, during treatment of CML with imatinib

Mobilised peripheral blood stem cells are widely used for autografting in patients with chronic myeloid leukaemia (CML) and it is generally thought that a high proportion of Ph-negative progenitor cells in the graft is desirable. We report here the results of 91 stem cell mobilisations performed with various chemotherapy regimens followed by G-CSF. We show that mobilisation of Ph-negative cells is possible after diagnosis as well as in advanced stages of the disease. The yield of Ph-negative cells is highly dependent on the chemotherapy regimen: while the combination of idarubicin and cytarabin for 3-5 days (IC3-5) mobilised Ph-negative cells in most patients, high-dose cyclophosphamide was ineffective. Mobilisation of Ph-negative progenitor cells after IC3 was at least as effective as after IC5; however, less apheresis sessions were required, and toxicity was much reduced after IC3. Compared to historical controls, IC was equally effective as the widely used ICE/miniICE (idarubicin, cytarabin, etoposide) protocol. No correlation was found between graft quality and the cytogenetic response to subsequent treatment with interferon-alpha. We conclude that IC3 is an effective and well-tolerated regimen for mobilising Ph-negative cells that compares well with more aggressive approaches such as IC5 and ICE/miniICE.

Background: the Registro Italiano Trombocitemie (RIT) was activated mainly to evaluate the diagnosis and therapy appropriateness in the thrombocythemic patients with Ph-negative myeloproliferative neoplasm (MPN) observed in the adhering centers. Objective: to evaluate how the diagnostic and therapeutic approach changed in the RIT patients diagnosed with thrombocythemic MPN in the last two decades. Methods: the RIT centers registered by a web-based system during the years 2005-2014 their thrombocythemic MPN patients, and semesterly updated their follow-up data. For patients diagnosed before 2005, the data on diagnosis and prior follow-up were retrospectively collected. The diagnostic process and the initial treatment (started into the first year after diagnosis) were comparatively analyzed in the patients diagnosed before and after 2005. Results: the RIT centers registered 2629 patients. 2388 of them, object of this analysis, were diagnosed between1995 and 2014: 1098 (46%) in the decade 1995-2004 (Group I), and 1290 (54%) in the decade 2005-2014 (Group II). The diagnostic process in the patients of Group II and Group I included bone marrow biopsy (BMB, performed into 1 year and before any cytoreduction): 85% vs 80%, p The patients of Group II, as compared with those of Group I, showed a similar gender distribution (M/F ratio 0.61 vs 0.65, p 0.452), and had at diagnosis: a higher age (median 60 vs 57 years, p 60 years in 50% vs 45% of cases, p Moreover, they had: a lower platelet (PLT) count (median 737 vs 775 x 109/L, p 10 x 109/L in 28% vs 26% cases); a similar median levels of hematocrit (HCT %, in females 41.4 vs 41.0; in males 44.7 vs 44.6) and hemoglobin (Hb g/dL, in females 13.8 vs 13.6; in males 15.0 vs 14.9). The BMB, revised according to the WHO 2008 criteria, showed a not different distribution (p 0.21) of ET (64% vs 61%), ep-PMF (16% vs 17%), PMF (3% vs 2%), PV (4% vs 4%), and U-MPN (13% vs 16%. The JAK2 V617F mutation in patients of Group II (at diagnosis) and of Group I (after diagnosis) was found in 62% and in 58% of tested cases (p 0.054), respectively. The patients at high standard thrombotic risk were 58% vs 52%, p 0.004. In the patients of Group II and Group I the distribution of the treatment started into the first year was significantly different (p The treatment CYT ± AntiPLT was started in the patients at high standard thrombotic risk with a rate of 81% vs 80%, respectively, and in the patients at low standard thrombotic risk in 37% vs 43% of cases, respectively. The initial treatment CYT±AntiPLT was related, in multivariate analysis, both in patients of Group II and Group I, with older age (>60 and 40-60 vs 1000 and 700-1000 vs Conclusion: in the studied thrombocythemic MPN patients the real-life diagnostic approach was improved after 2005 not only due to the routine use of JAK2 tests, but also due to the higher rate of BMB done (85% vs 80%). The appropriateness of the cytoreductive treatment (CYT±AntiPLT started into one year from diagnosis) remained high in patients at high standard thrombotic risk (over 80% of cases were treated). Concomitantly, the inappropriate use of the cytoreductive drugs in patients at low standard thrombotic risk appreciably decreased (from 43% to 37% of cases). Moreover, it has to be remarked that the therapeutic approach was significantly influenced not only by older age and prior thrombosis, but also by thrombocytosis (PLT count >700 x 109/L), disease-related symptoms, and inconstantly by leukocytosis and CVRFs. Table Table. Disclosures Gugliotta: SHIRE Co.: Honoraria. Gugliotta:Bristol Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria.