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Stathmin 1 (STMN1) is a microtubule-destabilizing protein highly expressed in hematological malignancies and involved in proliferation and differentiation. Although a previous study found that the PML-RARα fusion protein, which contributes to the pathophysiology of acute promyelocytic leukemia (APL), positively regulates STMN1 at the transcription and protein activity levels, little is known about the role of STMN1 in APL. In this study, we aimed to investigate the STMN1 expression levels and their associations with laboratory, clinical, and genomic data in APL patients. We also assessed the dynamics of STMN1 expression during myeloid cell differentiation and cell cycle progression, and the cellular effects of STMN1 silencing and pharmacological effects of microtubule-stabilizing drugs on APL cells. We found that STMN1 transcripts were significantly increased in samples from APL patients compared with those of healthy donors (all p < 0.05). However, this had no effect on clinical outcomes. STMN1 expression was associated with proliferation- and metabolism-related gene signatures in APL. Our data confirmed that STMN1 was highly expressed in early hematopoietic progenitors and reduced during cell differentiation, including the ATRA-induced granulocytic differentiation model. STMN1 phosphorylation was predominant in a pool of mitosis-enriched APL cells. In NB4 and NB4-R2 cells, STMN1 knockdown decreased autonomous cell growth (all p < 0.05) but did not impact ATRA-induced apoptosis and differentiation. Finally, treatment with paclitaxel (as a single agent or combined with ATRA) induced microtubule stabilization, resulting in mitotic catastrophe with repercussions for cell viability, even in ATRA-resistant APL cells. This study provides new insights into the STMN1 functions and microtubule dynamics in APL.

PURPOSE OF REVIEW Chronic myeloid leukemia (CML) management in developing countries has improved in the last years, but the availability of therapeutic resources, monitoring, reimbursement, and financial issues may be a challenge and interfere with the best practices and results of CML treatment. This review points out the main challenges in CML management in South America. RECENT FINDINGS In this review, we describe the access to tyrosine kinase inhibitors and monitoring in different countries of South America. We also address the ongoing discontinuation trials, the progress, and limitations of hematopoietic stem cell transplantation in the last years. There are still many challenges for achieving the best outcomes for CML patients in South America. The continuous efforts to provide continuous education, access to tyrosine kinase inhibitors, and monitoring, providing reference centers for CML management and hematopoietic stem cell transplantation may improve patients' outcomes.

Toll-like receptors (TLRs) are a family of transmembrane receptors whose signaling control cellular processes of cell proliferation, survival, apoptosis, angiogenesis, remodeling, and repair of tissues. Polymorphisms in TLR genes can change the balance between pro and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation, and cancer. Although many studies have demonstrated the direct involvement of TLR signaling in the benefit of tumor cells in certain cancers, little is known about the influence of these gene polymorphisms on myeloproliferative neoplasms (MPNs). In this context, the objective of the study was to investigate a possible association between the TLR polymorphisms and the development of MPNs. 167 patients diagnosed with MPN and 222 healthy controls from the same region were evaluated. Genomic DNA was extracted and the TLR2 (rs5743708), TLR4 (rs4986790, rs4986791), TLR9 (rs5743836, rs187084) and JAK2V617F polymorphisms were genotyped by PCR-RFLP. The statistical analysis was performed by OpenEpi and SNPstat software. The JAK2V617F mutation was found in 68.32% of patients. TLR9-1486C/T CT genotype was less frequent in patients with polycythemia vera (PV) (OR 0.39, 95% CI 0.20-0.78, P = 0.025). When haplotype frequencies were analyzed, -1237T/-1486C (TLR9) was also less frequent in men (OR 0.58, 95% CI 0.36-0.94) and JAK negative men patients (OR 0.43, 95% CI 0.21-0.88). We can infer that the TLR9-1486 CT genotype could be associated with protection for PV and the TLR9-1237T/-1486C haplotype, protection for men, as well as for JAK negative men patients with MPN. There were no associations between TLR2 and TLR4 gene polymorphisms and MPN.

Introduction: The incidence of grade 3–4 anemia was reported to be 3% with imatinib therapy for newly diagnosed chronic myeloid leukemia (CML) in the chronic phase (CP). However, there are few data regarding the causes and the development of anemia after long-term treatment. This study aimed to evaluate the incidence of anemia after at least two years of imatinib treatment of CML patients in the CP and to identify other contributing causes of anemia in this population. Patients and methods: We performed a retrospective analysis of 97 CML patients in the CP treated with imatinib for at least two years. We analyzed the hemoglobin (Hb) levels of CML patients at diagnosis, upon initiation of treatment with imatinib and after two years of imatinib treatment, and investigated other causes of anemia in this population. Results: Most of the patients presented Hb levels below the normal range (80.4%) after the second year of treatment, 17.9% grade 2 and 1.3% grade 3. In 13 cases (16.7%), anemia was attributed to resistance and in 13 cases (16.7%) the following causes were identified: iron deficiency (n = 5), hypothyroidism (n = 2), vitamin B12 deficiency (n = 3), acquired immune deficiency syndrome (AIDS) (n = 1), pulmonary tuberculosis (n = 1) and renal toxicity (n = 1). In 52 patients (66.6%), there were no other factors contributing to anemia, except imatinib treatment. Conclusion: Regular follow-up is required to identify the causes of anemia not related to CML or imatinib toxicity. The importance of investigating secondary causes of anemia should be emphasized, especially in patients with good adherence to treatment and satisfactory therapeutic response. Keywords: Chronic myeloid leukemia, Imatinib, Anemia, Adverse events

Myeloproliferative neoplasms (MPNs) constitute a group of hematologic clonal diseases that affect one or more myeloid lineages with an abnormal and abundant proliferation.16, 17 The World Health Organization (WHO) currently groups the MPNs into seven categories: Chronic myeloid leukemia (CML), chronic neutrophilic leukemia (CNL), polycythemia vera (PV), essential thrombocythemia (ET) primary myelofibrosis (PMF), chronic eosinophilic leukemia not otherwise specified (NOS) and, unclassifiable chronic myeloproliferative neoplasm (MPN-U). Mastocytosis is no longer included in that group.16 BCR-ABL1 fusion gene causes CML, identified by the translocation (9; 22) known as the Philadelphia chromosome (Ph), subject of prior guideline. Among the so-called Ph-negative MPNs, the most common ones include PV, ET, and PMF, herein the subject of this publication. PV, ET, and PMF share an anomaly in the JAK-STAT pathway, usually caused by genetic mutations on Janus kinase 2-JAK2 V617F, thrombopoietin receptor gene-myeloproliferative leukemia-MPL or calreticulin gene-CALR, which are mutually exclusive, and necessarily BCR-ABL negative (Table 1). PV, ET, and PMF share an anomaly in the JAK-STAT pathway, usually caused by mutations of the Janus kinase 2-JAK2 V617F genes, thrombopoietin receptor gene-myeloproliferative leukemia-MPL or calreticulin gene-CALR, that are mutually exclusive, and necessarily are BCR-ABL1 negative (Table 1). PV, ET, and PMF may arise alongside other mutations, as well as some cytogenetic abnormalities.16, 17 Despite the significant advances over recent years toward the characterization of genetic alterations, bone marrow morphological evaluation remains an important diagnosis tool.17 JAK2, MPL, and CALR mutations are not unique to these three conditions and may be present in other myeloid neoplasms, or even absent in some cases of PMF and ET.16 Table 1 Diagnostic criteria PV, ET, prefibrotic PMF and overt fibrotic PMF16(D).

We analyzed the management and outcomes of pregnancies of patients with chronic myeloid leukemia at a single center over fifteen years. Among the 203 CML female patients, there were ten pregnancies in seven women, all of them not planned. In three cases, the chronic myeloid leukemia diagnosis was made during pregnancy. Five patients received tyrosine kinase inhibitors in the first weeks of pregnancy and the drug was interrupted until delivery. One patient lost complete cytogenetic response, and two patients lost the hematological response. A patient with a stable major molecular response had two successful pregnancies without loss of response. There were four premature births. There were no maternal adverse events, fetal malformation or death. All patients received Interferon-alpha during gestation, and two received hydroxyurea for a short period. Leukapheresis was performed in two patients for hyperleukocytosis control. One patient with sickle cell disease died from disease progression six months after delivery. Conclusions: The tyrosine kinase inhibitors ministration should be interrupted during pregnancy. Patients should be advised to achieve a stable and deep molecular response if they plan to conceive, to avoid the risk of disease progression. Keywords: Chronic myeloid leukemia, Pregnancy, Imatinib, Interferon-alpha, Hydroxyurea, Dasatinib

The Estudo de Descontinuacao de Imatinibe apos Pioglitazona (EDI-PIO) is a single-center, longitudinal, prospective, phase 2, non-randomized, open, clinical trial (NCT02852486, August 2, 2016 retrospectively registered) for the discontinuation of imatinib after concomitant use of pioglitazone, being the first of its kind in a Brazilian population with chronic myeloid leukemia. Due to remaining of leukemic quiescent cells that are not affected by tyrosine kinase inhibitors, it has been suggested the use of pioglitazone, a PPARγ agonist, together with imatinib as a strategy for the maintenance of deep molecular response. The clinical benefit to this association is still controversial, and the metabolic alteration along this process remains unclear. Therefore, we applied a metabolomic protocol using high-resolution mass spectrometry to profile plasmatic metabolic response of a prospective cohort of ten individuals under discontinuation of imatinib and pioglitazone protocol. By comparing patients under pioglitazone and imatinib treatment with imatinib monotherapy and discontinuation phase, we were able to annotate 41 and 36 metabolites, respectively. The metabolic alterations observed during imatinib-pioglitazone combined therapy are associated with an extensive lipid remodeling, with activation of β-oxidation pathway, in addition to the presence of markers that suggest mitochondrial dysfunction.

Outside of clinical trials, few studies have addressed the outcomes of Ph+ acute lymphoblastic leukemia (ALL) in adults, especially from developing world. In this study, we conducted a multicenter analysis on the outcomes of patients aged > 15 years with Ph+ ALL, aiming to get to know an overview of the Brazilian experience as well as to explore baseline factors associated with relapse and mortality in our setting. Over these 10 years, patients were treated with diverse protocols, all of them always combined with a frontline tyrosine-kinase inhibitor. A total of 123 Ph+ ALL patients was included. Imatinib was the first line TKI in 97 %. The complete response rate was 79 %. The early death rate was 15 %, being associated with increasing age at diagnosis (p = 0.06). The use of intensive versus attenuated induction regimen was not associated with higher induction mortality (p = 0.99). Overall, 29 % of patients aged ≤ 60 years underwent allogeneic transplantation, 87 % in first CR. 4-year overall survival (OS) and relapse-free survival were 25 % and 24 %, respectively. The incidence of relapse (death as a competitor) was 29 %, while the non-relapse mortality was 42 %. Only age was independently associated with OS, and lactate dehydrogenase level and central nervous disease at diagnosis were related to relapse in our cohort. This is the first historical cohort multicenter study on Ph+ ALL from Brazil. Reporting these outcomes is essential to encourage public policies to expand access to new drugs and transplantation in middle-income countries.

Made available in DSpace on 2022-04-29T08:45:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This observational, multicenter study aimed to report the clinical evolution of COVID-19 in patients with chronic myeloid leukemia in Latin America. A total of 92 patients presented with COVID-19 between March and December 2020, 26% of whom were severe or critical. The median age at COVID-19 diagnosis was 48 years (22–79 years), 32% were 60 years or older, and 61% were male. Thirty-nine patients presented with at least one comorbidity (42.3%). Eighty-one patients recovered (88%), and 11 (11.9%) died from COVID-19. There was one case of reinfection. Patients with a major molecular response presented superior overall survival compared to patients with no major molecular response (91 vs. 61%, respectively; p = 0.004). Patients in treatment-free remission and receiving tyrosine kinase inhibitors showed higher survival rates than patients who underwent hematopoietic stem cell transplantation and those who did not receive tyrosine kinase inhibitors (100, 89, 50, and 33%, respectively; p < 0.001). Hematology and Hemotherapy Center University of Campinas Hospital Nacional Edgardo Rebagliati Martins Centro Médico Nacional Siglo XXI IMSS JM Ramos Mejia CABA Hospital de Transplantes Euryclides de Jesus Zerbini Faculdade de Medicina da Universidade Federal do Ceará Hospital Universitário Walter Cantídio Complexo Hospital de Clínicas–Universidade Federal do Paraná Laboratory of Medical Investigation in Pathogenesis and targeted therapy in Onco-Immuno-Hematology (LIM/31) Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Hospital de Valdivia Bueras Centro de Pesquisas Oncológicas Hospital dos Fornecedores de Cana de Piracicaba Hospital AC Camargo Cancer Center Hospital Universitário Antonio Pedro Universidade Federal Fluminense Hospitalization & Clinical Research Center Fundaleu Hospital Jorge Valente Hospital Santa Casa de Misericordia de Maceió Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto University of São Paulo Hospital Santa Marcelina São Paulo State University UNESP Medical School Campus de Botucatu Hemorio São Paulo State University UNESP Medical School Campus de Botucatu

Tyrosine kinase inhibitors (TKIs) have dramatically changed the survival of chronic myeloid leukemia (CML) patients, and treatment-free remission (TFR) has recently emerged as a new goal of CML treatment. The aim of this work was to develop recommendations for TKI discontinuation in Latin America (LA), outside of clinical trials. A working group of CML experts from LA discussed 22 questions regarding TFR and reached a consensus for TFR recommendations in the region. TFR is indicated in patients in first chronic phase, with typical BCR-ABL transcripts, under TKI treatment of a minimum of 5 years, in sustained deep molecular response (DMR; molecular response 4.5 [MR4.5]) for 2 years. Sustained DMR must be demonstrated on at least 4 international reporting scale quantitative polymerase chain reaction (PCR) tests, separated by at least 3 months, in the immediate prior 2 years. After second-line therapy, TFR is indicated in previously intolerant, not resistant, patients. Molecular monitoring is recommended monthly for the first 6 months, every 2 to 3 months from months 7 to 12, and every 3 months during the second year, indefinitely. Treatment should be reintroduced if major molecular response is lost. Monitoring of withdrawal syndrome, glucose levels, and lipid profile is recommended after discontinuation. After TKI reintroduction, molecular monitoring is indicated every 2 to 3 months until MR4.0 achievement; later, every 3 to 6 months. For the TFR attempt, having standardized and reliable BCR-ABL PCR tests is mandatory. These recommendations will be useful for safe discontinuation in daily practice and will benefit patients who wish to stop treatment in emergent regions, in particular, with TKI-related chronic adverse events.

The novel coronavirus has swept across the world in 2020 and ushered a new era. In the current scenario, it is not clear how patients with myeloproliferative neoplasms (including chronic myelogenous leukemia) should be managed, considering the risk of therapy, the need for social distancing and the risk of untimely therapy discontinuation of delay. This guideline aims to give providers a sense of direction in order to better take care of patients and prioritize care.

Non-T cell activation linker (NTAL) is a lipid raft-membrane protein expressed by normal and leukemic cells and involved in cell signaling. In acute promyelocytic leukemia (APL), NTAL depletion from lipid rafts decreases cell viability through regulation of the Akt/PI3K pathway. The role of NTAL in APL cell processes, and its association with clinical outcome, has not, however, been established. Here, we show that reduced levels of NTAL were associated with increased all-trans retinoic acid (ATRA)-induced differentiation, generation of reactive oxygen species, and mitochondrial dysfunction. Additionally, NTAL-knockdown (NTAL-KD) in APL cell lines led to activation of Ras, inhibition of Akt/mTOR pathways, and increased expression of autophagy markers, leading to an increased apoptosis rate following arsenic trioxide treatment. Furthermore, NTAL-KD in NB4 cells decreased the tumor burden in (NOD scid gamma) NSG mice, suggesting its implication in tumor growth. A retrospective analysis of NTAL expression in a cohort of patients treated with ATRA and anthracyclines, revealed that NTAL overexpression was associated with a high leukocyte count (P = 0.007) and was independently associated with shorter overall survival (Hazard Ratio: 3.6; 95% Confidence Interval: 1.17–11.28; P = 0.026). Taken together, our data highlights the importance of NTAL in APL cell survival and response to treatment.

A Leucemia mieloide cronica (LMC) e uma neoplasia mieloproliferativa da linhagem mieloide, resultante da translocacao cromossomica t(9:22); que codifica a oncoproteina BCR-ABL, com atividade tirosinoquinase. Apos a introducao dos inibidores de tirosinoquinase houve aumento da prevalencia da LMC, devido ao aumento da taxa de sobrevida em 10 anos. Nos casos em que o paciente obtem uma resposta molecular maior, a sobrevida iguala-se a da populacao em geral. Desse modo, e necessario avaliar outros fatores que afetam a sobrevida da populacao em geral e a sua relacao com o prognostico de pacientes com LMC. Esse estudo visa analisar o impacto das comorbidades e do tabagismo no prognostico e na sobrevida dos pacientes com LMC tratados no Hemocentro da UNICAMP. Apos coleta e analise de dados de 269 pacientes constatamos que a presenca de comorbidades clinicas acarretou diminuicao na sobrevida dos pacientes sendo relevante o diagnostico e controle das mesmas para aumento da qualidade e sobrevida de pacientes com LMC.

Introduction: in recent years the feasibility of the discontinuation of tyrosine kinase treatment in chronic myeloid leukemia (CML) has been proven, and several clinical factors influencing the duration of treatment-free remission (TFR) after discontinuation have been studied. Aim: we analyzed the influence of bone marrow (BM) lymphocyte subsets on the molecular recurrence after discontinuation of Imatinib (IM) in CML. Methods: in a recent discontinuation study performed at our Institution (EDI-PIO trial) we assessed BM lymphocyte subsets before and after introduction of pioglitazone which was given 3 months before discontinuation of IM. Criterias for discontinuation were: patient in chronic phase at diagnosis, a minimum of 3 years on TKI and sustained molecular remission MR4.5 for at least 2 years. Lymphocyte populations studied: B, TCD8, TCD4, T CD4+CD8+ and T CD4- CD8- besides T naïve and memory, TCRαβ, TCRγδ, NK-t and NK cells. The influence of Sokal score at diagnosis, the duration of imatinib treatment together with the BM lymphoid subsets on the time of treatment-free remission (TFR) were examined by uni- and multivariate Cox regressions. Results: we studied 30 out of 32 patients diagnosed between 1998 and 2013 that reached criteria for discontinuation that were included in EDI-PIO trial: 13 male and 17 female. Median age at diagnosis: 41 years (22-65). Median time of IM treatment: 116.3 months (38.2-209.3); 11 patients (36%) had a molecular recurrence in a median of 5,17 months (2.4-29.4). For patients remaining in TFR the median time of follow-up was 46 months (26.3-55.9). Median overall time of IM treatment (IM-Tr) was 65 months for patients recurring and 124 months for those remaining in TFR. In the univariate Cox regression a significant value was found for IM-Tr, higher percentages of T CD4+CD8+ and lower ones of TCRγδ lymphocytes at discontinuation. In the multivariate model only the T CD4+CD8+ remained. Conclusion: discontinuation of IM is feasible in patients remaining in continuous MR4.5 for more than 2 years. A longer time of IM treatment and higher values of BM T CD4+CD8+ predict a lower risk of relapse. Key words: chronic myeloid leukemia, imatinib, discontinuation, lymphocytes, pioglitazone Disclosures Pagnano: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pintpharma: Other: Lecture; EMS: Other: Lecture; Jansenn: Other: Lecture.

Used in the clinical practice for more than three decades, the all-trans retinoic acid (ATRA) rendered acute promyelocytic leukemia (APL) the most curable subtype of acute myeloid leukemia, and currently, its combination with arsenic trioxide (ATO) exceeded all expectations for a chemotherapy-free protocol. In terms of metabolic importance, ATRA can also modulate the mitochondria-mediated cellular metabolism and promote a shift from a glycolytic-driven metabolism to an oxidative phosphorylation profile, although this effect has never been demonstrated in APL. As part of the cellular metabolic machinery, mitochondrial DNA (mtDNA) content has been reported to be altered in different types of solid tumors with clinical implication on patient treatment outcomes, although its clinical significance in acute leukemias has not been investigated to the same extent. Particularly in acute promyelocytic leukemia (APL), the role of mtDNA content on prognostication is completely unknown. Considering that mostly APL samples display a glycolytic-driven metabolism, it is conceivable that APL patients harboring high mtDNA content may present a better response to ATRA-based therapies. To test this hypothesis, we determined the mtDNA content in samples from patients with APL enrolled in the International Consortium on Acute Promyelocytic Leukemia study (Rego et al. Blood. 2013 Mar 14;121(11):1935-43) and analyzed its relationship to treatment outcomes. Diagnostic bone marrow (BM) mononuclear cells from 156 consecutive patients with APL (median age: 35 years, range: 18-82 years; 45% male) were obtained at diagnosis. For comparison purposes, we also included peripheral blood (PB) from 293 age- and sex-adjusted healthy volunteers. First, we determined whether mtDNA content could be compared between PB mononuclear cells and BM. To do so, we measured the mtDNA content of 22 APL patients, for whom paired samples were available at the time of diagnosis and detected a strong correlation between PB and BM samples (Pearson correlation coefficient, r=0.78, 95% confidence interval, CI: 0.54 to 0.9). Next, we used the values of mtDNA higher than the 95 th percentile of healthy subjects (≥1.63. Note: this value represents a fold change relative to healthy control) to define APL patients with high mtDNA content. Patients that presented values within the range of normal control samples ( Disclosures Silveira: BMS/Celgene: Research Funding; Servier/Agios: Research Funding; Abbvie: Speakers Bureau; Astellas: Speakers Bureau. Pagnano: EMS: Other: Lecture; Jansenn: Other: Lecture; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pintpharma: Other: Lecture.

Background The iCMLf CANDID study represents the largest global cohort study to date characterizing COVID-19 in CML. This real world data collection, from 157 institutions in 49 countries, is essential to differentiate impact of patient, disease, and therapy specific factors on risk and outcomes, as the pandemic continues. Objective The primary aim of the CANDID study is to collect and analyze information on COVID-19 cases among CML patients (pts) to define risk factors, clinical evolution and outcome. Patients and methods Since March 2020, the iCMLf has collected data, with contributions from physicians treating CML pts and partner organizations. Country income was determined according to the World Bank Data. COVID-19 severity was classified according to the World Health Organization criteria. Univariate analysis was performed using log-rank test or logistic regression. Multivariate analysis was performed using Cox proportional hazards model or multivariate logistic regression. All the statistical analysis was performed using R statistical software (version 4.0.2). Results By April 2021, 642 cases of COVID-19 were reported from 50 countries. COVID-19 was diagnosed by PCR and/or serology in 601 pts (94%) and clinically suspected in 41 pts (6%). These 642 pts were reported by 186 physicians managing an estimated 37,449 CML pts (approximate incidence 0.7%). Most cases reported were from Europe (52%), followed by Asia (18%) and South America (16%). North America reported 10% of the cases and Africa 2.8%. The median age at the time of COVID-19 diagnosis was 53 years (18-94) and 59% of pts were males. Median time from CML diagnosis to COVID-19 was 8.34 years (range: 0-34). CML treatment at the time of COVID-19 diagnosis: hydroxyurea in 4 pts (6%), 38 (6%) bosutinib, 96 (15%) dasatinib, 275 (43%) imatinib, 92 (14%) nilotinib, 18 (3%) ponatinib, 3 (0.5%) other 4th generation TKIs; one alpha interferon. Ninety-nine (15%) pts were not receiving any treatment: 53 (8%) were in treatment free-remission (TFR) and 46 were without treatment (7%) for other reasons: treatment side effects (7), stem cell transplantation (12), pregnancy (3), lack of efficacy (2), unknown (1) and newly diagnosed CML (21). Significant comorbidities were present in 281 pts (44%), most common were: heart conditions, including hypertension (162), diabetes (76), lung diseases (47) obesity (42) and others (84). COVID-19 was asymptomatic in 53 cases (8%), mild in 363 cases (56%), moderate in 119 cases (18%), severe/critical in 86 cases (13%) and of unknown severity in 21 cases (3%). At the data cut-off, from the 606 pts with known outcome, 48 pts died (8%) and 558 (92%) recovered. Age >75y (Fig 1A, p75y (p=0.037), comorbidities (p=0.001), male gender (p=0.01), CML status (AP/BC vs CP in MMR; p=0.049), CML treatment (pre-TKI vs TFR; p=0.02) and length of time with CML (p75y (p=0.003) and low and lower middle income countries (p Conclusions We confirmed a higher mortality for CML pts with COVID-19 in older pts (>75y), pts with cardiovascular or pulmonary comorbidities and from low and low-middle income countries, the latter probably related to limitations in supportive care. Additionally, more deaths occurred in pts in advanced phases and in pts not in MMR. Acknowledgment The iCMLf CANDID Study would not have been possible without the 186 physicians who contributed case reports. Figure 1 Figure 1. Disclosures Pagnano: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pintpharma: Other: Lecture; EMS: Other: Lecture; Jansenn: Other: Lecture. Mauro: Sun Pharma / SPARC: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Pfizer: Consultancy; Takeda: Consultancy; Novartis: Consultancy, Research Funding. Cortes: Takeda: Consultancy, Research Funding; Bio-Path Holdings, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Research Funding; Bristol Myers Squibb, Daiichi Sankyo, Jazz Pharmaceuticals, Astellas, Novartis, Pfizer, Takeda, BioPath Holdings, Incyte: Consultancy, Research Funding; Sun Pharma: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Evans: Pfizer: Research Funding. Milojkovic: Pfizer: Honoraria, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Incyte: Honoraria, Speakers Bureau. Moiraghi: Novartis, Pfizer, Takeda: Speakers Bureau. Nicolini: Incyte Biosciences: Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; BMS: Honoraria; Kartos Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sun Pharma Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Research Funding. Rea: Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hughes: Novartis: Honoraria, Research Funding; BMS: Research Funding; Takeda: Honoraria.

Background: Primary myelofibrosis (PMF) is a chronic myeloproliferative neoplasm characterized by myeloid expansion associated with elevation of cytokines involved in fibrosis, angiogenesis, and osteosclerosis, leading to progressive fibrous connective tissue deposition in the bone marrow (BM) and BM failure. Although JAK2, CALR and MPL mutations are frequently seen in PMF, patients' molecular heterogeneity and the lack of an expressive clinical and laboratory response following JAK1/2 inhibitors suggest that other factors, such as unknown protein interactions, additional mutations or epigenetic mechanisms may be involved in the progression of PMF. Metformin (MTF) is an anti-diabetic drug, which has been described to possess anti-cancerous properties through the modulation of the AMPK/TORC1 pathway, thereby causing apoptosis in neoplastic cells. Previous reports demonstrated that MTF significantly reduced Ba/F3 JAK2V617F tumor burden and splenomegaly in Jak2V617F knock-in-induced MPN mice. In this context, our goal was to evaluate the effects of MTF treatment in PMF patients. Aims: To report final results of an open label phase II trial (FIBROMET), which evaluated outcomes of PMF patients after 24mo on MTF treatment. Methods: PMF non-diabetic adults were eligible. Patients received MTF in increasing doses until a maximum of 2500mg PO daily, according to tolerance. Primary endpoint was BM fibrosis reversion. Secondary endpoints included reduction of inflammation and downregulation of the JAK-STAT pathway. Samples were collected at the time points: screening (0), 3mo, 6mo, 12mo, 18mo and 24mo. The extent of collagen deposits in BM biopsies was semi-quantitatively assessed with Masson's trichrome stainings, following the recommendations of the European Consensus on grading of BM fibrosis (grades 0, 1, 2 or 3). The levels of CXCL4, sIL-2Ra, IP-10, VEFG-A, MIG, MCP-1, MIP-1b, FGF-2, IL-1RA, IL-5, IL-6, IL-8, IL-15, IL-18, TNFa and TGFb1 were analyzed in BM samples using multiplex assay. Phosphorylation status of intracellular proteins STAT3 and STAT5 was analyzed by flow cytometry and the percentage of cells was recorded using FlowJo software. This trial was approved by the Institutional and National Review Board; written informed consent was obtained from all subjects. REBEC registry number: RBR-52ty66. Results: 11 patients (aged 40-84y) were included between Aug/2018- Feb/2019. Two subjects had early treatment discontinuation due to non-related causes. One patient had disease progression after 12mo of treatment and was submitted to BM transplantation. The median exposure to MTF was 21 mo (3-24) and the median dose was 2500mg/day (1500-2500mg). The most frequent adverse event was diarrhea. No life threatening event occurred. BM collagen deposits were independently evaluated by two hematopathologists with an overall agreement of 80.64% (grade 0: 100%, grade 1: 62.5%, grade 2: 60.0%, grade 3: 90.0%); discordant cases were submitted to joint review. BM collagen deposits did not change when different time points were compared. After 24mo of MTF treatment, a significant 35.4% reduction in IL-5 levels was observed (p=0.03); a 36% reduction in MCP-1 levels was also observed, however this finding was not statistically significant (p=0.06). Flow cytometry analysis demonstrated a STAT3 phosphorylation decrease when comparing screening samples versus 6, 12, 18 and 24 mo of MTF use (all p Conclusions: Final results of the FIBROMET trial demonstrated that, in our study population, metformin was not capable of reversing established bone marrow fibrosis in PMF patients. However, a significant downregulation of the JAK-STAT pathway and reduction of cytokine secretion was observed. Finally, metformin showed to be a safe and well-tolerated drug. Phase III studies are required to confirm our results and to evaluate whether MTF treatment in early PMF phases could delay the progression of BM fibrosis through the downregulation of the JAK-STAT pathway. Disclosures Pagnano: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pintpharma: Other: Lecture; EMS: Other: Lecture; Jansenn: Other: Lecture. OffLabel Disclosure: Metformin for Primary Myelofibrosis treatment.

Background The prognostic significance of breakpoint cluster region gene-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL1) transcripts in chronic myeloid leukemia (CML) is still controversial. Patients and Methods All consecutive CML patients in chronic phase treated with imatinib in a single center were analyzed (n = 170). BCR-ABL1 transcript was evaluated using multiplex reverse transcription polymerase chain reaction. Exclusively patients with BCR-ABL transcripts e13a2 and/or e14a2 were included in this analysis. Results Patients with e14a2 transcripts presented higher rates of optimal molecular responses at 3 months and higher rates of complete cytogenetic response (CCR) at 6 months. E13a2, e14a2, and e14a2 with e13a2 (e14a2+e13a2) groups presented similar rates of 5-year event-free, progression-free, and overall survival. There was a superior 10-year overall survival in patients with transcripts e13a2 compared with e14a2 (alone or coexpressed with e13a2; 93% vs. 73%; P = .03), although the 5-year overall survival was 96% vs. 88%, respectively (P = not significant). In a multivariate analysis, high/intermediate Sokal score and e14a3/e14a3+e14a2 were independent factors for poor overall survival (hazard risk [HR], 4.63; P = .023 for Sokal score and HR, 10.6; P = .041 for BCR-ABL transcript). Conclusion Patients with BCR-ABL transcripts e14a2 transcripts have higher rates of CCR at 6 months and higher rates of optimal molecular response at 3 months compared with e13a2 or with both transcripts, but no difference in 5-year overall, progression-free, and event-free survival. There was a superior 10-year overall survival among patients with transcripts e13a2 compared with e14a2 (alone or coexpressed with e13a2).

(1) Background: Acute promyelocytic leukemia is curable, but bleeding complications still provoke a high early mortality. Therefore, a fast diagnosis is needed for timely starting treatment. We developed a diagnostic algorithm using flow cytometric features for discrimination between acute promyelocytic leukemia (APL) and other types of acute myeloid leukemias (AML). (2) Methods: we analyzed newly diagnosed AMLs where immunophenotyping was performed at diagnosis by an 8-color protocol. The mean fluorescence intensity (MFI) of each antigen used was assessed, and those best separating APL from other types of AML were obtained by a discriminant analysis. Phenotypic characteristics of myeloblasts of normal bone marrow were used as controls. (3) Results: 24 cases of APL and 56 cases of other primary AMLs entered the study. Among non-APL AMLs, 4 had fms-related tyrosine kinase 3 gene internal tandem duplications (FLT3-ITD) mutation, 2 had nucleophosmin (NPM1) and 10 had both mutations. SSC (p < 0.0001), HLA-DR (p < 0.0001), CD13 (p = 0.001), CD64 (p = 0.004) and CD33 (p = 0.002) were differentially expressed, but this was not the case for CD34 (50% of non-APLs had a low expression). In the discriminant analysis, the best differentiation was achieved with SSC and HLA-DR discriminating 91.25% of the patients. (4) Conclusion: MFC could differentiate APL from non-APL AML in the majority of the cases.

Introduction: Acute promyelocytic leukemia (APL) is a genetically and molecularly well-defined type of acute leukemia that is curable but has a frequent early mortality due to bleeding. So, there is a need for a fast diagnostic screening in order to start appropriate therapy. Multiparameter flow cytometry (MFC) is usually performed in all types of acute myeloid leukemias (AMLs) but only few features have been described as characteristic of APL. Aim: to develop a diagnostic algorithm based on the intensity of expression of several antigens examined by MFC in AML that could reliably discriminate between APL and the other types of AML. Material and Methods: Consecutive newly diagnosed AMLs treated in our Institution during the last 2 years entered the study. Immunophenotyping was included in the diagnostic workup. An 8-color platform based on the Euroflow recommendations was used. The mean fluorescence intensity (MFI) of each antigen tested was assessed and those best discriminating between APL and all other types of AML were obtained by a discriminant analysis. Phenotypic characteristics of normal myeloblasts taken from examinations of bone marrow (BM) MFC performed for the diagnosis of cytopenias were used as controls. Results: 24 cases of APL and 56 cases of other primary AML entered the study. Median age: 39 (23-56) and 62(26-81) years respectively. Concerning ELN risk groups of non-APL cases, 13 were favorable risk, 26 were intermediate and 09 were adverse risk. In 8 cases risk assessment was not possible due to the absence of cytogenetics. Moreover, among APL patients, 7 cases had a FLT3-ITD mutation. Among non-APL AMLs, 4 had FLT3-ITD mutation, 4 had NPM1 and 10 had FLT3-ITD and NPM1mutation. Concerning antigen expression, CD34 was expressed in only 1/24 APL samples, and in 18/56 samples from non-APL AMLs. The following flow features were differentially expressed in both groups: SSC (p Conclusion: MFC was adequate for a fast screening of APL in most cases. Expression of CD34 was not very useful, as many AMLs do not express this antigen, similar to APL, but SSC, together with HLA-DR could discriminate both types of leukemia in most cases. Disclosures Pagnano: Astellas: Other: Advisory Board and lecture; Novartis: Other: Advisory Board; Pintpharma: Other: Lecture; EMS: Other: Lecture. Duarte:Janssen: Other: Lecture; Astellas: Other: Lecture.

Background Comorbid conditions, including solid and hematologic malignancies, may impact risk of contracting SARS CoV-2 or having severe COVID-19. Data specific to individual cancer types is essential to differentiate impact of patient, disease, and therapy specific factors on risk and outcomes, as the pandemic remains uncontrolled. Goal The primary goal of the CANDID study was to rapidly collect and analyze information on COVID-19 cases among CML pts to define prognosis, risk factors and outcome. Defining risk and predisposing features in CML patients could guide interventions, therapy modifications, and clinical management for patients and physicians. Methods From March 12, 2020, the iCMLf sent an anonymized case collection form to its global network of physicians treating CML pts and partner organizations. Forms were reviewed and cases tracked by an iCMLf data manager. Updates were provided weekly. Only confirmed cases or those with high level of suspicion were collected. Denominators regarding affected cohort (% tested, % affected in CML population) were not available in most instances. Results As of July 1, 2020, 110 cases of COVID-19 were reported to iCMLf from 20 countries: 61% from Europe, 15% from Asia, 12% from South America, 10% from North America, 2% from Africa and 1% from Oceania. COVID-19 was diagnosed by PCR and/or serology in 93 pts (85%) and clinically suspected in 17 pts (15%). Forty-six physicians reported 91 of the CML pts with COVID-19 out of a total of 12,236 CML pts that they were following (0.7%). Median age at the time of COVID-19 diagnosis was 54 years (range: 18-89) and 55% of pts were males. Median time from CML diagnosis to COVID-19 was 7 years (range: 0-25). CML treatment at the time of COVID-19 diagnosis consisted of hydroxyurea in 1 pt (1%) and TKI in 77 (70%). Five (5%) pts were taking bosutinib, 12 (11%) dasatinib, 39 (36%) imatinib, 17 (16%), nilotinib, 2 (2%) ponatinib, 1 (1%) HQP1315 and 1 pt (1%) was treated with an unknown TKI. Eighteen (16%) pts were untreated at the time of COVID-19 diagnosis, 8 due to elective treatment discontinuation (TFR) and 10 for other reasons (toxicity (5), stem cell transplantation (1), unknown (1) and newly diagnosed CML (3)). CML treatment information was lacking at the time of cut-off in 14 cases (13%). Thirty-three (30%) cases were reported as having interrupted TKI therapy during COVID-19. From 110 reports COVID-19 was asymptomatic in 8 cases (7%). In the 102 symptomatic pts (93%), COVID-19 was considered as mild (no hospitalization) in 49 cases (45%), moderate (hospitalization) in 19 cases (17%), severe (intensive care) in 19 cases (17%) and of unknown severity in 15 cases (14%). At the data cut-off date, COVID-19 was still active in 14 pts (13%) and outcome was unknown in 9 pts (8%). Among the 87 others, outcome was favorable in 75 pts (86%) and fatal in 12 (14%). We analyzed overall survival in the 87 patients with known outcome according to sex, age, CML duration, type of CML treatment, line of TKI therapy, history of smoking, comorbidities, TKI interruption due to COVID-19, administration of any treatment against COVID-19 (antimicrobial agents, steroids, oxygen or anti-IL-6 antibodies) and economic status of country. Univariate analysis identified older age (75 vs < 75 years; mortality rate: 60% vs 7%, p Conclusion The CANDID study represents the largest global cohort study to date characterizing COVID-19 in CML. Currently, the mortality rate from COVID-19 in evaluable CML patients is 13.7%. Factors associated with a higher mortality rate are age and imatinib therapy. Imatinib may represent a confounder as opposed to a true adverse prognostic predictor given the strong link between imatinib treatment and advanced age. Further case reports and longer follow up are needed to better ascertain independent risk factors, the impact of COVID-19, and the possible role that TKI type may play in this population. Acknowledgment The authors thank Arlene Harriss-Buchan from the iCMLf for case collection and reporting and the 61 physicians from 20 countries who contributed case reports. Disclosures Rea: Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mauro:Bristol-Myers Squibb: Consultancy, Honoraria, Other: Travel, Accommodation, Expenses, Research Funding; Pfizer: Consultancy, Honoraria, Other: Travel, Accommodation, Expenses, Research Funding; Sun Pharma/SPARC: Research Funding; Novartis: Consultancy, Honoraria, Other: Travel, Accommodation, Expenses, Research Funding; Takeda: Consultancy, Honoraria, Other: Travel, Accommodation, Expenses, Research Funding. Cortes:BiolineRx: Consultancy, Research Funding; Arog: Research Funding; Amphivena Therapeutics: Research Funding; Astellas: Research Funding; Telios: Research Funding; BioPath Holdings: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sun Pharma: Research Funding; Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Immunogen: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Merus: Research Funding. Pagnano:Novartis: Other: Advisory Board; Astellas: Other: Advisory Board and lecture; Pintpharma: Other: Lecture; EMS: Other: Lecture. Hughes:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Foundation:Novartis: Other: Grants and sponsorship; BMS: Other: Grants and sponsorship; Pfizer: Other: Grants; Incyte: Other: Grants; Takeda: Other: Grants and sponsorship; Cepheid: Other: Grants and sponsorship.

Coronavirus disease (COVID-19) is an infectious disease caused by the newly discovered coronavirus Sars-Cov2. In Brazil, the first COVID-19 case was diagnosed in February 2020, and since then, the number of cases and deaths has increased exponentially, reaching 2.610.102 confirmed cases and 91.263 deaths on July 31st. Most people have a mild to moderate respiratory illness, but the clinical evolution may be severe in older adults and patients with comorbidities, such as cancer. There are few reports of COVID-19 in patients with chronic myeloid leukemia (CML). This ongoing study aims to collect data about COVID-19 in CML patients from Brazil and their outcomes. Methods: This is an observational, multicentric, ongoing register study. Hematologists from private and public CML reference centers from different regions of Brazil were invited to report their cases of COVID-19 in CML patients. Altogether, those centers are responsible for the care of approximately 4336 CML patients. COVID-19 was classified as mild/moderate, severe (defined as tachypnoea [≥30 breaths per min], oxygen saturation ≤93% at rest, or PaO2/FiO2 ratio Results: Between March and July 2020, 24 institutions contributed to this analysis, and reported 28 COVID-19 cases in CML patients. Eighteen centers were from the South and Southeast regions, 5 from Northeast, and one from the Central region. There were 19 cases (67.9%) from the Southeast region, 8 (28.6%) from the Northeast, one from South (3.6%). The median age was 54 years (24-79), with 13 (44%) older than 60. Male patients were predominant (67.9%). There was one patient in the accelerated phase. There were two cases of COVID-19 simultaneous to CML diagnosis, 10 using imatinib, 7 dasatinib, 6 nilotinib, one ponatinib, one asciminib, and one patient in treatment-free remission after imatinib discontinuation. The median time of CML diagnosis was 7.0 years (0-26). Current CML response was: no hematologic response (n=8), hematologic response (n=4), major molecular response (n=9), MR4.0 or MR5.0 (n= 7). Eleven patients interrupted treatment temporarily during COVID. COVID-19 was confirmed by RT-PCR of oral and nasal swab collection (20) or serologic test (07). One case is suspect, awaiting confirmation. The majority of the patients presented at least one comorbidity (60%): hypertension (7), diabetes (3), chronic renal failure (1), dyslipidemia (2), arterial disease (2), cirrhosis (1), chronic obstructive pulmonary disease/emphysema (2), pulmonary hypertension (1), HTLV1 (1), obesity (n=1). COVID-19 severity: mild/moderate (19), severe/critic (9). Five out of 9 (55%) of the severe/critic cases were older than 60, 4/9 presented comorbidities and 5/9 (55%) had no major molecular response (MMR)(one was in accelerated phase, one newly diagnosed, and 3 with only hematologic response). Among the mild/moderate cases, 12/19 had optimal response (63%) and 7/19 (36%) had no hematologic response. Twenty-one patients recovered, 4 are still hospitalized, and 3 died from COVID: one newly diagnosed case with high leukocytes counts and with a simultaneous bacterial infection, one elderly patient with comorbidities treated with imatinib and one patient treated with nilotinib, with hematologic response. A fourth patient in the accelerated phase died 2 months after discharge, from disease progression and pulmonary infection. Conclusion: Although the sample size is still small to make conclusions regarding COVID-19 behavior in CML patients, the most severe cases occurred in patients not in MMR. The continued register of the cases will increase our knowledge about this disease and how to manage these patients. Disclosures Pagnano: Astellas: Other: Advisory Board and lecture; Novartis: Other: Advisory Board; EMS: Other: Lecture; Pintpharma: Other: Lecture. Magalhães:AstraZeneca: Speakers Bureau; Novartis: Speakers Bureau. Santos:Novartis: Other: Speaker fee; Bristol-Myers Squibb: Other: Speaker fee. Clementino:EMS: Other: Financial support for congress.

7009 Background: BOS is approved for Philadelphia chromosome (Ph)+ CML resistant/intolerant to prior therapy and newly diagnosed Ph+ CP CML. In a phase 1/2 study, second-line BOS showed durable efficacy and manageable toxicity in pts with imatinib-resistant (IM-R) or -intolerant (IM-I) Ph+ CP CML. Methods: This final efficacy and safety analysis of the phase 1/2 study and extension study was based on ≥10 y of follow-up (FU). Ph+ CP CML pts who received BOS starting at 500 mg/d after prior treatment (Tx) with imatinib only were included. Results: 19% of pts were on BOS at y 10, and 13% were still on BOS at study completion after ≥10 y; 19% completed ≥10 y of FU. Median duration of Tx and FU were 26 and 54 mo, respectively. Median (range) dose intensity was 436 (87–599) mg/d. The most common primary reasons for permanent Tx discontinuation were lack of efficacy (unsatisfactory response or disease progression; 27%) and adverse events (AEs; 26%). In pts with a valid baseline assessment, cumulative complete cytogenetic response (CCyR), major molecular response (MMR) and MR4 rates (95% CI), respectively, were 50% (43–56), 42% (35–49) and 37% (30–44) (IM-R: 48% [41–56], 46% [37–55] and 39% [31–48]; IM-I: 53% [41–64], 36% [25–48] and 33% [22–45]). Responses were durable, with estimated probabilities of maintaining CCyR, MMR and MR4 > 50% after ≥10 y (Table). At 10 y, cumulative incidence of on-Tx progression/death was 24% and Kaplan-Meier (K-M) overall survival 72% (Table); 55 deaths (IM-R: n = 41; IM-I: n = 14) occurred on study, none BOS-related. Any grade Tx-emergent AEs (TEAEs) in ≥40% of pts were diarrhea (86%), nausea (46%) and thrombocytopenia (42%). Pleural effusion, cardiac and vascular TEAEs occurred in 13%, 12% and 11% of pts, respectively. 28% of pts had AEs leading to permanent Tx discontinuation; most common (≥2% of pts) were thrombocytopenia (6%), neutropenia (2%) and alanine aminotransferase increased (2%). Conclusions: These 10-y data are consistent with prior results of durable efficacy and manageable toxicity with second-line BOS and support long-term BOS use in CP CML pts after imatinib failure. Clinical trial information: NCT00261846 and NCT01903733. [Table: see text]

Socioeconomic status (SES) is a well-known determinant of outcomes in cancer. The purpose of this study was to analyze the impact of the SES on the outcomes of Hodgkin lymphoma (HL) patients from the Brazilian Prospective HL Registry. SES stratification was done using an individual asset/education-based household index. A total of 624 classical HL patients with diagnosis from January/2009 to December/2014, and treated with ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine), were analyzed. The median follow-up was 35.6 months, and 33% were classified as lower SES. The 3-year progression- free survival (PFS) in higher and lower SES were 78 and 64% (p

Data about Hodgkin lymphoma (HL) in developing countries are scarce and suggest the existence of substantial disparities in healthcare and outcomes in large areas of the world. In 2009, a prospective registry of HL was implemented in Brazil. Web-based data were contributed by 20 institutions across the country participating in the Brazilian Prospective Hodgkin's Lymphoma Registry. The aim of this study was to present the clinical features and outcomes of newly diagnosed patients with HL aged 13 to 90 years. Multivariate Cox regression models were used to estimate progression-free (PFS) and overall survival (OS) by clinical factors. A total of 674 patients with classical HL were analysed, with a median follow-up of 37 months. Median age was 30 years (13-90). The median time from the onset of symptoms to diagnosis was 6 months (0-60). Only 6% of patients had early favourable disease, while 65% had advanced disease. Stage IVB was present in 26% and a high-risk International Prognostic Score in 38%. Doxorubicin, bleomycin, vinblastine, and dacarbazine was used in 93%. The median dose of radiotherapy was 36 Gy for localized disease and 32 Gy for advanced disease. The 3 year PFS in early favourable, early unfavourable, and advanced disease were 95%, 88%, and 66%, respectively. High-risk International Prognostic Score, advanced disease, and age greater than or equal to 60 were independently associated with poorer PFS and OS; performance status greater than or equal to 2 was also associated with a poorer OS. Poor-risk patients predominated. Radiation doses for localized disease appear higher than current recommendations. Outcomes appear inferior in developing countries than in developed countries. Delayed diagnosis is probably a major factor underlying these findings. Scattered reports from developing nations suggest that many aspects of standard care in developed countries remain unmet needs for populations living in developing countries. The present report contributes to this body of data, with a proper description of what is currently achieved in urban areas in Brazil.

BACKGROUND: The clinical course of gastric lymphoma is heterogeneous and clinical symptoms and some factors have been related to prognosis. OBJECTIVE: The present study aims to identify prognostic factors in gastric diffuse B-cell non-Hodgkin lymphoma diagnosed and treated in different countries. METHODS: A consecutive series of gastric diffuse B-cell non-Hodgkin lymphoma patients diagnosed and treated in Brazil, Portugal and Italy, between February 2008 and December 2014 was evaluated. RESULTS: Of 104 patients, 57 were female and the median age was 69 years (range: 28-88). The distribution of the age-adjusted international prognostic index was 12/95 (13%) high risk, 20/95 (21%) high-intermediate risk and 63/95 (66%) low/low-intermediate risk. Symptoms included abdominal pain (63/74), weight loss (57/73), dysphagia (37/72) and nausea/vomiting (37/72). Bulky disease was found in 24% of the cases, anemia in 33 of 76 patients and bleeding in 22 of 72 patients. The median follow-up time was 25 months (range: 1-77 months), with 1- and 5-year survival rates of 79% and 76%, respectively. The multivariate Cox Regression identified the age-adjusted international prognostic index as a predictor of death (hazard risk: 3.62; 95% confidence interval: 2.21-5.93; p-value

The classical chromosome Philadelphia-negative myeloproliferative neoplasms (MPNs) are a group of disorders that share clinical, hematological, and histological features. Proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) are elevated in patients with MPN. The aim of this study was to verify the association between the polymorphisms of TNF gene (-308G/A and -238 G/A) in BCR-ABL-negative MPN in our population. Blood samples obtained from MPN patients were genotyped for the JAK2V617F mutation and both TNF polymorphisms using PCR-RFLP. Thirty three (26.8%) patients with polycythemia vera (PV), 35 (28.7%) essential thrombocythemia (ET), 22 (17.7%) primary myelofibrosis (PMF), and 33 (26.8%) with unclassifiable MPN (MPNu) were included in the study. The JAK2 V617F mutation was detected in 94 (76.42%) patients. Were observed a significant increase on the frequency of the TNF-238 GA genotype in MPN patients compared to controls (OR=2.21, 95% CI=1.02-4.80, P

Rosane Bittencourt, Teresa Cristina Bortolheiro, Maria de Lourdes Lopes Ferrari Chauffaille, Evandro Maranhao Fagundes, Katia Borgia Barbosa Pagnano, Eduardo Magalhaes Rego, Wanderley Marques Bernardo a Universidade Federal do Rio Grande do Sul (UFGRS), Porto Alegre, RS, Brazil b Irmandade da Santa Casa de Misericordia de Sao Paulo, Sao Paulo, SP, Brazil c Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP, Brazil d Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil e Universidade Estadual de Campinas (Unicamp), Campinas, SP, Brazil f Universidade de Sao Paulo (USP), Ribeirao Preto, SP, Brazil g Universidade de Sao Paulo (USP), Sao Paulo, SP, Brazil

The SLIT-ROBO axis plays an important role in normal stem-cell biology, with possible repercussions on cancer stem cell emergence. Although the Promyelocytic Leukemia (PML) protein can regulate SLIT2 expression in the central nervous system, little is known about SLIT2 in acute promyelocytic leukemia. Hence, we aimed to investigate the levels of SLIT2 in acute promyelocytic leukemia (APL) and assess its biological activity in vitro and in vivo. Our analysis indicated that blasts with SLIT2high transcript levels were associated with cell cycle arrest, while SLIT2low APL blasts displayed a more stem-cell like phenotype. In a retrospective analysis using a cohort of patients treated with all-trans retinoic acid (ATRA) and anthracyclines, high SLIT2 expression was correlated with reduced leukocyte count (p = 0.024), and independently associated with improved overall survival (hazard ratio: 0.94, 95% confidence interval: 0.92&ndash, 0.97, p &lt, 0.001). Functionally, SLIT2-knockdown in primary APL blasts and cell lines led to increased cell proliferation and resistance to arsenic trioxide induced apoptosis. Finally, in vivo transplant of Slit2-silenced primary APL blasts promoted increased leukocyte count (p = 0.001) and decreased overall survival (p = 0.002) compared with the control. In summary, our data highlight the tumor suppressive function of SLIT2 in APL and its deteriorating effects on disease progression when downregulated.

Background Cardiovascular events (CVEs) have been observed in patients with chronic myeloid leukemia treated with second-generation tyrosine kinase inhibitors. Patients and Methods We retrospectively evaluated the incidence of CVEs on 233 consecutive patients with chronic myeloid leukemia, of which 116 were treated with imatinib, 75 with dasatinib, and 42 with nilotinib. The median follow-up was 2047, 1712, and 1773 days, respectively. Results The cumulative incidence of CVEs was 4.29%. Three events occurred during dasatinib treatment, 6 during nilotinib treatment, and none during imatinib treatment (P ≤ .001). Arterial occlusive events occurred in 2 (2.6%) of 75 patients treated with dasatinib and in 6 (14.2%) of 42 patients treated with nilotinib (P ≤ .001). Furthermore, all of them occurred in patients with high-risk (n = 2) and very high-risk (n = 6) cardiovascular risk, contributing to 4.3% of mortality. Conclusion CVEs were more frequent in patients treated with second-generation tyrosine kinase inhibitors. Arterial occlusive events were more frequent in patients treated with nilotinib, with high and very high cardiovascular risk.

Background: Primary Myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (MPN) characterized by increased myeloid proliferation and associated with mutations that induce tyrosine-kinase activation mainly via JAK-STAT pathway, culminating in extensive bone marrow (BM) fibrosis in the course of disease progression. In contrast to the monoclonal origin of hematopoietic cells, fibroblasts proliferation is polyclonal, and mediators involved in fibrosis, neoangiogenesis and osteosclerosis seem to be involved in disease progression. Metformin (MTF) is a biguanide that exerts selective antineoplastic activity in a variety of malignancies, through its action on nutrients privation and hypoxia, leading to apoptosis. In JAK2-mutated cell lines, MTF reduced cell viability, proliferation and clonogenicity, while in Jak2V617F knock-in-induced mice, MTF reduced Ba/F3 JAK2V617F tumor burden and splenomegaly. These data suggest that MTF could have a therapeutic effect in PMF patients. Aims: To conduct an open label phase II study to evaluate MTF effects on BM fibrosis, inflammation mediators, JAK-STAT pathway activation and disease progression in PMF patients. Methods: PMF non-diabetic adults were eligible. Subjects with severe renal function impairment were not included. Patients received MTF (Glifage XR®) in rising doses until a maximum of 2500mg PO daily, according to tolerance. Primary endpoint was BM fibrosis reversion. Secondary endpoints included reduction of inflammation and downregulation of the JAK-STAT pathway. Clinical data was systematically compiled. Blood and BM samples were collected at the time points: pretreatment (0), 3 mo and 6 mo. Collagen was evaluated in BM biopsy specimens by Masson's trichrome stain: three representative areas from each slide were analyzed and the collagen/sample area was quantified using Image J software; the mean percentage of each slide was used for statistics. IL-6, IL-8 and TNF-α levels were analyzed in BM samples using multiplex assay. Phosphorylation status of intracellular proteins STAT3 and STAT5 was analyzed by flow cytometry and the percentage of cells was recorded using FlowJo software. In order to evaluate gene modulation following MTF exposure, samples at time points 0 and 6 mo were analyzed by PCR array for insulin signaling genes (PAHS-030Z, Qiagen). Genes with ±1.5 fold-change in both directions were selected for validation. For each experiment, statistical analysis was performed and a p value Results: 11 patients (aged 40-84y) were included. Two subjects had early treatment discontinuation due to non-related causes. The median exposure to MTF was 10 mo (5-11) and the median dose was 2000mg/day (1500-2500mg). The most frequent adverse event was diarrhea (n=3). No life threatening event occurred. A reduction in BM collagen area percentage was observed comparing pretreatment biopsies (26.9% (14.8-53.1%)) versus 3 months (3.8% (2.3-4.0%), p=0.062) and versus 6 months of MTF use (0.84% (0.12-17.1%), p=0.125), however, this result was not statistically significant probably due to the low number of patients analyzed (n=5). IL-6, IL-8 and TNF-α levels did not differ between time points. Flow cytometry analysis demonstrated a trend in STAT3 phosphorylation decrease when comparing pretreatment samples versus 6 months of MTF use, though this result was not statistically significant (p=0.06). Mean fluorescence intensity for pSTAT3 was: pretreatment 10.53 ± 5.75, 3 mo 7.34 ± 2.4, 6 mo 5.41 ± 1.14; and for pSTAT5: pretreatment 14.03 ± 7.41; 3 mo 10.71 ± 7.74; 6 mo 6.03 ± 1.41. PCR array for insulin signaling genes showed 21 genes downregulated after 6 months of MTF treatment, including genes previously associated with MPN phenotype: INS (0 and 6 mo treatment fold-decrease: 0.18), NOS2 (0.24), VEGFA (0.34), LEP (0.34), IGFBP1 (0.38) and IRS2 (0.62). Conclusions: In this study, metformin showed to be a safe and well-tolerated drug. Our preliminary results demonstrated a trend in BM collagen reduction in PMF patients following metformin treatment. Downregulation of important genes associated with MPN phenotype was also noted. The trial is ongoing and these results will be validated at other time points for all subjects. Disclosures Pagnano: Abbvie: Consultancy; Pint Pharma: Consultancy; Sandoz: Consultancy.

Quantitative RT-PCR (RQ-PCR) is an essential test for BCR-ABL transcripts monitoring in patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitors (TKI), to guide therapy and for monitoring after a discontinuation attempt in patients with deep molecular response. RT-PCR (RQ-PCR) is currently not reimbursed by the public health system in Brazil. Aims: To assess the proportion of CML patients treated with first-line imatinib eligible for discontinuation, and to calculate the financial impact resulting from IM discontinuation. Methods: Between January 2010 and December 2011, 151 consecutive cases of chronic phase myeloid leukemia treated with Glivec first-line therapy were evaluated. Between June and December 2013 there was a switch in treatment from Glivec to generic IM. Cases that exhibited stable MR4.5 for 2 years with first-line IM were selected for the study. Cases which switched treatment to second-generation inhibitors and patients older than 75 years of age were excluded from the study. The methodology used was a pharmacoeconomic cost-utility analysis. Glivec monthly cost has been estimated at U$ 3,257.54 and the generic IM U$ 365.48, while the unitary value for the PCR test was U$ 117.49. In order to calculate the period of IM consumption, the median age of the patients and the life expectancy data released in 2015 by the Brazilian Institute of Geography and Statistics (IBGE) of 75 years was considered. In the first analysis, the life expectancy for the sample group, and the total cost of treatment (cost of Glivec, generic IM and four annual RQ-PCR tests for each patient) were calculated. The second analysis consisted of a hypothetical calculation of costs under the scenario where the study group is therapy-free (estimating that the survival rate under discontinued therapy was similar to data available in the literature, with discontinuation success of 50% in this group) with molecular monitoring by PCR monthly in the first year, bimestrial in the second year and every three months from the third year on. Results: One hundred fifty-one cases were analyzed, with a median age at diagnosis of 45. From those, 56 (37%) patients achieved stable MR4.5 with a median time to achieve MR4.5 of 71 months. The median duration of follow-up was 8 (0-10) years. In the last follow-up, 108 patients were still in treatment, 10% (11/108) with Glivec, 90% (97/108) on generic IM. Patients excluded from the analysis: 4 cases aged more than 75 years; 13 that switched therapy to another TKI and one during the bone marrow transplant period. Finally, 38/56 (25%) patients who obtained MR4.5 with IM were eligible for analysis. Analysis 1: Total treatment cost for the 38 eligible cases, if the individuals sustained continuous use of IM, considering the life expectancy of 75 years. The calculations resulted in an average of 29 years of treatment, with an estimated cost of U$ 9,363,866.00. Analysis 2: The cost after discontinuation of generic IM, estimating that 50% of patients would resume the treatment. Nineteen cases were analyzed. The costs related to the monthly PCR exam in year 1, bimestrial exam in year 2 and trimester in year 3, until the patient reaches 75 years of age, have been calculated, with a total cost of U$ 7,823.515. Conclusions: The economy resulting from the discontinuation of treatment (US$1.540.340,00) by 19 patients could support 219 patients tests over 29 years, or 12.110 tests each year. This data is relevant, providing that RQ-PCR is essential for the appropriate management of CML and to allow safe discontinuation of the therapy in eligible patients. Such results may help to change the current health policies concerning RQ-PCR tests reimbursement for CML management and future attempting of TFR in Brazil. Disclosures Centrone: Novartis: Honoraria; Janssen: Honoraria. Magalhaes:Novartis: Honoraria. Pagnano:Pint Pharma: Consultancy; Abbvie: Consultancy; Sandoz: Consultancy.

Tyrosine kinase inhibitors treatment changed dramatically the survival of CML patients, approaching to the survival of the normal population. Comorbidities may also impact treatment results. Aim: to investigate the impact of comorbidities in the survival of CML patients treated with TKI Methods: We collected clinical and laboratory data from CML patients treated in a single center from medical records from January 2001 to December 2018. Comorbidities were collected at diagnosis before treatment and Charlson comorbidity index (CCI) was calculated. Because of CML diagnosis, the lowest possible score was 2. Patients were treated with imatinib 400-600 mg and one was treated with dasatinib in first line. Management followed the European Leukemia Net recommendations. OS probabilities were calculated using Kaplan-Meier method. OS was defined as the time between diagnosis and death of any cause, independent of treatment. Cox models were estimated for the multivariate analysis. All calculations were performed with version 24.0 SPSS software. Results: We included 273/310 patients in this analysis; 37 pts were excluded because of previous treated in other centers. Patients characteristics: 57.3% males, median age at diagnosis was 49 (14-86); 263 (96%) chronic phase and 11 (4%) accelerated phase; Sokal low risk 36.8%, intermediate 31.8% high risk 31.4%; EUTOS low risk (81.7%) and high risk (18.3%); median follow-up time was 92 months (1-223). Most frequent comorbidities: hypertension (27.2%); diabetes (7.5%). Smoking at diagnosis (15.3%). CCI group categories were: 2 (n=131), 3 (n=52), 4 (n=46), 5 or more (n=45). Probabilities of OS at 10 years for patients with CCI 2, 3 to 4 and ≥ 5 to were 81%, (95% confidence interval [CI]: 73-89%), 77% (95%CI: 63-100%), 69% (95%CI:53-85%), and 62% (95% CI: 38-86%), respectively. Probabilities of OS according to Sokal score was 86% (low risk) vs. 73% (intermediate) vs. 68% (high risk), P=0.002 and for EUTOS score 79% (low risk) vs. 61% (low risk), P=0.004. OS was lower in patients with hypertension (63% vs. 80%), P=0.018. In a multivariate analysis including CCI Sokal and EUTOS Score, smoking, diabetes, hypertension, the most powerful predictive factors for death were high and intermediate Sokal score and hypertension ((Wald test, P =0.003 and 0.049, respectively). There were 58 deaths, 22 not related to CML and 2 causes unknown. Conclusions: Comorbidities represents an important cause for mortality in CML patients treated in real life, besides known disease risk factors as Sokal and EUTOS scores. CCI high scores and hypertension were related to a lower OS. Figure 1 Disclosures Delamain: Novartis: Honoraria. Pagnano:Abbvie: Consultancy; Sandoz: Consultancy; Pint Pharma: Consultancy.

Background: TP73 isoforms gained particular relevance in acute promyelocytic leukemia (APL) since Bernasola et al (JEM. 2004) demonstrated that TAp73 was directly regulated by the PML protein in the nuclear body. The isoforms differ in their transcriptional activity, with those lacking domains in the N-terminal part of the protein exerting a dominant negative effect on TP73 function. In a retrospective analysis of patients with APL treated in ICAPL study, Lucena-Araujo et al (Blood 2015) demonstrated the association between higher ΔNp73/TAp73 ratio values and poor clinical outcome. However,there is a diversity of TP73 isoforms and specially those lacking N-terminal domains (e.g.ΔEx2p73, ΔEx2-3p73 and ΔN'p73) may be relevant in APL genesis and therapy response. Aims: Here, we quantified transcript levels of TP73 N-terminal variants TAp73, ΔNp73, ΔEx2p73, ΔEx2-3p73 and ΔN'p73, as well as the C-terminal variants TP73αand TP73β, and determined whether there is a prognostic correlation. In addition, we evaluated the effect of ΔNp73overexpression on APL cell lines survival and differentiation in vitro and in vivo. Methods: Bone marrow (BM) samples from 98 patients (age, 18-74y) with newly diagnosed APL enrolled in the International Consortium on Acute Leukemia (ICAPL2006) were included. For comparison, BM mononuclear cells from 14 healthy donors (age, 18-60y) were also included. TP73 transcripts were determined by qPCR and using survival ROC curve analysis and the C-index we dichotomized patients into "low" and "high" expression. Proportional hazard model on overall survival (OS) and disease-free survival (DFS) was performed to evaluate prognosis. In addition, empty vector (EV) or ΔNp73α was transduced in NB4 and NB4R2 (RA-resistant) APL cell lines using a lentivirus system. The apoptosis rate was evaluated in both cell lines upon ATO (1 μM) treatment for 24, 48 and 72h. ΔNp73α, cleaved caspase 3 and Bcl-2 protein abundance was detected by western blotting. Granulocytic differentiation induced by RA-treatment (1 μM) alone or in combination with ATO (1 μM) for 72 h was assessed by CD11b surface levels. Finally, lethally irradiated 8-12 week old C57/BL6 Boy (CD45.1) were transplanted with hCG-PMLRARa Blasts (CD45.2) ΔNp73α or EV transduced (ΔNp73α group=16 and EV group=12). Results: Compared to normal BM, APL patients presented higher levels of ΔNp73 (p=.004), ΔEx2p73 (p=.008), and TP73β (p.05) or disease progression in ΔNp73α blasts compared to the control group (p=.095). Conclusions: Our results suggest that transcript levels of ΔNp73, ΔEx2p73 and TAp73 predict outcomes in APL patients treated with RA plus chemotherapy. Additionally, RA plus ATO combination therapy seemed to overcome the effect of ΔNp73 overexpression in vitro. Disclosures Figueiredo-Pontes: Novartis: Honoraria. Pagnano:Abbvie: Consultancy; Sandoz: Consultancy; Pint Pharma: Consultancy. Tallman:Danbury Hospital Tumor Board: Honoraria; 14th Annual Miami Cancer Meeting: Honoraria; International Conference in Leukemia: Honoraria; KAHR: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Nohla: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; New Orleans Summer Cancer Conference: Honoraria; Indy Hematology Review: Honoraria; Mayo Clinic: Honoraria; Orsenix: Membership on an entity's Board of Directors or advisory committees, Research Funding; UpToDate: Patents & Royalties; Salzberg Weill Cornall MSKCC Seminar in Hematologic Malignancies: Honoraria; Hematology Oncology of Indiana: Honoraria; ADC Therapeutics: Research Funding; Arog Pharmaceuticals: Research Funding; Cellerant Therapeutics: Research Funding; University of Oklahoma Medical Center: Honoraria; Bioline: Membership on an entity's Board of Directors or advisory committees, Research Funding; BioSight: Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees. Dillon:Abbvie: Consultancy, Honoraria; TEVA: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Löwenberg:Chairman, Leukemia Cooperative Trial Group HOVON (Netherlands: Membership on an entity's Board of Directors or advisory committees; Clear Creek Bio Ltd: Consultancy, Honoraria; Editorial Board "European Oncology & Haematology": Membership on an entity's Board of Directors or advisory committees; Elected member, Royal Academy of Sciences and Arts, The Netherlands: Membership on an entity's Board of Directors or advisory committees; Frame Pharmaceuticals: Equity Ownership; Hoffman-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees; Royal Academy of Sciences and Arts, The Netherlands: Membership on an entity's Board of Directors or advisory committees; Supervisory Board, National Comprehensive Cancer Center (IKNL), Netherland: Membership on an entity's Board of Directors or advisory committees; Chairman Scientific Committee and Member Executive Committee, European School of Hematology (ESH, Paris, France): Membership on an entity's Board of Directors or advisory committees; CELYAD: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Up-to-Date", section editor leukemia: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Preliminary reports demonstrated that pioglitazone, an antidiabetic drug that is agonist of peroxisome proliferator-activated receptor gamma (PPAR-γ) was able to reduce expression of STAT5 and its downstream targets HIF2α and CITED2, which are key guardians of the quiescence and stemness of chronic myeloid leukemia (CML) leukemia stem cells (LSCs). Leaving quiescence would turn the LSCs more sensitive to imatinib (IM) and cause an erosion of the LSCs. This was demonstrated in vitro and in vivo in CML patients that achieved complete molecular response after pioglitazone use. This was the rational for the design of EDI-PIO trial (Pilot Study of Imatinib Discontinuation in Patients with Chronic Myeloid Leukemia with Deep Molecular Response - Evaluation of Pioglitazone in Treatment-Free Remission) (NCT02852486). In this trial, pioglitazone was given in association with IM, with the aim to pull out the LSCs from the quiescence and sensitizing them to IM effect, increasing treatment-free remission (TFR) rates after treatment interruption. Aims: to evaluate PPAR-γ, STAT5, HIF2α and CITED2 gene expression before and after pioglitazone use in CML patients with criteria for IM discontinuation Patients and methods: EDI-PIO is a prospective, phase II trial. Inclusion criteria: CML in chronic phase, treated with IM for at least 3 years, with stable deep molecular response (MR4.5) for at least 2 years. Patients received pioglitazone 30 mg/day, orally, for 3 months before IM discontinuation. BCR-ABL levels were measured by real-time quantitative PCR monthly in the first year after discontinuation, every two months in the second year, and then every 3 months during the subsequent follow-up. Imatinib was reinitiated at molecular relapse (loss of major molecular response or confirmed loss of MR4.0). Total RNA was extracted from peripheral blood leukocytes, pre and post pioglitazone, and at 3 and 6 months after IM discontinuation. After cDNA synthesis, an aliquot was used for gene expression analysis by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), using specific primers for PPAR-γ, STAT5, HIF2α and CITED2. The relative gene expression was calculated using the equation, 2-ΔΔCT. GAPDH was used as control gene. Statistical analysis was performed using ANOVA. Treatment-free remission (TFR) was calculated from IM discontinuation until molecular relapse, reintroduction of IM by any cause, progression to advanced phases or death to any cause. Results: The study is closed for enrollment. Between June 2016 and January 2019, 32 chronic phase CML patients were recruited, of which 30 patients were included in gene expression analysis. Median age was 55 years at trial initiation; 56.7% were men, 50% low risk Sokal and the median time of IM treatment was 117 months (41-191). The median follow-up time was 20 months. TFR was 60% at 24 months. Eleven patients relapsed and IM was reintroduced, but none presented hematologic relapse or progression to advanced phases. There was no significant difference in STAT5, PPAR-γ, HIF2α and CITED2 expression pre and post pioglitazone, at 3 and 6 months after IM discontinuation. No difference was found in the comparison of the relapsed vs. non-relapsed group. Conclusions: pioglitazone did not affect STAT5, PPAR-γ, HIF2α and CITED2 gene expression in this group of pts with deep molecular response. The ACTIM trial demonstrated a reduction in STAT5 expression in bone marrow cells 6 months after pioglitazone exposure, but pioglitazone was given to pts with MMR, without MR4.0. There was no difference in gene expression in the groups with or without molecular relapse. TFR rates remains similar to those reported in other discontinuation trials. Disclosures Delamain: Novartis: Honoraria. Pagnano:Sandoz: Consultancy; Pint Pharma: Consultancy; Abbvie: Consultancy.

Introduction: Described as a well know marker of worse prognosis in acute myeloid leukemia (AML), MN1 overexpression has been associated with inv(16) or EVI1 overexpression (Heuser et al., Blood 2007). The promoter region of the MN1 gene has Retinoic Acid Response Elements (RAREs), and higher levels of MN1 expression have been associated with decreased response to retinoic acid (RA) in vitro. Nevertheless, in the context of acute promyelocytic leukemia, little is known about MN1 gene expression and functionality in vivo. Aims: Here, we investigated the effects of in vitro treatment with RA plus arsenic trioxide (ATO) in APL cell lines and primary blasts overexpressing MN1. Additionally, we quantified MN1 expression and correlated its levels with treatment outcome in a cohort of patients enrolled in the International Consortium on Acute Leukemia (ICAPL2006) study. Methods: Primary leukemic blasts from hCG-PMLRARα transgenic mice (TM; n=2) and APL patients (age, 36-45y; n=2) were transduced with MN1 or empty vector (EV, control) to evaluate cell proliferation, differentiation and apoptosis. Confirmatory assays were performed using transduced NB4 and NB4R2 (RA-resistant) cell lines. After synchronization using double thymidine block, transduced cells were submitted to proliferation and clonogenic (treated with RA and ATO, as well) assays. To evaluate the apoptotic rate, cells were treated with ATO (1 µM) alone or in combination with RA (1 µM each), for 24, 48 and 72 hours. The granulocytic differentiation in response to RA treatment alone (1 µM) or in combination with ATO (1 µM) was evaluated based on the CD11b and CD11c surface levels. In addition, 116 patients (age, 18-82y; 51% males) with newly diagnosed APL enrolled in the ICAPL2006 study were included. To validate our data, Bootstrap resampling procedure with 1000 repetitions from the original database was performed to assess the model bias. Results: Primary APL cells transduced with MN1 (from TM/APL patients) presented higher proliferation rates compared to controls (P.05), while NB4R2-MN1 cells were able to form colonies in the presence of ATO (P.05). In accordance with our results using primary APL samples, ATO treatment (alone or in combination with RA) does not modulate the drug-induced apoptosis in a time-dependent manner in NB4 and NB4R2-MN1 cells (P Disclosures Pagnano: Sandoz: Consultancy; Pint Pharma: Consultancy; Abbvie: Consultancy. Tallman:International Conference in Leukemia: Honoraria; 14th Annual Miami Cancer Meeting: Honoraria; New Orleans Summer Cancer Conference: Honoraria; Indy Hematology Review: Honoraria; ADC Therapeutics: Research Funding; Arog Pharmaceuticals: Research Funding; Cellerant Therapeutics: Research Funding; Orsenix: Membership on an entity's Board of Directors or advisory committees, Research Funding; UpToDate: Patents & Royalties; Mayo Clinic: Honoraria; Rigel: Membership on an entity's Board of Directors or advisory committees; Nohla: Membership on an entity's Board of Directors or advisory committees, Research Funding; Salzberg Weill Cornall MSKCC Seminar in Hematologic Malignancies: Honoraria; BioSight: Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; KAHR: Membership on an entity's Board of Directors or advisory committees; Bioline: Membership on an entity's Board of Directors or advisory committees, Research Funding; University of Oklahoma Medical Center: Honoraria; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy; Danbury Hospital Tumor Board: Honoraria; Hematology Oncology of Indiana: Honoraria. Dillon:Abbvie: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; TEVA: Consultancy, Honoraria. Heuser:Bayer Pharma AG, Berlin: Research Funding; Synimmune: Research Funding. Löwenberg:Up-to-Date", section editor leukemia: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; CELYAD: Membership on an entity's Board of Directors or advisory committees; Chairman Scientific Committee and Member Executive Committee, European School of Hematology (ESH, Paris, France): Membership on an entity's Board of Directors or advisory committees; Chairman, Leukemia Cooperative Trial Group HOVON (Netherlands: Membership on an entity's Board of Directors or advisory committees; Clear Creek Bio Ltd: Consultancy, Honoraria; Editorial Board "European Oncology & Haematology": Membership on an entity's Board of Directors or advisory committees; Elected member, Royal Academy of Sciences and Arts, The Netherlands: Membership on an entity's Board of Directors or advisory committees; Frame Pharmaceuticals: Equity Ownership; Hoffman-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees; Royal Academy of Sciences and Arts, The Netherlands: Membership on an entity's Board of Directors or advisory committees; Supervisory Board, National Comprehensive Cancer Center (IKNL), Netherland: Membership on an entity's Board of Directors or advisory committees.

Several trials have demonstrated the feasibility of discontinuation of tyrosine kinase inhibitors (TKI) treatment in chronic myeloid leukemia (CML) patients (pts) with deep molecular response. Aims: to report the results of two Brazilian imatinib (IM) discontinuation trials and to evaluate factors impacting in treatment-free remission (TFR) and treatment-free survival (TFS) after IM discontinuation. Methods:Between September 2016 and January 2019, 60 CML pts were included in two ongoing phase II, single arm, prospective Brazilian discontinuation trials: Pilot Study of Discontinuation in Patients With Chronic Myeloid Leukemia With Deep Molecular Response - Evaluation of Pioglitazone in Treatment-free Remission (TFR) (EDI-PIO UNICAMP)(NCT02852486)and Imatinib Discontinuation in Patients With Chronic Myeloid Leukemia Chronic Phase With Sustained MR4log(USP) (NCT03239886). Inclusion criteria: age >18 years, chronic phase, minimum of 3 years of IM therapy, deep molecular response for ≥ 2 years (confirmed by 4 tests in the last 2 years, defined as MR4.0 in USP trial and MR4.5 in EDI-PIO). Patients participating in EDI-PIO trial used pioglitazone 30 mg/day plus IM for 3 months before IM discontinuation (n=30). After discontinuation, pts were monitored by quantitative RQ-PCR monthly in the first year, every 2 months in the second year and every 3 months in the third year. Criteria for IM re-initiation: loss of MMR (in one test), loss of cytogenetic response, loss of hematologic response, disease progression or confirmed loss of MR4.0 (this criteria used only in EDI-PIO trial). TFR was calculated from the date of discontinuation until first event (loss of MMR; IM reintroduction; death any cause or last follow-up); TFS was calculated from the date of IM discontinuation until reintroduction or last follow-up (censoring deaths not related to CML). Adverse events after IM discontinuation were reported according to CTCAE. Results:Data cut-off for analysis was February 2019. In the 1stanalysis 48 pts who discontinued IM in MR4.5 were analyzed. Patient's characteristics from EDIPIO (n=30) and USP (n=18) trials were: 57% vs. 67% male, median age of 55 (29-77) and 56 (33-95) years (29-95) at discontinuation; 16% and 33% had used previously Interferon; median duration of IM treatment of 10 (3-16) vs. 10 (5-15) years; median duration of MMR 95 (30-149) vs. 93 (57-130) months; MR4.0 was 90 (26-135) vs. 89 (30-123) months; and MR4.5 was 76 (23-135) vs. 75 (30-102) months; none variable had statistical difference.One patient died in MMR due to cardiac failure. TFR was 61% (95% CI 47-75) at 20 months. Sixteen (33%) out 48 re-initiated IM (2 with confirmed loss of MR4.0 and 14 with loss of MMR) in a median time of 20 (1-26) months. All relapsed pts recovered MMR after IM reintroduction, in a median time of 2 months (0-4). There was no transformation to advanced phases. No serious adverse events were reported during pioglitazone treatment. In the Cox regression the duration of MMR was associated with a longer TFR HR: 0.96 (beta-) (CI 95%:0.94-0.99, P= 0.006). Gender, age at diagnosis, age at discontinuation, treatment with pioglitazone, Sokal and EUTOS scores, BCR-ABL transcripts type, duration of IM therapy, duration of MR4.0 and MR4.5 and previous use of Interferon did not affect TFR.In the second analysis all 60 pts were included. TFS was 56% and was higher in pts who discontinued IM in sustained MR4.5 vs. MR4.0 (63% vs. 33%, P=0.04)(Figure). The independent factors for TFR in the multivariate analysis by Cox-regression were the duration of MMR [HR: 0.97 (beta-), 95%CI: 0.95-0.98, P=0.001] and intermediate/high risk Sokal [HR 3.14 95%CI: 1.08-9.11, P= 0.035]. Twenty-four out of 60 pts (40%) re-initiated IM (2 with confirmed loss of MR4.0 and 22 with loss of MMR).Adverse events occurred in 38 (63%) pts, 30% attributed to withdrawal syndrome. Some pts presented more than one event. Grade 1-2: arthralgia or muscular pain (17), hyperglycemia (4), hypertriglyceridemia (2), polycythemia (2), hypertension (3), and others (11). Four pts had grade 3-4 event: arthralgia (1), death for cardiac failure (1), abortion and hypertriglyceridemia (1). Conclusions:both trials demonstrated the feasibility and safety of IM discontinuation in pts in sustained deep molecular response. The duration of MMR was associated with a higher TFR and TFS rate. Imatinib discontinuation was more successful in pts in stable MR4.5. Figure Disclosures Pagnano: Pint Pharma: Consultancy; Abbvie: Consultancy; Sandoz: Consultancy. Delamain:Novartis: Honoraria.

Despite the improved results achieved with dose-intense treatments, the prognosis of acute myeloid leukemia (AML) patients remains poor, with cure rates ranging from 60% to 70% in patients