ALBERT

Description: Introduction: Mutations localized in the tyrosine kinase domain activation loop of FLT3 (FLT3-TKD), representing point mutations in codon D835/I836 and rarely deletions of codon I836, induce constitutive tyrosine phosphorylation and activation of the receptor tyrosine kinase similarly to FLT3 internal tandem duplication (ITD) mutations. However, the prognostic role of FLT3-TKD in AML, particularly in the presence of NPM1 mutations, is not well established. The phase 3 RATIFY trial [NCT00651261; Stone et al. N Engl J Med. 2017] showed that in combination with standard chemotherapy, midostaurin (PKC412) improved survival outcomes across all 3 FLT3 stratification subgroups (ITD high allelic ratio [≥ 0.7], ITD low allelic ratio [〈 0.7], and TKD) vs placebo in patients with newly diagnosed FLT3-mutated AML. Here, we evaluated the prognostic impact of FLT3-TKD and NPM1 mutations in a post hoc analysis from the RATIFY trial. Methods: In RATIFY, newly diagnosed patients with AML 18-60 years old were randomly assigned to receive midostaurin or placebo together with standard induction and consolidation therapy followed by 12 28-day cycles of maintenance therapy with midostaurin or placebo. FLT3-TKD mutation was detected by PCR and capillary electrophoresis at 9 reference laboratories. Patients were categorized as NPM1 mutated (mut) or NPM1 wild-type (WT) using PCR. Efficacy outcomes included complete remission (CR), overall survival (OS), event-free survival (EFS) and disease-free survival (DFS). EFS and DFS analyses were performed considering CR within a 60-day window. P values presented have not been adjusted for multiplicity. Results: Of the total randomized 162 FLT3-TKD patients, 134 with available NPM1 data had consented for exploratory analysis and thus were included in this study (see Table for subgroup distribution). Overall, 47.8% of patients were male, and the median age was 49 years (95% CI, 45.5-51.1 years). The median white blood cell (WBC) count was higher in patients with NPM1-mut than in patients with NPM1-WT (34.1 vs 15.5 × 109/L, P = .0011). CR rates (during the first 60 days) were higher in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT (66% vs 53%); however, this was driven by the higher rate of CR in the midostaurin arm (76% NPM1-mut vs 44% NPM1-WT) rather than the placebo arm (53% NPM1-mut vs 60% NPM1-WT). The overall CR rate (regardless of NPM1 genotype) was 64% for midostaurin and 56% for placebo in FLT3-TKD patients. The prognostic effect of the NPM1 mutation concurrent with FLT3-TKD was seen for all endpoints consistently with hazard ratios (HRs) around 0.50 or lower (Figures 1 and 2 and Table). Overall (regardless of treatment) OS, EFS, and DFS estimates at 3 years were 73% vs 52%, 48% vs 25%, and 74% vs 47%, respectively, in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT. Whereas the HRs for midostaurin vs placebo were 0.73 for both OS and EFS, the impact of treatment on outcomes varied between the individual NPM1/TKD subgroups and was not consistently observed when endpoints were censored at stem cell transplant (SCT) (Table). It should be noted that the number of patients in each subgroup was small and therefore the HRs with 95% CIs should be interpreted with caution. Multivariate analyses in these FLT3-TKD patients revealed that NPM1 genotype was an independent prognostic factor for OS, EFS and DFS (2-sided P 〈 .05), whereas study drug, age, sex, WBC at baseline and SCT (no/yes) did not reach this level of significance in the Cox model. Conclusions: This post hoc analysis of the FLT3-TKD patient subset in the RATIFY trial showed the high prognostic value of NPM1 mutational status. Whereas midostaurin showed an overall benefit in the FLT3-TKD patients for OS, EFS, CR and DFS, the impact of treatment on outcome varied between the individual NPM1 subgroups within these FLT3-TKD patients and was not consistently observed.Further analyses using additional endpoints and additional multivariate analyses are planned. Support: U10CA180821, U10CA180882, U10CA180820, U10CA180791, U10CA180888, U10CA180863, (CCSRI) #704970, U24CA196171; ClinicalTrials.gov Identifier: NCT00651261 Disclosures Voso: Celgene: Research Funding, Speakers Bureau. Larson:Ariad/Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding. Heuser:Janssen: Consultancy; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; StemLine Therapeutics: Consultancy; Astellas: Research Funding; BergenBio: Research Funding; Karyopharm: Research Funding; Bayer Pharma AG: Consultancy, Research Funding; Tetralogic: Research Funding; Sunesis: Research Funding; Daiichi Sankyo: Research Funding. Wei:Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Pfizer: Honoraria, Other: Advisory committee; Amgen: Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Celgene: Honoraria, Other: Advisory committee, Research Funding. Brandwein:Lundbeck: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding. de Witte:Novartis: Research Funding; Amgen: Consultancy, Research Funding; Celgene: Honoraria, Research Funding. Medeiros:Celgene: Consultancy, Research Funding; Genentech: Employment. Tallman:Cellerant: Research Funding; Orsenix: Other: Advisory board; BioSight: Other: Advisory board; ADC Therapeutics: Research Funding; AROG: Research Funding; AbbVie: Research Funding; Daiichi-Sankyo: Other: Advisory board. Schlenk:Pfizer: Research Funding, Speakers Bureau. Ganser:Novartis: Membership on an entity's Board of Directors or advisory committees. Cheng:Novartis: Employment. Gathmann:Novartis: Employment. Tiecke:Novartis: Employment. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding. Döhner:AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Celator: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Agios: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Pfizer: Research Funding; Pfizer: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Stone:Otsuka: Consultancy; Argenx: Other: Data and Safety Monitoring Board; Amgen: Consultancy; Agios: Consultancy, Research Funding; Orsenix: Consultancy; Ono: Consultancy; Novartis: Consultancy, Research Funding; Astellas: Consultancy; Arog: Consultancy, Research Funding; Merck: Consultancy; Cornerstone: Consultancy; Fujifilm: Consultancy; Jazz: Consultancy; Celgene: Consultancy, Other: Data and Safety Monitoring Board, Steering Committee; Pfizer: Consultancy; Sumitomo: Consultancy; AbbVie: Consultancy.

Description: Background: Midostaurin (M) is a multi-targeted small molecule FLT3 inhibitor which has single agent activity in both internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutant FLT3 AML. The objective of this global rand phase III trial was to determine if the addition of M to ind and consol therapy followed by one year of maint would improve overall survival (OS) compared to standard chemotherapy in younger adults with activating FLT3 muts. Methods: Between May 2008 and October 2011, 3279 previously untreated AML pts age 18-60 (exclusive of acute promyelocytic leukemia) in 225 sites/17 countries were screened for FLT3 muts at one of 7 academic labs (subject to extensive assay cross-validation). Hydroxyurea was allowed for up to 5 d prior to beginning ind therapy while awaiting results of mut testing. Pts were rand for the duration of therapy to M or P stratified by FLT3 mut subtype (TKD v ITD high allelic mut fraction (〉0.7) vs low mut fraction (0.05-0.7). Ind therapy consisted of D 60 mg/m2 IV d1-3 and C 200 mg/m2 d1-7 CIV plus M or P (50 mg po bid, d 8-22). Re-treatment with a second blinded course was allowed if residual AML was noted on a d 21 marrow exam. Pts achieving complete remission (CR) received 4 cycles of C 3g/m2 over 3h q 12h on days 1, 3, and 5 plus M or P (50 mg po bid, d 8-22) followed by a year of maint therapy with M or P (50 mg po bid). Transplantation (SCT) was allowed. With a sample size of 717 pts, the trial was powered to detect an improvement from 16.3 (P) to 20.9 (M) months in median OS (HR = 0.78) using a one-sided alpha of 0.025 and power of 84%. The final analysis was to occur after 509 deaths, but given the slow rate of events (359 deaths by April 2015), the trial was amended to change the timing of the OS analysis, and promote event free survival (EFS, defined as the earliest of death, relapse, or no CR within 61 d of the start of ind) as a key secondary endpoint. The critical value for this primary analysis is set at 0.02286 (1-sided) accounting for the alpha spent at the interim analysis (0.5%). Support: U10CA180821, U10CA180882, CA31946, Novartis Results: 717 pts (341 FLT3 ITD-Low, 214 FLT3 ITD-High; 162 FLT3 TKD) were rand to either M (n=360) or P (n=357). There were no significant differences between the arms in age (median, 48y), race, FLT3 subtype, or baseline CBC except for gender (M, 48.2% male; P, 40.6% male; p=.04). All pts are off active treatment, with a median follow-up of 57 months for surviving pts. No statistically significant differences were observed in the overall rate of grade 3 or higher hematologic or non-hematologic adverse events (AEs) between M and P (regardless of attribution). A total of 37 grade 5 AEs were reported (M, 5.3%; P, 5.0%; p=1.0). No differences in treatment-related grade 5 AEs were observed (M, 3.1%; P, 2.5%; p=0.82). CR rate is 59% (M) and 54% (P) (p=0.18). The HRs comparing M to P for OS is 0.77 (one-sided p = 0.007; Figure 1), and for EFS is 0.80 (one-sided p = 0.004; Figure 2). 402/717 (57%) pts received an allogeneic SCT (M, 58%; P, 54%) at any time; 177/717 (25%) in CR1 (M, 27%; P, 22%). Median time to allogeneic SCT was similar on each arm (M, 5.0 months; P, 4.6; p=0.23). Secondary analyses for OS and EFS censoring at the time of SCT provided similar results (Table). The benefit of M was consistent across all FLT3 subgroups for both EFS and OS (Figure 3). Conclusions: The C10603 trial demonstrated that a prospective trial in a pre-therapy genetically defined subgroup of AML pts was feasible and that the addition of the multi-kinase inhibitor M to standard chemotherapy and for one year of maint therapy significantly improved EFS and OS (in both uncensored and censored for transplant analyses) in pts whose blasts had a TKD or ITD (low or high FLT3 mut burden). These findings may lead to improved outcomes through the use of M as a component of therapy in younger adults with mutant FLT3 AML. Table.ArmMedian, mos (95% CI)p-value 15-year Event rate% (95% CI)HR2(95% CI)OSM74.7 (31.5, * )0.00750.8 (45.4-55.9)0.77 (0.63, 0.95)P26.0 (18.5, 46.5)43.1 (37.6-48.4)OS, SCT censoredM* (*,*)0.04762.6 (54.6-69.7)0.77 (0.56,1.05)P* (36.9, *)54.9 (46.2-62.8)EFSM8.0 (5.3, 10.6)0.004426.7 (22.2-31.5)0.80 (0.67, 0.95)P3.0 (1.9, 5.8)19.1 (15.1-23.6)EFS, SCT censoredM8.2 (5.5, 10.7)0.02524.2 (18.9-29.8)0.84 (0.70, 1.0020)P3.0 (1.9, 5.8)21.8 (16.8-27.3)1Stratified on FLT3 subtype; one-sided, log-rank p-value.2Cox model stratified on FLT3 subtype.*= not attained Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Stone: Celgene: Consultancy; Sunesis: Consultancy, Other: DSMB for clinical trial; Novartis: Research Funding; Amgen: Consultancy; Agios: Consultancy; Roche/Genetech: Consultancy; Merck: Consultancy; Pfizer: Consultancy; AROG: Consultancy; Celator: Consultancy; Juno: Consultancy; Abbvie: Consultancy; Karyopharm: Consultancy. Off Label Use: midostaurin- FLT 3 inhibitor. Thiede:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AgenDix GmBH: Equity Ownership. Niederwieser:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Medeiros:Celgene: Honoraria, Research Funding; Agios Pharmaceuticals: Honoraria. Schlenk:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Research Funding; Arog: Honoraria, Research Funding; Teva: Honoraria, Research Funding; Boehringer-Ingelheim: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Research Funding. Larson:Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Ariad: Consultancy, Research Funding; Pfizer: Consultancy.

Description: INTRODUCTION: Essential Thrombocytemia (ET) is the most common of the myeloproliferative neoplasms, vascular complications contribute mostly to both morbidity and mortality. The ability to identify thrombotic risk of the individual patient is necessary for a correct therapeutic management. Traditionally, risk stratification for thrombosis in ET pts was based on the respective absence and/or presence of either age 〉60 years or history of thrombosis. Recently, the IPSET score (International Prognostic Score Of Thrombosis for ET) was developed to better predict the occurrence of thrombotic events in ET patients. Risk factors included in the new score were: age, cardiovascular risk factors, previous thrombosis, presence of JAK 2 V617F mutation. AIM: to evaluate the validity of IPSET-thrombosis score in a cohort of ET patients from "Gruppo Laziale for Myeloproliferative Ph negative Neoplasms" in predicting thrombosis incidence. METHODS: from January 1978 to December 2011 we observed 1249 ET patients, median follow up was 105 months (range 12.1-417.7). We were able to retrospectively evaluate all the IPSET risk factors in 680 ET patients and estimated the clinical implication of the IPSET-thrombosis score system. According to the score 27.3 %, 19.1% and 53.5% of pts were stratified in low, intermediate and high risk group respectively. RESULTS: median age at the time of diagnosis was 61.8 yrs (range 19.9 -94; 64% females), median hemoglobin was 14 g/dl (range 6-20); median leukocyte count was 8.8 x 109/L (range 1,2-57); median platelets count was 812x 109/L (range 108-3582). We observed, during a median follow-up of 200 months, 82 thrombotic events (total incidence 17,89 %). According IPSET-thrombosis risk, in our ET population was documented a statistically different thrombosis free survival (TFS) (Gray test 0.1316): 85%, 78%, 77% in low,intermediate and high risk group respectively. During all the observation period the intermediate and high risk group showed a similar probability of thrombotic events. CONCLUSIONS: in our retrospective study the IPSET score was able to differentiate the rate of thrombosis events in low-risk (0-1 risk factors) from that of intermediate (〉= 2 risk factors) and high risk (〉= 3 risk factors) ET pts. Unfortunately the intermediate and high risk groups show a similar incidence of thrombotic events during the whole observation period. We were not able to verify the clinical benefit resulting from the different treatment strategies. Because treatment options in ET pts are tailored according to thrombotic risk, and since we have specified therapeutic indications for patients with low and high risk, it is necessary to validate the score IPSET in a large prospective, long term study to discriminate a true "intermediate" subset of patients for which there are no currently defined therapeutic guidelines. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Therapeutic agents approved by the FDA are required to undergo postmarketing safety surveillance to meet regulatory and contractual requirements. Arsenic trioxide (Trisenox®) is approved for the treatment of patients with acute promyelocytic leukemia (APL) in the second-line setting, but is also commonly used in first-line regimens in combination with all-trans retinoic acid. Here, we summarize the accumulated safety data from global postmarketing surveillance of arsenic trioxide since its initial approval in 2000 to better understand its long-term safety in patients with APL. Methods: Cumulative data were collected from patients with APL since initial approval in 2000 from spontaneous reports submitted by healthcare professionals and consumers. The data collected were housed in the Teva Pharmaceuticals safety database. Adverse events (AEs) were coded according to MedDRA terms and classified by seriousness and expectedness (unexpected AEs are those not included in the product label at the time of the report or those that occurred at a higher incidence than previously reported). Results: As of July 7, 2016, a total of 2197 AE reports were received in association with arsenic trioxide use in patients with APL. There were 1735 reports classified as serious and 462 classified as nonserious. The most frequently reported (≥ 30 reports) serious AEs and serious AEs of interest are summarized in the table. Serious QT prolongation was the most commonly reported event, but the majority of events were expected, including four cases of torsades de pointes that may be associated with prolonged QT. Serious hematologic toxicities, including neutropenia and leukocytosis, were also common and expected, as was liver toxicity. The most common serious and unexpected events reported included white blood cell decrease, pancytopenia, increased gamma-glutamyltransferase level, and cardiac disorders (primarily ventricular tachycardia, ventricular extrasystoles) that may be associated with prolonged QT in some patients. Conclusions: The overall safety profile of arsenic trioxide is consistent with known toxicities; the majority of serious AEs are associated with QT prolongation. The clinical significance of the reported QT events is unclear, and reporting rates may change in the future because of evolving criteria for QT assessments (Roboz GJ, et al. J Clin Oncol 2014;32(33):3723). This overview was limited by voluntary reporting. However, the long-term, real-world experience with arsenic trioxide administration as a single agent or in combination provides a broader understanding of its safety profile. Sponsor: Teva Branded Pharmaceutical Products R&D Disclosures Lo-Coco: Teva, Novartis, Baxalta, Pfizer: Consultancy; Teva, Lundbeck: Honoraria, Speakers Bureau. Pathak:Teva Pharmaceuticals: Employment, Equity Ownership.

Description: Background. Similar probabilities of survival have been reported for patients transplanted from Matched Unrelated Donor (MUD), Umbilical Cord Blood (UCB) or Haploidentical (Haplo) donors as alternative hematopoietic stem cell sources. However, few studies have compared these results with those obtained in patients transplanted from HLA Id-siblings (Id-sib). Moreover, all reported studies are retrospective and the criteria of donor selection were not predefined. We report the intention to treat (ITT) analysis results on 238 patients with high-risk acute myeloid leukemia (AML) prospectively transplanted according to the policy of the Rome Transplant Network (RTN), a metropolitan transplant program established in Rome in 2006. Patients and Methods. For AML patients eligible to an allogeneic transplant, the RTN policy consists of an algorithm of donor choice based on a hierarchy according to the following criteria: 1) HLA identical sibling; 2) MUD ≥8/10 HLA 3) UCB as single unit selected on the base of cell dose and number of HLA disparities (0-1/6 HLA: TNC ≥2.5x107/kg and CD34 ≥1x105/kg; 2/6 HLA: TNC ≥3.5x107/kg and CD34 ≥2x105/kg); 4) G-CSF primed, unmanipulated bone marrow Haplo donor. Myeloablative (MAC) or reduced intensity (RIC) TBF (Tiothepa, Busulfan, Fludarabine) conditioning regimen was identical for all patients, GVHD prophylaxis was uniform for each categories. of transplant Results. From January 2006 to December 2014, 238(89%) out of 303 adult patients candidates to an allogeneic transplant for high-risk AML were considered eligible. Overall, a donor was available for 205 (86%) of 238 eligible patients. At time of the analysis, 17 of these 205 patients (8%) had lost the transplant eligibility and 4 (2%) were still scheduled for transplant, therefore 184/205 (90%) patients with an available donor were finally transplanted from Id-sib (n=76), MUD (n=38), UCB (n=17) or Haplo (n=53) donors. The 8-yrs overall survival (OS) of the 238 eligible patients from time of HLA typing and of the 184 transplanted patients from time of the graft was 40±4%and 43±4%, respectively. By excluding the low number of UCB recipients (n=17), the OS was particularly dismal for the 34 patients transplanted in advanced disease phase (7±4% at 4 yrs), whereas for the 132 patients transplanted in early (CR1+ CR2) phase the 8-yr OS was 56±5%: 58±7% for 61 HLA Id-sib, 50±8% for 40 Haplo and 63±10% for 27 MUD recipients (P=NS). The OS of patients transplanted in early phase was 63±5% for 97 patients receiving MAC and 33±9% for RIC recipients. For these 97 patients, the survival by type of donor was 62±10% either for 47 Id-sib or 28 Haplo and 70±10% for 22 MUD recipients (P=NS). The results were analyzed by various donor/recipient (D/R) combinations such as age, sex and CMV status. The median donor age was 39 years (range, 18-70) and the median patient age was 43 years (range, 16-59): the 8-yr OS of patients (n=30) with younger D/R combination (D

Description: Background. Much uncertainty remains over the aetiology of Acute Myeloid Leukemia (AML) and of its biological subtypes, of which Acute Promyelocytic Leukemia (APL) is the best defined. In recent years, an elevated Body Mass Index (BMI) has been identified as a risk factor for several diseases. Whether BMI influences risk of developing AML and APL is not well understood. Methods. We have collated information from population-based and case-control studies conducted in four different countries. In the population-based study, we obtained data from the Clinical Practice Research Datalink, that includes primary care data of 5.2 million UK citizens. We identified APL and other leukemia cases using ICD identifiers ("APL" (n=24), "non APL-AML" (n=972), lymphoid leukemias ("LL", n=2724) and "other" (n=1850). We fitted linear models to investigate the association between BMI and any of the above leukemic classes. In the case-control studies, we analysed data from patients included in the PETHEMA (Spain, n=414) and GIMEMA (Italy, n=134) databases and patients from the USA-based AML genome sequencing study (the AML TCGA cohort with 22 additional cases characterized at Washington University-St Louis, n=42) ("case" cohorts). We then created age-, gender, ethnicity- and year of diagnosis-matched control cohorts from national BMI surveys and tested deviation of observed cases from expected controls. Lastly, we applied Quantitative Set Analysis for Gene Expression (quSAGE) analysis to investigate APL- or BMI-specific gene expression signatures from TCGA data Findings. In the UK population study, the Hazard Ratio per each 5 kg/m2 increase was 1.44 for APL (95% CI 1.0-2.08), 1.17 for non APL-AML (95% CI 1.10-1.26), 1.04 for LL (95% CI 1.0-1.09) and 1.10 for other leukemias (95% CI 1.04-1.15). In the case-control studies, BMI distribution in cases was significantly higher than expected from controls for all three cohorts: (Italy p

Description: Despite advances in treatment and supportive therapies, outcome of acute myeloid leukemia (AML) remains dismal with approximately 40% of younger and less than 20% of elderly patients becoming long-term survivors. Stem cell transplantation (SCT) is a well-established post-remission therapeutic option, and in both its variants, autologous (AuSCT) and allogeneic (ASCT), it is often incorporated in modern treatment programs for it may reliably improve long-term prognosis. Ten years ago we demonstrated that the levels of minimal residual disease (MRD) before autologous stem cell transplant (AuSCT), assessed at the post-consolidation time point by multiparametric flow cytometry (MFC), affected outcome (1). Moreover, we have preliminarily observed that in MRD positive (MRDpos) patients, allogeneic stem cell transplant (ASCT) attenuates the negative prognostic impact of pre-transplant MRD positivity by conferring a significant survival advantage in terms of either overall (OS) or disease free survival (DFS) (2). At variance with this, others have shown that even in the setting of ASCT, pre-transplant MRD positivity is associated with a poor prognosis regardless of the graft-versus-leukemia (GVL) effect (3). The aim of the present analysis was to evaluate, in 81 MRDpos patients submitted to ASCT (45) or AuSCT (36), the impact on clinical outcome of different MRD levels. As previously reported, counting 3.5x10-4 (0.035%) residual leukemic cells (RLCs) or more in the bone marrow (BM) upon full hematological recovery after consolidation cycle, was regarded as a condition of MRD positivity. Patients with or above 3.5x10-4 RLC were arbitrarily divided into 3 different cohorts: 1) ≥0.035%≤0.1% (13 patients, 6 ASCT and 7 AuSCT); 2) 〉0.1%≤1% (52 patients, 31 ASCT and 21 AuSCT); 3) 〉1% (16 patients, 8 ASCT and 8 AuSCT). In the category no. 2, ASCT gave a significant 5-years OS (64,9% vs 17,9%, p

Description: Introduction: FOXO3A is a transcription factor shown to be involved in all-trans retinoic acid (ATRA)-induced granulocytic differentiation and apoptosis in acute promyelocytic leukemia (APL). Its biological activity may be significantly enhanced upon metformin, raising the possibility that ATRA and Metformin may act synergistically; which could be useful to overcome ATRA resistance. Despite progress in APL treatment, approximately 10-15% of patients will relapse after treatment with ATRA and anthracyclines and frequently present with ATRA resistance. Relapsed patients respond well to arsenic trioxide (ATO) treatment, but the cost of ATO is a significant barrier in many countries. Aims: Here, we investigated the effects of in vitro treatment with ATRA plus metformin in APL cell lines and primary blasts, and quantified FOXO3A expression and correlated its levels with treatment outcome in a cohort of patients enrolled in the International Consortium on Acute Leukemia (ICAPL2006) study. Finally, we evaluated the effect of induced overexpression of FOXO3A gene in regards to cell viability and proliferation. Methods: Primary leukemic blasts from hCG-PMLRARα transgenic mice (TM; n=4) and APL patients (age, 25-47y; n=4) were treated with metformin alone (5mM/ 10mM) or in combination with ATRA (1µM) and evaluated for cell viability. In addition, 106 patients (age, 18-82y) with newly diagnosed APL enrolled in the ICAPL2006 study were included. As controls, eight samples of bone marrow mononuclear cells (BMMC) from healthy volunteers (age, 18-60y) were analyzed. To validate our data, FOXO3A transcript levels from an independent cohort was used (31 patients from Amazonia!, Probe n. 204131_s_at, and five normal BMMC samples included in the same databank). NB4/NB4R2 (ATRA-resistant) cell lines were transduced with FOXO3A or empty vector (control). After synchronization using double thymidine block, transduced cells were submitted to proliferation and cell cycle assays. For dose-response curves, cells were treated with graded concentrations of ATRA, ATO and metformin. For the apoptosis analysis, cells were treated with ATRA (1µM), metformin (5mM) and combination for 24, 48 and 72 hours. The granulocytic differentiation in response to ATRA treatment was evaluated based on the CD11b surface levels. Results: In primary cells (from TM/APL patients) a 2-fold reduction in viable cells was observed after metformin and metformin plus ATRA treatment (P