ALBERT

Description: Background: NMS-03592088 is a novel, potent inhibitor of the FLT3, CSF1R and KIT receptor tyrosine kinases (KD 〈 1 nM for all three targets). The compound demonstrated high preclinical efficacy following oral administration in all tested target-dependent tumor models, including those harboring kinase domain secondary resistance mutations, such us the FLT3 residue 691 gatekeeper mutation and the KIT residue 670 and exon 17 mutations. In a FLT3-ITD model of disseminated AML, efficacy observed following single agent treatment with NMS-03592088 was further significantly increased when administered in combination with cytarabine, with excellent tolerability. In preclinical studies conducted in non-human primates, a dose-related increase of circulating CSF1 levels was observed in association with the administration of NMS-03592088, consistent with in vivo inhibition of CSF1R by the compound, thus providing the opportunity for the use of CSF1 levels as a potential pharmacodynamic biomarker of CSF1R modulation in the clinical setting. All three targets of NMS-03592088 are relevant in different settings of hematologic malignancies and solid tumors. In particular, FLT3 mutations occur in approximately 30% of acute myeloid leukemia patients (AML), and are associated with a poor prognosis; KIT mutations are reported in patients with the core-binding factor (CBF) subtype of AML and the CSF1 and/or CSF1R genes are frequently expressed in AML blasts. Recent experimental evidence suggests a potential therapeutic rationale for CSF1R blockade in AML, possibly due to interference with microenvironmental support [Edwards DK et al, Blood, 2019, 133: 588]. Furthermore, chronic myelomonocytic leukemia (CMML) blasts express high levels of CSF1R and NMS-03592088 was able to effectively inhibit their proliferation, concomitant with the suppression of intracellular CSF1R dependent signalling. A clinical trial exploring safety, tolerability and efficacy of NMS-03592088 in patients with AML and CMML is therefore warranted. Trial design: This first-in-human study (EudraCT Number: 2018-002793-47) is designed as an open-label multicenter Phase I/II trial including patients with relapsed or refractory AML or CMML who have exhausted standard treatment options, or for whom standard therapy is considered unsuitable. The study is designed to characterize the safety, tolerability, pharmacokinetics, pharmacodynamics and to explore the preliminary anticancer activity of NMS-03592088 administered orally as single agent once daily for 21 consecutive days, followed by a 7-day break within a 28 day cycle. The study includes an initial conventional phase I part with an accelerated dose titration design in subsequent cohorts of 3+3 patients aimed at defining the maximal tolerated dose (MTD) and the recommended phase 2 dose (RP2D), followed by a limited dose expansion to confirm the RP2D. Once the RP2D is confirmed, a single-stage exploratory Phase II part will start comprising two parallel cohorts, one cohort will consist of AML FLT3 mutated patients and one of patients with CMML. Patients previously treated with FLT3 inhibitors are allowed to participate. The primary endpoint of the Phase II portion of the study is Overall Response Rate. Efficacy will be assessed according to standard criteria [Döhner H et al, Blood 2017, 129: 424; Savona MR et al., Blood, 2015, 125: 1857]. Exploratory endpoints are included to evaluate the potential effects of treatment with NMS-03592088 on circulating levels of CSF1 in plasma, the potential correlation of cellular CSF1R expression levels with clinical outcome in both AML and CMML, and the mutational status of a panel of leukemia-related genes, not limited to FLT3. The Phase I part started in Italy in March, 2019 and is currently ongoing. Disclosures Ciomei: NMS: Employment. Zanetta:Clioss: Employment. Fiorentini:Accelera: Employment. Bosotti:NMS: Employment. Ardini:NMS: Employment. Lombardi Borgia:NMS: Employment. Pulci:Accelera: Employment. Gatto:Clioss: Employment. Di Sanzo:Clioss: Employment. Colajori:Clioss: Consultancy. Davite:Clioss: Employment. Galvani:NMS: Employment. Gan:NMS: Employment. Rossi:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria; Daiichi-Sankyo: Consultancy; Roche: Membership on an entity's Board of Directors or advisory committees. Rambaldi:Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau, travel support; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Italfarmaco: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Omeros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Isacchi:NMS: Employment.

Description: Although CD4+CD25+ regulatory T cells are pivotal in the prevention of autoimmunity and appear to mediate transplantation tolerance, little is known concerning their antigen specificity. Here we describe the induction of a human CD4+CD25+ regulatory T-cell line specific for a defined peptide alloantigen (human leukocyte antigen A2 [HLA-A2] 138-170) by priming purified CD4+CD25+ cells ex vivo. The regulatory cells were anergic and retained their ability to suppress antigen-driven responses of CD4+CD25– cells. They inhibited not only interleukin 2 (IL-2) secretion by CD4+CD25– T cells specific for the same peptide but also direct alloresponse of naive CD4+CD25– T cells stimulated by semiallogeneic dendritic cells (DCs) in the presence of the peptide (“linked suppression”). They also suppressed the response of CD4+ T cells specific for viral and bacterial antigens. The suppressive T-cell line showed sustained high CD25 expression. These findings suggest that peripheral CD4+CD25+ regulatory cells are a precommitted cell lineage from which cells with specificity for non–self-peptides can be selected. This may pave the way for inducing and expanding peptide antigen-specific regulatory T cells ex vivo for cell therapy in transplantation, allergy, and autoimmune disease.

Description: The SCL gene, initially discovered at the site of a translocation breakpoint associated with the development of a stem cell leukemia, encodes a protein that contains the highly conserved basic helix-loop- helix (bHLH) motif found in a large array of eukaryotic transcription factors. Recently, we have described a nonrandom, site-specific SCL rearrangement in several T-cell acute lymphoblastic leukemia (ALL) cell lines that juxtaposes SCL with a distinct transcribed locus, SIL. The SIL/SCL rearrangement was found in leukemic blasts from 11 of 70 (16%) newly diagnosed T-cell ALL patients, a prevalence substantially higher than that of the t(11;14) translocation, which has previously been reported as the most frequent nonrandom chromosomal abnormality in T- cell ALL. We did not detect the SIL/SCL rearrangement in the leukemic blasts from 30 patients with B-cell precursor ALL, indicating that the rearrangement was specific for T-cell ALL. Analysis of RNA from these patients indicated that an SIL/SCL fusion mRNA was formed, joining SIL and SCL in a head-to-tail fashion. The fusion occurs in the 5′ untranslated region (UTR) of both genes, preserving the SCL coding region. The net result of this rearrangement is that SCL mRNA expression becomes regulated by the SIL promoter, leading to inappropriate SCL expression. The resultant inappropriate expression of this putative transcription factor may then contribute to leukemic transformation in T-cell ALL.

Description: Introduction In the non-thalassemic population hypothyroidism has been associated with an increased risk of cardiac disease while the link thyroid-heart disease has been little explored in thalassemia major (TM). This retrospective cohort study aimed to systematically evaluate in a large historical cohort of TM in the cardiovascular magnetic resonance (CMR) era whether hypothyroidism was associated with a higher risk of heart complications (heart failure, arrhythmias and pulmonary hypertension). Methods From a cohort of 957 TM patients who underwent CMR for myocardial iron overload (MIO) assessment, quantification of biventricular function and detection of myocardial fibrosis within the MIOT network (Myocardial Iron Overload in Thalassemia), we identified 115 (12%) hypothyroid patients. Each hypothyroid patient was matched by sex and age (at the time of the CMR) with two non-hypothyroid patients, creating 115 triples. A cardiac event was considered valid if diagnosed at an age older than the hypothyroidism’s onset age for the hypothyroid patient in the belonging triple. Results Hypothyroid and non-hypothyroid patients had comparable MIO, but hypothyroid patients showed significantly lower biventricular stroke volume index, ejection fraction and left ventricular cardiac index. Accordingly, the prevalence of overall heart dysfunction (LV, RV or both) was higher in hypothyroid patients (43.5% vs 33.5%, P=0.0314). Hypothyroid patients had a significant higher frequency of heart failure (19.1% vs 9.1%, P=0.003) and arrhythmias (11.3% vs 4.3%; P=0.003). Figure1 shows odds ratios (OR) estimating the relationship between hypothyroidism and cardiac involvement. Hypothyroid patients had a significant higher risk of heart dysfunction, heart failure and arrhythmias, also adjusting for the endocrine co-morbidity. Conclusions Hypothyroidism seems to increase the risk for heart failure, arrhythmias and heart dysfunction in TM patients. Our data confirm the link thyroid-heart disease also in TM patients and they stress the need to prevent hypothyroidism in this population. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3194 Introduction: Using T2* Magnetic Resonance (MR) a randomized placebo controlled study from Sardinia demonstrated combination therapy with deferiprone and desferrioxamine (DFP+DFO) significantly more effective than DFO in improving myocardial iron. One non-randomized study from Sardinia and one observational study from Greece seem to confirm for DFP+DFO therapy the most rapid clearance of cardiac iron. No data are available in literature about prospective comparisons on cardiac iron and function and liver iron in TM patients treated with DFP+DFO versus DFP and DFO in monotherapy. The aim of our multi-centre study was to assess prospectively in a large clinical setting the efficacy of the DFP+DFO versus DFP and DFO in TM patients by quantitative MR. Methods: Among the 1135 TM patients enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) network we selected those with an MR follow up study at 18±3 months who had been received one chelator alone between the 2 MR scans We evaluated prospectively the 51 patients treated with DFP+DFO versus the 39 patients treated with DFP and the 74 patients treated. Iron overload was measured by T2* multiecho technique. Biventricular function parameters were quantitatively evaluated by cine images. Results: The dosages were: combined therapy DFP 61.9±24.3 mg/kg per 6.1±1.4 days/week and DFO 40.7±6.0 per 3.5±1.1 days/week; DFP 73±13 mg/kg per 6.1±1.4 days/week; DFO 40.7±6.5 per 5.4±0.93 days/week. Excellent/good levels of compliance were comparable in the DFP+DFO (90.2%) versus DFP (94.9%) and DFO (95.9%) groups. The percentage of patients who maintained a normal global heart T2* value (≥20 ms) was comparable between DFP+DFO (96%) versus (100%) and DFO (98.1%) groups. Among the patients with myocardial iron overload at baseline (global heart T2*

Description: Abstract 5293 Introduction. Cardiovascular Magnetic Resonance (CMR) has provided the opportunity to quantify right ventricular (RV) parameters with excellent reproducibility and accuracy. The role of the RV is gaining ground in thalassemia major (TM) patients and this population could experience different “normal” RV values due to chronic anemia and eventually pre-existing iron burdens. The aim of this study was to establish the ranges for normal RV volumes, mass and ejection fraction (EF) normalized to the influence of body surface area (BSA), age and sex from CMR in a large cohort of well-treated TM patients without myocardial iron overload. Methods. Among the 923 TM patients enrolled in the Myocardial Iron Overload (MIOT) network who underwent CMR for the assessment of cardiac iron overload, function and fibrosis, we selected 142 patients with no known risk factors or history of cardiac disease, normal electrocardiogram, no myocardial iron overload (all the cardiac segments with a normal T2* value) and no myocardial fibrosis. All patients had been regularly transfused and chelated since early childhood. Moreover, we studied 71 healthy subjects matched for age and sex. RV function parameters were quantitatively evaluated in a standard way by SSFP cine images using MASS® software. RV end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV) were normalized by body surface area (EDVI, ESVI, SVI). Results. The table shows the comparison of the CMR parameters with differentiation for sex and age in TM patients and healthy subjects and the cut-off of normality defined as mean – 2 standard deviation (SD). TM patients showed significantly lower BSA than the controls (P

Description: The t(11;14)(q13;q32) chromosomal translocation, which is the hallmark of mantle cell lymphoma (MCL), is found in approximately 30% of multiple myeloma (MM) tumors with a 14q32 translocation. Although the overexpression of cyclin D1 has been found to be correlated with MM cell lines carrying the t(11;14), rearrangements of theBCL-1/cyclin D1 regions frequently involved in MCL rarely occur in MM cell lines or primary tumors. To test whether specific 11q13 breakpoint clusters may occur in MM, we investigated a representative panel of primary tumors by means of Southern blot analysis using probes derived from MM-associated 11q13 breakpoints. To this end, we first cloned the breakpoints and respective germ-line regions from a primary tumor and the U266 cell line, as well as the germ-line region from the KMS-12 cell line. DNA from 50 primary tumors was tested using a large panel of probes, but a rearrangement was detected in only one case using the KMS-12 breakpoint probe. Our results confirm previous findings that the 11q13 breakpoints in MM are scattered throughout the 11q13 region encompassing the cyclinD1 gene, thus suggesting the absence of 11q13 breakpoint clusters in MM.

Description: Background: Aurora kinases play essential roles in regulating cell division, and increased expression has been noted in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). We previously conducted a phase I study of alisertib combined with "7+3" induction chemotherapy in untreated patients with AML, and found the combination to have an adverse event profile similar to 7+3 alone, with promising efficacy, particularly for patients with high-risk disease, such as those who were older, with high-risk molecular features, or with secondary AML. These patients collectively have a historically grim prognosis, with an approximate rate of remission, in trials, of 45%. CPX-351, a liposomal daunorubicin-cytarabine product, was recently approved for use in secondary AML after it was demonstrated to be superior to 7+3 induction, with a median survival of 9.6 months versus 5.9 months among older patients, in a phase 3 trial. We recently completed accrual to a phase II study of alisertib plus induction chemotherapy in patients with untreated, high-risk AML. Methods: Patients were eligible if they had AML defined by WHO 2016 and either an adverse-risk karyotype (European Leukemia Net Guidelines), secondary (post-MDS/MPN) AML, therapy-related AML, or age ≥ 65 vears. We used a Simon two-stage design, assuming a null composite remission rate (complete remission [CR] and CR with incomplete count recovery [CRi]) of 45%. Patients could be enrolled prior to cytogenetic classification, but those without adverse-risk karyotype who lacked other eligibility criteria were removed before day 8 and replaced. All patients received continuous infusion cytarabine 100mg/m2 on days 1-7 [D1-7] and idarubicin 12mg/m2 [or daunorubicin 60mg/m2] D1-3 (7+3). On D8 through D15, alisertib at 30mg BID orally (PO) was administered. All underwent a mid-induction marrow biopsy to assess for residual disease, which if present, was treated with 5+2 re-induction without alisertib. Following remission, patients could receive up to 4 consolidation cycles with cytarabine (3g/m2 BID D1,3,5 for age

Description: The landscape of chronic myeloid leukemia (CML) has radically changed since the introduction of tyrosine kinase inhibitor (TKI), imatinib (IM), now considered as standard therapy. Although excellent cytogenetic responses are obtained, minimal residual disease still persists in a proportion of patients (pts) when measured by serial molecular monitoring by quantitative real-time polymerase chain reaction (RQ-PCR) to measure BCR-ABL transcript levels (Baccarani M et al. Blood2006; 108:1809–20). We monitored BCR-ABL transcript levels by RQ-PCR in 176 chronic phase (CP) –complete cytogenetic response (CCyR) CML pts treated with IM. Median follow-up from start of therapy with IM was 35 (6–80) months. Pts were recruited from 33 centers in Argentina and 2 in Uruguay. Median follow up from the first assessment at our Institution was 18 (6–32) months. Seventy nine patients (45%) had received interferon as 1st line prior to IM and 97/176 (55%) pts received imatinib as 1st line. Eighty eight percent (155/176) pts had received IM 400mg/d and 12% (21/176) 600–800mg at study initiation. Fifty four percent presented with low Sokal score at diagnosis. Peripheral blood samples were tested by RQPCR every 6 months. Major molecular response (MMR) was defined as BCR-ABL/ABL ratio of