Cycles Of Azacitidine Research Articles

Prophylactic or Preemptive Low-Dose Azacitidine (AZA) and Donor Lymphocyte Infusion (DLI) Prevent Disease Relapse Following Allogeneic Transplantation in High Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome

Introduction: Despite therapeutic advances in recent years, disease relapse is still observed in up to 50-60% of the patients (pts) receiving allogeneic transplantation for high risk AML and MDS. In an initial Phase II trial of 30 pts treated with prophylactic low-dose AZA and escalated doses of DLI to prevent relapse, we reported that such prophylactic treatment can be safely administered and compared favorably to patients receiving no post-transplant maintenance. We here update 16 pts from our center, included in that protocol, as well as a larger cohort of additional patients treated with combined epigenetic and cellular therapy and the resultant effect on their event-free survival and their overall survival. Patients and methods: Fifty-nine pts (median age 59 yrs (range, 37-70); 30 M/29 F), comprising 40 pts with AML and 19 pts with MDS, were treated. Among the AML pts (ELN classification FAV n=2, INT n=17, ADV n=21), high risk criteria were as follows: 15 had complex karyotypes, 7 Flt3-ITD, 1 MECOM (EVI1) rearr., 3 monosomies, 2 t(9;11), and 1 t(11;19)); 9 were in CR≥2, 4 were refractory, and 13 had 2ary AML to MDS/chemotherapy/or MPS. Among the MDS pts, high risk criteria included 6 pts with complex caryotypes, 2 monosomies, 1 MECOM (EVI1) rearr., and 4 had 2ary MDS. IPSS-R median was 5.5 (3 - 7.5). MDS pre-transplant status included 7 CR1, 1 CR2, 5 PR, 1 relapse, 4 upfront, and 1 refractory. The therapeutic protocol administered to the initial 16 pts consisted of AZA, starting between d56 and d100 post-transplant, at a dose of 32 mg/m²/d SC, for 5 consecutive days, every 28 days, for up to a total of 12 cycles followed by DLI commencing after 3 cycles of AZA and 4 weeks following discontinuation of immunosuppressive prophylaxis. Two additional DLI were scheduled every 8 weeks following the 1st DLI. The doses of DLI 1, 2 and 3 were, respectively, 5x106, 1x107, and 5x107 CD3+ cells/kg for matched related donor (MRD), and 1x106, 5x106, and 1x107 CD3+ cells/kg for unrelated donor (UD). In the extended patient cohort, presented here, we slightly modified the schedule: DLI could be given earlier (after one or two cycles of AZA) and haploidentical pts could receive AZA/DLI as well, with DLI at the escalated doses of 1x105, 5x105, and 1x106 CD3+ cells/kg. Immunosuppression included cyclosporine A (CsA) in case of MRD, CsA and mycophenolate mofetil (MMF) in case of UD or haplo. MMF was progressively reduced during the first 2 months. CsA was tapered starting at day 60-100 post-transplant. Patients could start AZA while they were still receiving CsA. The conditioning regimens consisted of MAC for 5 pts, RIC for 46 pts and sequential for 8 pts. Donors were MRD, MUD, UD 9/10, and haplo for 20, 30, 1 and 8 pts respectively. Results: The median number of cycles AZA was 7 (range 1-12), 17 pts received 12 cycles of AZA, while 42 pts (71%) received at least one DLI. The median number of DLI was 1 (range 0-4), 15 pts received ≥ 3 DLI. The median time for the first post-transplant AZA injection was 83 days (range 56-145 d) and the median time post-transplant for those pts who received a first DLI was 148 days (range 78-245 d). The median pt-follow-up was 17 months (range 2-83). Eight pts (13%) relapsed (7 AML and 1 MDS). The cumulative incidence of relapse and NRM at 1 year was 12% and 11.5% respectively. Fifteen pts (25%) died. Causes of death included relapse in 6 pts, infection in 7 pts, myocardial infarction in 1 pt, and GvHD in 1 pt. Overall survival and event free survival for the entire group at 2 years was 71% (95% CI 54-82%) and 67% (95% CI 50-80%) respectively. The cumulative incidence of acute GvHD grade 1-4 and chronic GvHD were 32% (95% CI 16-49%) and 39% (95% CI 20-58%). Among the 8 pts who developed grade 3 acute GvHD, 4 occurred in pts who had received DLI. One pt died from grade 4 digestive GvHD post-AZA alone. Conclusion: We conclude that, despite their very high risk disease, prophylactic/preemptive low-dose AZA and DLI can be readily and safely administered with an acceptable incidence of subsequent GvHD to the AML and MDS pts described here. Significantly, in the poor-prognosis pts under study, the incidence of relapse is lower than expected. Furthermore, considering the immune escape mechanisms prophylactic or pre-emptive either AZA or DLI might be associated to additive non-cross reactive interventions, such as checkpoint inhibitors, in order to further decrease disease relapse and increase overall survival. Disclosures Peterlin: Jazz Pharma: Consultancy; Astellas: Consultancy; Daiichi-Sankyo: Consultancy; AbbVie Inc: Consultancy. Orvain:Novartis: Honoraria; Incyte: Honoraria. Chevallier:Jazz Pharmaceuticals: Honoraria; Daiichi Sankyo: Honoraria; Incyte: Consultancy, Honoraria.

Azacitidine for Pre-Emptive Treatment of Measurable-Residual Disease in MDS/AML Patients at High Risk of Hematological Relapse: Results of the Second Cohort of the RELAZA2 Trial

Azacitidine for Pre-Emptive Treatment of Measurable-Residual Disease in MDS/AML Patients at High Risk of Hematological Relapse: Results of the Second Cohort of the RELAZA2 Trial

Impact of Clinical Features, Cytogenetics, Genetic Mutations and Methylation of CDKN2B and DLC-1 Promoters on Treatment Response to Azacitidine

Introduction : Azacitidine (AZA) is a DNA hypomethylating agent used in myeloid neoplasms, however approximately half of patients show treatment failure or relapse. Last years, several studies have showed that genetic mutations may influence on response and survival of the treated patients. Other biomarkers that have traditionally been associated with the response to AZA are the recovery of the platelet count and the presence of abnormalities in the chromosome 7. Finally, the methylation dynamics of genes promoters could be a useful tool to predict the clinical response. Aim: To assess the predictive value on response to AZA of clinical features, cytogenetics, genetic mutations and the methylation dynamics of CDKN2B and DLC-1 promoters in a series of patients with myeloid neoplasms. Methods: We studied 85 patients with myelodysplastic syndromes (MDS) and 28 patients with acute myeloid leukemia (AML) who received AZA. Treatment schedules included 5-azacytidine 75 mg/m2/day for 7 days (n=62) and 5-azacytidine 75 mg/m2/day for 5 days (n=51). According to the International Working Group (IWG) 2006 criteria for MDS, responders were defined as patients achieving complete remission (CR), bone marrow CR (mCR), partial remission (PR) or stable disease with hematologic improvement (SDHI). Sixteen genes with prior implication in the pathogenesis of myeloid diseases were analyzed: NPM1, FLT3, CEBPA, TET2, DNMT3A, IDH1, IDH2, ASXL1, EZH2, RUNX1, SETBP1, TP53, SF3B1, SRSF2, U2AF1 and ETNK1. For methylation assay, EZ DNA Methylation-Gold kit (Zymo Research) was employed for the bisulfite treatment of DNA. Methylation of CDKN2B and DLC-1 were qualitatively studied pre- and post-AZA with unmethylated and methylated primers and analysis of the PCR products in a QIAxcel System (Qiagen). Overall survival (OS) was measured from start of AZA treatment until the last follow-up or death from any cause. P values <0.05 were considered as statistically significant. Results: Of the 113 patients analyzed, 46 patients (41%) showed response to AZA (median cycles=6): CR=19, mCR=6, PR=12, and SDHI=9. Stable disease and treatment failure were observed in 20 (17%) and 47 patients (42%), respectively. Analysis of clinical features showed that platelet doubling after the first AZA cycle was significantly associated with a better response (58% vs. 31% responders, P=0.041). Forty-seven patients (42%) had chromosomal abnormalities. A positive co-occurrence between del(7q)/-7 and del(17p) was found (n=6, P<0.001) and was significantly associated with a worse response to AZA (P=0.039). Pre-treatment, genetic mutations were presented in 98 patients (87%) and methylation of CDKN2B and DLC-1 promoters were detected in 50 (44%) and 37 (33%) patients respectively (Figure 1). Patients with SF3B1 mutations showed a better response to AZA (68% vs. 35% responders, P=0.008) and a higher OS (30 vs. 15 months, P=0.019) than the remaining patients. In contrast, patients with mutations in transcription factors (RUNX1, SETBP1, NPM1) showed a worse response to AZA (20% vs. 47% responders, P=0.014) and a lower OS (10 vs. 19 months, P=0.010). Splicing genes mutations (SF3B1, SRSF2 and U2AF1) were related to favourable karyotypes (90% vs. 59%, P<0.001) and a lower DLC-1 methylation (31% vs. 57%, P=0.006). Interestingly, patients with DLC-1 methylation showed higher levels (>5%) of bone marrow blasts (63% vs. 40%, P=0.016), higher frequency of complex karyotypes (40% vs. 15%, P=0.002), a positive co-occurrence with TP53 alterations (38% vs. 16%, P=0.009) and its methylation dynamics showed a strong trend towards predict the response to AZA: 57% of patients without DLC-1 methylation or who reduced it post-treatment responded favourably to the drug and 65% of patients who maintained or increased it did not respond (P=0.053). In addition, leukemia transformation was higher in MDS patients with DLC-1 methylation post-AZA than in the remaining MDS patients (58% vs. 21%, P=0.002). Conclusion: The combination of chromosomal alterations and genetic mutations together with the monitoring of platelet count and DLC-1 methylation could contribute to give light in myeloid neoplasms to the heterogeneity observed both in the response to AZA and in patient survival. Samples and data from patients included in this study were provided by the INCLIVA Biobank (PT13/0010/0004). Disclosures Hernandez Boluda: Incyte: Other: Travel expenses paid.

Multi-Center Phase 2 Study of Pembroluzimab (Pembro) and Azacitidine (AZA) in Patients with Relapsed/Refractory Acute Myeloid Leukemia (AML) and in Newly Diagnosed (≥65 Years) AML Patients

Multi-Center Phase 2 Study of Pembroluzimab (Pembro) and Azacitidine (AZA) in Patients with Relapsed/Refractory Acute Myeloid Leukemia (AML) and in Newly Diagnosed (≥65 Years) AML Patients

In Vivo Assessment of Intracellular Dynamics Comparing Injection Versus Oral Azacitidine in a Phase IIb Investigator Initiated Clinical Trial

In Vivo Assessment of Intracellular Dynamics Comparing Injection Versus Oral Azacitidine in a Phase IIb Investigator Initiated Clinical Trial

Updated Study Results of CX-01, an Inhibitor of CXCL12/CXCR4, and Azacitidine for the Treatment of Hypomethylating Agent Refractory AML and MDS

Hypomethylating agents (HMAs) are standard first line therapy for patients with high risk MDS and older patients with AML. Outcomes for patients who do not respond or progress on HMAs are poor, and there are no standard treatment options for these patients. The interaction between leukemic blasts and the bone marrow microenvironment is thought to play an important role in disease pathogenesis and possibly chemotherapy resistance, so we hypothesized that blocking the CXCL12/CXCR4 axis with CX-01 may improve response rates to azacitidine in patients who have failed HMA therapy. CX-01 is a low molecular weight heparin derivative with minimal anticoagulant activity that binds CXCL12 as well as neutralizes PF4, a negative regulator of megakaryopoiesis. We report updated study results of a single institution a pilot study (NCT02995655) that enrolled patients with HMA-refractory (received 4 or more cycles of HMA without response or disease progression on HMA therapy) AML or MDS (INT-1 or greater). Patients received 7 day continuous infusion of CX-01 (0.25 mg/kg/hr) and azacitidine 75 mg/m2 daily days 1-7, in 28 day cycles. The primary objective of this trial was to assess the overall response rate (ORR). 20 patients were enrolled between May 2017 and February 2018. The median age was 74 years (range 62-88 years) and 35% were female. Nine patients had MDS and 11 had AML, with 7 patients having antecedent MDS and 2 having therapy-related AML. Half of the patients had high risk cytogenetic abnormalities and 3 had TP53 mutations. Patients had a median of 2 prior lines of therapy (range 1-3) with median of 6 prior cycles of HMA therapy (range 4-20). Only 4 patients had a confirmed response to prior HMA therapy. Of the 20 patients that were enrolled, 15 were considered evaluable for response with a bone marrow biopsy after cycle 2. Of the 5 unevaluable patients, 3 were removed from the trial before completing C1 due to transaminitis, discovery of a second primary malignancy, and an elevated PTT on day 2. One patient had grade 5 sepsis during C1, and another withdrew for unrelated reasons. As expected with azacitidine therapy in this patient population, hematologic toxicity was common with 16 instances of grade 3/4 neutropenia/leukopenia, 5 instances of grade 3/4 anemia, and 10 instances of grade 3/4 thrombocytopenia. Other common grade 3/4 adverse events were various infections (20), febrile neutropenia (13), hypertension (10), electrolyte disturbance (9), and transaminitis (3). Mild prolongations in PTT (22) and INR (7) were common, and there was one instance of grade 3 PTT prolongation, two instances of grade 3 epistaxis, and one instance of grade 3 hematuria. The incidences of bleeding were not thought related to CX-01 infusion. The 15 evaluable patients received a median of 3 cycles of CX-01 and azacitidine (range 2-9). Of 15 evaluable patients, there was 1 CR and 3 bone marrow CRs (mCR, with incomplete blood count recovery), 9 stable disease, and 2 progressive disease for an ORR of 27%. Of the 3 patients with a mCR after cycle 2, two had hematologic improvement of their neutrophil and platelet counts, respectively, by the end of cycle 4. A patient with stable disease also had hematologic improvement in platelets. The median OS of evaluable patients was 221 days (95% CI 179 days-not reached) and median overall survival was not significantly different between AML patients at 221 days and MDS patients at 248 days (p = 0.8). In this pilot study we demonstrated the feasibility of treating HMA-refractory AML and MDS with CX-01 and azacitidine. While this study is limited by its small sample size, we observed higher than expected response rate and favorable OS compared to historical controls. Figure Disclosures Cashen: Celgene: Other: Speaker's Bureau; Seattle Genetics: Other: Speaker's Bureau; Novartis: Other: Speaker's Bureau. DiPersio:Incyte: Consultancy, Research Funding; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Magenta Therapeutics: Equity Ownership; Amphivena Therapeutics: Consultancy, Research Funding; Celgene: Consultancy; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; NeoImmune Tech: Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; Karyopharm Therapeutics: Consultancy. Jacoby:Celgene: Speakers Bureau; Novo Nordisk: Consultancy; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees. Uy:Astellas: Consultancy; Pfizer: Consultancy; Curis: Consultancy; GlycoMimetics: Consultancy.

High Activity of Cladribine (2-CdA) Combined with Low-Dose Cytarabine in Patients with Acute Myeloid Leukemia or Myelodysplastic Syndrome after Azacitidine Failure

Background: Azacitidine (AZA) therapy is the standard of care for higher-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients not eligible for intensive treatment. Although nearly 50% of patients respond to AZA treatment, most of them experience disease progression within 2 years of remission. The prognosis of patients after AZA failure is dismal with a median overall survival (OS) reaching 3-6 months. Interestingly, recent studies have demonstrated clinical efficacy of cladribine combined with cytarabine in newly diagnosed AML patients. In view of epigenetic properties of cladribine and known synergy with cytarabine, it may be speculated that combination of cladribine and low-dose cytarabine (LD-AraC) exerts some clinical activity also in the setting of relapsed/refractory AML/MDS. Aim: The aim our study was to assess activity and toxicity of combination of cladribine and LD-AraC in patients with MDS/AML after AZA failure. Methods: This retrospective analysis included patients with AML with 20% to 30% blasts, high and intermediate-2 risk MDS and CMML patients with AZA failure who were treated with combination of cladribine and LD-AraC in centers of the Polish Adult Leukemia Group (PALG). Therapy started with induction phase consisting of 2 cycles of cladribine 5 mg/m2 iv on days 1-5 (cycle 1) and on days 1-3 (cycle 2) in combination with LD-AraC 40 mg/m2 sc (days 1-10). Patients who achieved remission moved on to maintenance therapy with LD-AraC 40 mg/m2 sc, days 1-10), every 4 weeks. The treatment was continued for as long as tolerated and there was a clinical benefit. Treatment response was determined in accordance with the 2017 European Leukemia Net (ELN) and the 2006 International Working Group (IWG) criteria after each cycle. Results: Overall, 16 patients (8 patients with diagnosis of AML, 7 with diagnosis of MDS, and 1 with diagnosis of CMML myelodysplastic subtype at AZA therapy initiation) who had been treated with combination of cladribine and LD-AraC at AZA failure in 3 centers of PALG between 2014 and 2019 were identified. There were 9 males and 7 females, with median age of 72 years (range 64 - 78). The patients had previously received a median of 15 cycles of AZA (range 4 - 33). At the initiation of cladribine and LD-AraC therapy the median number of blasts was 27,5% (range 15,5 - 77) with 13 patients fulfilling the criteria of AML. At the data cut-off the median of administered chemotherapy cycles reached 4 (range 1-14), with 4 patients continuing treatment. The regimen was relatively well tolerated with no treatment related deaths and the most common non-hematological adverse events of grade 3 or worse being neutropenic fever and pneumonia. Response assessment revealed that nine patients (56%) achieved a remission, including 6 complete remissions (CR) and 3 complete remissions with incomplete recovery (CRi). The median time to response was 1 cycle. Median progression-free survival was 8 months, and the median OS reached 10.6 months. The estimated 6-months and 12-months OS probability were 79.3% and 44.6%, respectively. Conclusions: The combination of cladribine and LD-AraC appears to be an attractive option in the therapy of AML/MDS patients after AZA failure. Although prospective studies are needed to confirm these findings such treatment seems to be associated with an improvement in OS compared to the historical data. Disclosures Gora Tybor: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Expanding on Current Definitions of Hematologic Improvement in MDS, CMML and AML: Landmark Analyses of 1301 Patients Treated with Azacitidine in the Austrian Registry of Hypomethylating Agents By the AGMT-Study Group

Expanding on Current Definitions of Hematologic Improvement in MDS, CMML and AML: Landmark Analyses of 1301 Patients Treated with Azacitidine in the Austrian Registry of Hypomethylating Agents By the AGMT-Study Group

A Phase II Study of Midostaurin and 5-Azacitidine for Untreated Elderly and Unfit Patients With FLT3 Wild-type Acute Myelogenous Leukemia

BackgroundMidostaurin, a multikinase inhibitor, is approved for treatment of FLT3-mutant acute myeloid leukemia (AML). A phase I study established that midostaurin 75 mg orally twice daily for 14 days with standard dose azacitidine was safe and tolerable in elderly patients with AML. Herein, we report the phase II expansion cohort of previously untreated elderly or unfit patients with AML. Patients and MethodsPrimary objectives were to further describe the toxicity profile and determine the response rate in untreated patients with AML. Patients received midostaurin 75 mg orally twice daily on days 8 to 21 in combination with intravenous azacitidine at 75 mg/m2 on days 1 to 7. Plasma inhibitory activity assay for FLT3 was performed pretreatment and on day 8 and day 15 of each cycle. ResultsTwenty-six patients (median age, 74 years; range, 59-85 years) with FLT3 wild-type AML were accrued. Patients received a median of 2 cycles of therapy (range, 1-10 cycles). Seven (29%) of 24 evaluable patients achieved a clinical response (4 complete response; 1 complete response with incomplete count recovery; and 2 partial response). The median overall survival was 244 days (95% confidence interval, 203-467 days). Hematologic, infectious, and gastrointestinal toxicities were comparable to similar studies. Peripheral blood FLT3 wild-type phosphorylation declined to 8% to 55% of pretreatment by day 15 of cycle 1 (7 patients) and declined with subsequent cycles (< 10% baseline) in 2 patients who were analyzed after cycle 3. ConclusionMultiple cycles of azacitidine and midostaurin were not well-tolerated, but persistent inhibition of FLT3 wild-type phosphorylation suggest intermittent dosing of midostaurin should be considered in future low-intensity regimens for FLT3-mutant AML.

1374TiP - PRIME002: Early phase II study of azacitidine and carboplatin priming for avelumab in patients with advanced melanoma who are resistant to immunotherapy

BackgroundMelanoma patients with disease progression on immunotherapy have very limited treatment options. Low-dose azacitidine results in demethylation and increase in neoantigen expression and carboplatin increases DNA-damage and cellular stress. This trial is testing if sequential treatment with azacitidine and carboplatin “primes” for immunotherapy rechallenge with anti-PDL1 antibody Avelumab, via a decrease in the disease burden and re-establishment of immune sensitivity. Primary Objective: Quantify complete response (CR), partial response (PR), stable disease (SD), overall response rate (ORR) and clinical benefit rate (CBR) after 2 cycles of priming (1 cycle= azacitidine x 5 days followed by Carboplatin Day 8/28 days) according to RECIST 1.1 and 6 cycles of immunotherapy (1 cycle= 1 dose of Avelumab/14 days) according to irRECIST criteria. Secondary Objectives: 1. Determine DNA methylation levels before, and immediately after priming with azacitidine and carboplatin treatment i.e. at study entry and after 2 months; 2. Quantify immune-response markers (PDL-1, PD-1, CD4/CD8, and CD68) in blood, tumour and microenvironment and immune response in blood before treatment, after 2 priming cycles and after 6 immunotherapy cycles. Trial designInterventional early phase II study that consists of 2 cycles of azacitidine 40mg/m2 IV/day for 5 days followed by Carboplatin AUC 4.5 IV on D8/ 28day cycle and RECIST1.1 after completion of priming; followed by Avelumab 10mg/kg IV/14day cycle until disease progression according to irRECIST. A favourable or stable response in 20% patients and no grade 4 or persistent (>4 weeks) grade 3 treatment-related adverse events (TRAEs) is required for continuation of the trial. This early phase II study will assess the feasibility and determine outcome measures required to calculate sample sizes and develop a statistical plan for multi-centre Phase II study. This study has been approved by the Northern Sydney Local Health District HREC, reference number HREC/17/HAWKE/55’. Clinical trial identificationACTRN12618000053224; registered 16th January 2018. Legal entity responsible for the studyAndre van der Westhuizen. FundingRamaciotti Foundation and Hunter Medical Research Institute, Australia. DisclosureAll authors have declared no conflicts of interest.

Impact of cytogenetic abnormalities on response to azacitidine in patients with myelodysplastic syndrome

Abstract Background The AZA-001 phase III randomized study showed that azacitidine (AZA) significantly improved overall survival (OS) compared with conventional care in high- risk myelodysplastic syndrome (MDS), but prolonged treatment of 4-6 cycles is required before a failure to achieve response can be declared. Although selection of patients who are unlikely to derive benefit from AZA has become a top clinical priority, prognostic factors for response to and survival with AZA remain unclear. Here we examined prognostic factors for AZA in MDS patients in our hospital. Patients and Methods We retrospectively analyzed MDS patients treated with AZA between November 2011 and June 2018 in our hospital. Predictors of response were baseline cytogenetic characteristics (including IPSS-R cytogenetic classification) and the number of cytogenetic abnormalities. Univariate analyses were performed with log-rank tests and OS was measured from the onset of AZA. Results The male: female ratio was 4:1. Median age was 72 years, and median number of cycles of AZA was 11. Univariate analysis identified high score for IPSS-R cytogenetic classification and large number of cytogenetic abnormalities as factors associated with poor OS. In particular, patients with 17p abnormalities, possibly related to the presence of TP53 mutation, showed significantly shorter OS. Most rapidly developed leukemia and treatment became difficult to continue (median number of cycles of AZA, 2). Conclusion In the group with a high score for IPSS-R cytogenetic classification and large number of cytogenetic abnormalities, few patients showed survival advantage or delayed transformation to a leukemic state despite receiving AZA. An alternative to AZA monotherapy is considered necessary for patients expected to show poor response to AZA.

PF553 CLONES WITH COMPLEX ABERRATIONS AND TP53 MUTATIONS RESPOND TO AZACITIDINE IN MYELODYSPLASTIC SYNDROMES AND ACUTE MYELOID LEUKEMIA

Background:Mutations in TP53 are associated with poor outcome in pts with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). This holds also true for allogeneic stem cell transplantation (Lindsley et al, NEJM, 2017). Regarding hypomethylating agents, it was suggested that pts with TP53 mutations preferentially respond to decitabine (Welch et al, NEJM, 2016), although more recent studies also suggest response to azacitidine (AZA) (Döhner et al, Leukemia, 2018).Aims:Our aim was to retrospectively study real life data in terms of response to AZA in pts with TP53 mutations.Methods:We included 34 pts diagnosed with MDS or AML that were analyzed by banding analysis, fluorescence in situ hybridization (FISH‐panel, 10 probes), and sequencing (54 genes). The cohort comprised pts with TP53 mutations (N = 16, all with complex aberrant karyotypes, 9/16 with additional mutations) and without TP53 mutations (N = 18, 6x normal karyotype, 10x 1–2 cytogenetic aberrations, 2x complex aberrations, 17/18 with mutations other than TP53). For 6 pts with TP53 mutations treated with AZA at least two sequential genetic analyses (before and during treatment) were available. For the other 10 pts with TP53 mutations clinical but not genetic follow up was available or they received other treatment than AZA. All 18 pts without TP53 mutations received at least four cycles of AZA and genetic analyses were available from at least two time points. The IWG criteria (Cheson et al, Blood, 2006) for cytogenetic response were adapted and genetic response was defined as 50% reduction in FISH clone size or in variant allele frequency (VAF).Results:Clones with a TP53 mutation responded to AZA (50% VAF reduction) in 6/6 pts with TP53 mutations and genetic follow up (Figure 1A). Two of these pts were subjected to allogeneic transplantation, best clinical response for the other four pts was 3x hematologic improvement and 1x stable disease.From the other 10 pts with TP53 mutations, two responded to induction chemotherapy and were subjected to allogeneic transplantation; six started or intended to start treatment with AZA (5x) or decitabine (1x); two received best supportive care.At least one clone responded to AZA (50% reduction in FISH or VAF) in 10/18 pts (56%) without TP53 mutations. Aberrations that responded were: ASXL1, IDH2, RUNX1, SF3B1, SRSF2, TET2, U2AF1, +1, t(3;3), 5q‐, −7, i(12q), 17p‐, 17q‐, 20q‐. Although med. overall survival (OS) was shorter in pts with responding TP53 mutations than in pts without TP53 mutations but other responding clones (432 vs 682 days, P = 0.02, Figure 1B), it was longer than in pts with TP53 mutations where no genetic follow up analysis was available that could prove genetic response (266 days, P = 0.08).Summary/Conclusion:While pts without proven reduction of the TP53 clone size showed the poor outcome (med. OS 266 days) expected due to the presence of this high‐risk genetic abnormality, pts with documented reduction of the TP53 clone size also clinically profited with a med. OS of 432 days. We want to emphasize that a TP53‐mutated clone responded in 6/6 pts with TP53 mutations and genetic follow up analysis. This response rate of 100% is remarkably, as only 56% of pts with other mutations than TP53 had genetic aberrations responding to AZA. Although a retrospective analysis on a small patient number was performed, our observation supports the suggestion that pts with TP53 mutations not only respond to decitabine, but also to AZA. Even though response is not persistent, treatment with AZA could gain survival time, postpone progression and bridge interval until transplantation.image

PB2095 OUTCOME AFTER AZACITITINE TREATMENT IN PATIENTS WITH HIGH‐RISK MYEOLODYSPLASTIC SYNDROME, CHRONIC MYELOMONOCYTIC LEUKEMIA TYPE 2 AND ACUTE MYELOID LEUKEMIA–A SINGLE CENTER EXPERIENCE

Background:Hypomethylating agents have become a standard therapy for intermediate‐2 and high‐risk International Prognostic Scoring System (IPSS) myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia with 10‐29% blasts (CMML‐2) and elderly patients with acute myeloid leukemia (AML).Aims:The aim of this preliminary study was to assess the efficacy and safety of azacitidine treatment in patients with MDS, CMML‐2 and AML by analyzing the therapeutic response, progression‐free survival (PFS) and overall survival (OS) for each group of treated patients.MethodsTwenty‐six (69% male and 31% female) patients treated for the period April 2017 to October 2018 year in the Clinic of Hematology at Military Medical Academy, Sofia were included in the study. Azacitidine was administered subcutaneously at a dose of 75 mg/m2 for 7 days. Disease assessment was performed after the 3rd cycle, 6th cycle, and at progression.Results:The median age was 67.8 years (58‐80 years old). Thirteen had MDS intermediate‐2 IPSS MDS, 2 had high‐risk IPSS MDS, 2 had CMML‐2 and 9 were with AML. Azacitidine was administered as a first‐line therapy at 17 (65.4%), and as the second line in 9 (34.6%) patients. The median number of administered cycles was 6 (1‐16). Thirteen patients completed 6 cycles of azacitidine (8 patients with MDS, 2 with CMML‐2 and 4 with AML), 8 MDS patients have not complete due to progression, 3 (2 MDS, 1 AML) because of death and 2 patients (1 MDS, 1 AML) were ongoing but not reached 6 cycles. Erythroid response was achieved in 46.7% (n = 7, 4 MDS, 3 AML) after 3rd cycle and 66.7% (n = 10, 3 MDS, 1 CMML II, 2 AML) after 6th cycle. Platelet response was reached in 72.7% (n = 8, 6 MDS, 1 CMML II, 1 AML) after 3rd cycle and 40% (n = 2, 1 CMML II, 1 AML) after 6th cycle. Neutrophil response in 27.3% (n = 3, 2MDS, 1 AML) and 50%(n = 2, 2 MDS, 1 AML) after 3rd and 6th cycle. Bone marrow complete response was achieved in 4 patients (33.3%) (2 MDS, 1 AML and 1 CMML‐2), partial response in 3 (25.0%) (2 MDS and 1 AML), stable disease in 4 (33.3%) (2 MDS, 1 AML and 1 CMML‐2) and progression in 1 patient with AML (8.3%) after 6th cycle. For one patient there is missing data for bone marrow blast count. The median PFS in the MDS group was 7.9 months and in the AML group 9.7 months. None of the patients with CMML‐2 progressed at the end of the study. The median OS was 10.7 months in MDS group and 11.5 months in AML group. The most frequent grade≥ 3 adverse events was neutropenia 38.5 (n = 10), followed by anemia 15.4% (n = 4) and thrombocytopenia 11.5% (n = 3). The only found factor to correlate with shortened PFS and OS was IPSS high risk MDS (IPSS intermediate‐2 vs high ‐ PFS: 1.05 months vs 7.9 months, P = 0,01; OS: 1.4 months vs 12.39 months, P = 0.01).Summary/Conclusion:The therapy with azacitidine is an option for elderly patients with high‐risk MDS, AML and CMML II that provides PFS and OS for approximately one year irrespective of age or nosological subgroup. These are preliminary data and larger patient cohort and a longer follow‐up period are needed for clinical conclusions.

PB2230 SYSTEMIC MASTOCYTOSIS WITH ASSOCIATED HEMATOLOGIC NEOPLASM, EVOLVING TO SIMULTANEOUS CD33 POSITIVE MAST CELL LEUKEMIA AND ACUTE MYELOID LEUKEMIA, TREATED WITH GEMTUZUMAB‐OZOGAMICIN

Background:Mast cell leukemia (MCL) is an extremely rare subtype of systemic mastocytosis (SM), with only 50 cases described so far. It confers an extremely bad prognosis, with an overall survival of few months.Aims:To describe an extremely rare case of MCL and AML treated with Gemtuzumab‐Ozogamicin (GO).Methods:NAResults:A 69‐year old lady started in November 2016 with diarrhea, weight loss and eosinophilia, in the range of 2 × 109/L, with slight elevation of serum tryptase (40 ug/L) and no cytopenias. In April 2017, the patient developed severe fatigue, increasing eosinophilia, and cytopenias. Bone marrow (BM) exam was consistent with SM‐with associated hematologic neoplasm (SM‐AHN), in this case, an eosinophilic leukemia. A CT scan showed involvement of colon, liver, and bone. Molecular exams were negative, including D816 V assessment. On May 31st Midostaurin and prednisone were started, with clinical and eosinophil response. Two months later, clinical deterioration, progressive eosinophilia (max: 4.6 × 109/L) and transfusion‐dependent cytopenias developed. BM exam disclosed the D816 V mutation. Four cycles of Azacitidine were added, with no response.In March 2018, a BM exam disclosed a diffuse (&gt;90%) infiltration of atypical immature CD 25+ CD33High mastocytes. Cladribine was added on March 2018 and a noteworthy clinical and hematologic response ensued. A compassionate use of GO was requested.On July 2018, the clinical status deteriorated, with severe cytopenia, and 76% blasts in blood (CD34+CD117+Cd33+CD25‐). BM showed a mixed population of dysplastic mastocytes (80%) CD25+cKIT+ with intercalated myeloblasts. Decitabine was started, with no benefit. On August 2018, the patient was very ill, with fever, diarrhea, cachexia, anasarca, and marked liver and spleen enlargement. Blood exam showed severe anemia and thrombocytopenia with 43% myeloblasts. Serum tryptase rose again. The BM exam disclosed 2 populations. 80% of the cells were atypical fusiform mastocytes, CD117+CD25+ CD33high and 10% were myeloblasts (CD34+ CD33+w). D816 V was detected by PCR. NGS studies disclosed: c‐KIT mutation D816 V (p.Asp816Val) with an allelic frequence of 8.2%. 2.RUNX1 mutation p.Arg162Lys: 85.4%, AXL1 mutation p.Glu635fs: 48,.8%, and AXL1 mutation p.Gly966del: 47.6%. No other mutations were detected.GO was given at a dose of 6 mg/m2, on August 30th, and was repeated after 20 days at dose of 3 mg/m2. Thereafter doses of 6 mg/m2 and 3 mg/m2, with an interval of 10 days. Between GO doses, Decitabine was given in 5 days cycle, two cycles. The only response seen was the great diminution of splenomegaly and lowering of tryptase. The clinical status did not improve, and cytopenias and PB blasts remained unchanged. BM yielded a dry tap. The patient condition worsened, and she died shortly thereafter.Summary/Conclusion:This case illustrates several findings of interest. Despite the dismal prognosis of MCL and SM‐AHN, two cases of successful use of GO have been reported in CD33+ cases, one in a child with SM‐AML, and another, reported previously by one of us, in a 69‐year‐old woman with CD33+ refractory MCL who, similar to our case, had received several lines of treatment. Whereas in our first case a complete response was obtained, in the case here presented the only effect was seen at the spleen level, probably reflecting a mast cell response. These different outcomes probably could be explained by two facts. The first one is the weak expression of CD33 in the accompanying AML population, and the second one, the mutations of RUNX1 and AXL1, which confer a bad prognosis not only in AML, but in advanced SM.image

Comprehensive geriatric assessment predicts azacitidine treatment duration and survival in older patients with myelodysplastic syndromes

BackgroundTreatment of older patients with myelodysplastic syndrome (MDS) is based on disease biology and performance status. Performance status, however, does not reflect increasing co-morbidities, functional dependence or psychosocial issues in older patients. Patients and MethodsThis prospective study evaluated the burden of geriatric related health issues, assessed feasibility of “tailored” Comprehensive Geriatric Assessment (CGA), and compared treatment duration and survival in older patients with MDS and oligoblastic acute myeloid leukemia with and without deficits in CGA domains (n = 98). ResultsAlthough only 27 (28%) patients had an Eastern Cooperative Oncology Group score ≥2, 78% (n = 77) patients had deficits in at least one CGA domain. Deficits were spread across all CGA domains, including dependence for instrumental activity of daily living (iADL; n = 33, 34%).Importantly, patients who were dependent for iADL (3.7 ± 2.6 vs 12.1 ± 7.9; p = .009), had cognitive impairment (3.5 ± 2.1 vs. 10.9 ± 7.9; p = .034) or impaired mobility (3.8 ± 2.5 vs. 13.2 ± 7.6; p = .001) completed significantly less azacitidine cycles as compared to those without these deficits.Cox-proportional regression showed that iADL dependency (hazard ratio 3.37; p = .008) and higher comorbidities (hazard ratio 4.7; p < .001) were associated with poor prognosis independent of disease related factors. Poor survival of iADL dependent patients was seen in both azacitidine (6 vs 19 months; p < .001) and supportive care cohorts (26 vs 48 months; p = .01). ConclusionCGA detected geriatric related health issues, predicted poor survival and identified patients less likely to continue and benefit from azacitidine. Hence, CGA should be included in the treatment decision algorithm of older patients with MDS.

Azacitidine maintenance after intensive chemotherapy improves DFS in older AML patients

AbstractThe prevention of relapse is the major therapeutic challenge in older patients with acute myeloid leukemia (AML) who have obtained a complete remission (CR) on intensive chemotherapy. In this randomized phase 3 study (HOVON97) in older patients (≥60 years) with AML or myelodysplastic syndrome with refractory anemia with excess of blasts, in CR/CR with incomplete hematologic recovery (CRi) after at least 2 cycles of intensive chemotherapy, we assessed the value of azacitidine as postremission therapy with respect to disease-free survival (DFS; primary end point) and overall survival (OS; secondary end point). In total, 116 eligible patients were randomly (1:1) assigned to either observation (N = 60) or azacitidine maintenance (N = 56; 50 mg/m2, subcutaneously, days 1-5, every 4 weeks) until relapse, for a maximum of 12 cycles. Fifty-five patients received at least 1 cycle of azacitidine, 46 at least 4 cycles, and 35 at least 12 cycles. The maintenance treatment with azacitidine was feasible. DFS was significantly better for the azacitidine treatment group (logrank; P = .04), as well as after adjustment for poor-risk cytogenetic abnormalities at diagnosis and platelet count at randomization (as surrogate for CR vs CRi; Cox regression; hazard ratio, 0.62; 95% confidence interval, 0.41-0.95; P = .026). The 12-month DFS was estimated at 64% for the azacitidine group and 42% for the control group. OS did not differ between treatment groups, with and without censoring for allogeneic hematopoietic cell transplantation. Rescue treatment was used more often in the observation group (n = 32) than in the azacitidine maintenance group (n = 9). We conclude that azacitidine maintenance after CR/CRi after intensive chemotherapy is feasible and significantly improves DFS. The study is registered with The Netherlands Trial Registry (NTR1810) and EudraCT (2008-001290-15).

High Healthcare Utilization and Costs in Patients with Higher-Risk MDS/Low Blast Count AML Treated with Azacitidine in Ontario, Canada

Background: Azacitidine (AZA) use in higher-risk MDS has been adopted because it improves survival. Despite this, “real-world” data on the economic impact and resource utilization remains unknown. We used the Ontario provincial AZA MDS registry, which captures all AZA-treated patients in the province, to analyze “real-world” data on healthcare use, associated costs and their predictors in AZA treated higher-risk patients.Methods: We linked the provincial MDS AZA registry (single-payer/universal access), which captures baseline characteristics and treatment response for all AZA-treated patients in Ontario, to population-based health system administrative databases. Only higher-risk MDS patients (IPSS intermediate-2, high) and low blast count AML (21-30% blasts) treated from May 30, 2010 to March 16, 2015 were included. Patients were followed for 24 months following first AZA treatment and censored at the earliest of 90 days after last AZA treatment, date of death, time of acute leukemia induction/allogeneic stem cell transplant or March 31, 2016. We estimated healthcare resource utilization and the mean (and overall) standardized 28-day healthcare cost in Canadian dollars ($1 CDN = 0.76 USD$). Quantile regression was used to explore predictors of cost. Negative binomial regression models were used to explore predictors for higher rate of emergency department (ED) visits, and for longer length of stay, with the natural logarithm of length of follow-up as an offset variable in each model.Results: The registry had 652 higher-risk MDS and 225 low blast count AML patients (n = 877) with median follow up of 8 months (IQR 4-13). Median age was 73 years (IQR 66-79), 66.0% were male, 17.8% were secondary MDS and IPSS scores of those calculable were intermediate-2 (64.9%) and high-risk (35.1%). At the time of AZA initiation, 587 patients (66.9%) were transfusion dependent. The median number of cycles received was 6 (range 3 to 11) and median overall survival was 16.1 months (95% CI 13.9 to 18.3). Overall, 705 patients (80.4%) had at least 1 ED visit and 290 (33.1%) had an ED visit during their first cycle of AZA. In addition, 680 patients (77.5%) had at least 1 hospital admission with a mean hospital stay of 17.7 days (95% CI 16.3 to 19.1) over the entire study period. 141 patients (16.1%) required admission to an intensive care unit. Older age (Rate ratio [RR] = 1.33, 95% CI 1.09-1.62), rurality (RR=1.75, 95% CI 1.42-2.15), high IPSS score (RR=1.31, 95% CI 1.06-1.62), and increased comorbidity level were each independent predictors of increased ED visits; while higher comorbidity level (RR=1.51, 95% CI 1.08-2.11), high IPSS score (RR=1.39, 95% CI 1.01-1.92), and transfusion dependence (RR=1.51, 95% CI 1.13-2.01) were associated with longer hospital stays.The overall mean cost was $146,675 per patient (95% CI $139,537 to $153,812) including AZA and $103,580 (95% CI 98,675 to 108,486) excluding AZA drug costs. The mean standardized cost per 28-day period per patient was $17,638 (95% CI $16, 870 to $18,407) with AZA and $13,450 (95% CI $12,730 to $14,170) without AZA drug costs. Inpatient admissions ($4,631, 95% CI $4,010 to $5,251) and non-physician outpatient cancer clinic costs ($6,092, 95% CI $5,851 to $6,333) were the major cost drivers. Excluding AZA costs, the mean standardized 28-day costs were higher in those receiving less than 4 cycles of AZA (n= 295) at $19,408 (95% CI $17,568 to $21,248), compared with those receiving 4 or more cycles (n= 582) at $10,430 (95% CI $10,069 to $10,790) with inpatient admissions as the major driver (mean $10,192, 95% CI $8,594 to $ 10,192 vs. $1,812, 95% CI $1,558 to $2,065). On multivariable analysis, only greater comorbid disease burden (β = $2,074, 95% CI $665 to $3,483) and transfusion dependence (β = $2,402, 95% CI $1,190 to $3,613) were associated with higher median standardized 28-day cost.Conclusions: In our analysis of “real-world” patients with uniformly higher-risk MDS treated with AZA we demonstrate a significant economic impact above and beyond the cost of AZA alone. The costs are higher in patients who are transfusion dependent and have greater comorbidity and appear to be driven by inpatient care and outpatient non-physician ambulatory care. This group of patients are high users of healthcare resources with the majority having ED visits and inpatient admissions. These results will inform patients and providers about the “real-world” anticipated toxicities of AZA. DisclosuresBuckstein:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Does Trial Participation Improve Outcomes for Higher-Risk Myelodysplastic Syndromes (MDS) Patients Treated at Specialty Centers?

Background: For some rare cancers, better outcomes have been reported for patient (pts) treated at high volume or specialty centers compared to pts who did not receive such care. Greater availability of interventional clinical trials may be one of the drivers of better outcomes in specialty centers. However, not all pts referred to specialty centers are eligible or willing to participate in trials, and it is not known how outcomes compare for pts treated at specialty centers on clinical trials versus standard of care. In this study, we compared the outcomes of higher-risk MDS pts treated in and out of clinical trials at MDS specialty centers.Methods: Pts treated at MDS Clinical Research Consortium institutions (Moffitt Cancer Center, Cleveland Clinic, MD Anderson Cancer Center, Cornell University, Dana-Farber Cancer Institute, and Johns Hopkins) from 2006-2016 were included. Pts were diagnosed with MDS according to 2008 WHO criteria and identified as having “higher-risk” disease based on the revised IPSS (IPSS-R) criteria that included Intermediate, High and Very high risk categories. All pts treated outside clinical trials received hypomethylating agents (HMAs), either azacitidine (AZA) or decitabine (DAC). Trial and non-trial pts were matched 1:1 based on age, sex, number of treatment regimens prior to HMA (for non-trial pts) or experimental regimen (for trial pts) and IPSS-R categories. All non-trial pts included in the analysis received at least 4 cycles of AZA or DAC at the same institution. Transplant rates and overall survival (OS) were evaluated for association with trial participation. OS was estimated by the Kaplan-Meier method and compared using Cox proportional hazard regression with two-sided Wald test with adjustment for matching variables. The relative odds of transplant following initial treatment were estimated using logistic regression and compared with two-sided Wald test.Results: Of 774 pts in the MDS CRC database for whom complete data were available, 323 were treated in clinical trials and 451 were treated with AZA or DAC. The trial and non-trial MDS cohorts were well matched with regards to median age (68.5 vs 68.2 yrs; P=0.65), females (28.4% vs 29.9%, P=0.75), numbers of regimens (3 vs 3, P=0.77) and IPSS-R risk categories (P=0.86). Estimated median OS of pts treated in and out of clinical trials was 44.5 and 50.6 months (P=0.67), respectively. Compared to standard of care, trial participation was not associated with any survival advantage [Hazard ratio (HR), 95% CI, 0.94 (0.72-1.24), P=0.67] (Figure 1). Clinical trial participation did not significantly increase the odds of proceeding to transplant [Odds Ratio (OR) (95% CI), 1.5 (0.68, 1.61), P = 0.83)]. As shown in Table 1, in multivariate analyses, among all factors, increasing number of regimens received was significantly associated with better survival, possibly reflecting a bias towards healthier pts who survived longer to receive multiple regimens.Conclusions: In a matched-pair analysis, we found comparable survival outcomes between trial and non-trial higher-risk MDS pts treated at specialty centers. Our matched analysis failed to identify any statistical evidence to suggest that an average patient benefited from trial participation within the MDS CRC sites. Additional research is necessary to interrogate these comparisons for specific patient subpopulations by genetic alterations, co-morbidities and regimen sequence, for which trial participation may have been beneficial. Based on the population-average findings, however, we expect any improvement in survival to be modest. [Display omitted] DisclosuresKomrokji:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Roboz:Orsenix: Consultancy; Celltrion: Consultancy; Janssen Pharmaceuticals: Consultancy; Astex Pharmaceuticals: Consultancy; Eisai: Consultancy; Daiichi Sankyo: Consultancy; Novartis: Consultancy; Astex Pharmaceuticals: Consultancy; Celgene Corporation: Consultancy; AbbVie: Consultancy; AbbVie: Consultancy; Eisai: Consultancy; Celltrion: Consultancy; Roche/Genentech: Consultancy; Aphivena Therapeutics: Consultancy; Sandoz: Consultancy; Roche/Genentech: Consultancy; Daiichi Sankyo: Consultancy; Argenx: Consultancy; Jazz Pharmaceuticals: Consultancy; Pfizer: Consultancy; Cellectis: Research Funding; Celgene Corporation: Consultancy; Orsenix: Consultancy; Bayer: Consultancy; Novartis: Consultancy; Bayer: Consultancy; Jazz Pharmaceuticals: Consultancy; Pfizer: Consultancy; Sandoz: Consultancy; Argenx: Consultancy; Otsuka: Consultancy; Aphivena Therapeutics: Consultancy; Janssen Pharmaceuticals: Consultancy; Otsuka: Consultancy; Cellectis: Research Funding. Nazha:MEI: Consultancy. Maciejewski:Apellis Pharmaceuticals: Consultancy; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Ra Pharmaceuticals, Inc: Consultancy; Apellis Pharmaceuticals: Consultancy; Ra Pharmaceuticals, Inc: Consultancy; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Opsona: Membership on an entity's Board of Directors or advisory committees; Opsona: Membership on an entity's Board of Directors or advisory committees.

Exome Sequencing Identifies Mecom Missense Variant As Prognostic Marker for Overall Survival of Elderly Acute Myeloid Patients Treated with Azacitidine

Hypomethylating agents (HMA) azacitidine (AZA) and decitabine are approved low-intensity frontline therapy for AML pts, but patient selection between intensive versus low-intensity therapy remains mater of debate. To date, description of biomarker of response to HMA has brought few convincing findings. Most studies have focused on somatic mutations in candidate epigenetic genes such as DNMT3A, TET2, and IDH1/2 or tumor suppressor TP53 and led to controversies with none of this gene currently used to guide therapy decision in clinical practice. We performed an hypothesis-free, innovative, exome sequencing study to identify predictive biomarkers of outcome of AML pts treated with AZA.From Jan 2007 to Dec 2016, 279 newly diagnosed non-M3 AML pts were consecutively treated with AZA in the regional cancer network ONCOMIP. The median age was 76 yrs (45-93 yrs). Median follow-up was 5.5 yrs. AML was secondary of MDS, MPN or therapy related in 141 pts (50.5%). Karyotype was adverse in 135 pts (49.1%). Median WBC count was 2.7 G/L. Overall, 54 pts obtained CR/CRi (19,4%) and median OS was 10.6 months. Among the 279 pts, we identified a discovery cohort of 49 pts with extreme phenotype consisting in 26 pts achieving CR/CRi versus 23 pts in failure despite at least 3 cycles of AZA, and a validation cohort of 175 pts with baseline DNA sample and evaluable for response. Adverse karyotypes were more frequent in the validation set (30% vs 53% respectively, p=.004), which was likely due to an enrichment of responders pts in the discovery cohort.For exome sequencing of the discovery cohort, libraries were captured from baseline DNA BM samples with Sureselect all-exome V4 kit (Agilent) followed by paired-end, 150bp reads sequencing on a NextSeq sequencer (Illumina). Sequences were aligned with Nextgene and non-synonymous SNV were filtered according to 3 different patterns defined on gene function (nucleotide analogs metabolism/COSMIC census genes/AML genes), read depth, variant allele frequency and recurrence. An elastic-net regularization combining LASSO and Ridge penalties simultaneously (Zou & Hastie, 2005) was used to identify association between variants and clinical response. Using a resampling approach, bootstrap stability selection (BSS) were computed for each variant and only those with a BSS≥75% were selected. The exon capture baits targeted 98% of genes in the Consensus CDS database. A mean coverage depth of 85× per sample was achieved, with 92.5% of targets covered at ≥ 20× depth. From the 3 gene/SNV filtering patterns, bootstrapping of the data obtained with elastic-net regularization identified 4 candidate SNV in C11orf80, DZIP, ZNF543 and MECOM genes. Inspection of the exome-seq data for MECOM revealed that 11 of the 26 individuals in the responders sample had an heterozygous missense variant in the coding sequence of MECOM at position 169098992 (rs7622799; encoding p.Pro120Ser; MAF = 0.13 in the Exome Aggregation Consortium[ExAC]).We screened the 4 candidates SNV by targeted sequencing in the validation set and identified MECOM rs7622799, in 34/175 pts (19.4%). Response rates did not differ between pts with rs7622799 (8.8% CR/CRi) and without rs7622799 (9.2% CR/CRi, p=1.00). We then assessed whether genotype rs7622799 predicted OS in time dependent analysis using a Piecewise Cox model and demonstrated that pts with rs7622799 had improved OS from 3 months after diagnosis compared with non-rs7622799 (HR 0.56 95%CI[0.34;0.93]; p=0.024). The 3 other SNVs were not associated with patient outcome.We used an extreme phenotype study design, to discover that the missense variant rs7622799 of MECOM is correlated in time dependent analysis with the overall survival of older AML pts treated with AZA. MECOM is a complex locus gene which encodes for several isoforms namely EVI1, a very aggressive oncogene when overexpressed in AML, and MDS1-EVI1 (or PRDM3), which has epigenetic function as histone methyltransferase activity. Both isoforms directly interact with epigenetic modifiers (HDAC, DNMT3A). Further analyses are needed to best understand the functional impact of rs7622799. Although our findings could indicate that rs7622799 is associated with outcome of older AML pts in the setting of AZA, it remains unknown if it could be used to stratify pts between intensive and low-intensity therapy. Targeted sequencing of this SNV in a control cohort treated with intensive chemotherapy is ongoing [Display omitted] DisclosuresFornecker:Takeda: Honoraria; Servier: Honoraria.

Bone Marrow T Cell Changes By Multiplex IHC after Treatment with Flotetuzumab, a CD123 x CD3 Bispecific Dart® Protein, in a Primary Refractory t-AML Patient

Therapy-related acute myelogenous leukemia (t-AML) is associated with adverse genetic lesions, complex karyotype, and TP53 mutation; it is challenging to treat and confers a poor prognosis. We describe a 74-year-old female patient with AML that developed 9 years after receiving 6 cycles of cytotoxic (FOLFOX) chemotherapy as adjuvant treatment of colorectal carcinoma. At diagnosis, the bone marrow (BM) biopsy revealed blast count of 35%, with normal karyotype, 5q loss and AML1 (RUNX1) locus (21q22) amplification by fluorescence in situ hybridization (FISH). Initial treatment with 5 cycles of azacitidine (AZA) failed to induce a response. The patient was subsequently treated on a Phase 1 trial of flotetuzumab (MGD006/S80880) (FLZ), a novel T-cell redirecting (CD123 x CD3) DART protein [NCT02152956]. Prior to FLZ, BM blasts demonstrated clonal evolution with a complex karyotype (92,XXXX, t(14;21)(q22;q22)) and new IDH1, and TET2 mutations.Patient received a total of 3 cycles (28 days/cycle) of FLZ. After one FLZ cycle, the patient achieved a (complete response) CR, with normal cytogenetics, and residual IDH1 and TET2 mutations. After 2 additional cycles of FLZ consolidation, the CR was maintained, with loss of the IDH1 mutation, but persistence of the TET2 mutation. CR was maintained with no additional therapy for approximately 7 months. Serial BM samples were evaluated for T cells (CD3, CD4, CD8, FOXP3 and PD-L1) using multiplex IHC (Fig 1). BM T cells were unchanged during AZA treatment. At the initial bone marrow on FLZ (CR), significant increases in CD3+, CD3+CD8-, CD3+ CD8+, and FOXP3-positive T cells and PD-L1 expression compared to baseline were noted. CD3+CD8+ T cells persisted in the BM 1 month beyond completion of the additional 2 cycles of consolidation with FLZ, while other T cells subsets and PD-L1 expression returned to baseline (Fig. 1) Three months after the last FLZ treatment, all T cell subsets had returned to baseline, with an early increase in leukemic blasts (8%), but normal cytogenetics. Five months after FLZ treatment blasts were unchanged, but a new abnormal cytogenetic clone, with additional mutations, accompanied by a rise in PD-L1 expression cells was observed. Seven months after FLZ treatment, frank leukemia with 50% blasts developed, and all T cell subsets and PD-L1 expression had returned to pre-treatment levels.Consistent with its proposed mechanism of action, these data highlight for the first time the induction of an increase in T-cell infiltration, which persist beyond FLZ, in the bone marrow microenvironment of an AML patient that also achieved a complete and durable anti-leukemic response after treatment with FLZ. [Display omitted] DisclosuresLelièvre:Servier: Employment. Wigginton:MacroGenics: Employment. Davidson-Moncada:MacroGenics: Employment. Fox:MacroGenics: Research Funding.