Treatment Of Higher-risk Myelodysplastic Syndromes Research Articles

Efficacy and safety of venetoclax combined with hypomethylating agents in the treatment of 83 patients with higher-risk myelodysplastic syndromes

Objective: This study aimed to evaluate the efficacy and safety of venetoclax (VEN) combined with hypomethylating agents (HMA) in the treatment of higher-risk myelodysplastic syndromes (HR-MDS) and analyze the factors influencing their therapeutic effect. Methods: The clinical data of 83 patients with HR-MDS who were diagnosed at the First Affiliated Hospital of Zhengzhou University between November 2019 and May 2023 were retrospectively analyzed. All patients were treated with VEN combined with HMA. The Kaplan-Meier method was used to depict the survival curves, and the log-rank test was used to compare survival between the groups. Results: The median age was 57 (15-82) years old, and 51 patients (61.4%) were male. Forty-five patients (54.2%) were initially treated with HMA, 23 (27.7%) received ≤4 cycles of HMA, and 15 (18.1%) demonstrated HMA failure. At the median follow-up of 10.3 (0.6-34.4) months, the overall response rate (ORR) was 62.7% (52/83), including 18 patients (21.7%) with a complete response (CR), 14 (16.9%) with a bone marrow CR (mCR) with hematological improvement, and 20 (24.1%) with a mCR. The ORR of patients with initial treatment, ≤4 HMA cycles, and HMA failure were 66.7%, 60.9%, and 53.3%, respectively (P=0.641). The median overall survival time was 14.6 (95% CI 7.2-22.0) months, and the median progression-free survival time was 8.9 (95% CI 6.7-11.1) months. The multivariate analysis showed that serum alkaline phosphatase (ALP) ≥90 U/L (OR=14.574, 95% CI 3.036-69.951, P=0.001), TP53 mutation (OR=13.052, 95% CI 1.982-85.932, P=0.008), and U2AF1 mutation (OR=7.720, 95% CI 1.540-38.698, P=0.013) were independent risk factors for poor efficacy of VEN combined with HMA. Hematological toxicity occurred in all patients, and the incidence of treatment-induced grade 3-4 leukopenia was 48.2% (40/83). Infection was the most common non-hematological adverse event, mainly pulmonary infection (31.3%) . Conclusion: VEN combined with HMA had a high response rate in patients with HR-MDS, both at initial treatment and with HMA failure. ALP ≥ 90 U/L, TP53 mutation, and U2AF1 mutation were independent risk factors for non-response to treatment.

Efficacy and safety analysis of venetoclax combined with hypomethylating agents for the treatment of higher-risk myelodysplastic syndromes in the real world

Objective: To investigate the efficacy and safety of combining venetoclax (VEN) with hypomethylated drugs (HMA) in the treatment of higher-risk (IPSS-R score >3.5) myelodysplastic syndromes (MDS) . Methods: From March 2021 to December 2022, forty-five MDS patients with intermediate and high risk were treated with VEN in combination with HMAs. Clinical data were collected and analyzed retrospectively, including gender, age, MDS subtype, IPSS-R score, treatment regimen, and efficacy, etc. Kaplan-Meier method and Cox regression model were used to analyze univariate and multivariate of survival prognosis. Results: ①Forty-five patients with MDS, including ninety-one percent were classified as high or very high risk. According to the 2023 consensus proposal for revised International Working Group response criteria for higher-risk MDS, the overall response rate (ORR) was 62.2% (28/45), with the complete response rate (CR) was 33.3% (15/45). For twenty-five naïve MDS, the ORR was 68% (17/25) and the CR rate was 32% (8/25). In nonfirst-line patients, the ORR and CR were 55% (11/20) and 35% (7/20) respectively. The median cycle to best response was 1 (1-4). ②With a median followup of 189 days, the median overall survival (OS) time was 499 (95% confidence interval, 287-711) days, and most patients died from disease progression. Responders had a significantly better median OS time than nonresponders (499 days vs 228 days, P<0.001). Multifactor analysis revealed that IPSS-R score and response to treatment were independent prognostic factors for OS; the presence of SETBP1 gene mutations was associated with a longer hospital stay (51.5 days vs 27 days, P=0.017) . Conclusions: There is clinical benefit of venetoclax in combination with hypomethylated agents in patients with higher-risk MDS, but adverse events such as severe hypocytopenia during treatment should be avoided.

Evaluation of Disparities in Higher-Risk Myelodysplastic Syndromes (HR-MDS) Patient Treatment Patterns in a Large US Health System

BACKGROUND Myelodysplastic syndromes (MDS) are a heterogenous group of myeloid neoplasms. Patients may present with nonspecific signs and symptoms such as fatigue, infections, bleeding, and bruising. Bone marrow aspiration and biopsy are used to confirm diagnosis and are critical in the evaluation of bone marrow cell morphology and cellularity necessary for risk classification. Patients stratified as higher-risk MDS (HR-MDS) have worse overall survival and a higher risk of transformation to acute myeloid leukemia (AML). Treatment of HR-MDS can be challenging. While hypomethylating agents azacitidine and decitabine are the only approved drugs for HR-MDS, there are clinical and translational studies for other treatment approaches. The only curative treatment at present is hematopoietic stem cell transplantation (HSCT), for which only a portion of patients may qualify. This study sought to identify potential missed opportunities in care, including time to diagnosis (Dx) and treatment, by evaluating differences based on underlying sociodemographic and clinical characteristics of newly diagnosed patients with HR-MDS. METHODS This is a retrospective cohort study of commercial and Medicare Advantage health plan members with evidence of newly diagnosed HR-MDS in the Optum Research Database (ORD). Additional Optum datasets were linked to the standard ORD to allow for the inclusion of additional socioeconomic (SES) and social determinants of health (SDoH) variables. The study period was 1 January 2016 to 31 July 2022. Adults with ≥1 inpatient claim for HR-MDS or ≥2 outpatient claims for either MDS or HR-MDS (requiring at least 1 to be HR-MDS) on 2 separate dates between 1 January 2017 and 30 April 2022 were eligible for inclusion. The earliest HR-MDS claim was the index date. A period of 12 months prior to the index date was used to assess baseline characteristics. Patients were followed for at least 3 months post-index until the earliest of AML Dx, death, end of continuous enrollment, or end of the study period. RESULTS The study criteria were met by 1710 patients. Median age at HR-MDS Dx was 77 years, and 40% of patients had baseline Charlson comorbidity score ≥3; 22% had no claim for a bone marrow biopsy or aspiration in the 12 months prior to index or during variable follow-up. Patients were categorized hierarchically based on level of treatment received: HSCT occurred in 4% of patients, 33% had evidence of active treatment, 26% received MDS supportive treatment, and 37% had no treatment in the variable follow-up period. Patients who received HSCT had the lowest Charlson score (mean 1.3), followed by those who received active treatment (mean 2.2), no treatment (mean 2.3), and MDS supportive treatment (mean 2.8). Patients who received active treatment and those who received no treatment appeared to have a similar average age (76 years), similarities in baseline comorbidities (autoimmune conditions, diabetes, and hepatic and renal diseases), and similarities in underlying SDoH and SES characteristics. Male patients made up 58% of the total study population; the prevalence by sex varied within treatment groups where male patients were 64% of the active treatment group but only 54% of the MDS supportive treatment group (Fig. 1a). HSCT patients had the least likelihood of unmet SDoH need, whereas those in MDS supportive care generally had the lowest chance of no unmet need (Fig. 1b). Few patients (7%) had claims indicative of clinical trial participation after index; clinical trial participants were healthier (mean Charlson score 1.9 vs 2.4) and younger (only 37% were aged 75+ vs 64% of non-participants in this age group). Patients not participating in clinical trials were more likely to have unmet financial or housing security and transportation access challenges. White and Asian patients had the highest rates of whole blood transfusions (5.4 and 5.7 per 100 person-months, respectively), while Hispanic patients had the lowest rate (2.5 per 100 person-months). CONCLUSION A large proportion of HR-MDS patients had no evidence of active treatment during the variable follow-up. HSCT and clinical trial participation were low in the study; these patients were younger, had fewer comorbidities, and did not experience financial, housing, or transportation issues. To ensure guideline concordant care, there is a need to further contextualize drivers of treatment in clinical practice, including patients' preferences.

Safety and Efficacy of Selinexor Sequential Azacytidine in Newly Diagnosed Patients with Myelodysplastic Syndromes EB1 or EB2: A Single-Center, Single-Arm, Phase Ib/II Trial

Background: Azacytidine is one of the hypomethylating agents (HMAs) for the treatment of higher-risk myelodysplastic syndromes (MDS). However, clinical outcomes of patients treated with azacytidine monotherapy were far from satisfactory with overall response rate (ORR) of 41%-59% and overall survival (OS) of 15-18 months. Selinexor is an oral, first-in-class selective inhibitor of nuclear export compound that inhibits exportin 1 (XPO1). Preclinical studies have shown that inhibition of XPO1 causes nuclear accumulation of p53 and disruption of NF-κB signaling, both relevant targets for myelodysplastic syndromes. Prior study reported an ORR of 26% and mOS of 8.7 months with selinexor in HMAs-refractory MDS patients. We therefore aimed to assess the safety and efficacy of selinexor sequential azacytidine in newly diagnosed patients with MDS-EB1 or EB2. Methods: The effectiveness of simultaneous and sequential treatment of azacytidine and selinexor was measured by cell death rate, cell cycle and colony formation rate in vitro. Western Blot was performed to detect the sublocation of p53. MOLM-13-luciferase xenograft murine model was established to verify the synergetic effect in vivo. Based on the experiments, we conducted a single-center, single-arm, phase Ib/II trial, which included newly diagnosed patients 18 years or older with MDS-EB1 or EB2. Eligible patients received 2-4 weeks long cycles of oral selinexor (40mg qw for 4 weeks; 40mg biw for 2 weeks; 60mg qw for 4 weeks). The primary endpoints were to find the recommended phase 2 dose (RP2D) and maximum tolerated dose (MTD). The secondary endpoint was ORR including complete remission (CR), partial remission (PR), marrow complete remission (mCR), and hematological improvement (HI). This trial was registered with the Chinese Clinical Trial Registry (#ChiCTR2200065167). Results: First we treated three AML cell lines: AML-OCI2, THP1, MV4-11 and three MDS cell lines: SKM-1, MOLM-13, MDSL with azacitidine and selinexor simultaneously or sequentially. Sequential treatment showed stronger synergetic effect (Figure 1A) and reduced colony formation by 90% in SKM-1 and MOLM-13 (Figure 1B). Cell cycle arrest were induced and the percentage of Annexin V cells obviously increased with sequential treatment (Figure 1C). Sequential treatment decreased leukemia burden and prolonged survival of MOLM-13-luciferase xenograft murine model (Figure 1D, E). Mechanistically, pretreatment of azacitidine on SKM-1 and MOLM-13 upregulated the expression level of p53, and selinexor led to massive nuclear accumulation of p53, resulted in better vulnerability lethal to MDS cells (Figure 1F). Secondly, 15 patients were enrolled in our trial with a median age of 57. 26.7% of patients were MDS-EB1, 73.3% were EB2. 93.3% of patients were high or very high risk by the Revised International Prognositic Scoring System (IPSS-R) (see the Table). At Phase Ib, the following selinexor dosages were administered: 40mg qw (n=3), 40mg biw (n=3) and 60mg qw (n=3). One patient in the 60mg qw group discontinued treatment because of nausea, vomiting, fatigue and Herpes simplex virus infection. Subsequently, in order to find RP2D, an extension cohort of 3 additional patients were treated with 40mg qw and 40mg biw, respectively. Therefore, 14 patients were evaluable for efficacy assessment. ORR was 78.6% in 11 patients including CR in 3 patients (21.4%); mCR+HI in 1 patient (7.1%); and mCR in 7 patients (50.0%) (see the swimmer plot). Especially, among the TP53 mutated patients (n=3), one achieved CR, the other two achieved mCR. The common adverse events were neutropenia (93.3%), anemia (86.7%), thrombocytopenia (80.0%), fatigue (53.3%), nausea (26.7%), dizziness (26.7%), vomiting (20.0%) and decreased appetite (20.0%). There were no treatment related deaths. Conclusion: We verified the activity of selinexor sequential azacytidine in MDS both in vitro and in vivo. The treatment showed with encouraging efficacy in newly diagnosed patients with MDS-EB1 or EB2. Adverse events were manageable with supportive care implementation. Enrollment is ongoing to assess the efficacy and safety of this sequential therapy, which may be a new treatment option for EB subjects.

Abstract 3269: Reappraisal of immunologic mechanisms of hypomethylating agents in treatment of high-risk myelodysplastic syndrome and acute myeloid leukemia

Abstract Hypomethylating agents (HMA) have been used for the treatment of high-risk myelodysplastic syndrome (HR-MDS) and acute myeloid leukemia (AML) of the elderly. In addition to direct cytotoxic effect of HMA on MDS/AML, HMA upregulates effector T-cell function by demethylating T-cell exhaustion-associated genes (Hazem, Cell 2017) and promoting effector T-cells trafficking to tumor microenvironment by Th1-type chemokines reactivation (Peng, Nature 2019). To elucidate dynamic changes of immune cells profile and gene expression after HMA treatment in MDS/AML, we conducted single cell RNA sequencing of three sequential bone marrow (BM) samples from one HR-MDS patient treated with azacitidine. In BM samples at diagnosis (‘diagnosis’), after 2 cycles of azacitidine (BM blasts increased from 6 to 11%; ‘progression’), and after 3 additional cycles of azacitidine (BM blasts decreased to 3.5% with trilineage hematopoiesis; ‘response’), cell clusters were identified according to immune cell types. The relative proportion of the NK-cell cluster showed the most significant increase up to response (1.3% at ‘diagnosis’, 4.3% at ‘progression’, and 11.8% at ‘response’). By contrast, the CD8 T-cells cluster showed modest increase of proportion at the 3 timepoints (2.7%, 3.9%, and 7%, respectively). Differentially Expressed Gene (DEG) analysis showed CXCR4 was overexpressed in the BM NK-cell cluster at the ‘response’ time point. To determine whether the NK cells can be trafficked to BM by HMA treatment in mouse MDS/AML models, mouse myeloid leukemia cells (C1498 cells) were transplanted into the tail vein of 6-to-8-week aged syngeneic C57/BL6 mice. C1498 bearing mice were intraperitoneally treated with HMA (decitabine) or vehicle for 5 consecutive days. While HMA inhibited in vivo AML proliferation, the quantity of NK cells (NK1.1+) was significantly increased in BM of HMA-treated mice than vehicle controls. In addition, CXCR4 expression in NK1.1+ cells from BM of HMA-treated mice were significantly up-regulated, compared with vehicle controls. The NK depletion in HMA-treated AML mice decreased anti-leukemic effect, suggesting that NK cells may be one of immune cell subsets responsible for HMA induced anti-leukemia effect. Taken together, recruitment of NK cells into MDS/AML BM through CXCR4 overexpression and anti-leukemic cytotoxicity exerted by NK cells can be one of the important immunologic mechanisms of HMA in MDS/AML. Treatment strategy of recruiting more NK cells BM by HMA and maximizing cytotoxicity of NK cells should be further investigated. Citation Format: Junshik Hong, Suji Min, Jihyun Park, Carly M. Fielder, Qianni Hu, Sung-Soo Yoon, Tae Kon Kim. Reappraisal of immunologic mechanisms of hypomethylating agents in treatment of high-risk myelodysplastic syndrome and acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3269.

SOHO State of the Art and Next Questions: Treatment of Higher-Risk Myelodysplastic Syndromes.

Higher-risk myelodysplastic syndromes (MDS) carry a dismal prognosis with rapid disease progression, disease-related complications that impact quality of life, high risk of transformation to acute myeloid leukemia (AML), and poor long-term survival. Higher-risk disease is determined by a number of factors including the depth and type of cytopenias, percentage of myeloblasts occupying the bone marrow, cytogenetic abnormalities, and increasingly also by the presence of higher-risk molecular alterations. In addition to disease characteristics, a patient's performance status and degree of co-morbidity strongly influence treatment decisions and clinical outcomes. A critical first step in the management of patients with higher-risk MDS is evaluating eligibility for allogeneic hematopoietic stem cell transplant (HCT), which currently remains the only curative therapy, and is available to an ever-increasing number of patients. Outside of stem cell transplant, treatment with hypomethylating agent chemotherapy, azacitidine or decitabine, remains the cornerstone of therapy with improvements in overall survival and reduced transformation to AML; however, these approaches are palliative in nature and outcomes remain very poor overall. With a deepening understanding of disease pathophysiology has come a burgeoning array of novel targeted therapies that are currently in pre-clinical and early phase clinical trials offering hope for new treatment options for this malignancy.

Treatment of higher-risk myelodysplastic syndrome

Introduction. The myelodysplastic syndromes are a group of clonal haematopoietic stem cell disorders characterized by cytopenia, dysplasia, ineffective hematopiesis, recurrent genetic abnormalities, and increased risk of developing acute myeloid leukemia. In this paper, we present the review and recommendations for treatment of high risk myelodysplastic syndromes on behalf of the Serbian myelodysplastic syndromes group. Material and Methods. A literature review was conducted using the following bibliographic databases: Google Scholar, MEDLINE and Kobson. The recommendations treatment of high risk myelodysplastic syndromes are based on expert opinion based on review of literature and contemporary recommendations for treatment of high risk for myelodysplastic syndromes. Recommendations. Higher-risk myelodysplastic syndromes should be defined in patients risk group with &gt; 3.5 IPSS-R score. Allo- HSCT is recommended in fit higher-risk patients with IPSS-R &gt; 3.5 as well as in fit lower-risk patients with poor risk features according to EBMT/ELN International expert panel and myelodysplastic syndromes right group. Acute myeloid leukemia like or hypomethylation treatment before Allo-HSCT is indicated in patients with myelodysplastic syndromes with ? 10% of blasts. Azacitidine is recommended in intermediate-2 and high risk IPSS patients who are not eligible for transplantation with minimal number of six cycles to define response. Acute myeloid leukemia like treatment is recommended in fit higher-risk for patients with myelodysplastic syndromes with excess of blasts, good performance status, without substantial comorbidities, and with no poor/very poor cytogenetics/genetics. Conclusion. The treatment of fit higher-risk patients should be based on allo-SCT. In patients who are not candidates for transplant hypomethylation treatment is indicated as well as acute myeloid leukemia like treatment in selected patients.

Combination of Decitabine and ATRA in Newly Diagnosed Myelodysplastic Syndromes Subtype EB-Interim Analysis of a Multicenter, Randomized, Open-Label Trial

Background: HMAs are mainstay treatment of higher-risk myelodysplastic syndromes (MDS). However, clinical outcomes of patients treated with decitabine (DEC) monotherapy were far from satisfactory with an overall response rate (ORR) of 33%-55.4% and an overall survival (OS) of 17.7-22 months. Some clinical researches reported that the addition of all-trans retinoic acid (ATRA) to DEC increased response rate and prolonged survival of MDS and elderly acute myeloid leukemia (AML) patients. Our data showed ATRA enhanced the cytotoxic effect of DEC on MDS via activating RARα-Nrf2 complex (2021 EHA abstract EP891). These findings suggested that addition of ATRA to DEC in treatment-naive patients may improve response rate based on the synergetic function. We therefore conducted a study of combination of DEC and ATRA in MDS subtype excessive blasts (EB) patients.Methods: In this randomized, multicenter, open-label trial, patients with newly diagnosed MDS subtype EB based on the 2016 WHO classification from 7 different tertiary medical centers in China were included. Patients were randomized 1:1 to receive either oral ATRA (25mg/m 2/day on days 1-28) plus DEC (20 mg/m 2 daily on days 1-5) or DEC monotherapy（Figure 1）. The primary endpoint was overall response rate ORR, defined as complete remission (CR), partial remission (PR), marrow complete remission (mCR), or hematological improvement (HI). Key secondary endpoints were mCR, HI, overall survival (OS), and progress free survival (PFS). Response was assessed after completion of four cycles of treatment. For patients who bridged to allo-HSCT later on and did not complete four cycles of treatments, response was defined as best response ever observed before receiving allo-HSCT. Here, we report results of the interim analysis.Results: Between May 2018 and July 2021, 165 patients were randomly allocated into either DEC plus ATRA (n=82) or DEC monotherapy (n=83). 63.6% of patients were male and 36.4% were female, with a median age of 62 years (range, 19 to 81 years). 38.8% of patients had EB1 and 61.2% had EB2. As of July 31, 2021, 126 patients were available for the assessment of treatment results.After a median follow up of 9.6 months, median number of courses on treatment was 4 courses (range, 1-14), 61 in DEC plus ATRA arm and 65 in DEC arm . OR was achieved in 85.2% of DEC plus ATRA patients compared to 56.9% in DEC monotherapy (p<0.001). mCR rate was 73.8% in patients treated with DEC plus ATRA and 53.8% in those with DEC monotherapy (p=0.02). HI rate was 63.9% and 44.6% in patients with DEC plus ATRA and DEC monotherapy, respectively (p=0.03). The median OS and PFS were 18.8 months and 13.5 months for DEC plus ATRA arms, 19.2 months and 13.0 months for in DEC arm, respectively.72.7% patients developed at least one adverse event (AE) during the trial, 73.3% in the DEC plus ATRA arm and 72.0% in DEC arm, respectively. Grade 3/4 Hematological toxicity occurred in 73.68 % of DEC plus ATRA arm and 76.92 % of DEC arm. Hyperlipidemia occurred in 31 patients in DEC plus ATRA arm (3.2% grade 3/4), and 18 (no grade 3/4) in DEC arm (p<0.001). Incidence of headache was higher in DEC plus ATRA arm (14.7% vs 4.0% in DEC arm, respectively, p<0.001). No other statistically significant differences were observed in the incidence of treatment-related AEs between the two groups. No early death occurred.Conclusion: Combination of DEC and ATRA achieved an OR rate of 85.2% in MDS subtype EB. Enrollment is ongoing to assess its efficacy and safety in treating EB. This therapy may be a new treatment option for EB subjects. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Poster: MDS-128: Azacitidine and Venetoclax Combination for Upfront Treatment of Higher-Risk Myelodysplastic Syndromes

Poster: MDS-128: Azacitidine and Venetoclax Combination for Upfront Treatment of Higher-Risk Myelodysplastic Syndromes

Treatment of Higher-Risk MDS

Introduction Myelodysplastic syndromes (MDS) comprise a spectrum of myeloid neoplasms resulting in ineffective clonal hematopoiesis; patients are at risk of life-threatening infections or bleeding complications and progression to acute myeloid leukemia (AML). Disease risk is based on a number of factors, including depth and type of cytopenias, bone marrow blasts, cytogenetics, and, increasingly, molecular alterations. MDS at diagnosis is generally divided into lower-risk and higher-risk disease; in higher-risk MDS, survival is poor, and treatment is meant to reduce MDS-specific complications and improve quality and quantity of life. The general approach in patients with higher-risk MDS involves consideration of allogeneic transplant, the use of hypomethylating agents, as well as the role of emerging therapies and clinical trials.

MDS-128: Azacitidine and Venetoclax Combination for Upfront Treatment of Higher-Risk Myelodysplastic Syndromes

<h3>Context:</h3> Azacitidine (aza) remains the backbone of treating higher-risk MDS patients (pts), with less than 20% of pts achieving complete response (CR) and median overall survival of 14–18 months. Ongoing studies in higher-risk MDS are assessing the role of adding venetoclax (ven) to aza in higher-risk MDS. <h3>Objective:</h3> We report, here, single-institution experience of aza/ven combination in the upfront treatment of higher-risk MDS, comparing it to historical aza alone. <h3>Design:</h3> We identified 35 pts who received aza/ven for intermediate or higher-risk MDS by R-IPSS compared to 1175 similar-risk MDS pts who historically received aza upfront therapy alone. <h3>Results:</h3> The median follow-up for the aza/ven group was 15 months (mo) compared to 93 mo for aza alone. No differences were observed in baseline demographic or disease characteristics comparing aza/ven group to aza alone except for higher rates of ASXL-1 and N-RAS somatic mutations (SM) among aza/ven treated pts. There was no difference in median OS among the two groups: median OS was 20 mo for both groups. The CR/marrow CR (mCR) rate was higher with the aza/ven combination, 71% (31%/40%), compared to 25% for aza alone (13%/12%) (p<.005). Among pts with ASXL-1 SM, the CR rate was 47% compared to 9% for aza alone (p <.005). More pts treated with aza/ven proceeded to allogeneic hematopoietic stem cell transplant (AHSCT) (40% <i>vs</i> 23%, p=.04). The median OS for pts treated with aza/ven followed by AHSCT was not reached compared to 31 mo for aza alone followed by AHSCT (p=.17). The 2-year survival rate for pts who underwent AHSCT was 90% for aza/ven compared to 51% for the aza alone group. <h3>Conclusion:</h3> Aza/ven combination is associated with higher responses overall and among ASXL-1 SM higher-risk MDS pts and encouraging early data support aza/ven as a bridge to AHSCT, with 90% 2-year OS.

Predicting outcome in higher-risk myelodysplastic syndrome patients treated with azacitidine.

5-Azacitidine (5-AZA) is widely used for the treatment of higher-risk myelodysplastic syndromes. However, response and survival rates vary considerably, while indicated treatment duration remains undefined. For these reasons, factors determining response and survival are of major importance. Clinical, morphological, flow cytometry, cytogenetic and molecular factors are discussed in this review. Biomarkers predictive of response and prognosis, as well as their link to the mode of action of 5-AZA are also addressed, shifting the focus from clinical practice to investigational research. Their use could further improve prognostic classification of 5-AZA treated higher-risk myelodysplastic syndromes in the near future.

5-Azacytidine Transiently Restores Dysregulated Erythroid Differentiation Gene Expression in TET2-Deficient Erythroleukemia Cells.

DNA methyltransferase inhibitors (DNMTI) like 5-Azacytidine (5-Aza) are the only disease-modifying drugs approved for the treatment of higher-risk myelodysplastic syndromes (MDS), however less than 50% of patients respond, and there are no predictors of response with clinical utility. Somatic mutations in the DNA methylation regulating gene tet-methylcytosine dioxygenase 2 (TET2) are associated with response to DNMTIs, however the mechanisms responsible for this association remain unknown. Using bisulfite padlock probes, mRNA sequencing, and hydroxymethylcytosine pull-down sequencing at several time points throughout 5-Aza treatment, we show that TET2 loss particularly influences DNA methylation (5mC) and hydroxymethylation (5hmC) patterns at erythroid gene enhancers and is associated with downregulation of erythroid gene expression in the human erythroleukemia cell line TF-1. 5-Aza disproportionately induces expression of these down-regulated genes in TET2KO cells and this effect is related to dynamic 5mC changes at erythroid gene enhancers after 5-Aza exposure. We identified differences in remethylation kinetics after 5-Aza exposure for several types of genomic regulatory elements, with distal enhancers exhibiting longer-lasting 5mC changes than other regions. This work highlights the role of 5mC and 5hmC dynamics at distal enhancers in regulating the expression of differentiation-associated gene signatures, and sheds light on how 5-Aza may be more effective in patients harboring TET2 mutations. IMPLICATIONS: TET2 loss in erythroleukemia cells induces hypermethylation and impaired expression of erythroid differentiation genes which can be specifically counteracted by 5-Azacytidine, providing a potential mechanism for the increased efficacy of 5-Aza in TET2-mutant patients with MDS. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/3/451/F1.large.jpg.

Different methylation signatures at diagnosis in patients with high-risk myelodysplastic syndromes and secondary acute myeloid leukemia predict azacitidine response and longer survival

BackgroundEpigenetic therapy, using hypomethylating agents (HMA), is known to be effective in the treatment of high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) patients who are not suitable for intensive chemotherapy and/or allogeneic stem cell transplantation. However, response rates to HMA are low and there is an unmet need in finding prognostic and predictive biomarkers of treatment response and overall survival. We performed global methylation analysis of 75 patients with high-risk MDS and secondary AML who were included in CETLAM SMD-09 protocol, in which patients received HMA or intensive treatment according to age, comorbidities and cytogenetic.ResultsUnsupervised analysis of global methylation pattern at diagnosis did not allow patients to be differentiated according to the cytological subtype, cytogenetic groups, treatment response or patient outcome. However, after a supervised analysis we found a methylation signature defined by 200 probes, which allowed differentiating between patients responding and non-responding to azacitidine (AZA) treatment and a different methylation pattern also defined by 200 probes that allowed to differentiate patients according to their survival. On studying follow-up samples, we confirmed that AZA decreases global DNA methylation, but in our cohort the degree of methylation decrease did not correlate with the type of response. The methylation signature detected at diagnosis was not useful in treated samples to distinguish patients who were going to relapse or progress.ConclusionsOur findings suggest that in a subset of specific CpGs, altered DNA methylation patterns at diagnosis may be useful as a biomarker for predicting AZA response and survival.

Treatment of High-risk Myelodysplastic Syndrome

Treatment of High-risk Myelodysplastic Syndrome

GTB-3550 TriKE™ for the Treatment of High-Risk Myelodysplastic Syndromes (MDS) and Refractory/Relapsed Acute Myeloid Leukemia (AML) Safely Drives Natural Killer (NK) Cell Proliferation At Initial Dose Cohorts

Introduction: Relapsed/refractory AML and MDS present a clinical challenge. Despite FDA approval of multiple new targeted agents, many patients lack actionable mutations and have exhausted conventional chemotherapeutic options. We have shown that NK cell infusions after lymphodepleting chemotherapy can induce remissions in relapsed/refractory AML. However, this cell-based therapy lacks antigen specificity. To address this, we developed GTB-3550 TriKE, a novel CD16/IL-15/CD33 Tri-Specific Killer Engager (TriKE). GTB-3550 TriKE is comprised of two single chain variable fragments (scFvs); one that binds CD16 on NK cells and one that binds CD33 on myeloid malignancies, plus an IL-15 linker bridging the CD16 and CD33 scFvs for sustained cell activation. Pre-clinical data shows specific NK cell activation and targeted cytolytic activity in xenogeneic AML mouse models. Methods: Patients with CD33+ malignancies (primary induction failure or relapsed AML with failure of one reinduction attempt or high risk MDS progressed on two lines of therapy) age 18 and older were eligible (NCT03214666) if they had adequate renal, hepatic, cardiac and lung function and absolute lymphocyte count (ALC) ≥ 200 cells/µL or absolute circulating CD56+/CD3- NK cell count &amp;gt;25 cells/µL within the 14 days prior to start of therapy. The primary endpoint is to identify the maximum tolerated dose (MTD) of GTB-3550 TriKE. Correlative objectives include the number, phenotype, activation status and function of NK cells and T cells. During phase 1, each patient received the GTB-3550 TriKE at 5-200 mcg/kg/day (in 6 cohorts) for 3 weeks (infusion block #1, #2, and #3) of 96 hours continuous infusion separated by a 72-hour rest. Two patients enrolled per dose cohort. Disease response assessed by bone marrow biopsy between Days 21-42. Results: Four patients have enrolled, two at 5 mcg/kg/day and two at 10 mcg/kg/day, and three have completed therapy. Two patients with stable disease and one had substantial disease progression in the setting of a FLT-3 ITD mutation (Figure 1A). The first patient at 5 mcg/kg/day had stable disease after course 1 and qualified for retreatment with a second course of 3 weeks of GTB-3550 TriKE due to improved platelet transfusion requirements. Of the four complete courses of treatment delivered, all were delivered on schedule without treatment interruptions. The previous MTD of continuous infusion rhIL-15 was 2 mcg/kg/day (Conlon et al, Clin. Ca Res.) with associated fevers, tachycardia and constitutional symptoms. Validating our pre-clinical data showing decreased IL-15 potency when sandwiched between the CD16 and CD33 scFvs, patients treated with GTB-3550 TriKE treatment displayed no signs of clinical immune activation or SAE's in the 5 and 10 mcg/kg/day cohorts. Correlative studies have shown reproducible NK cell activity in all patients. NK cell activation (CD69+) increases early during treatment (Figure 1B). The greatest NK cell proliferation (Ki-67+) starts at day 3, is maximal at Day 8, and maintained above baseline at Day 15 and Day 22 (Figure 1C). This correlated with an increase proportion and absolute number of NK cells during treatment (Figure 1D). Targeted delivery of IL-15 to NK cells through the anti-CD16 engager showed preferential proliferation of NK cells and significantly less effect on CD8+ T cells. Additionally, the frequency of NK cells and absolute lymphocyte count decreased early during the continuous infusion of the GTB-3550 TriKE, which rebounded after the 72-hour rest period to higher levels than the pre-treatment baseline. Conclusion: This novel GTB-3550 TriKE administered by continuous infusion led to NK cell proliferation in all patients at initial dose levels and no clinically significant targeted toxicity. Though no objective responses were seen at the initially low dose cohorts tested, these early data suggest proof of principle that the drug has immune activity in humans. Subsequent patients given higher dose levels will determine if NK cell proliferation translates into clinical efficacy. Disclosures Weisdorf: Incyte: Research Funding; FATE Therapeutics: Consultancy. Vallera:GT Biopharma: Consultancy, Patents &amp; Royalties, Research Funding. Schroeder:GT Biopharma: Consultancy, Current equity holder in publicly-traded company. Felices:GT Biopharma: Consultancy. Miller:Fate Therapeutics, Inc: Consultancy, Patents &amp; Royalties, Research Funding; GT Biopharma: Consultancy, Patents &amp; Royalties, Research Funding; Vycellix: Consultancy; Onkimmune: Honoraria, Membership on an entity's Board of Directors or advisory committees; Nektar: Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: GTB-3550 TriKE is a cytokine immune engager binding to CD16 on NK cells, CD33 on myeloid blasts and IL-15 between the two engager components.

MDS-141: The Prognostic Impact of Cytogenetic Scores in Patients with Higher-Risk Myelodysplastic Syndrome Treated with Venetoclax and Azacitidine in a Phase 1 Study

Background/Aims: Venetoclax (Ven), a selective oral BCL-2 inhibitor, has shown synergy with hypomethylating agents (HMAs) such as Azacitidine (Aza), in treatment of higher-risk myelodysplastic syndrome (HR)-MDS. We evaluate prognostic impact of cytogenetic categories of revised International Prognostic Scoring System (IPSS-R) among HR-MDS patients treated with Ven+Aza. Methods: This study enrolled patients age ≥ 18 yrs, untreated for MDS, with IPSS score of ≥1.5, bone marrow blasts Results: As of 8/21/2019, 57 patients (75% male, median age 71yrs) received Ven+Aza combination. According to IPSS-R classification, at baseline, 9 (16%) patients were at intermediate risk, 13 (24%) at high risk, and 33 (60%) at very high risk. Cytogenetic risk based on IPSS-R: 2 (4%) were very good, 18 (32%) good, 8 (15%) intermediate, 13 (23%) poor, and 15 (26%) very poor. Ten genes were mutated in >10% of patients, including poor prognosis conferring TP53, RUNX1, TET2, ASXL1, SRSF2, STAG2, and IDH1/2. Median follow-up time was 8.9 months. Complete remission (CR)+marrow CR (mCR) rates by IPSS-R cytogenetic risk were: very good 100% (2/2), good 94% (17/18), intermediate 63% (5/8), poor 62% (8/13), and very poor 73% (11/15). Median with 95% confidence interval (CI) in progression-free survival (PFS) was 6.7 (0.7–not estimable), 9.3 (3.2–not estimable), and 9.5 months (2.7–9.5) in the intermediate, poor, and very-poor risk groups, respectively, and not reached in the good and very-good risk groups. Median overall survival (OS) in patients with very poor risk was 16.2 months (2.0–16.2). The estimated 12-month OS were 53%, 88%, and 100% in the poor, intermediate, and good risk groups, respectively. Conclusion: This preliminary analysis shows promising efficacy of Ven+Aza combination treatment across all IPSS-R cytogenetic risk categories and suggests prognostic relevance of the IPSS-R cytogenetic scoring system. Abstract was previously published at EHA25.

Myelodysplastic syndromes: moving towards personalized management.

The myelodysplastic syndromes (MDS) share their origin in the hematopoietic stem cell but have otherwise very heterogeneous biological and genetic characteristics. Clinical features are dominated by cytopenia and a substantial risk for progression to acute myeloid leukemia. According to the World Health Organization, MDS is defined by cytopenia, bone marrow dysplasia and certain karyotypic abnormalities. The understanding of disease pathogenesis has undergone major development with the implementation of next-generation sequencing and a closer integration of morphology, cytogenetics and molecular genetics is currently paving the way for improved classification and prognostication. True precision medicine is still in the future for MDS and the development of novel therapeutic compounds with a propensity to markedly change patients’ outcome lags behind that for many other blood cancers. Treatment of higher-risk MDS is dominated by monotherapy with hypomethylating agents but novel combinations are currently being evaluated in clinical trials. Agents that stimulate erythropoiesis continue to be first-line treatment for the anemia of lower-risk MDS but luspatercept has shown promise as second-line therapy for sideroblastic MDS and lenalidomide is an established second-line treatment for del(5q) lower-risk MDS. The only potentially curative option for MDS is hematopoietic stem cell transplantation, until recently associated with a relatively high risk of transplant-related mortality and relapse. However, recent studies show increased cure rates due to better tools to target the malignant clone with less toxicity. This review provides a comprehensive overview of the current status of the clinical evaluation, biology and therapeutic interventions for this spectrum of disorders.

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

Abstract 3092: Activation of evolutionarily young transposable elements and the host innate immune system are linked to clinical response to 5-azacitidine

Abstract The DNA methyltransferase inhibitors 5-azacitidine (AZA) and 5-aza-2-deoxycytidine (DAC) have been approved for the treatment of higher-risk myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML). A more comprehensive understanding of the molecular changes in patients treated with AZA is needed to help explain why only about 50% of these patients have clinical responses. We examined gene expression profiles in a total of 150 RNA samples taken before, during and after treatment with AZA, in three cohorts of patients with hematological cancers (40 patients total; 15 non-responders, 25 responders). We show that activation of the innate immune system is linked to clinical response to AZA treatment. We also measured the induced expression of transposable elements (TEs) to determine whether this was a potential trigger for the immune response. Both responders and non-responders showed robust upregulation of TEs however responders showed the statistically significant upregulation of specific classes of evolutionarily young transposable elements (TEs). These include short and long nuclear elements (SINEs and LINEs) and endogenous retroviruses (ERVs). Moreover, the upregulation of type I interferon signaling pathway genes in responders was significantly higher than non-responders, but not cancer testis antigens (CTAs) or tumor suppressor genes with the exception of CDKN2A and CDKN2B. Therefore, we suggest that induction of specific subsets of silenced evolutionarily young TEs may be a key to the success of epigenetic therapy in hematological cancer patients. Citation Format: Hitoshi Ohtani, Andreas D. Ørskov, Alexandra S. Helbo, Linn Gillberg, Minmin Liu, Wanding Zhou, Johanna Ungerstedt, Eva Hellstrom-Lindberg, Weili Sun, Gangning Liang, Peter A. Jones, Kirsten Grønbæk. Activation of evolutionarily young transposable elements and the host innate immune system are linked to clinical response to 5-azacitidine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3092.