Combination Of Aza Research Articles

Abstract 2630: Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach

Abstract Combining epigenetic therapy with immunotherapy is a promising strategy to address the complexities of cancer biology. However, it's important to note that the field is still evolving, and more research is needed to understand the optimal combinations, timing, and patient populations that will benefit the most from these approaches. We evaluated a combination of two different checkpoint inhibitor therapies (anti-CTLA4 and anti-PD1) with two different hypomethylating agents (5-azacytidine, AZA and Decitabine, DEC) in vitro and in vivo using a mouse breast cancer cell line 4T1 known to be resistant towards checkpoint inhibition (CPi). Beside tumor cell killing and tumor volume measurement, cytokine expression and immune cell phenotyping was determined. In a co-culture assay with autologous T cells and 4T1 cells, antitumor efficacy weas increased in all combination arms using AZA but not in combination with DEC. The combination of AZA with anti-CTLA4 was significantly better than the respective monotherapies (oneway ANOVA, p< 0.001). This effect was observed as well in the combination with anti-PD1 and AZA, however it was less pronounced (oneway ANOVA, p< 0.01). Of note, AZA restored the CTLA4 expression on CD8+ T cells in vitro, which was reduced by co-culture with tumor cells alone. In the follow-up in vivo experiment we focus on the combination of both CPi with AZA on different treatment schedules in the combination arms. The combination of anti-CTLA4 and AZA in a staggered treatment schedule displayed significant efficacy compared to control (oneway ANOVA, p< 0.05). The implantation of 4T1 reduced the number of T cells in bone marrow (BM), peripheral blood (PB) and spleen of the mice, confirming the immune-suppressive nature of the breast cancer line. This effect was restored under treatment with AZA in monotherapy and combination with CPi. Interestingly AZA reduced the number of immunosuppressive MDSC in BM, spleen and in tumor tissue. Vice versa NK cells were increased in BM, spleen and tumor tissue under treatment with AZA. AZA reduced the number of circulation tumor cells in PB and increased as already shown in vitro the percentage of CD8/CTLA4++ in PB. The PCA analysis of 36 mouse cytokines in vivo displayed two main clusters separated mainly by the presence of absence of AZA in the treatment arms. The combination arms which displayed the highest efficacy showed an increase in CXCL1, G-CSF, IL-6, LIF, M-CSF, MCP-1 (CCL2) and MCP-3 (CCL7) and a decrease of IFN-gamma, CXCL2. This is in line with the more inflammatory pattern of the tumor infiltrating lymphocytes in those groups. In summary, we have strong evidence that AZA influences the immune landscape of breast cancer towards a more inflammatory subtype. The combination with CPi was superior to the monotherapy. In addition, our data indicate that the treatment schedule of the combination might have a crucial influence on efficacy. Citation Format: Hannah Silberzahn, Mattias Bleisch, Anne Löhr, Volker Knauff, Kanstantsin Lashuk, Julia B. Schueler. Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2630.

LOWER MORTALITY RISK WITH COMBINATION THERAPY WITH ANTI-TNF THERAPY AND THRIOPURINE COMPARED TO THIOPURINE ALONE IN ELDERLY PATIENTS WITH UC

Abstract INTRODUCTION Despite increasing incidence rates of ulcerative colitis (UC) in the elderly, efficacy and safety data for medical management in this cohort is lacking due to underrepresentation in clinical trials and registries. Selection of medical therapy is often complex, taking into consideration a multitude of factors, including real and perceived risks of infection and malignancy. In the past, immunomodulators, such as thiopurines, were commonly used as monotherapy for maintenance, offering the added advantages of affordability and oral administration. Indeed, there are elderly patients who have been maintained for decades on thiopurine monotherapy. Further, thiopurines can be used in combination with anti-TNF therapy for improved efficacy and reduced immunogenicity compared to monotherapy with either agent in ulcerative colitis (UC). Whether the use of combination therapy imposes an additive risk compared to thiopurine monotherapy is still unclear. This study aimed to investigate outcomes of thiopurine monotherapy versus combination therapy with anti-TNF agents in elderly patients (age ≥65 years) with UC. METHODS The TriNetX Research Network was accessed on October 15th, 2023, to compare outcomes in elderly patients 65 years or older with UC who are receiving thiopurine monotherapy and patients who are receiving combination therapy with an anti-TNF (adalimumab, certolizumab pegol, golimumab, or infliximab). The outcomes examined were 1-year rate of corticosteroid and colectomy as well as 10-year rate of mortality, colon cancer, skin cancer, and respiratory and urinary tract infections. Statistical risk analysis was performed using the TriNetX analytical platform. RESULTS A total of 2,597 patients (2,245 thiopurines monotherapy and 352 AZA plus anti-TNF combination therapy) were included in the study (Table 1). Among the monotherapy and combination therapy cohorts, mean age was 71 years old and approximately 56% male. Ten-year mortality was higher in the thiopurine monotherapy group (OR 1.67, p=0.002). The combination therapy cohort had higher rates of steroid use (32.4% vs. 24.3%, p=0.001) and colectomy at 1 year compared to the monotherapy cohort (4.5% vs. 1.2%, p<0.001). There was no significant difference in 10-year risk of colon cancer (OR 1.05, p=0.88), skin cancer (OR 1.51, p=0.06), incidence of respiratory (OR 1.48, p=0.07) and urinary tract infections (OR 1.18, p=0.23). CONCLUSION The study findings highlight the risks of thiopurine use in patients over the age of 65 given the significantly higher 10-year mortality risk in thiopurine monotherapy-treated patients. The results also suggest that combination therapy with thiopurine and anti-TNF therapies - despite utilization in patients with more active disease indicators - is not associated with an additive risk in terms of infection and mortality in elderly patients. Table 1 Characteristics and Outcomes of Elderly Patients with UC either on Thiopurine Monotherapy or Combination Therapy with anti-TNF agents

Evaluation of Synergistic Anti-Leukemic Efficacy of PHI-101 in Preclinical Model of FLT3-ITD Acute Myeloid Leukemia

Background: AML is a heterogeneous disease with an overall cure rate of 40-50%. Some types of AML have even poorer prognosis with FLT3 mutant AML patients having only a 20-25% cure rate with chemotherapy alone. In order to improve the outcome for this high-risk AML, a number of tyrosine kinase inhibitors (TKI) have been developed and to date. Given the difficulty of identifying appropriate targets and treatment options for AML, combining drug options for AML treatment may produce clinical benefits. PHI-101 is a selective next-generation type I FLT3 inhibitor that shows potent anti-leukemic activity against AML samples harboring FLT3-ITD and/or TKD mutations. In a clinical trial, PHI-101 demonstrates significant clinical responses and tolerability in refractory or relapsed AML patients as monotherapy. To investigate the optimal way to combine PHI-101 with other therapies, a number of other drugs utilized in treating AML were tested both, in vitro and in vivo to determine synergistic or additive effects that might improve efficacy for relapsed/refractory/elderly FLT3 mutant AML patients. Study Design and Methods: Combination effects of simultaneous versus sequential treatment of PHI-101 with other agents, including daunorubicin, cytarabine, venetoclax (Ven), and azacytidine (Aza) were tested using human leukemia cell lines harboring FLT3-ITD mutations (MV4-11, Molm13, Molm14) or FLT3-wild type as controls. The cell growth inhibition was assessed by CCK-8, MTT and/or CellTiter-Glo assays as well as annexin V-binding by flow cytometry and the Chou-Talalay method was used to calculate the combination index (CI. using Compusyn software. The potential mechanisms of effect on combination therapy were explored by Western blotting of a variety of signal transduction pathways including FLT3 phosphorylation and downstream pathways BCL-2 family expression, and DNA damage. The MV4-11 xenograft mouse model was used to assess in vivo efficacy of PHI-101 combination therapy. Results: Among the substances tested for combination therapy with PHI-101 in FLT3-ITD cell lines MV4-11 and Molm14 cell lines, Aza and Ven treatment both showed synergy with both simultaneous and sequential treatment. Ven was highly synergistic when used simultaneously with PHI-101 in MV4-11 cells. Cell growth inhibition effect (GI 50) of PHI-101, Aza, and Ven used alone was measured first to calculate the CI in combination with increasing concentrations of each drug together of treatment for 72hrs. The GI 50 of PHI-101 in FLT3-mutant cell lines (MV4-11, Molm13, Molm14) were 7.0, 3.8, and 3.4 nM, respectively. The GI 50 of the gilteritinib was 5.7, 10.2, and 10.8 nM, respectively. On the other hand, the GI 50 of Aza were 198.9, 140.4, and 85.4 nM, that of Ven were 38.2, 8.4, and 56.5 nM. PHI-101 was the most efficient antitumor agent compared to other drugs tested in this study. The CI of Aza and PHI-101 was 0.01216 (EC 50), 0.05981 (EC 75), 0.29468 (EC 90) in MV4-11 cells. The observed synergistic effects were confirmed in the other FLT3-ITD cell lines as well. PHI-101 and venetoclax combined therapy in MV4-11 showed synergism (CI<0.1), and the CI was 0.00002 (EC 50), 0.00104 (EC 75), 0.01243 (EC 90). By Western blotting, the combination of Aza or Ven with PHI-101 resulted in a significant induction of p-H2AX and PARP cleavage in the FLT3-ITD cell lines (MV4-11), but not in FLT3-WT cell lines (THP-1). To further validate the synergistic anti-leukemic activity of PHI-101 with these agents, MV4-11-derived mouse xenograft models were generated and treated at various doses. In the MV4-11-xenograft model, PHI-101 alone or combined with Ven or Aza significantly decreased tumor volume. In line with the cell viability data, Ven and Aza combined with PHI-101 induced significant cell-killing in vivo. Conclusion: Treatment of AML cells with the combination of Ven or Aza with PHI-101 in vitro induced rapid induction of apoptosis and inhibition of cell growth that showed significant synergy. In vivo data showed improved efficacy for the combination treatment with these agents. In vitro and in vivo data from the preclinical AML models provides a rationale to evaluate the activity of PHI-101 in combination for patients who are ineligible for more intensive chemotherapeutic induction therapy. Improved anti-leukemic efficacy by combined therapy with PHI-101 represent a promising therapeutic strategy for newly diagnosed or R/R FLT3-mutant AML patients

Combination of Venetoclax and Azacytidine As First-Line Induction Therapy for Acute Myeloid Leukemia in Patients Younger Than 60 Years: A Tertiary Care Center Experience from Our Low Middle Income Country

INTRODUCTION: Anthracycline- and cytarabine-based “7+3” induction chemotherapy has been the frontline treatment option for acute myeloid leukemia (AML) in the non-elderly and fit patient population. Sixty percent of these patients (pts) achieve Complete remission (CR). However, an estimated 30-40% of pts relapse (Tara L. Lin & Livio Pagano et al., Expert Review of Hematology, 2021). In addition, based on a large US database study and studies from India, the “7+3” regimen is associated with high rates of induction mortality, intensive care unit (ICU) admission, and duration of hospital stay. BCL2 inhibition with venetoclax has been a new paradigm for the treatment of AML. Herein, we present our institutional experience in treating AML in pts younger than 60 years (yrs) old with a combination of venetoclax (ven) and azacytidine (aza). METHODS: We conducted a retrospective review of patients aged 18-60 who were newly diagnosed with AML between May 2020 and May 2023, and in this study, we included all pts, who met the WHO criteria for AML, did not have APML, had no prior history of treatment for other malignancies, and had not received prior induction treatment. Pts received aza 75 mg/m2 on days 1-7 and ven, which escalated from 100 to 200 to 400 mg on days 1-3. Ven continued at 400 mg without posaconazole or 100 mg with posaconazole from days 4-28, and bone marrow aspiration and biopsy were performed after day 28. Patients who achieved morphological remission without count recovery had up to 14 days off therapy before subsequent cycles. Non-responders received up to 1-2 additional cycles. Post-response (defined as a complete remission [CR] ), and patients with measurable residual disease (MRD) negative by multiparameter flow cytometry (MFC) with the residual blast cutoff being < 0.1% proceeded to further cycles. The primary objective of the study is to focus on the induction mortality rate and complete remission in younger, newly diagnosed AML pts who received aza and ven in the induction period. Responses to induction and subsequent post-remission therapy were recorded. RESULTS: A total of 17 patients with AML aged ≥ 18 years and ≤60 years were treated with a combination of aza and ven from May 2020 to May 2023. The median patient age was 47 yrs (interquartile range [IQR]: 30-56 yrs, 52.9% age <50 yrs ), and 52.9% of the pts were males. According to the European Leukemia Network (ELN) guidelines for 2022, using FISH and next-generation sequencing (NGS), 5 out of 17 pts (41.2%) were categorized as having favorable risk, 3 out of 17 patients (17.6%) were categorized as having intermediate risk, and 9 out of 17 pts (41.2%) were categorized as having adverse risk. During their inpatient stay, none of the pts required renal replacement therapy (RRT), and 1 out of 17 (5.8%) pts required mechanical ventilation. The dose of ven was 400 mg in 8 out of 17 patients (47%). One pt was on sertraline and received 200mg of ven. The remaining pts (8/17) received 100 mg of ven with posaconazole, which reduced the cost of the treatment to 50%. The median pretreatment white cell count (WCC) was 11.49 x 10^9/L (IQR: 6.25 to 39.74 x 10^9/L). The platelet count took a median of 31 days to recover above 50 x 10^9/L (IQR: 28-43 days), while the median time for the absolute neutrophil count (ANC) to recover above 1 x 10^9/L was 52 days (IQR: 47-60 days). 11 out of 17 (64%) of our patients achieved complete remission (CR1) after the first cycle. Additionally, 5 out of 17 (29.4%) were MRD-negative when compared to a large US study database and an Indian study (see table1). The median duration of hospital stay was 16 days (IQR: 10-20 days), and the induction mortality rate was 1/17 (5.8%) (see table1). This death occurred in a patient with adverse risk. CONCLUSIONS: The response to induction therapy with venetoclax and azacytidine in young adults with AML was similar to the standard “7+3” induction therapy, with around 64% of pts achieving CR after the first cycle. The median duration of hospital stay, frequency of ICU admission, and especially induction mortality have been lower than the “7+3” regimen. BCL2 inhibition has indeed resulted in a paradigm shift in the treatment of AML. Therefore, it may be the right time to consider the combination of ven and aza as the standard first-line induction therapy for all pts with AML.

Efficacy and Safety of Venetoclax in Combination with Azacitidine for the Treatment of Patients with Treatment-Naive, Higher-Risk Myelodysplastic Syndromes

Introduction: Azacitidine (Aza) has been shown to prolong survival in patients with treatment-naive, higher-risk myelodysplastic syndrome (HR MDS) compared to lower-intensity, conventional treatment regimens; however, improvement in clinical outcomes are needed. Clinical data on the synergy of Aza with venetoclax (Ven)-a selective, potent BCL-2 inhibitor-in the treatment of myeloid malignancies and the unmet need in HR MDS provide a rationale to evaluate Ven in combination with Aza in treatment-naive HR MDS. Here, we report efficacy and safety data in patients with treatment-naive HR MDS treated with Ven+Aza at the recommended Phase 2 dose (RP2D) in the safety expansion part of the Phase 1b study (NCT02942290). Methods: Adult patients were enrolled with de novo treatment-naive HR MDS defined by the Revised International Prognostic Scoring System (IPSS-R) score of >3 with an Eastern Cooperative Oncology Group performance status of ≤2, and bone marrow (BM) blasts <20% at baseline. Patients received Ven 400 mg orally daily on Days 1-14 and Aza 75 mg/m 2 intravenously or subcutaneously on Days 1-7 or on Days 1-5, 8, and 9 of each 28-day cycle (RP2D). The primary objective was to assess the complete remission (CR) rate. Key secondary objectives included determining marrow CR (mCR), overall response rate (ORR), hematologic improvement (HI), postbaseline red blood cell (RBC) and platelet transfusion independence (TI), overall survival (OS), duration of CR, time to next treatment (TTNT), transformation to acute myeloid leukemia (AML), and time to AML transformation. Responses were assessed by International Working Group 2006 criteria. Prophylactic antibiotics were mandated in Cycle 1 and recommended for Grade ≥3 neutropenia thereafter. Safety was analyzed in patients who received ≥1 dose of study treatment. Results: At thedata cutoff of May 31, 2023, 107 patients had received Ven+Aza at the RP2D. Key baseline characteristics for all treated patients are shown in Table 1A. Median age was 68 years (range, 26-87), 64% of patients had intermediate or poor cytogenetic risk, and >89% had ≥5% BM blasts. Median number of treatment cycles before transplantation was 3.0 (range, 1.0-11.0). At the median follow-up of 31.9 months (95% CI, 30.4-42.5), CR rate was 29.9% (95% CI, 21.4-39.5), with a median CR duration of 16.6 months (95% CI, 10.0-not reached [NR], Table 1B). Median OS was 26 months (95% CI, 18.1-51.5), with an estimated 12-month OS of 71.2% (95% CI, 61.4-78.9)and 24-month OS of 51.3% (95% CI, 41.2-60.5). Median OS for CR was NR. Median TTNT including transplantation was 6.8 months (95% CI, 5.6-8.3). Sixty-two (57.9%) patients received subsequent treatment, including transplantation in 42 (39.3%) patients; the median time to transplantation was 4.8 months (range, 1.4-16.8). Among patients who received transplantation post-study, 17 were transplant ineligible at study entry. Postbaseline TI rate was 61.7% for RBC and 72.0% for platelets. Median maximal duration of TI achieved was 5.4 months (range, 1.8-50.8) and 5.4 months (range, 1.9-56.0) for RBC and platelets, respectively. Postbaseline overall hematologic improvement (HI) was achieved in 51 (49.0%) of 104 evaluable patients, and specific responses included erythroid (40/93; 43.0%), platelet (32/74; 43.2%) and neutrophil (10/57; 17.5%) indices. All patients experienced ≥1 treatment-emergent adverse event (TEAE), with 94.4% of patients reporting grade ≥3 TEAEs. Serious adverse events (SAEs) occurred in 68.2% of patients. Common TEAEs of any grade were constipation (53.3%), nausea (49.5%), neutropenia (48.6%), thrombocytopenia (44.9%), febrile neutropenia (42.1%), diarrhea (41.1%), anemia (39.3%), vomiting (36.4%), and hypokalemia (26.2%). Grade ≥3 TEAEs reported in ≥20% of patients were neutropenia (48.6%), thrombocytopenia (43.0%), febrile neutropenia (42.1%), and anemia (34.6%). Infections were reported in 57% of patients, including SAEs in 40.2% of patients. Of the 59 deaths (55.1%) reported, 23 (21.5%) were due to disease progression and 7 (6.5%) to adverse events. Within 60 days after study start, 7 deaths (6.5%) were reported. Conclusion: Ven 400 mg for 14 days plus Aza combination was well tolerated with favorable responses of CR+PR+mCR in >80% and HI in nearly 50% of patients with treatment-naïve HR MDS. A separate Phase 3 study of this combination is ongoing to confirm survival benefit.

SUMOylation inhibitor TAK-981 (subasumstat) synergizes with 5-azacytidine in preclinical models of acute myeloid leukemia.

Acute myeloid leukemias (AML) are severe hematomalignancies with dismal prognosis. The post-translational modification SUMOylation plays key roles in leukemogenesis and AML response to therapies. Here, we show that TAK-981 (subasumstat), a first-in-class SUMOylation inhibitor, is endowed with potent anti-leukemic activity in various preclinical models of AML. TAK-981 targets AML cell lines and patient blast cells in vitro and in vivo in xenografted mice with minimal toxicity on normal hematopoietic cells. Moreover, it synergizes with 5-azacytidine (AZA), a DNA-hypomethylating agent now used in combination with the BCL-2 inhibitor venetoclax to treat AML patients unfit for standard chemotherapies. Interestingly, TAK-981+AZA combination shows higher anti-leukemic activity than AZA+venetoclax combination both in vitro and in vivo, at least in the models tested. Mechanistically, TAK-981 potentiates the transcriptional reprogramming induced by AZA, promoting apoptosis, alteration of the cell cycle and differentiation of the leukemic cells. In addition, TAK-981+AZA treatment induces many genes linked to inflammation and immune response pathways. In particular, this leads to the secretion of type-I interferon by AML cells. Finally, TAK-981+AZA induces the expression of natural killer-activating ligands (MICA/B) and adhesion proteins (ICAM-1) at the surface of AML cells. Consistently, TAK-981+AZA-treated AML cells activate natural killer cells and increase their cytotoxic activity. Targeting SUMOylation with TAK-981 may thus be a promising strategy to both sensitize AML cells to AZA and reduce their immune-escape capacities.

Incidence of drug-induced myelosuppression and associated adverse events (AEs), quality of life (QOL), and medical resource use (MRU) in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML).

e19072 Background: This study aimed to provide a comprehensive overview of the evidence available on drug-induced myelosuppression in patients with MDS or AML. Methods: A systematic literature review (SLR) was conducted using MEDLINE, Embase, and Cochrane to identify studies published 2002-2022 explicitly targeting drug-induced myelosuppression with current and emerging treatments used for MDS and/or AML (venetoclax [VEN], azacitidine [AZA], magrolimab, sabatolimab, decitabine [DEC], cedazuridine, lenalidomide [LEN], low-dose cytarabine [LDAC], intensive chemotherapy [IC]) in terms of drug-induced AEs, treatment discontinuation, QOL, and MRU. Article selection was based on predefined eligibility criteria (PICO+ framework), with a focus on specific geographic regions (USA, UK, Spain, Italy, France, Germany). Results: A total of 48 studies reporting on VEN, AZA, DEC, LEN, LDAC, and IC based regimens met the inclusion criteria. In MDS populations, myelotoxicity was reported in all blood cell lineages in association with AZA, DEC, and LEN monotherapies. In AML populations, myelosuppression was reported in all blood cell lineages in association with all regimens except LEN. In general, the reported incidence of myelosuppressive AEs was higher in studies published prior to 2010 and in studies of patients with AML or MDS who had received prior treatments vs more recent studies (2018-2022) and studies of treatment-naive patients, respectively. Differences observed between the two time periods might be explained by improved supportive care (AEs prophylaxis and management). In treatment-naive AML populations, the incidence of any-grade febrile neutropenia, leukopenia, and anemia was up to 3-fold higher with AZA combination therapy vs monotherapy, and the incidence of any-grade neutropenia and febrile neutropenia was 2-fold higher with LDAC combination regimens vs monotherapy, suggestive of an additive effect. The most common reasons for treatment discontinuation were AEs and disease progression. QOL significantly improved with AZA monotherapy; however, hematologic improvement was not explicitly mentioned as the main driver. There were no data on combination therapies to indicate whether the improvement in QOL compensated for the added drug-induced AEs. The few studies that reported on the impact of myelosuppression on MRU did not provide conclusive results. Conclusions: This SLR suggests that combining ≥2 myelosuppressive drugs may result in increased toxicity; however, the lack of evidence on the impact of myelotoxicity on QOL and MRU with ≥2 myelosuppressive drugs limits informed decision-making in routine clinical practice. Further research is needed to explore the impact of drug-induced myelosuppression in patients with MDS or AML.

Demethylating therapy increases cytotoxicity of CD44v6 CAR-T cells against acute myeloid leukemia.

CD44v6 chimeric antigen receptor T (CD44v6 CAR-T) cells demonstrate strong anti-tumor ability and safety in acute myeloid leukemia (AML). However, the expression of CD44v6 on T cells leads to transient fratricide and exhaustion of CD44v6 CAR-T cells, which affect the application of CD44v6 CAR-T. The exhaustion and function of T cells and CD44v6 expression of AML cells are associated with DNA methylation. Hypomethylating agents (HAMs) decitabine (Dec) and azacitidine (Aza) have been widely used to treat AML. Therefore, there may be synergy between CD44v6 CAR-T cells and HAMs in the treatment of AML. CD44v6 CAR-T cells pretreated with Dec or Aza were co-cultured with CD44v6+ AML cells. Dec or aza pretreated AML cells were co-cultured with CD44v6 CAR-T cells. The cytotoxicity, exhaustion, differentiation and transduction efficiency of CAR-T cells, and CD44v6 expression and apoptosis in AML cells were detected by flow cytometry. The subcutaneous tumor models were used to evaluate the anti-tumor effect of CD44v6 CAR-T cells combined with Dec in vivo. The effects of Dec or Aza on gene expression profile of CD44v6 CAR-T cells were analyzed by RNA-seq. Our results revealed that Dec and Aza improved the function of CD44v6 CAR-T cells through increasing the absolute output of CAR+ cells and persistence, promoting activation and memory phenotype of CD44v6 CAR-T cells, and Dec had a more pronounced effect. Dec and Aza promoted the apoptosis of AML cells, particularly with DNA methyltransferase 3A (DNMT3A) mutation. Dec and Aza also enhanced the CD44v6 CAR-T response to AML by upregulating CD44v6 expression of AML cells regardless of FMS-like tyrosine kinase 3 (FLT3) or DNMT3A mutations. The combination of Dec or Aza pretreated CD44v6 CAR-T with pretreated AML cells demonstrated the most potent anti-tumor ability against AML. Dec or Aza in combination with CD44v6 CAR-T cells is a promising combination therapy for AML patients.

High efficacy of azacitidine combined with homoharringtonine, idarubicin, and cytarabinein newly diagnosed patients with AML: A single arm, phase 2 trial.

This study aims to evaluate the efficacy and safety of the novel combination of Aza and HIA as the frontline induction therapy in newly diagnosed AML patients eligible for intensive chemotherapy (IC) (registered on ClinicalTrials.gov, number NCT04248595). Aza (75mg/m2/d on days1-5 subcutaneous) is administered in combination with HIA [HHT 2mg/m2/d on days 4-8 intravenous over 3 hours, idarubicin 6mg/m2/d on days 4-6 intravenous, and cytarabine 100mg/m2/d on days 4-10 intravenous]. The primary endpoint was complete remission (CR) or CR with incomplete blood count recovery (CRi). Secondary endpoints were overall survival (OS), relapse-free survival (RFS), and adverse events (AEs). A total of 20 AML patients (aged 18-70 years) were enrolled between Jan 2020 and Sep 2022. 95% (19/20) of patients achieved CR/CRi, and 89.5% (17/19) had undetectable MRD, in which 94.7% (18/19) reached CR/CRi, and 88.9% (16/18) obtained MRD negative after the 1st cycle of induction therapy. Median OS and RFS were both not reached during the follow-up. The estimated 2-year OS and RFS were 87.5% (95%CI, 58.6% to 96.7%) and 87.1% (95%CI, 57.3% to 96.6%), respectively. No patient discontinued the treatment for AEs. This study provides preliminary evidence for this novel combination therapy as the first-line induction therapy for young or older AML patients fit for IC.

Trial in Progress: An Open-Label Phase II Study of Relatlimab with Nivolumab in Combination with 5-Azacytidine for the Treatment of Patients with Relapsed/Refractory and Elderly Patients with Newly Diagnosed Acute Myeloid Leukemia (AARON)

The approval of venetoclax in combination with hypomethylating agents (HMA) for newly diagnosed acute myeloid leukemia (AML) has significantly improved the outcomes of patients that are not fit for intensive chemotherapy regimens. However, a considerable proportion of patients are primary refractory or relapse, highlighting the need for novel combinatorial treatment options in this patient population. Preclinical models have shown that blocking of the PD-1/PD-L1 pathway enhances antileukemic responses. However, in AML, early clinical trials evaluating the single-agent efficacy of nivolumab and other PD-1 inhibitors have demonstrated only limited activity. Based on preclinical findings that hypomethylating agents (HMA) like 5-Azacytidin (AZA) can induce an upregulation of PD-1 expression and the IFNγ signaling pathway, combinatorial treatment approaches have been studied. In relapsed/refractory (R/R) AML, the combination of AZA + Nivolumab demonstrated higher response rates and improved median overall survival compared to historical outcomes with HMA-based salvage clinical trials (Daver N et al, Cancer Discovery 2019). In our own previous work, we uncovered that blocking the inhibitory checkpoint molecule LAG-3 significantly increases the generation of anti-leukemic T-cell responses, in particular in combination with PD-1/PD-L1 blocking (Lichtenegger FS et al, Front Immunol 2018). Clinical trials are evaluating relatlimab, a monoclonal IgG4 antibody blocking LAG-3 and its interaction with HLA-class II molecules, in various indications, and it has recently been approved in combination with nivolumab for the treatment of patients with untreated advanced malignant melanoma by the FDA. Here, we describe a trial designed to assess the safety and efficacy of the combination of 5-azacytidine, nivolumab, and relatlimab in patients with r/r AML (cohort 1). The AARON trial (NCT04913922) is a phase 2, single arm, open-label trial. Additionally, we plan to amend the protocol to enroll patients aged ≥65 years with previously untreated AML (excluding patients with NPM1 and IDH1/2 mutations) who are unfit for or decline standard induction therapy (cohort 2). For this cohort, the trial will evaluate the combination of relatlimab, nivolumab and 5-azacytidine in combination with venetoclax. Importantly, in preclinical data venetoclax has been shown to promote T cell-mediated antileukemic activity (Lee JB et al, Blood 2021), making it a promising combination partner. The study will enroll a total of 30 adult patients with histologically or cytologically documented AML (excluding APL, and excluding patients with NPM1 and IDH1/2 mutations in the first-line cohort). A lead-in phase, recruited independently for both patient cohorts, will establish the safety of the study treatment in 6-12 patients per cohort. Patients must have adequate organ function and an ECOG performance score of ≤2. Patients with previous allogeneic stem cell transplantation can be enrolled in cohort 1 (from day +100 after allo-SCT) in the absence of higher-grade GvHD. Pre-treatment with HMAs is allowed for patients in cohort 1. Patients with a history of or active autoimmune disease are excluded. 5-azacytidine is applied as in routine care (75 mg/m2 BSA, days 1-7 of a 4-week cycle). Nivolumab (480mg flat dose) and relatlimab (160mg flat dose) are infused on day 1 of each cycle. For cohort 2, we plan to dose venetoclax at 70mg daily (with mandatory posaconazole co-medication from d1 to 28, or shorter in case of significant hematotoxicity). If dose-limiting toxicities occur in ≥2/6 patients in the lead-in phase, the dose of relatlimab will be reduced to 80mg (flat dose), and the safety of the treatment will be re-assessed with a new 6-patient lead-in phase. Response will be assessed after completion of cycle 1, then every 1-3 cycles. The primary endpoint of the lead-in phase is the establishment of a recommended phase 2 dose, and overall response rate. The latter will be assessed in both patients from the lead-in and the expansion phase. Secondary endpoints, assessed in all enrolled patients, include the safety, duration of response and survival. A comprehensive accompanying immunomonitoring program will study immunological changes in the peripheral blood and bone marrow. Funding: Bristol-Myers Squibb. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Iadademstat Combination with Azacitidine Is a Safe and Effective Treatment in First Line Acute Myeloid Leukemia. Final Results of the Alice Trial

Background: Acute myeloid leukemia (AML) is a heterogenous disease with a broad spectrum of cytogenetic and molecular aberrations. Emerging targeted therapies have improved overall survival (OS) for some specific subgroups. Outcomes, however, remain poor, particularly for patients (pts) with high-risk characteristics and not eligible for intensive treatments. Combinations with hypomethylating agents are the standard of care (SoC) for unfit patients. Azacitidine (aza) plus venetoclax has shown an OS of 14.7 months (mo) and a complete remission or complete remission with incomplete hematological recovery (CR/CRi) rate of 66% (VIALE-A trial). The presence of mutations in TP53 or FLT3-ITD predicts resistance to this combination. Overall, 50% of AML pts relapse after first line treatments, generally attributed to the persistence of leukemic stem cells (LSC) and/or their clonal evolution, emphasizing the need to develop new strategies targeting LSC, to improve outcomes. One such investigational strategy is iadademstat (iada), an oral, potent and selective inhibitor of the Lysine-Specific Demethylase 1 (LSD1/KDMA1) enzyme. This enzyme works as a master regulator of transcription by a double mechanism of action: 1) removing methyl groups from histone 3 lysines (epigenetic eraser); and 2) disrupting multiprotein transcriptional complexes on genes governing cell differentiation and stemness. In myeloid cells, LSD1 provides a scaffold for assembly of the GFI1/CoREST transcriptional repressor complex, which regulates hematopoietic differentiation. Iada-induced gene expression shifts from a proliferation to differentiation signature has been preclinically characterized in AML cells (Maes, et al., Cancer Cell 2018) and in the clinic in a Ph1 study in Relapsed/Refractory AML (Salamero, et al., JCO 2020). To date, iada has been administered to more than 100 oncology pts in Ph1 and Ph2 trials, showing manageable toxicity and encouraging preliminary activity. Herein, we present the results of the Phase 2 ALICE study (EudraCT 2018-000482-36) testing the combination of iada plus aza for the frontline treatment of unfit AML patients, with a median follow-up of 6.9 mo (range 0.7-41.9) (cut-off June 30, 2022). The final data (cut-off September 30, 2022) will be presented at the ASH meeting. Methods: Unfit adult patients with AML per WHO 2017 classification who had not received previous treatment were enrolled. Two cohort doses of iada at 60 or 90μg/m2/d (PO, 5d ON, 2d OFF weekly) were explored in combination with aza (75mg/m2 SC for 7d, either d1-5, 8-9, or d1-7 every cycle) in a 28d cycle. Primary endpoints are safety, tolerability, and establishment of the recommended phase 2 dose (RP2D); secondary endpoints include remission rates, time to response (TTR), duration of responses (DoR) and OS. Additional assessments include measurable residual disease (MRD), PK/PD determinations and molecular correlations with response. Results: Baseline characteristics for 34 per protocol pts out of 36 accrued are shown in Table 1. Safety and efficacy results are detailed in Table 2. Main safety events remain consistent with previous updates, with the most frequently reported adverse reactions (AR) being platelet reduction in 53% of pts (58% of pts entered the study with grade ≥3 thrombocytopenia). Only 2 drug-related SAEs have occurred to date. Of 27 pts evaluable for efficacy, 81% responded (64% of those with CR/CRi). Responses were rapid (91% by end of C2). 71% of CR/CRi pts became transfusion independent and 82% of CR/CRi pts evaluable for MRD were negative by flow cytometry. Mean/median DoR (CR/CRi) are 9.3 mo (SE: 1.0 mo) / NE (95% CI 10.1mo, NE). Mean/median OS are 8.2 mo (SE: 0.80 mo)/9.3 mo (95% CI 11.0 mo, NE). Median OS for pts achieving CR/CRi is ~14.3 mo. Based on PK/PD, safety and efficacy, iada at 90 μg/m2/d is the RP2D for the combination. Response assessment per specific mutations shows that 3 out of 3 (3/3) with FLT3 mutations, 7/7 with RAS pathway mutations, and 6/8 pts with TP53 mutations responded. Gene expression and cell differentiation analyses are ongoing and correlations with clinical responses will be presented. Conclusion: The combination of iada with aza produces robust, rapid and durable responses in previously untreated unfit AML patients, including those with high-risk features, with a manageable toxicity profile. Further research with iada in combination with SoC treatments for AML is warranted. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Novel Therapies for De Novo or Relapsed/Refractory AML with TP53 Mutations : A Glimmer of Hope

Background: The prognosis of TP53 mutated acute myeloid leukemia (AML) is dismal. Due to their correlation with universally bad outcomes, TP53 mutations play a crucial role in risk assessment and treatment selection in 5-10% of AML cases. Traditional Therapies have shown limited response and poor overall survival (OS). With current therapy, the median OS of a patient with newly diagnosed TP53m-AML is 6-9 months, and only around 10% of patients survive three years after allogenic hematopoietic stem cell transplantation (alloHCT). We present the safety and efficacy of novel therapeutic agents that target specifically TP53 mutated AML. Materials & Method: A comprehensive literature search was performed on PubMed, Cochrane Library, Embase, and Web of Science. We used the following mesh terms and Emtree terms, "acute myeloid leukemia" OR "AML" AND "TP53 mutations" from the inception of literature till 06/01/2022. We screened 2300 articles and included articles citing novel therapies such as "Venetoclax" (VEN), "Hypomethylating agents (HMA), 5-azacytidine (5-AZA), "checkpoint inhibitors, and "MDM2 inhibitors". We extracted data for "complete response (CR), Overall Survival (OS), and Progression-free survival (PFS) and safety variables such as grade III-IV adverse events. We excluded case reports, case series, preclinical trials, single-arm studies, review articles, meta-analyses, and controlled. STATA version 14.2 was used. Results: A total of 1814 patients were included in three-phase III and eleven phase II trials. Bcl-2 inhibitors :For VEN in combination with two phase III trials incorporating 641 patients were evaluated; In both trials, encouraging remission rates were reported in de-nov or relapsed or refractory patients harboring TP53 mutations. However, the median OS was 14.7 vs 5.17 (mTP53 vs wTP53) months in the treatment group compared to 4.9 vs 9.6 (mTP53 vs wTp53) months in the control group respectively. For VEN +AZA combination group, CR rates in mTP53 patients was 55% versus 0% in AZA alone (p < 0.001). VEN with low-dose cytarabine (LDAC) had 27% CR, whereas LDAC alone had 7%. Checkpoint inhibitors such as nivolumab showed favorable responses, as in the phase II study of nivolumab in combination with azacitidine in relapsed/refractory (R/R) AML; it demonstrated acceptable toxicity and an overall response rate (ORR) of 33%. However, increased response rates were seen in HMA-naïve patients. HDAC inhibitors : In two phase II trials incorporating AZA vs AZA + entinostat, the CR was 46% vs 44% . The mOS achieved in AZA was 18 months vs. combination therapy with entinostat. In the study by Manero et al. , the combination therapy of Decitabine and valproic acid showed CR of 34% and mOS of 11.9 months. The results of other trials with respect to TP53 mutation is shown in table 1. APR-246 inhibitors: In two phase II trials combining Eprentapopt with AZA , 29 patients were enrolled and CR of 41% was achieved.Sallman et al. described a remission of 82% with a median OS of 14.7 months in Eprenetapopt + 5-AZA. The most common grade ≥ 3 hematological adverse events were anemia, neutropenia, thrombocytopenia, and leukopenia. MDM2 Inhibitors : In the MIRROS trial, a phase III trial incorporating idasanutlin + cytarabine + placebo + cytarabine in R/R AML;436 patients were enrolled. The CR was 20.3%vs 17.1%(odds ratio [OR], 1.23; 95%CI, 0.70-2.18). Common any-grade adverse events (≥ 10%incidence in any arm) were diarrhea (87.0%vs 32.9%), febrile neutropenia (52.8%vs 49.3%), and nausea (52.5%vs 31.5%). The grade ≥3 hematological and non-hematological adverse events have been reported in Table 1. Conclusion: Emerging therapies employ unique therapeutic pathways that have led to increased optimism regarding the therapeutic potential of TP53 mutations. Although the median OS remains approximately a year with these therapies, hypomethylating drugs in combination with VEN or as independent therapy demonstrated greater response rates than induction chemotherapy. Initial progress has resulted from eprenetapopt's direct targeting of mutant p53 protein, showing a favorable 82% complete response. Still a daunting challenge, a combination of these therapies may ultimately be necessary to obtain adequate and sustained responses. Participation in clinical trials for all newly diagnosed AML patients should be encouraged to promote the development of innovative therapeutics. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

PB1921: A RANDOMIZED, DOUBLE-BLIND, PHASE 3 STUDY OF TAMIBAROTENE/AZACITIDINE VERSUS PLACEBO/AZACITIDINE IN NEWLY DIAGNOSED ADULT PATIENTS SELECTED FOR RARA-POSITIVE HR-MDS (SELECT-MDS-1)

Background: A novel genomically defined subset of higher-risk MDS (HR-MDS) patients with an actionable target characterized by overexpression of RARA has been identified (McKeown 2017). Approximately 30% of HR-MDS patients are RARA-positive (RARA+) by a blood-based biomarker test (Vigil, 2017). This RARA positivity enables biologically targeted therapy with tamibarotene (formerly SY-1425), an oral selective RARα agonist with potential to provide clinical benefit for HR-MDS patients, irrespective of mutation or cytogenetic risk. Initial Phase 2 clinical data in RARA+ relapsed/refractory HR-MDS patients treated with single agent tamibarotene showed myeloid differentiation, improved blood counts, and reduced bone marrow blasts, including one patient who achieved marrow complete remission with hematologic improvement (Jurcic 2017). Tamibarotene in combination with azacitidine (aza) demonstrated high complete response rates with rapid onset of response in RARA+ newly diagnosed (ND) unfit AML patients, including those with low blast count (≤ 30%) AML, and a majority of patients achieved or maintained transfusion independence (de Botton 2020). Tamibarotene plus aza was generally well tolerated with no increase in myelosuppression compared to single agent aza (de Botton 2020). HR-MDS and AML have common cytogenetic abnormalities and gene mutations present in the blast populations in each condition. The historical precedent demonstrating similar clinical outcomes among patients with HR-MDS and AML, particularly low blast count AML (Estey 2021), supports further development of the combination of tamibarotene plus aza in the HR-MDS population, with the opportunity to improve upon the clinical outcomes of standard of care treatment with hypomethylating agents (HMAs). Aims: This is a global Phase 3, multi-center, randomized, double-blind, placebo-controlled study comparing the activity of tamibarotene plus aza, to placebo plus aza in RARA+ patients with ND HR-MDS. The primary objective is to compare the complete remission rate of tamibarotene plus aza vs. placebo plus aza, with secondary objectives to compare objective response rate, event-free survival, overall survival, transfusion independence rate, time to and duration of initial and complete responses, and safety. Methods: Patients must be RARA+ based on the investigational biomarker test, ND with HR-MDS by WHO classification (Arber 2016), classified by IPSS-R risk category as very high, high, or intermediate risk with a bone marrow blast count > 5% at study entry. Patients suitable for allogeneic HSCT at the time of screening, or who received prior treatment for MDS with any HMA, chemotherapy or allogeneic HSCT are excluded. Aza will be administered at 75 mg/m2 IV/SC daily on days 1-7 (or days 1-5, 8-9) followed by tamibarotene/placebo at 6 mg BID orally days 8-28 of each 28-day cycle. Response will be assessed per the modified IWG MDS criteria (Cheson 2006). Results: Approximately 190 patients will be randomized 2:1 and stratified by IPSS-R risk group and geographic region, providing 90% power to detect the difference in CR rates between the experimental and control arms, respectively, with one-sided alpha of 0.025. Summary/Conclusion: The SELECT-MDS-1 trial opened to enrollment in February 2021, recruitment is ongoing, with sites located in North America, Israel, and Europe (NCT04797780).

Venetoclax and Azacitidine in the Treatment of Patients with Relapsed/Refractory Myelodysplastic Syndrome

Venetoclax and Azacitidine in the Treatment of Patients with Relapsed/Refractory Myelodysplastic Syndrome

Treatment of MDS, AML and CMML Relapse after Allogeneic Blood Stem Cell Transplantation with Azacitidine, Lenalidomide and Donor Lymphocyte Infusions - Final Results of the Prospective Azalena-Trial (NCT02472691)

BackgroundAzacitidine (Aza) in combination with donor lymphocyte infusions (DLI) is an established treatment option for pts with relapse of myeloid malignancies after allo-SCT. Accounting for its immunomodulatory and anti-leukemic properties, we considered Lenalidomide (Len) to be a synergistic partner for Aza and DLI that may further improve response rate and outcome. To investigate the tolerability and efficacy of the combination of Aza, Len and DLI as first salvage therapy for relapsed MDS, AML and CMML after allo-SCT we performed a prospective, multicenter, single-arm phase-II trial. Results from two safety interim analyses have previously been reported. Here, we report the final results from this investigator-initiated trial.Design/Methods:Patients with relapse of MDS, AML and CMML after first allo-SCT were eligible. Envisaged treatment according to the protocol consisted of up to 8 cycles Aza (75 mg/m 2/d d1-7, every 28 days) and up to 3 DLI with increasing T cell dosages (0.5×10 6 - 1.5×10 7 cells/kg). Len was administered concomitantly for 21 days of a 28-day cycle. Following a positive first interim safety analysis in 10 patients the daily dose of Len was increased from 2.5 to 5mg. The primary endpoint of the study was safety, while secondary efficacy endpoints included response type and rates, time to and duration of response and overall survival.Results:Overall, 50 pts with molecular (n=29, 58%) or hematological (n=21, 42%) relapse of MDS (n=24, 48%), AML (n=23, 46%) or CMML (n=3, 6%) detected after median of 233 days (range, 98 to 2659) after allo-SCT were included. Fourteen patients (28%) received Len at a daily dosage of 2.5 mg and 36 patients (72%) at a daily dosage of 5 mg with no DLTs observed in the interim analyses. Median number of Len cycles per patient was 7 (range, 1 to 8) with no differences between the two dose levels. Concomitantly, 34 pts (68%) received at least one DLI (median: 3, range: 1-11).Overall response rate (ORR) during treatment was 56% (CR n=25, 50%, PR n=3, 6%). ORR and CR rates did not differ between Len dose levels. Of interest, CR rate did not differ between pts treated at the stage of molecular relapse and those initiated at hematological relapse (52% vs. 48%). Median time to CR was 112 days (range 1-286) corresponding to 4 cycles (range 1 to 8). At the time of data lock, 20 patients (80%) were still in CR without additional therapy for a median of 15 months, while 5 patients (20%) had relapsed again after a median of 8 months. With a median follow-up of 20 months median OS was 21 months and 1-year OS rate 65%.While therapy-related CTC grade III/IV neutropenia (92%), thrombopenia (80%) or anemia (36%) occurred frequently, drug-related non-hematological adverse events (AE) >grade II were rare and mainly consisted of gastrointestinal toxicity (6%), laboratory findings (28%) and infections (22%). Twenty-three pts (46%) developed acute GvHD including 5 patients (10%) with grade III/IV aGvHD, and 26 pts (52%) chronic GvHD (mild n=10; moderate n=11; severe n=5). During the study period, 3 secondary malignancies (squamous cell, basal cell and vulvar carcinoma) occurred. There were no therapy related deaths.Conclusion:Len up to a dosage to 5 mg/day can be safely added to the combination of AZA and DLI without excess of GvHD and toxicity. Furthermore, these data suggest that the combination of Aza, Len and DLI has promising clinical activity for relapse of myeloid malignancies after allo-SCT and is able to induce durable responses and survival in a substantial proportion of pts. DisclosuresSchroeder: Celgene: Honoraria, Other: Travel support, Research Funding. Stelljes: Kite/Gilead: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Medac: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau. Holtick: Celgene: Honoraria; Sanofi: Honoraria. Germing: Janssen: Honoraria; Bristol-Myers Squibb: Honoraria, Other: advisory activity, Research Funding; Jazz Pharmaceuticals: Honoraria; Celgene: Honoraria; Novartis: Honoraria, Research Funding. Kröger: AOP Pharma: Honoraria; Celgene: Honoraria, Research Funding; Gilead/Kite: Honoraria; Jazz: Honoraria, Research Funding; Neovii: Honoraria, Research Funding; Novartis: Honoraria; Riemser: Honoraria, Research Funding; Sanofi: Honoraria. Kobbe: Celgene: Research Funding. OffLabel Disclosure:Lenalidomide is not licensed for AML, CMML and advanced MDS except for MDS with isolated del5q

Treatment of Relapse of MDS, AML and CMML after Allogeneic Blood Stem Cell Transplantation with Azacitidine, Lenalidomide and Donor Lymphocyte Infusions - Results from the First Interim Analysis of the Azalena-Trial (NCT02472691)

Background:Azacitidine (Aza) and donor lymphocyte infusions have become a standard treatment of myeloid malignancies relapsing after allo-SCT. Studies so far showed response rates ranging from 10% to 75% following treatment with Aza with or without donor lymphocyte infusions (DLI) and particularly patients (pts) with MDS and AML with low disease burden seem to benefit most. Lenalidomide (Len), due to its immunomodulatory and antileukemic properties, may act synergistically with Aza and DLI.Design/Methods:We initiated a prospective, multicenter, single-arm phase-II trial combining Aza, Len and DLI in patients with MDS, AML or CMML as first salvage treatment for relapse after allo-SCT. Pts were envisaged to receive up to 8 cycles Aza (75 mg/m2/d d1-7, every 28 days) and 3 DLI with increasing dosages (0.5×106 - 1.5×107 cells/kg) after cycles 4, 6 and 8. Concomitantly, eight cycles of Len were administered with a daily dose of 2.5 mg for the first 21 days of a 28 day-cycle each.To cope with the potential risk of GvHD induction by Len after allo-SCT the primary endpoint is safety and the study incorporates two interim analyses scheduled after the first 10 and 20 patients respectively. If no dose limiting toxicity (DLT) defined as steroid refractory acute GvHD grade III/IV, chronic GvHD NIH score severe or any unexpected hematologic and non-hematological toxicity grade ≥ III is observed in more than 3 patients in the first interim analysis, the dose of Len will be increased to 5 mg/day for the next 10 patients. Otherwise the study will be stopped.Results:Here we present the results of the first interim analysis (data lock February 20th 2017), which includes 10 patients (median age: 64 years, range 43 to 73) who experienced molecular (70%) or hematological (30%) relapse of MDS (70%), AML (20%) or CMML (10%) after median of 275 days (range: 91 to 937) following allo-SCT. So far, these 10 patients have received a total of 54 cycles of Len corresponding to median of 7 cycles per patient (range: 1 to 8). In addition, patients received a median of 7 courses of Aza (range 1-8) and 7 of 10 pts (70%) received at least one DLI (median: 1, range: 0-5).No DLT was observed. Two patients either developed acute GvHD (20%, overall grade I and III) and chronic GvHD (20%, NIH score mild and moderate). Treatment-associated neutropenia, thrombocytopenia or anemia CTC grade III/IV occurred in 75%, 50% and 0% of the patients, respectively. Common adverse events were gastrointestinal side effects, elevation of liver enzymes as well as infections. Nevertheless, during the treatment period only 2 patients needed to be hospitalized. Although efficacy was not the major scope of this first interim analysis, of 7 evaluable patients (early drop-out of 3 patients) 4 (57%) achieved complete remission and 1 patient (14%) achieved partial remission resulting in overall response rate of 71%.Conclusion:This interim-analysis shows that the combination of Aza, Len (21x2.5 mg/cycle) and DLI as first salvage therapy for relapse after allo-SCT is safe and feasible and not associated with excess GvHD. According to the protocol, the dose of Lena will now be increased to 21x5 mg/cycle for the next 10 patients. Furthermore, due to the label extension of Aza, the inclusion criteria will also be amended to AML patients with >30% BM blasts. DisclosuresSchroeder:Celgene: Consultancy, Honoraria, Other: travel support. Rautenberg:Celgene: Other: travel support. Scheid:BMS: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Nachtkamp:Celgene: Other: Travel Support. Germing:Janssen: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Kröger:RIEMSER Pharma: Research Funding; Novartis AG: Research Funding; Amgen Inc.: Speakers Bureau; Janssen Global Services, LLC: Speakers Bureau; Neovii Pharmaceuticals AG: Speakers Bureau; Novartis AG: Speakers Bureau; Sanofi: Speakers Bureau. Kobbe:Celgene: Other: Advisory Board, Research Funding.

Selective Inhibition of HDAC1 and HDAC3 Inhibits Survival of Diffuse Large Cell Lymphoma Via Epigenetic Modulation of Death Associated Protein (DAPK)

Histone deacetylases (HDACs) are key players of epigenetic regulation of gene expression and are therefore attractive targets for cancer therapy. Many epigenetic drugs including HDAC inhibitors (HDACi) have shown anti-tumor activity in several types of cancers. Recently SAHA and belinostat Pan-HDACi have been FDA-approved for the treatment of T cell lymphoma. However, the capacity of Pan-HDACi for distinguishing different classes and isoforms of HDACs is limited, and may produce profound side effects. Therefore, it is important to identify cancer-relevant HDACs to promote selective HDAC inhibition for therapy in other malignancies such as diffuse large B cell lymphoma (DLBCL), the most aggressive non-Hodgkin lymphoma. Recent studies have shown that HDAC1 (HDACs class I) are commonly overexpressed in multiple cancer types and contribute to poor overall survival. However, the role of HDAC3 is not well known. The goal of this study was to determine the mechanistic role of HDAC3 and HDAC1 in DLBCL.Immunohistochemistry performed on DLBCL tumors (n=29) demonstrate 42% positivity for HDAC3 and 100% positivity for HDAC1. Ectopically expressed HDAC3 led to increased thymidine uptake, whereas HDAC3 knockdown using siRNA led to a significant decrease in thymidine uptake (p<0.001) suggesting that HDAC3 could be necessary for DLBCL cell growth. Moreover, inhibition of HDAC3 using a selective pharmacological inhibitor RGFP966 suppressed cell proliferation in a dose dependent manner in several DLBCL cell lines (SUDHL6, OCILY1, OCILy10 and OCILy3). However, the effect of RGFP966 on cell survival as determined by annexin V/ propidium iodide was underwhelming. We sought to target both HDAC1 and HDAC3 using the pharmacological inhibitor RG283 and assessed biological effect of dual inhibition. Interestingly, dual inhibition of HDAC1 and HDAC3 with RG2833 significantly suppressed both cell proliferation (<0.0001) and survival (p<0.001) in most of the DLBCL cell lines tested. As expected, treatment with RG2833 increased acetylation of H3K9, H3K14, H3K27 and H4K5 histone marks and led to P21 upregulation in DLBCL cells. Interestingly, exogenously overexpressed HDAC3 but not HDAC1 increased sensitivity of DLBCL cells to Pan-HDAC inhibitors vorinostat and belinostat, which suggest that endogenous HDAC3 in DLBCL cells may exist in a protein complex that may evade targeting by Pan-HDACi. In order to identify a potential mechanism of action for dual HDAC3 and HDAC1 inhibition, we have focused on tumor suppressor gene DAPK (Death associated protein), which has been previously shown to be silenced in DLBCL patients via DNA methylation. DAPK is a serine/threonine kinase and possesses pro-apoptotic and tumor-suppressive functions. We have confirmed by RT-PCR that DAPK was suppressed/silenced in DLBCL cell lines (n=8) as compared to CD19+ (n=3) normal B cells. HDAC inhibition alone or in combination with DNA methyltransferase inhibitors (DNMTi) can induce apoptosis by modulating expression of tumor suppressor genes. We next asked whether HDAC3 and HDAC1 dual inhibition through RG2833 alone or its combination with DNMTi, azacytidine (AZA) will be able to restore expression of DAPK in DLBCL cells. Quantitative RT-PCR analysis in OCILy3 and OCILY10 cells demonstrated that treatment with RG2833 alone modestly increased DAPK expression; however, co-treatment with RG283 and AZA led to marked increase in DAPK expression. As expected, the combination of RG2833 and Aza had significantly greater pro-apoptotic effect in DLBCL cells than either drug alone suggesting that DAPK expression may be an important determinant of response to HDAC1/HDAC3 dual inhibitor in DLBCL cells.In summary, our study provides first evidence of antitumor activity of dual HDAC3 and HDAC1 targeted agent therapy in DLBCL patients. Moreover, we have identified epigenetic modulation of DAPK as potential modulator of cellular response to HDAC1/HDAC3 dual inhibition. This study suggests for further clinical trials and/or development of selective inhibitors of HDAC3 or HDAC1/HDAC3 in DLBCL patients. DisclosuresNo relevant conflicts of interest to declare.

Venetoclax and azacitidine combination in chemotherapy ineligible untreated patients with therapy-related myeloid neoplasms, antecedent myelodysplastic syndromes, or myelodysplastic/myeloproliferative neoplasms.

7011 Background: Patients (pts) with therapy-related myeloid neoplasms (tMN), antecedent myelodysplastic syndrome, or antecedent myelodysplastic/myeloproliferative neoplasms (A-MDS/MPN) may have poor outcomes due to age and adverse genetic/karyotypic features. In the VIALE-A study, pts with tMN and A-MDS/MPN unfit for intensive chemotherapy treated with venetoclax (Ven) and azacitidine (Aza) demonstrated superior response rates and overall survival (OS) than Aza alone. Herein, the efficacy and safety of Ven+Aza among pts with tMN and A-MDS/MPN are described. Methods: Data were pooled from pts enrolled in VIALE-A (NCT02993523) comparing pts who received Ven+Aza or placebo (Pbo)+Aza and a prior phase 1b study (NCT02203773) where pts received Ven+Aza. Enrolled pts were ≥18 years, treatment-naïve with no prior exposure to hypomethylating agents, and ineligible for intensive chemotherapy. Pts on Ven+Aza received Ven 400 mg orally (days 1–28) and Aza (75 mg/m2; days 1-7/28-day cycle). Composite complete remission rate (CRc; complete remission [CR] + CR with incomplete hematologic recovery [CRi]), duration of response (DoR), and OS were assessed. Disease assessments were per modified International Working Group response criteria for AML. Results: In this pooled analysis, tMN was observed in (Ven+Aza/Pbo+Aza) 31/9 and A-MDS/MPN in 59/26 pts. Poor-risk cytogenetics were observed in 18 (58%)/6 (67%) with tMN (5 or 5q deletion [del]: 4/1 ; 7 or 7q del: 6/1 ; complex [≥ 3 clonal abnormalities]: 10/4), and 19 (32%)/13 (50%) with A-MDS/MPN (5 or 5q del: 10/5; 7 or 7q del: 6/1; complex: 14/9). TP53 mutation was observed in 5/3 pts with tMN and 8/0 pts with A-MDS/MPN. Pts with tMN received a median (Ven+Aza/Pbo+Aza) of 5/4 cycles of treatment. CRc was achieved by 19 (61%)/1 (11%). The mDoR was not reached (NR) (95% CI: 17.8, NR)/8.5 (NR, NR) months. The mOS was 16.4 (95% CI: 4.1, NR)/11.3 (0.6, 17.5) months. Pts with A-MDS/MPN received a median (Ven+Aza/Pbo+Aza) of 9/5 cycles of treatment. CRc was achieved by 39 (66%)/7 (27%) pts with mDoR of 17.3 (95% CI: 9.6, NR)/5.8 (1.1, NR) mos. The mOS was 15.9 (95% CI: 11.5, NR)/10.1 (4.7, 14.5) mos. Common grade≥3 adverse events (Ven+Aza/Pbo+Aza) were febrile neutropenia (tMN: 39%/11% and A-MDS/MPN: 36%/12%) neutropenia (tMN: 29%/33%; A-MDS/MPN: 39%31%), and thrombocytopenia (tMN: 32%/33%; A-MDS/MPN: 39%/62%). Conclusions: Ven+Aza compared to Aza monotherapy resulted in higher CRc rates with longer DoR and median OS among treatment-naïve pts with tMN and A-MDS/MPN ineligible for intensive chemotherapy. The safety profile was similar to overall pts with the Ven+Aza combination. Outcomes by cytogenetic and molecular risk-groups will be presented. Clinical trial information: NCT02993523, NCT02203773.

Differences in the Expression of KIR, ILT Inhibitory Receptors, and VEGF Production in the Induced Decidual NK Cell Cultures of Fertile and RPL Women.

Results KIR2DL1 and ILT-2 expression on idNK cells was higher in healthy women than in RPL patients. Sildenafil enhanced NKG2A expression in RPL patients. VEGF concentration was higher in fertile woman idNK cell cultures. idNK cells were more sensitive for necrosis in RPL than in fertile women. SC did not influence VEGF production or idNK cell apoptosis. Conclusions A combination of hypoxia, IL-15, and AZA promotes the conversion of pbNK into idNK cells CD56+CD16−-expressing KIR receptors and produces VEGF. Alterations in KIR2DL1 and ILT-2 expression as well as impaired VEGF production were associated with RPL. SC affects NKG2A expression on RPL idNK cells. SC had no effect on VEGF release or idNK cell apoptosis.

Synthesis and biological activity of aza and deaza analogues of purine nucleosides

Analogues and derivatives of nucleic acid components have been used as key drugs in different areas of medicine over the past decades. The replacement of one or more nitrogen atoms of the heterocyclic base with a CH group affords deazapurine nucleoside analogues, and the replacement of the methine group with a nitrogen atom gives azapurine derivatives. A combination of aza and deaza moieties in the purine base leads to aza(deaza)-modified bases. Some nucleoside analogues were found to exhibit pronounced anticancer and antiviral activity. The synthesis and evaluation of biological activity of aza- and deazapurine nucleoside analogues have attracted interest from researchers four decades ago. This review describes and integrates the studies concerning certain aspects of the synthesis and(or) activity of various representatives of this class of compounds. The structure–biological activity relationships are analyzed. The successful approaches to the design of aza- and deazapurine nucleoside analogues are considered. A comparison is given for the methods of chemical and enzymatic synthesis of these compounds.The bibliography includes 161 references.