Combination Of Venetoclax Research Articles

Combining the novel FLT3 and MERTK dual inhibitor MRX-2843 with venetoclax results in promising antileukemic activity against FLT3-ITD AML

FMS-like tyrosine kinase 3 (FLT3) mutations occur in approximately one third of acute myeloid leukemia (AML) patients. FLT3-Internal tandem duplication (FLT3-ITD) mutations are the most common FLT3 mutations and are associated with a poor prognosis. Gilteritinib is a FLT3 inhibitor that is US FDA approved for treating adult patients with relapsed/refractory AML and a FLT3 mutation. While gilteritinib monotherapy has improved patient outcome, few patients achieve durable responses. Combining gilteritinib with venetoclax (VEN) appears to make further improvements, though early results suggest that patients with prior exposure to VEN fair much worse than those without prior exposure. MRX-2843 is a promising inhibitor of FLT3 and MERTK. We recently demonstrated that MRX-2843 is equally potent as gilteritinib in FLT3-ITD AML cell lines in vitro and primary patient samples ex vivo. In this study, we investigated the combination of VEN and MRX-2843 against FLT3-ITD AML cells. We found that VEN synergistically enhances cell death induced by MRX-2843 in FLT3-mutated AML cell lines and primary patient samples. Importantly, we found that VEN synergistically enhances cell death induced by MRX-2843 in FLT3-ITD AML cells with acquired resistance to cytarabine (AraC) or VEN+AraC. VEN and MRX-2843 significantly reduce colony-forming capacity of FLT3-ITD primary AML cells. Mechanistic studies show that MRX-2843 decreases Mcl-1 and c-Myc protein levels via transcriptional regulation and combined MRX-2843 and VEN significantly decreases oxidative phosphorylation in FLT3-ITD AML cells. Our findings highlight a promising combination therapy against FLT3-ITD AML, supporting further in vitro and in vivo testing.

Discovery of a Covalent Inhibitor That Overcame Resistance to Venetoclax in AML Cells Overexpressing BFL-1.

Clinical and biological studies have shown that overexpression of BFL-1 is one contributing factor to venetoclax resistance. The resistance might be overcome by a potent BFL-1 inhibitor, but such an inhibitor is rare. In this study, we show that 56, featuring an acrylamide moiety, inhibited the BFL-1/BID interaction with a Ki value of 105 nM. More interestingly, 56 formed an irreversible conjugation adduct at the C55 residue of BFL-1. 56 was a selective BFL-1 inhibitor, and its MCL-1 binding affinity was 10-fold weaker, while it did not bind BCL-2 and BCL-xL. Mechanistic studies showed that 56 overcame venetoclax resistance in isogenic AML cell lines MOLM-13-OE and MV4-11-OE, which both overexpressed BFL-1. More importantly, 56 and venetoclax combination promoted stronger apoptosis induction than either single agent. Collectively, our data show that 56 overcame resistance to venetoclax in AML cells overexpressing BFL-1. These attributes make 56 a promising candidate for future optimization.

HGG-41. COMBINATORIAL BH3-MIMETIC STRATEGY FOR OVERCOMING RADIORESISTANCE IN PEDIATRIC HIGH-GRADE GLIOMA

Abstract BACKGROUND High-grade gliomas (HGGs) are a leading cause of cancer-associated death in children. Radiation therapy (RT) continues to be the only standard-of-care treatment across HGG subtypes, but disease frequently recurs following only a transient response. We have recently identified that HGGs utilize the pro-survival BCL-2 family of proteins to evade cell death after radiation, and we demonstrated that effective inhibition of BCL-2 with the CNS-penetrant drug venetoclax could be utilized to disrupt this resistance and augment radiation-induced cell killing. While this treatment significantly prolonged survival in orthotopic mouse models of pediatric HGG, tumors invariably developed resistance to single-agent venetoclax and recurred. METHODS We profiled tumors from venetoclax-resistant animals for alternate BCL-2 family binding. We then assessed susceptibility to MCL1 inhibition in venetoclax-treated or treatment naïve culture models. Synergy was tested in vitro, and mitochondrial ROS production and induction of apoptosis was assessed using the MCL1-specific agent S63845. Finally, venetoclax and S63845 were tested in combination following fractionated radiotherapy in orthotopic models of DIPG. RESULTS MCL1 is an acquired dependency following treatment with RT + venetoclax. S63845 synergizes with venetoclax following RT to drive mitochondrial ROS production and apoptosis. The combination of venetoclax and S63845 significantly prolongs survival in xenograft models of DIPG. CONCLUSIONS Combinatorial targeting with BH3 mimetics augments radiation-induced cell killing and may open new therapeutic avenues for pediatric HGG.

CELESTIAL-TNCLL: An ongoing, open-label, multiregional, phase 3 study of sonrotoclax (BGB-11417) + zanubrutinib vs venetoclax + obinutuzumab for treatment-naïve (TN) CLL.

TPS7087 Background: The combination of venetoclax (ven), the first-generation BCL2 inhibitor, and ibrutinib, a BTK inhibitor, has demonstrated efficacy in patients with CLL (Wierda et al. J Clin Oncol. 2021); however, the toxicity profile of this regimen suggests a need for a more tolerable BTK/BCL2 inhibitor combination. Sonrotoclax, a next generation BCL2 inhibitor, is a more selective and more pharmacologically potent inhibitor of BCL2 than venetoclax. In a phase 1 study in patients with TN CLL treated with sonrotoclax + zanubrutinib, efficacy data was promising with ORR and 1-year progression-free survival (PFS) rates of 100% and deep responses based on undetectable measurable residual disease at <10-4 sensitivity (uMRD4). The most common grade ≥3 TEAE was neutropenia, and no tumor lysis syndrome or cardiac toxicity was observed (Tam et al. Blood. 2023). Zanubrutinib, a next-generation BTK inhibitor, significantly improved PFS and had a more tolerable safety profile, including fewer cardiac adverse events vs ibrutinib in a randomized, head-to-head study of patients with CLL/SLL (Brown et al. N Engl J Med. 2023). Presented here is the design of a phase 3 trial aimed at comparing the efficacy of sonrotoclax + zanubrutinib vs ven + obinutuzumab (obi) in patients with TN CLL. Methods: CELESTIAL-TNCLL (BGB-11417-301; NCT06073821) is a randomized, open-label, phase 3 study. Eligible patients must have previously untreated CLL that requires treatment per 2018 iwCLL criteria, measurable disease by CT/MRI, an ECOG performance score of 0-2, and adequate hematologic and organ function. Approximately 640 patients will be randomized 1:1 to receive either 3 cycles of zanubrutinib monotherapy (320 mg total daily dose, orally), followed by zanubrutinib + sonrotoclax for 12 cycles, or standard ven + obi treatment for 12 cycles. Randomization will be stratified by age (<65 vs ≥65 years) and IGHV and del(17p)/ TP53 mutation status. The primary endpoint is PFS as assessed by independent review committee (IRC) according to 2018 iwCLL guidelines with modifications for treatment-related lymphocytosis for patients with CLL (Cheson et al. 2012). Key secondary endpoints include complete response rate (CRR), defined as CR or CR with incomplete hematopoietic recovery, assessed by IRC; rates of uMRD4 in bone marrow and peripheral blood at the first post-treatment follow-up visit based on next-generation sequencing by clonoSEQ; and overall survival. Other secondary endpoints include PFS as assessed by investigator (INV); CRR by INV; rate of uMRD4 based on flow cytometry; overall response rate by IRC and INV; duration of response by IRC and INV; patient-reported outcomes; and safety and tolerability. Recruitment is ongoing. Clinical trial information: NCT06073821 .

Association of Fried’s frailty phenotype, but not the clinical frailty scale, with overall survival in older adults with acute myeloid leukemia.

e23222 Background: Frailty is a geriatric syndrome marked by increased vulnerability to stressors. “Fitness,” is utilized to guide treatment in acute myeloid leukemia (AML) where the intensity of initial induction may be high (anthracycline and cytarabine-based), intermediate (venetoclax combinations), or low (single hypomethylating agent or targeting therapy). Fried’s Frailty Phenotype (FP) combines subjective (self-reported exhaustion, weight loss > 5%, activity level) and objective (4-meter walk speed and grip strength) measures to categorize patients into fit, pre-frail, and frail. In prior work, we demonstrated an association of FP with survival for newly diagnosed older adults with AML. Clinical Frailty Scale (CFS) is a purely subjective score that utilizes chart data to stratify the degree of fitness. The incorporation of objective measures into clinical practice is limited due to time constraints, we sought to determine if CFS could similarly identify frailty and risk-stratify older adults with AML. Methods: Eighty-three patients 60 years or older with a new diagnosis of AML were enrolled on an IRB approved study from September, 2018 to May, 2023 at the Hospital of the University of Pennsylvania. FP was performed prior to initiation of therapy. A CFS certified trainee blinded to FP scores retrospectively reviewed electronic medical records to assign a CFS score. CFS was collapsed into variations defined as CFS fit (1-3), pre-frail (4), and frail (5 or greater); CFS Collapse 1 fit (1-2), pre-frail (3-4), and frail (5 or greater), and CFS Collapse 2 fit (1-4) and mild to moderately frail (5-6). Variations were based on the scale’s descriptions and literature. Results: Median patient age was 71 (range 60-91) years. By European LeukemiaNet 2017, 64% of patients had adverse-risk AML. 39% of patients received IC, 52% received HMA/ven, 6% received HMA alone or targeted therapy, and 2% received supportive care. By FP, 18% were fit, 38% were pre-frail, and 45% were frail. FP was significantly associated with OS (p = 0.047): 2-year OS was 57%, 42%, and 21% in fit, pre-frail, and frail. By CFS, 43% were fit, 32% pre-frail, and 24% frail. CSF was not significantly associated with OS (p = 0.495); 2-year OS was 24%, 35%, and 19% for fit, pre-frail, and frail patients, respectively. CSF collapse 1 (p = 0.249) and 2 (p = 0.070) were not significant. Conclusions: FP identified more patients as frail and was associated with a doubling of early mortality and inferior 2-year OS. CFS identified more patients as fit and was not associated with 2-yr OS. The discrepancy emphasizes the importance of objective measurements to capture frailty and the difficulty in determining frailty based on chart reviews in an acutely ill population. Future work to streamline objective measurements in frailty assessments to increase utilization in clinics given its likely importance for accurate risk-stratification.

Interim safety and efficacy of BP1001 in a phase II acute myeloid leukemia (AML) study.

6511 Background: Oncogenic tyrosine kinases induce AML progression via the growth factor receptor bound protein-2 (Grb2). BP1001, a liposome-incorporated Grb2 antisense oligonucleotide,enhanced cancer cell sensitivity to chemotherapy, such as decitabine (DEC) and venetoclax (VEN). A multi-center open-label Phase II study was initiated to assess whether the BP1001 + DEC + VEN combination provides higher response rates than historically reported responses of DEC + VEN in newly diagnosed AML (including secondary AML) (cohort 1) or refractory/relapsed (R/R; cohort 2) AML patients (pts) considered unsuitable for intensive chemotherapy. Per protocol, when 19 evaluable pts are enrolled in each cohort, interim analysis will be performed to determine which cohort has ≥5 complete responses and will continue with enrollment. Methods: BP1001 was given, beginning on Day 4, at 60 mg/m2 IV, 2x weekly for a total of 8 doses over a 28-day cycle. DEC was given IV on days 1 to 5 at 20 mg/m2. VEN was given PO at 100 mg on day 1, 200 mg on day 2, and 400 mg from day 3 to day 14 or 21. Eligible pts were considered unsuitable for or refused intensive chemotherapy and had ECOG performance status of 0-2. Interim analysis was performed on Jan 24, 2024 on pts enrolled between July 28, 2020 and December 26, 2023. Evaluability for efficacy was defined as: completion of at least 4 cycles of combination therapy, documented Progressive Disease (PD) or any drug toxicity at any time, or CR/CRi/CRh prior to 4 cycles. Results: In Cohort 1, 31 newly diagnosed pts were enrolled; 20 evaluable pts (9 male: 45%) with a median age of 75 years (range, 69 - 84), treated with at least 1 cycle of BP1001 + DEC + VEN, had adverse-risk (n=12, ELN 2017 classification) or secondary AML (sAML; n=7) evolved from MDS (n=4), CMML (n=1) or treatment-related AML (n=2). Fifteen pts (75% of evaluable; 54% of enrolled) achieved CR/CRi/CRh; 2 pts achieved partial remission (PR) and 2 achieved stable disease (SD). In Cohort 2, 38 R/R pts were enrolled; 23 evaluable pts (13 male: 57%) with a median age of 63 years (range, 24 - 89), treated with at least 1 cycle of BP1001 + DEC + VEN, had adverse-risk (n=13) or sAML (n=5). Twelve pts (55% of evaluable; 32% of enrolled) achieved CR/CRi/CRh; 1 pt achieved PR, 8 achieved SD and 1 had treatment failure. Among the evaluable pts of both cohorts, adverse events were consistent with those expected with DEC, VEN and/or AML, including fatigue (72%), anemia (60%) and neutropenia (49%), while the most frequent serious adverse events were febrile neutropenia (26%) and sepsis (5%). Conclusions: BP1001 + DEC + VEN has been safely administered to pts without drug-related toxicity. Since >5 responses are observed in both cohorts, the study will continue with enrollment up to 98 and 54 evaluable pts in cohorts 1 and 2, respectively. Efficacy data are encouraging in a challenging population of frontline adverse-risk, sAML and R/R pts. Clinical trial information: NCT02781883 .

Synergistic effects of RPT1G, a first-in-class small molecule NAMPT inhibitor, with venetoclax and olaparib in hematological malignancies.

e18512 Background: MultipleBCL-2 and PARP inhibitors are currently in clinical trials, or have been approved for use, in hematological malignancies and solid tumors. Venetoclax, an inhibitor of the apoptosis regulator B-cell lymphoma-2 (BCL-2), has activity in patients with chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML). PARP inhibitors, such as Olaparib, exploit synthetic lethality in homologous recombination-deficient tumors, notably in breast and ovarian cancers. However, patients treated with BCL-2 or PARP inhibitors often face relapse and refractory disease, requiring alternative strategies to counter adaptive responses. Nicotinamide Phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway, is upregulated in malignancies and plays a key role in cancer metabolism (e.g., Warburg effect). NAMPT makes nicotinamide mononucleotide which is then converted to NAD+, while PARP enzymes consume NAD+, placing NAMPT directly upstream of PARP. NAMPT overexpression is associated with Venetoclax resistance in leukemia patients, highlighting the link between NAD+, mitochondrial metabolism, and BCL-2 inhibition. Consequently, NAMPT inhibition may synergize with BCL-2 or PARP inhibitors, potentially enhancing 1st-line of treatment outcomes and re-sensitizing refractory cancer cells to BCL-2 or PARP inhibition. Methods: In this study, we investigated the combination effects of Venetoclax and Olaparib with RPT1G, a novel hyperbolic NAMPT inhibitor that simultaneously inhibits and stabilizes NAMPT in a catalytically active state. RPT1G disrupts NAMPT activity without ever turning it off completely avoiding the severe on-target toxicities seen with complete NAMPT inhibitors. Several cell lines, including OCI-AML3 and MV4;11 (AML), RS4;11 (ALL), and RL (diffuse large B-cell lymphoma) were treated with RPT1G and either Venetoclax or Olaparib to determine the degree of drug interactions. In a follow up in vivo study, we treated mice in a human xenograft model using semi-resistant MV4;11 cells with RPT1G alone or in combination with Venetoclax to measure the ability of RPT1G to enhance the effects of Venetoclax. Results: RPT1G achieves significant single-agent efficacy in leukemia and lymphoma mouse xenograft models. When RTP1G is used in combination with either Venetoclax or Olaparib significant synergy is seen across a broad range of concentrations in vitro. Consistent with in vitro synergy results, in a xenograft model of human AML, mice treated with a combination of RPT1G and Venetoclax show enhanced efficacy as compared to Venetoclax alone. Conclusions: Combination of RPT1G with either Venetoclax or Olaparib synergistically enhances killing of leukemic cells and presents as an effective strategy to improve treatment outcomes for patients with diverse malignancies.

Pharmacodynamics of venetoclax plus cirtuvivint a first-in-class splice variant regulator.

e15093 Background: NSC835563 (SM08502, cirtuvivint) is a first-in-class pan CDC-like kinase (CLK) and dual specificity tyrosine kinase (DYRK) inhibitor that targets alternative splicing of genes in multiple pathways and modifies their protein expression. Preclinical screening of hematologic malignancy models has shown sensitivity to cirtuvivint, leading to proposed clinical trials in AML in combinations with venetoclax. We performed pharmacodynamic studies to identify probable mechanisms of combination activity in AML models. Methods: In vivo tolerability, efficacy and pharmacodynamic (PD) studies were performed in two AML xenograft models, MV411 and KG1a in NSG mice, at 6.25-25 mg/kg PO cirtuvivint and 25 mg/kg PO venetoclax. Body weights (BW) and tumor volumes were recorded periodically to assess toxicity and anti-tumor efficacy. Tumor tissue samples were collected at 6 and 24 h post venetoclax to assess PD response. Multiplexed analysis of apoptosis pathway proteins/protein-protein complexes was performed by clinically validated assays (PMID 26446940). Results: Cirtuvivint alone at high doses (25 mg/kg) caused tumor regressions in MV411 but only a modest tumor growth inhibition (TGI) in KG1a, a resistant AM model. Importantly, the lowest dose of 6.25 mg/kg cirtuvivint combined with 25 mg/kg venetoclax led to tumor regression in the MV411 model and a moderate TGI in KG1a. Cirtuvivint alone caused a transient 25% reduction (p<0.05) in Mcl-1 levels at 6 h post dose in MV411. The venetoclax combination triggered a sustained (for 24 h) 50-75% disruption of Bcl-2 and Mcl-1 complexes with Bax and Bim, resulting in >20-fold increased mitochondrial Bax/Bak heterodimer and >10-fold increased cytosolic cleaved caspase-3. In KG1a, combination treatment resulted in only modest (<20%) changes in biomarkers. Overall, biomarkers provided evidence of the combination MoA. Conclusions: Venetoclax and cirtuvivint in combination effectively induced tumor regressions at low tolerable doses in an AML model. Mitochondrial Bax/Bak heterodimer provided a sensitive biomarker of combination activity. Cirtuvivint contributed its combinatorial effect primarily through disruption of Bim complexes and inhibition of Mcl-1. PD biomarkers identified in this study can confirm MoA of drug combination in ongoing clinical trials.

First-line venetoclax combinations versus chemoimmunotherapy in fit patients with chronic lymphocytic leukaemia (GAIA/CLL13): 4-year follow-up from a multicentre, open-label, randomised, phase 3 trial

First-line venetoclax combinations versus chemoimmunotherapy in fit patients with chronic lymphocytic leukaemia (GAIA/CLL13): 4-year follow-up from a multicentre, open-label, randomised, phase 3 trial

Monitoring Response and Resistance to Treatment in Chronic Lymphocytic Leukemia.

The recent evolution in chronic lymphocytic leukemia (CLL) targeted therapies led to a progressive change in the way clinicians manage the goals of treatment and evaluate the response to treatment in respect to the paradigm of the chemoimmunotherapy era. Continuous therapies with BTK inhibitors achieve prolonged and sustained control of the disease. On the other hand, venetoclax and anti-CD20 monoclonal antibodies or, more recently, ibrutinib plus venetoclax combinations, given for a fixed duration, achieve undetectable measurable residual disease (uMRD) in the vast majority of patients. On these grounds, a time-limited MRD-driven strategy, a previously unexplored scenario in CLL, is being attempted. On the other side of the spectrum, novel genetic and non-genetic mechanisms of resistance to targeted treatments are emerging. Here we review the response assessment criteria, the evolution and clinical application of MRD analysis and the mechanisms of resistance according to the novel treatment strategies within clinical trials. The extent to which this novel evidence will translate in the real-life management of CLL patients remains an open issue to be addressed.

Anlotinib synergizes with venetoclax to induce mitotic catastrophe in acute myeloid leukemia

Venetoclax is a BCL2-targeted drug employed in treating various cancers, particularly hematologic malignancies. Venetoclax combination therapies are increasingly recognized as promising treatment strategies for acute myeloid leukemia (AML). In this study, we conducted an unbiased drug screen and identified anlotinib, a promising multi-targeted receptor tyrosine kinase inhibitor with oral activity currently utilized in the treatment of solid tumor, as a potent enhancer of venetoclax's anticancer activity in AML. Our investigation encompassed AML cell lines, primary cells, and mouse models, demonstrating effective low-dose combination therapy of anlotinib and venetoclax with minimal cytopenia or organ damage. Proteomic analysis revealed abnormal mitotic signals induced by this combination in AML cells. Mechanistically, anlotinib synergized with venetoclax by suppressing ARPP19 protein, leading to sustained activation of PP2A-B55δ. This inhibited AML cells from entering the mitotic phase, culminating in mitotic catastrophe and apoptosis. Additionally, we identified a specific synthetic lethal vulnerability in AML involving an ARPP19 mutation at S62 phosphorylation. These findings underscore the therapeutic potential of anlotinib and venetoclax combination therapy in AML, warranting further clinical investigation.

The efficacy of the combination of venetoclax and hypomethylating agents versus HAG agents in patients with acute myeloid leukemia: a retrospective study

ABSTRACT Objectives: The purpose of this study was to compare the effectiveness of the combination of venetoclax and hypomethylating agents with the HAG regimen. Methods: We studied 52 cases of newly diagnosed AML and 26 cases of relapsed refractory AML, (including AML patients with treatment-related and ELN-adverse risk disease (n = 50)). These patients were treated with venetoclax and hypomethylating agents and HAG regimens, respectively. Results: Twenty-nine patients newly diagnosed with acute myeloid leukemia were treated with VEN-HMA (venetoclax-hypomethylating agent), while 23 patients were treated with HAG. The median age of the VEN-HMA group was 70 years, while the HAG group had a median age of 69 years. The VEN-HMA group achieved a significantly higher rate of complete remission (82.7%) compared to the cohort treated with the HAG regimen (21.7%) (P < 0.001). At the same time, the VEN-HMA group exhibited a significant survival advantage compared to the HAG treatment group(HR = 0.328, 95%CI: 0.158-0.683, P = 0.003). In patients with relapsed and refractory acute myeloid leukaemia, 43.8% of patients in the VEN-HMA treatment group achieved complete remission, which was similar to the 50% in the HAG treatment group (P > 0.99). The median overall survival was similar between the VEN-HMA and HAG groups, with 4 and 3.67 months, respectively (P = 0.290). Conclusions: In conclusion, our analyses indicated that VEN-HMA resulted in better therapeutic outcomes compared to HAG for newly diagnosed AML patients, with higher rates of complete remission and overall survival. In relapsed/refractory AML patients, there was no significant difference in the efficacy of the two treatments and further studies with larger sample sizes are warranted.

Ex vivo characterization of acute myeloid leukemia patients undergoing hypomethylating agents and venetoclax regimen reveals a venetoclax-specific effect on non-suppressive regulatory T cells and bona fide PD-1+TIM3+ exhausted CD8+ T cells.

Acute myeloid leukemia (AML) is an aggressive heterogeneous disease characterized by several alterations of the immune system prompting disease progression and treatment response. The therapies available for AML can affect lymphocyte function, limiting the efficacy of immunotherapy while hindering leukemia-specific immune reactions. Recently, the treatment based on Venetoclax (VEN), a specific B-cell lymphoma 2 (BCL-2) inhibitor, in combination with hypomethylating agents (HMAs) or low-dose cytarabine, has emerged as a promising clinical strategy in AML. To better understand the immunological effect of VEN treatment, we characterized the phenotype and immune checkpoint (IC) receptors' expression on CD4+ and CD8+ T cells from AML patients after the first and second cycle of HMA in combination with VEN. HMA and VEN treatment significantly increased the percentage of naïve CD8+ T cells and TIM-3+ CD4+ and CD8+ T cells and reduced cytokine-secreting non-suppressive T regulatory cells (Tregs). Of note, a comparison between AML patients treated with HMA only and HMA in combination with VEN revealed the specific contribution of VEN in modulating the immune cell repertoire. Indeed, the reduction of cytokine-secreting non-suppressive Tregs, the increased TIM-3 expression on CD8+ T cells, and the reduced co-expression of PD-1 and TIM-3 on both CD4+ and CD8+ T cells are all VEN-specific. Collectively, our study shed light on immune modulation induced by VEN treatment, providing the rationale for a novel therapeutic combination of VEN and IC inhibitors in AML patients.

FLT3-selective PROTAC: Enhanced safety and increased synergy with Venetoclax in FLT3-ITD mutated acute myeloid leukemia

Acute myeloid leukemia (AML) patients carrying Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations often face a poor prognosis. While some FLT3 inhibitors have been used clinically, challenges such as short efficacy and poor specificity persist. Proteolytic targeting chimera (PROTAC), with its lower ligand affinity requirement for target proteins, offers higher and rapid targeting capability. Gilteritinib, used as the ligand for the target protein, was connected with different E3 ligase ligands to synthesize several series of PROTAC targeting FLT3-ITD. Through screening and structural optimization, the optimal lead compound PROTAC Z29 showed better specificity than Gilteritinib. Z29 induced FLT3 degradation through the proteasome pathway and inhibited tumor growth in subcutaneous xenograft mice. We verified Z29's minimal impact on platelets in a patient-derived xenografts (PDX) model compared to Gilteritinib. The combination of Z29 and Venetoclax showed better anti-tumor effects, lower platelet toxicity, and lower hepatic toxicity in FLT3-ITD+ models. The FLT3-selective PROTAC can mitigate the platelet toxicity of small molecule inhibitors, ensuring safety and efficacy in monotherapy and combination therapy with Venetoclax. It is a promising strategy for FLT3-ITD+ patients, especially those with platelet deficiency or liver damage.

Efficacy of Venetoclax and Azacitidine in Acute Myeloid Leukemia Compared to Azacitidine Monotherapy: Real-World Experience.

The combination of venetoclax (VEN) and azacitidine (AZA) (VEN+AZA) leads to higher complete remission rates and longer overall survival (OS) in patients with untreated acute myeloid leukemia (AML) who are ineligible for intensive combination chemotherapy. In practice, the doses of VEN and AZA are reduced at the attending physician's discretion to avoid adverse events; however, the impact of dose and duration reductions has not been fully clarified. We analyzed whether the efficacy was maintained with reduced VEN+AZA compared to AZA monotherapy in the real world. A total of 33 patients were included; 17 (10 newly diagnosed, 7 primary refractory or relapsed) received VEN+AZA, and 16 (7 newly diagnosed, 9 primary refractory or relapsed) received AZA. We analyzed complete remission (CR) and CR with incomplete hematologic recovery (CRi) rates, OS, and the incidence of adverse events. CR/CRi were achieved in 7/17 (41.2%) and 11/17 (64.7%) patients in the VEN+AZA group and 0/15 (0%) and 2/15 (6.7%) patients in the AZA group, respectively. The CR/CRi rate was higher in the VEN+AZA group than in the AZA group (p=0.001). OS was longer in the VEN+AZA group than in the AZA group (p=0.03), with a median of 506 days [95% confidence interval (CI)=234-585 days] and 208 days (95% CI=52-343 days), respectively. The doses of the VEN+AZA combination were reduced at the attending physician's discretion, resulting in a higher CR/CRi rate and longer OS than AZA monotherapy and is considered useful for AML in the real world.

Combination of venetoclax and azacitidine in relapsed/refractory acute B-cell lymphoblastic leukemia: a case series from a single center

ABSTRACT Objectives Relapsed/refractory acute B-cell lymphoblastic leukemia (R/R B-ALL) often responds poorly to induction chemotherapy. However, recent research has shown a novel and effective drug treatment for R/R B-ALL. Methods A total of eight patients with R/R B-ALL were enrolled in the study from November 2021 to August 2022. All patients received chemotherapy based on a combination regimen of venetoclax and azacitidine. The regimen was as follows venetoclax 100 mg d1, 200 mg d2, 400 mg d3–14, azacitidine 75 mg/m2 d1–7. Results Five of eight patients achieved very deep and complete remission (CR) with minimal residual disease (MRD) less than 0.1%. One patient achieved partial remission. Two patients did not achieve remission. There were no serious adverse events and all patients were well tolerated. Three patients were eligible for consolidation chemotherapy and were bridged to CAR-T therapy. Conclusions The combined regimen of venetoclax and azacitidine may be beneficial for patients with R/R B-ALL.

Fix low dose venetoclax-azacitidine treatment of unfit acute myeloid leukemia patients.

The prognosis of elderly AML patients had not even been improved by using hypomethylating agents; however, synergistic effect of combining azacitidin with venetoclax had resulted in a remarkable therapeutic advance. Our goal was to study the latter treatment with a new dosing regimen in a retrospective/observational study. In our department, we analyzed the data of AML patients who were unfit for curative high-dose treatment and accepted the medication with a fixed-dose of azacitidin and venetoclax combination (AZA-VEN, 100 mg sc for 7 days-100 mg per os continuously). The primary end point was the overall survival. In total, 55 AML patients received the treatment between OCT/2019-DEC/2022. Mean age was 69.4-year (48-84), median overall survival was 17.2-month (95% CI, 14.3-20.10) Composite CR: (CR + CRi) 62%. Side effect CTCAE 3 or higher: neutropenia with fever: 36.4%, anemia: 29.1%, thrombocytopenia: 16.4% and nausea 20%. AZA-VEN combination treatment of our unfit AML patients was found to be a good therapeutic option. The results achieved with significantly lower doses of the fixed dose of AZA-VEN are comparable to the conclusions of the VIALE-A study, and the less severe side effects we have observed are explained by the milder neutropenia of the newly introduced regimen.

Acalabrutinib, venetoclax, and obinutuzumab in relapsed/refractory CLL: final efficacy and ctDNA analysis of the CLL2-BAAG trial

AbstractThe phase 2 CLL2-BAAG trial tested the measurable residual disease (MRD)–guided triple combination of acalabrutinib, venetoclax, and obinutuzumab after optional bendamustine debulking in 45 patients with relapsed/refractory chronic lymphocytic leukemia (CLL). MRD was measured by flow cytometry (FCM; undetectable MRD <10–4) in peripheral blood (PB) and circulating tumor DNA (ctDNA) using digital droplet polymerase chain reaction of variable-diversity-joining (VDJ) rearrangements and CLL-related mutations in plasma. The median number of previous treatments was 1 (range, 1-4); 18 patients (40%) had received a Bruton tyrosine kinase inhibitor (BTKi) and/or venetoclax before inclusion, 14 of 44 (31.8%) had TP53 aberrations, and 34 (75.6%) had unmutated immunoglobulin heavy-chain variable region genes. With a median observation time of 36.3 months and all patients off-treatment for a median of 21.9 months, uMRD <10–4 in PB was achieved in 42 of the 45 patients (93.3%) at any time point, including 17 of 18 (94.4%) previously exposed to venetoclax/BTKi and 13 of 14 (92.9%) with TP53 aberrations. The estimated 3-year progression-free and overall survival rates were 85.0% and 93.8%, respectively. Overall, 585 paired FCM/ctDNA samples were analyzed and 18 MRD recurrences (5 with and 13 without clinical progression) occurred after the end of treatment. Twelve samples were first detected by ctDNA, 3 by FCM, and 3 synchronously. In conclusion, time-limited MRD-guided acalabrutinib, venetoclax, and obinutuzumab achieved deep remissions in almost all patients with relapsed/refractory CLL. The addition of ctDNA-based analyses to FCM MRD assessment seems to improve early detection of relapses. This trial was registered at www.clinicaltrials.gov as #NCT03787264.

Combination of dasatinib and venetoclax in newly diagnosed chronic phase chronic myeloid leukemia.

The dual inhibition of the BCR::ABL1 tyrosine kinase and BCL-2 could potentially deepen the response rates of chronic myeloid leukemia in chronic phase (CML-CP). This study evaluated the safety and efficacy of the combination of dasatinib and venetoclax. In this phase 2 trial, patients with CML-CP or accelerated phase (clonal evolution) received dasatinib 50 mg/day for three courses; venetoclax was added in course 4 for 3 years. The initial venetoclax dose was 200 mg/day continuously but reduced later to 200 mg/day for 14 days, and to 100 mg/day for 7 days per course once a molecular response (MR)4.5 was achieved. After 3 years of combination, patients were maintained on single-agent dasatinib. The primary end point was the rate of major molecular response (MMR) by 12 months of combination. Sixty-five patients were treated. Their median age was 46 years (range, 23-73). By 12 months of combination, the MMR, MR4, and MR4.5 rates were 86%, 53%, and 45%, respectively. After a median follow-up of 42 months, the 4-year event-free and overall survival rates were 96% and 100%, respectively. Outcomes with the combination were comparable to historical outcomes with single-agent dasatinib (cumulative 12-months MMR rate of 79% with both strategies). The incidence of grade 3-4 neutropenia was 22% with the combination and 11% with single-agent dasatinib (p<.001). Treatment with dasatinib and venetoclax was safe and effective in CML-CP. The cumulative response rates with the combination were similar to those with single-agent dasatinib. Further follow-up is needed to evaluate the rates of durable deep molecular response and treatment-free remission.

A phase I study of pevonedistat, azacitidine, and venetoclax in patients with relapsed/refractory acute myeloid leukemia.

Azacitidine/venetoclax is an active regimen in patients with newly diagnosed acute myeloid leukemia (AML). However, primary or secondary resistance to azacitidine/venetoclax is an area of unmet need and overexpression of MCL1 is suggested to be a potential resistance mechanism. Pevonedistat inhibits MCL1 through activation of NOXA, and pevonedistat/azacitidine has previously shown activity in AML. To assess the tolerability and efficacy of adding pevonedistat to azacitidine/ venetoclax in relapsed/refractory AML, we conducted a phase I, multicenter, open-label study in 16 adults with relapsed/ refractory AML. Patients were treated with azacitidine, venetoclax along with pevonedistat intravenously on days 1, 3 and 5 of each 28-day cycle at doses of 10, 15 or 20 mg/m2 in successive cohorts in the dose escalation phase. The impact of treatment on protein neddylation as well as expression of pro-apoptotic BCL2 family members was assessed. The recommended phase II dose of pevonedistat was 20 mg/m2. Grade 3 or higher adverse events included neutropenia (31%), thrombocytopenia (13%), febrile neutropenia (19%), anemia (19%), hypertension (19%) and sepsis (19%). The overall response rate was 46.7% for the whole cohort including complete remission in five of seven (71.4%) patients who had not previously been treated with the hypomethylating agent/venetoclax. No measurable residual disease was detected in 80.0% of the patients who achieved complete remission. The median time to best response was 50 (range, 23-77) days. Four patients were bridged to allogeneic stem cell transplantation. The combination of azacitidine, venetoclax and pevonedistat is safe and shows encouraging preliminary activity in patients with relapsed/refractory AML. (NCT04172844).