Genetic characteristics predict response to venetoclax plus hypomethylating agents in relapsed or refractory acute myeloid leukemia

Treatment of minimal residual disease in myeloid malignancies after allo-HSCT with venetoclax-based regimens in patients ineligible for or failed in the immunotherapy

BACKGROUND

Relapse was the major cause of treatment failure in patients with myeloid malignancies after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients who still suffer from the disease while cannot be detected by morphological analysis can be identified by the minimal residual disease (MRD) monitoring. The most used first-line regimens for MRD are immunotherapies. However, for patients who were ineligible for or failed in first-line immunotherapies, options were limited.

METHODS

A total of 20 patients with myeloid malignancies with recurrent MRD after allo-HSCT were included in this study. The safety and efficacy of venetoclax-based regimens were analyzed.

RESULTS

There were 13 patients (65%) treated with venetoclax combined with hypomethylating agents concomitantly and seven patients (35%) treated with venetoclax monotherapy. After venetoclax-based regimens, MRD was eliminated in 11 patients (55%) with 6 subsequently developing recurrent MRD and 5 remaining in molecular remission. MRD declined in two patients (10%), and no responses in seven patients (35%). Among the two patients with declined MRD, one patient finally eliminated MRD after two cycles of the venetoclax-based regimen, and the other patient's MRD further declined after the second regimen. The objective response rate (ORR) was 65%. The median duration of response was 103 (12-313) days. The incidences of grades 3-4 neutropenia, anemia, and thrombocytopenia independently of pretreatment status were 30%, 20% and 20%, respectively.

CONCLUSION

Venetoclax-based regimens are efficient and safe for MRD in patients with myeloid malignancies ineligible for or failed in the first-line immunotherapies after allo-HSCT.

Reduced duration and dosage of venetoclax is efficient in newly diagnosed patients with acute myeloid leukemia

OBJECTIVES

The combination of Venetoclax (VEN) and Azacitidine (AZA) increases survival outcomes and yields excellent responses in patients with acute myeloid leukemia (AML). However, dose reduction (or discontinuation) is commonly encountered due to therapy-related toxicity. Thus, this study aimed to investigate the efficiency and safety of a lower dosage of venetoclax for the treatment of AML.

METHODS

This observational study analyzed the characteristics and outcomes of newly diagnosed AML patients who received 100 mg VEN combined with AZA for 14 days at our institution.

RESULTS

A total of 36 patients were enrolled, and the median age at diagnosis was 64 years. After a median follow-up of 15 (range 4-29) months, the median overall survival (OS) and progression-free survival (PFS) for the whole cohort were 17 (4-29) months and 12 (1-28) months, respectively. Meanwhile, the overall response rate (ORR) was 69.4%, and the CRc rate was 66.7% in the whole cohort. Subgroup analysis revealed that NPM1 mutations and FAB-M5 subtype were associated with higher response rates, whereas the adverse ELN risk group was predictive of an inferior response. Moreover, ASXL1, NPM1, and IDH1/2 mutations negatively impacted PFS.

DISCUSSION

Our study optimized the administration of venetoclax plus azacytidine for the treatment of AML patients. Response rates were favorable, with median survival in agreement with the findings of earlier reports, offering valuable insights for optimizing VEN-based regimens.

CONCLUSION

In summary, the VEN combination regimen is effective for the treatment of newly diagnosed AML patients in the real world despite VEN dose reductions .

Homoharringtonine sensitized resistant acute myeloid leukemia cells to venetoclax-induced apoptosis

Venetoclax (VEN), a B-cell lymphoma 2 (BCL-2) selective inhibitor, is widely used for treating acute myeloid leukemia (AML) with promising results. However, the anti-leukemic effect of VEN in relapsed/refractory (R/R)- AML requires improvement. In this study, we observed that combining homoharringtonine (HHT) with VEN plus azacitidine resulted in a significantly higher response and better survival than VA alone in patients with R/R-AML. Basic research indicates that HHT combined with VEN has a highly synergistic effect against both resistant AML cells and primary cells with/without mesenchymal stem cell (MSC) co-culture in vivo, inhibiting proliferation and colony-forming capacity of AML cells associated with concomitant cell cycle arrest. Mechanistically, HHT sensitizes AML cells to VEN by downregulating the anti-apoptotic proteins MCL-1/BCL-xL, activating reactive oxygen species (ROS), leading to mitochondrial membrane potential loss, and attenuating fatty acid (FA) uptake. These findings adding HHT to VEN-based regimens may enhance outcomes in R/R-AML patients.

Emerging roles of cohesin-STAG2 in cancer

Cohesin, a crucial regulator of genome organisation, plays a fundamental role in maintaining chromatin architecture as well as gene expression. Among its subunits, STAG2 stands out because of its frequent deleterious mutations in various cancer types, such as bladder cancer and melanoma. Loss of STAG2 function leads to significant alterations in chromatin structure, disrupts transcriptional regulation, and impairs DNA repair pathways. In this review, we explore the molecular mechanisms underlying cohesin-STAG2 function, highlighting its roles in healthy cells and its contributions to cancer biology, showing how STAG2 dysfunction promotes tumourigenesis and presents opportunities for targeted therapeutic interventions.

Consensus on the monitoring, treatment, and prevention of leukaemia relapse after allogeneic haematopoietic stem cell transplantation in China: 2024 update

The consensus in 2018 from The Chinese Society of Haematology (CSH) on the monitoring, treatment, and prevention of leukaemia relapse after allogeneic haematopoietic stem cell transplantation (HSCT) facilitated the standardization of clinical practices in China and progressive integration with the world. To integrate recent developments and further improve the consensus, a panel of experts from the CSH recently updated the following consensus: (1) integrate risk-adapted, measurable residual disease (MRD)-guided strategy on modified donor lymphocyte infusion (DLI) and interferon-α into total therapy, which was pioneered and refined by Chinese researchers; (2) provide additional evidence of the superiority of haploidentical HSCT (the dominant donor source in China) to matched HSCT for high-risk populations, especially for pre-HSCT MRD-positive patients; (3) support the rapid progress of techniques for MRD detection, such as next-generation sequencing (NGS) and leukaemia stem cell-based MRD detection; and (4) address the role of new targeted options in transplant settings. In conclusion, the establishment of a "total therapy" strategy represents a great step forward. We hope that the consensus updated by Chinese scholars will include the latest cutting-edge developments and inspire progress in post-HSCT relapse management.

Cohesin mutations in acute myeloid leukemia

The cohesin complex, encoded by SMC3, SMC1A, RAD21, and STAG2, is a critical regulator of DNA-looping and gene expression. Over a decade has passed since recurrent mutations affecting cohesin subunits were first identified in myeloid malignancies such as Acute Myeloid Leukemia (AML). Since that time there has been tremendous progress in our understanding of chromatin structure and cohesin biology, but critical questions remain because of the multiple critical functions the cohesin complex is responsible for. Recent findings have been particularly noteworthy with the identification of crosstalk between DNA-looping and chromatin domains, a deeper understanding of how cohesin establishes sister chromatid cohesion, a renewed interest in cohesin's role for DNA damage response, and work demonstrating cohesin's importance for Polycomb repression. Despite these exciting findings, the role of cohesin in normal hematopoiesis, and the precise mechanisms by which cohesin mutations promote cancer, remain poorly understood. This review discusses what is known about the role of cohesin in normal hematopoiesis, and how recent findings could shed light on the mechanisms through which cohesin mutations promote leukemic transformation. Important unanswered questions in the field, such as whether cohesin plays a role in HSC heterogeneity, and the mechanisms by which it regulates gene expression at a molecular level, will also be discussed. Particular attention will be given to the potential therapeutic vulnerabilities of leukemic cells with cohesin subunit mutations.

Relapse and resistance in acute myeloid leukemia post venetoclax: improving second lines therapy and combinations

INTRODUCTION

The combined use of the BCL-2 inhibitor venetoclax with azacitidine now is the standard of care for patients with acute myeloid leukemia (AML) unfit for intensive chemotherapy with outcomes exceeding those achieved with hypomethylating agents alone. Venetoclax in combination with intensive chemotherapy is also increasingly used both as frontline as well as salvage therapy. However, resistance to and relapse after venetoclax-based therapies are of major concern and outcomes after treatment failure remain poor.

AREAS COVERED

A comprehensive search was performed using PubMed database (up to April 2024). Studies evaluating venetoclax-based combination treatments in AML and studies assessing markers of response and resistance to venetoclax were investigated. We summarize the status of venetoclax-based therapies in the frontline and relapsed/refractory setting with focus on the main mechanisms of resistance to BCL-2 inhibition. Further, strategies to overcome resistance including combinatorial regimens of hypomethylating agent (HMA) + venetoclax + inhibitors targeting actionable mutations like IDH1/2 or FLT3-ITD and the introduction of novel agents like menin-inhibitors are addressed.

EXPERT OPINION

Although venetoclax is reshaping the treatment of unfit and fit AML patients, prognosis of patients after HMA/VEN failure remains dismal, and strategies to abrogate primary and secondary resistance are an unmet clinical need.

Triplet therapy with gilteritinib, venetoclax, and azacitidine for relapsed/refractory FLT3mut acute myeloid leukemia

The FMS-related tyrosine kinase 3 (FLT3) inhibitor gilteritinib is standard therapy for relapsed/refractory (R/R) FLT3-mutated (FLT3mut) acute myeloid leukemia (AML) but the overall survival (OS) is only approximately 20 % and few patients achieve deep and/ or durable response. We retrospectively analyzed 29 R/R FLT3mut AML patients treated on triplet regimens (gilteritinib+ venetoclax［VEN] +azacitidine［AZA]). Nineteen patients (65.5 %) had received prior FLT3 inhibitor therapy. The modified composite complete remission (mCRc) rate was 62.1 % (n = 18; CR, 4/29,13.8 %; CRi, 6/29, 20.7 %; MLFS, 8/29, 27.6 %). Among 18 patients achieved mCRc, FLT3-PCR negativity was 94.4 % (n=17), and flow-cytometry negativity was 77.7 % (n=14). The mCRc rate was 70 % (n=7) in 10 patients without prior FLT3 TKI exposure and 57.8 % (n=11) in 19 patients with prior FLT3 TKI exposure (P=0.52). At the end of the first cycle, the median time to ANC > 0.5× 109/L was 38 days and platelet > 50× 109/L was 31 days among responders, but 60-day mortality was 0 %. The estimated 2-year OS was 60.9 % for all R/R FLT3mut patients. The 1-year OS was 80 % and 58.8 % in patients without and with prior FLT3 TKI exposure, respectively (P=0.79). The estimated 2-year OS was 62 % in 19 (65.5 %) patients who received allo-HSCT after triplet therapy and 37 % in 10 patients who did not receive allo-HSCT (P=0.03). In conclusion, triplet therapy with gilteritinib, VEN, and AZA is effective and safe and an excellent frontline option for R/R FLT3mut AML.

[Efficacy and safety of venetoclax combined with decitabine, modified HA regimen and DLI in the treatment of relapsed pediatric AML/MDS after allogeneic hematopoietic stem cell transplantation]

Objective: To investigate the efficacy and safety of venetoclax combined with the decitabine, cytarabine, and homoharringtonine (HHT) regimen and donor lymphocyte infusion (DLI) for the preventive and salvage therapy of pediatric acute myeloid leukemia (AML) /myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (HSCT) . Methods: A total of 29 relapsed pediatric/minimal residual disease-positive AML after HSCT were recruited at the Peking University Institute of Hematology from January 1, 2021, to June 1, 2023. They were treated with the above combination regimen and administered with DLI after 24-48 hours at the end of chemotherapy, and the treatment response and adverse reactions were regularly assessed. Results: The overall response rate (ORR) was 75.8%, CR rate was 88.9% (8/9) in the hematologic relapse group, and MRD negativity rate was 61.1% (11/18) in the MRD-positive group. The incidence of agranulocytosis, anemia, and thrombocytopenia with a classification above grade 3 were 100%, 82.7%, and 100%, respectively. The median time of the granulocyte deficiency period was 15 days. Acute graft-versus-host diseases (aGVHD) with a classification of grades Ⅲ-Ⅳ occurred in 11.1% of the patients after DLI, while moderate or severe cGVHD occurred in 7.4% of the patients. The single risk factor for ORR was MNC counts of less than 10×10(8)/kg, and the relapse occurred within 100 days. At a median follow-up of 406 days, the 1-year OS was 65%, and the 1-year OS was 57% in the group with no reaction (P=0.164) compared with 71% in the group who had an overall reaction. Conclusion: The combined regimen based on the DAC, VEN, and modified HA regimen showed a high response rate in the salvage therapy for pediatric AML after the relapse of HSCT. However, bridging to transplantation should be performed immediately after remission to result in a long survival rate.

Homoharringtonine may help improve the outcomes of venetoclax and azacitidine in AML1-ETO positive acute myeloid leukemia

PURPOSE

T(8;21)(q22;q22.1)/AML1-ETO positive acute myeloid leukemia (AE-AML) is sensitive to conventional chemotherapy with a favorable prognosis. However, recent small case reports suggest the limited effectiveness of venetoclax (VEN) and hypomethylating agents (HMA) in treating AE-AML. The aim of this retrospective study was to evaluate the effectiveness of VEN plus AZA (VA) in AE-AML and explore whether adding homoharringtonine (HHT) to VA (VAH) could improve the response.

METHODS

Patients who received VEN plus AZA and HHT (VAH) or VEN plus AZA (VA) regimens were included in this retrospective study. The endpoints of this study were to evaluate the rate of composite complete remission (CRc), measurable residual disease (MRD), event-free survival (EFS), overall survival (OS), and relapse between VAH and VA groups.

RESULTS

A total of 32 AE-AML patients who underwent VA or VAH treatments (newly diagnosed with VA, ND-VA, n = 8; relapsed/refractory with VA, R/R-VA, n = 10; relapsed/refractory with VAH, R/R-VAH, n = 14) were included. The CR (complete remission) /CRi (CR with incomplete count recovery) rate of ND-VA, R/R-VA and R/R-VAH were 25%, 10%, and 64.3%, respectively. Measurable residual disease (MRD) negative was observed in 66.7% of R/R-VAH and none of VA-R/R patients. Co-occurring methylation mutations are associated with poor outcomes with VA but exhibit a more favorable response with VAH treatment. Additionally, patients with c-kit mutation presented inferior outcomes with both VEN-based regimens. All regimens were tolerated well by all patients.

CONCLUSION

Our data confirmed the poor response of VA in AE-AML, whether used as frontline or salvage therapy. Adding HHT to VA may improve outcomes and enhance the efficacy of VEN in this population.

BCL-2 inhibition in haematological malignancies: Clinical application and complications

B-cell lymphoma-2 (BCL-2) family proteins are fundamental regulators of the intrinsic apoptotic pathway which modulate cellular fate. In many haematological malignancies, overexpression of anti-apoptotic factors (BCL-2, BCL-XL and MCL-1) circumvent apoptosis. To address this cancer hallmark, a concerted effort has been made to induce apoptosis by inhibiting BCL-2 family proteins. A series of highly selective BCL-2 homology 3 (BH3) domain mimetics are in clinical use and in ongoing clinical trials for acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML), chronic lymphocytic leukaemia (CLL), and multiple myeloma (MM). These inhibitors serve as promising candidates, both as single agents or in combination therapy to improve patient outcomes. In other diseases such as follicular lymphoma, efficacy has been notably limited. There are also clinical problems with BCL-2 family inhibition, including drug resistance, disease relapse, tumour lysis syndrome, and clinically relevant cytopenias. Here, we provide a balanced view on both the clinical benefits of BCL-2 inhibition as well as the associated challenges.

Oral decitabine and cedazuridine plus venetoclax for older or unfit patients with acute myeloid leukaemia: a phase 2 study

BACKGROUND

Hypomethylating agents combined with venetoclax are effective regimens in patients with acute myeloid leukaemia who are ineligible for intensive chemotherapy. Decitabine and cedazuridine (ASTX727) is an oral formulation of decitabine that achieves equivalent area-under-curve exposure to intravenous decitabine. We performed a single centre phase 2 study to evaluate the efficacy and safety of ASTX727 plus venetoclax.

METHODS

This study enrolled patients with newly diagnosed (frontline treatment group) acute myeloid leukaemia who were ineligible for intensive chemotherapy (aged ≥75 years, an Eastern Cooperative Oncology Group [ECOG] performance status of 2-3, or major comorbidities) or relapsed or refractory acute myeloid leukaemia. Being aged 18 years or older and having an ECOG performance status of 2 or less were requirements for the relapsed or refractory disease treatment cohort, without any limits in the number of previous lines of therapy. Treatment consisted of ASTX727 (cedazuridine 100 mg and decitabine 35 mg) orally for 5 days and venetoclax 400 mg orally for 21-28 days in 28-day cycles. The primary outcome was overall response rate of ASTX727 plus venetoclax. Living patients who have not completed cycle one were not evaluable for response. Safety was analysed in all patients who started treatment. This study was registered on ClinicalTrials.gov (NCT04746235) and is ongoing. The data cutoff date for this analysis was Sept 22, 2023.

FINDINGS

Between March 16, 2021, and Sept 18, 2023, 62 patients were enrolled (49 frontline and 13 relapsed or refractory) with a median age of 78 years (IQR 73-82). 36 (58%) were male; 53 (85%) were White, 4 (6%) Black, 2 (3%) Asian and 3 (5%) other or did not answer. 48 (77%) of 62 patients were European LeukemiaNet 2022 adverse risk, 24 (39%) had antecedent myelodysplastic syndromes, 12 (19%) had previously failed a hypomethylating agent, ten (16%) had therapy-related acute myeloid leukaemia, and 11 (18%) had TP53 mutations. The median follow-up time was 18·3 months (IQR 8·8-23·3). The overall response rate was 30 (64%) of 47 patients (95% CI 49-77) in frontline cohort and six (46%) of 13 patients (19-75) in relapsed or refractory cohort. The most common grade 3 or worse treatment-emergent adverse events were febrile neutropenia in 11 (18%) of 62 patients, pneumonia in eight (13%), respiratory failure in five (8%), bacteraemia in four (6%), and sepsis in four (6%). Three deaths occurred in patients in remission (one sepsis, one gastrointestinal haemorrhage, and one respiratory failure) and were potentially treatment related.

INTERPRETATION

ASTX727 plus venetoclax is an active fully oral regimen and safe in most older or unfit patients with acute myeloid leukaemia. Our findings should be confirmed in larger multicentric studies.

FUNDING

MD Anderson Cancer Center Support Grant, Myelodysplastic Syndrome/Acute Myeloid Leukaemia Moon Shot, Leukemia SPORE, Taiho Oncology, and Astex Pharmaceuticals.

Sorafenib plus triplet therapy with venetoclax, azacitidine and homoharringtonine for refractory/relapsed acute myeloid leukemia with FLT3-ITD: A multicenter phase 2 study

BACKGROUND

Patients with relapsed or refractory acute myeloid leukemia (R/R AML) and FLT3-internal tandem duplication (FLT3-ITD) respond infrequently to salvage chemotherapy.

OBJECTIVE

To investigate the efficacy of sorafenib plus triplet therapy with venetoclax, azacitidine, and homoharringtonine (VAH) as a salvage therapy in this population.

METHODS

This multicenter, single-arm, phase 2 study was conducted at 12 hospitals across China. Eligible patients had R/R AML with FLT3-ITD (aged 18-65 years) who were treated with VAH. The primary endpoint was composite complete remission (CRc) after two cycles. Secondary outcomes included the overall response rate (ORR), safety, and survival.

RESULTS

Between July 9, 2020, and March 19, 2022, 58 patients were assessed for eligibility, 51 of whom were enrolled. The median patient age was 47 years (interquartile range [IQR] 31-57). CRc was 76.5% with ORR of 82.4%. At a median follow-up of 17.7 months (IQR, 8.7-24.7), the median duration of CRc was not reached (NR), overall survival was 18.1 months (95% confidence interval [CI], 11.8-NR) and event-free survival was 11.4 months (95% CI, 5.6-NR). Grade 3 or 4 adverse events occurring in ≥10% of patients included neutropenia in 47 (92.2%), thrombocytopenia in 41 (80.4%), anemia in 35 (68.6%), febrile neutropenia in 29 (56.9%), pneumonia in 13 (25.5%), and sepsis in 6 (11.8%) patients. Treatment-related death occurred in two (3.9%) patients.

CONCLUSIONS

The sorafenib plus VAH regimen was well tolerated and highly active against R/R AML with FLT3-ITD. This regimen may be a suitable therapeutic option for this population, but larger population trials are needed to be explored.

TRIAL REGISTRATION

Clinical Trials Registry: NCT04424147.

Clinical and genetic characteristics predict outcomes of acute myeloid leukemia patients with FLT3 mutations receiving venetoclax-based therapy

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous disease, and its heterogeneity is associated with treatment response. Despite the demonstrated success of venetoclax (VEN)-based therapy for AML, the effect of FLT3 mutations on the efficacy of the therapy is poorly understood. We aimed to compare the efficacy of VEN-based therapy between FLT3-mutated (FLT3mut ) and FLT3 wild-type (FLT3wt ) patients and identify the predictors of efficacy in FLT3mut patients.

METHODS

A total of 266 AML patients (127 newly diagnosed [ND] and 139 refractory/relapsed [R/R]) receiving VEN-based regimens were enrolled in this study. A retrospective analysis was performed, and the treatment responses and overall survival (OS) of FLT3mut and FLT3wt patients were compared. Logistic regression and Cox proportional hazards model were applied to examine the clinical and genetic predictors of outcomes.

RESULTS

With a median of two cycles of VEN-based therapy, for the ND AML cohort, the FLT3mut group had a comparable composite complete remission (CRc) rate with the FLT3wt group (79.3% vs. 61.2%, p = 0.072). For the R/R AML cohort, the FLT3mut group exhibited a lower CRc rate than the FLT3wt group. With a median follow-up of 8.6 months (95% confidence interval [CI], 8.0-10), the median OS observed in the FLT3mut and FLT3wt groups for both cohorts were close (14.0 vs. 19.9 months, p = 0.356; 10.0 vs. 11.9 months, p = 0.680). For the ND AML cohort, in FLT3mut patients, MRD-positive and RNA-splicing mutation predicted inferior survival (hazard ratio [HR], 10.3; 95% CI: 2.0-53.8; p = 0.006; HR 11.3; 95% CI: 1.2-109.3; p = 0.036, respectively). For the R/R AML cohort, in FLT3mut patients, adverse ELN risk was associated with an inferior response (odds ratio [OR], 0.2; 95% CI: 0.1-0.8; p = 0.025), whereas NPM1 co-mutation was associated with a superior response (57.1%; OR, 6.7; 95% CI: 1.5-30.1; p = 0.014). CR/CRi predicted a better survival (HR 0.2; 95% CI: 0.1-0.8; p = 0.029), while DNMT3A mutation predicted an inferior survival (HR, 4.6; 95% CI: 1.4-14.9; p = 0.011).

CONCLUSIONS

FLT3 mutations may influence response to VEN-based therapy in R/R AML patients but not in ND AML patients. Furthermore, clinical and genetic characteristics could predict outcomes of FLT3mut patients receiving VEN-based therapy.

Venetoclax and Hypomethylating Agent Combination in Myeloid Malignancies: Mechanisms of Synergy and Challenges of Resistance

There has been a widespread adoption of hypomethylating agents (HMA: 5-Azacytidine (5-Aza)/decitabine) and venetoclax (Ven) for the treatment of acute myeloid leukemia (AML); however, the mechanisms behind the combination's synergy are poorly understood. Monotherapy often encounters resistance, leading to suboptimal outcomes; however, the combination of HMA and Ven has demonstrated substantial improvements in treatment responses. This study elucidates multiple synergistic pathways contributing to this enhanced therapeutic effect. Key mechanisms include HMA-mediated downregulation of anti-apoptotic proteins, notably MCL-1, and the priming of cells for Ven through the induction of genes encoding pro-apoptotic proteins such as Noxa. Moreover, Ven induces sensitization to HMA, induces overcoming resistance by inhibiting the DHODH enzyme, and disrupts antioxidant pathways (Nrf2) induced by HMA. The combination further disrupts oxidative phosphorylation in leukemia stem cells, amplifying the therapeutic impact. Remarkably, clinical studies have revealed a favorable response, particularly in patients harboring specific mutations, such as IDH1/2, NPM1, CEBPA, or ASXL1. This prompts future studies to explore the nuanced underpinnings of these synergistic mechanisms in AML patients with these molecular signatures.

Venetoclax in adult acute myeloid leukemia

Venetoclax is a potent inhibitor that specifically targets B-cell lymphoma-2 (BCL-2), which has been demonstrated to be effective in preclinical studies utilizing acute myeloid leukemia (AML) cell lines and xenograft models. Significant antileukemic activity was also observed in clinical trials, both as a monotherapy and in combination with other drugs. This novel therapeutic approach has revolutionized the treatment prospects for AML patients with unfavorable prognoses and those who are unable to tolerate intensive chemotherapy. Nevertheless, further investigations are required to establish the optimal dosing, sequencing, and combinational strategies of venetoclax for AML treatments. Additionally, identifying biomarkers is crucial for predicting response and resistance to this targeted intervention. In this review, we provide an overview of venetoclax-based therapy for AML and explore potential avenues for future research.

Hypomethylating agents plus modified priming regimens compared with venetoclax-based regimens based on molecular characteristics for newly diagnosed patients with acute myeloid leukemia: a multi-center cohort study

Venetoclax (VEN)-based regimens are the standard of care for elderly or unfit patients with newly diagnosed (ND) acute myeloid leukemia (AML). Some single-arm studies have implied that hypomethylating agents (HMAs) plus priming regimens may potentially provide an alternative therapeutic approach, owing to encouraging efficacy seen. However, no comparative data exists yet regarding these two treatment approaches. In this retrospective multi-center cohort study, we enrolled 294 ND AML patients, allocating 167 to the HMA + priming group and 127 to the VEN-based group. Treatment response and overall survival (OS) were compared between groups. Molecular subgroup analyses were also conducted. With a median of two cycles for HMA + priming group, the overall response (ORR) was 65.3%, including 55.1% complete remission (CR), 9.6% CR with incomplete hematologic recovery (CRi) and 0.6% morphologic leukemia-free state (MLFS). With a median of two cycles for VEN-based group, the ORR was 70.9%, including 46.5% CR, 18.9% CRi, and 5.5% MLFS. Response differences (ORR or CR/CRi) between groups were not significant (p > 0.05). With a median follow-up of 10.1 months, median OSs were similar between groups (20.9 vs 16.3 months, p = 0.41). However, VEN regimens demonstrated superior CR/CRi for patients with mutations in FLT3, IDH1/2, and NPM1 compared to HMA + priming (80.0% vs 35.0%, p = 0.01; 90.9% vs 65.5%, p = 0.02; 90.9% and 65.5%, p = 0.02, respectively). In conclusion, HMAs plus modified priming regimens might be a potential alternative therapeutic approach for patients with ND AML, but VEN-based regimens presented predominance in specific molecular subgroups. Molecular characteristics contribute to guiding choice of treatment.

Impact of previous anthracycline therapy in patients with acute myeloid leukemia receiving venetoclax

Venetoclax (VEN) combination regimens are now recognized as effective against acute myeloid leukemia (AML). However, the prognosis of patients who do not attain a composite complete response (cCR) is extremely poor, and clinical determinants of response remain unknown. Medical records of 57 patients with AML treated with VEN combination regimens from April 2021 to March 2022 at six institutions were retrospectively analyzed. The primary endpoint was cCR, complete remission, or complete remission with incomplete hematologic recovery after one cycle of VEN combination regimen. Five patients had previously relapsed after allogeneic hematopoietic stem cell transplantation (allo-SCT). The treatment regimen was azacitidine-VEN in 48 patients (84%) and low-dose cytarabine-VEN in 9 patients (16%). Thirty patients (53%) achieved cCR after one cycle of a VEN regimen. In univariate analysis, the number of prior chemotherapy regimens, post-allo-SCT relapse, and cytogenetic risk category were associated with a decreased likelihood of achieving cCR. In multivariate analysis, second-line chemotherapy remained a significant predictor of response. Patients who received anthracycline immediately before the VEN regimen had a higher cCR rate than patients who did not receive anthracycline. In this study, prior chemotherapy/allo-SCT and cytogenetic risk were associated with VEN treatment outcomes.

Venetoclax-based therapy for relapsed or refractory acute myeloid leukaemia following intensive induction chemotherapy

BACKGROUND

The treatment of relapsed or refractory (R/R) acute myeloid leukaemia (AML) remains challenging and outcomes extremely poor. The introduction of venetoclax has transformed the treatment of AML and emerging data suggest that venetoclax-based therapy may enforce salvage treatment.

MATERIALS AND METHODS

In this nationwide Danish retrospective study, we analysed treatment outcomes of venetoclax-based salvage treatment for R/R AML between 2019 and 2022. Only venetoclax-naive patients who had previously received treatment with intensive chemotherapy therapy were included.

RESULTS

The cohort consisted of 43 R/R patients with a median age of 57 years. Nine (20.9%) were primary refractory and 34 (79.1%) patients had relapsed, including 21 after previous allogeneic stem cell transplantation. The overall response rate was 76.2% including 61.9% with composite complete remission (CRc: CR + CRi). Among CRc-responders with information on measurable residual disease (MRD), 8/13 (61.5%) obtained an MRD-negativity response. The overall survival was 9.3 months for all patients with an estimated 1-year overall survival of 34%. For CRc-responders the median overall survival was 13.3 months, and the median relapse-free survival was 12.8 months.

CONCLUSION

Venetoclax-based salvage treatment for R/R AML produced high response rates; however, for most patients the response was of limited duration. This study is limited by an observational design and prone to selection bias.

Alteration of gut microbiome and correlated amino acid metabolism are associated with acute myelocytic leukemia carcinogenesis

BACKGROUND

The aim of this study is to investigate the profiles of gut microbiota and metabolites in acute myelocytic leukemia (AML) patients treated with/without chemotherapy.

METHODS

Herein, high-throughput 16S rRNA gene sequencing was performed to analysis gut microbiota profiles, and liquid chromatography and mass spectrometry were performed to analysis metabolites profiles. The correlation between gut microbiota biomarkers identified by LEfSe and differentially expressed metabolites were determined by spearman association analysis.

RESULTS

The results showed the distinguished gut microbiota and metabolites profiles between AML patients and control individuals or AML patients treated with chemotherapy. Compared to normal populations, the ratio of Firmicutes to Bacteroidetes was increased at the phylum level than that in AML patients, and LEfSe analysis identified Collinsella and Coriobacteriaceae as biomarkers of AML patients. Differential metabolite analysis indicated that, compared to AML patients, numerous differential amino acids and analogs could be observed in control individuals and AML patients treated with chemotherapy. Interestingly, spearman association analysis demonstrated that plenty of bacteria biomarkers shows statistical correlations with differentially expressed amino acid metabolites. In addition, we found that both Collinsella and Coriobacteriaceae demonstrate remarkable positive correlation with hydroxyprolyl-hydroxyproline, prolyl-tyrosine, and tyrosyl-proline.

CONCLUSION

In conclusion, our present study investigated the role of the gut-microbiome-metabolome axis in AML and revealed the possibility of AML treatment by gut-microbiome-metabolome axis in the further.

The Molecular Context of Oxidant Stress Response in Cancer Establishes ALDH1A1 as a Critical Target: What This Means for Acute Myeloid Leukemia

The protein family of aldehyde dehydrogenases (ALDH) encompasses nineteen members. The ALDH1 subfamily consists of enzymes with similar activity, having the capacity to neutralize lipid peroxidation products and to generate retinoic acid; however, only ALDH1A1 emerges as a significant risk factor in acute myeloid leukemia. Not only is the gene ALDH1A1 on average significantly overexpressed in the poor prognosis group at the RNA level, but its protein product, ALDH1A1 protects acute myeloid leukemia cells from lipid peroxidation byproducts. This capacity to protect cells can be ascribed to the stability of the enzyme under conditions of oxidant stress. The capacity to protect cells is evident both in vitro, as well as in mouse xenografts of those cells, shielding cells effectively from a number of potent antineoplastic agents. However, the role of ALDH1A1 in acute myeloid leukemia has been unclear in the past due to evidence that normal cells often have higher aldehyde dehydrogenase activity than leukemic cells. This being true, ALDH1A1 RNA expression is significantly associated with poor prognosis. It is hence imperative that ALDH1A1 is methodically targeted, particularly for the acute myeloid leukemia patients of the poor prognosis risk group that overexpress ALDH1A1 RNA.

Venetoclax Combined with Azacitidine and Homoharringtonine in Relapsed/Refractory AML: A Multicenter, Phase 2 Trial

BACKGROUND

Relapsed or refractory acute myeloid leukemia (R/R AML) has a dismal prognosis. The aim of this study was to investigate the activity and tolerability of venetoclax combined with azacitidine plus homoharringtonine (VAH) regimen for R/R AML.

METHODS

This phase 2 trial was done at ten hospitals in China. Eligible patients were R/R AML (aged 18-65 years) with an Eastern Cooperative Oncology Group performance status of 0-2. Patients received venetoclax (100 mg on day 1, 200 mg on day 2, and 400 mg on days 3-14) and azacitidine (75 mg/m² on days 1-7) and homoharringtonine (1 mg/m² on days 1-7). The primary endpoint was composite complete remission rate [CRc, complete response (CR) plus complete response with incomplete blood count recovery (CRi)] after 2 cycles of treatment. The secondary endpoints include safety and survival.

RESULTS

Between May 27, 2020, and June 16, 2021, we enrolled 96 patients with R/R AML, including 37 primary refractory AML and 59 relapsed AML (16 relapsed after chemotherapy and 43 after allo-HSCT). The CRc rate was 70.8% (95% CI 60.8-79.2). In the patients with CRc, measurable residual disease (MRD)-negative was attained in 58.8% of CRc patients. Accordingly, overall response rate (ORR, CRc plus partial remission (PR)) was 78.1% (95% CI 68.6-85.4). At a median follow-up of 14.7 months (95% CI 6.6-22.8) for all patients, median overall survival (OS) was 22.1 months (95% CI 12.7-Not estimated), and event-free survival (EFS) was 14.3 months (95% CI 7.0-Not estimated). The 1-year OS was 61.5% (95% CI 51.0-70.4), and EFS was 51.0% (95% CI 40.7-60.5). The most common grade 3-4 adverse events were febrile neutropenia (37.4%), sepsis (11.4%), and pneumonia (21.9%).

CONCLUSIONS

VAH is a promising and well-tolerated regimen in R/R AML, with high CRc and encouraging survival. Further randomized studies are needed to be explored. Trial registration clinicaltrials.gov identifier: NCT04424147.