Outcomes of allogeneic transplantation after hypomethylating agents with venetoclax in acute myeloid leukemia

The approach of HMA plus VEN with or without BMT for all patients with AML

Treatment options for acute myeloid leukemia (AML) have expanded over the last 5 years. New regimens are increasing the options for patients who previously may not have been offered any antineoplastic therapy. The use of the hypomethylating agent (HMA) decitabine or azacitidine combined with the BCL2 inhibitor venetoclax (HMA-VEN) has improved overall survival in an older and unfit population compared to HMA therapy alone. Delivering these regimens outside academic centers allows more patients with AML to be treated, though support and collaboration with allogeneic stem cell transplant (SCT) centers should still be considered to determine eligibility and promptly initiate a donor search for potential transplant candidates. Expanding the use of HMA-VEN to younger and fit patients who are also candidates for intensive chemotherapy (IC) is being studied prospectively and is not recommended at this time outside of a clinical trial. Retrospective studies suggest populations that may benefit from HMA-VEN over IC, but this is not yet confirmed prospectively. Utilizing HMA-VEN prior to allogeneic SCT is also under investigation, and some retrospective data show feasibility and the ability to achieve measurable residual disease negativity pretransplant. Upcoming prospective randomized clinical trials aim to answer the comparability or superiority of HMA-VEN vs IC in fit populations and its potential use as a standard pretransplant induction regimen.

Selinexor Synergistically Promotes the Antileukemia Activity of Venetoclax in Acute Myeloid Leukemia by Inhibiting Glycolytic Function and Downregulating the Expression of DNA Replication Genes

Introduction

The BCL-2 inhibitor venetoclax has been widely used in the treatment of acute myeloid leukemia (AML); however, AML patients treated with venetoclax gradually develop resistance. The exportin-1 (XPO1) inhibitor selinexor can synergistically promote the antileukemia activity of venetoclax, but the mechanism remains unclear.

Methods and Results

Annexin V/7-aminoactinomycin D assays were used to examine the effects of a combination of venetoclax and selinexor (VEN+SEL) on AML cell lines and primary AML cells. RNA sequencing and oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) determinations by a Seahorse XF analyzer were employed to investigate the molecular mechanism of the toxicity of the VEN+SEL combination to AML cells. The cytotoxicity of NK cell combined with VEN+SEL combination was assessed in vitro using flow cytometry. VEN+SEL enhanced the apoptosis of AML cells (KG-1A and THP-1) and primary AML samples in vitro. The ECAR and OCR results demonstrated that the VEN+SEL combination significantly inhibited glycolytic function. RNA sequencing of THP-1 cells demonstrated that DNA replication-related genes were downregulated after treatment with the VEN+SEL combination.

Conclusion

This study indicated that selinexor can synergistically enhance the antileukemia activity of venetoclax in AML cells in vitro by inhibiting glycolytic function and downregulating DNA replication-related genes. Based on our experimental data, combining selinexor with venetoclax is an appropriate advanced treatment option for AML patients.

A Successful Bridge Therapy Combining Hypomethylating Agents with Venetoclax for Adult Patients with Newly Diagnosed or Relapsed/Refractory Acute Myeloid Leukemia

Recently, the combination of VEN-HMA has been shown to achieve durable responses in patients with both newly diagnosed (ND) and R/R-AML. We retrospectively evaluated the post-allo-HCT outcomes of 50 patients who received VEN-HMA therapy. In total, 10 were ND and 40 were R/R and, at the time of HCT, the median age was 53 years. In the ND- and R/R-AML groups, the percentage of patients who achieved CR/CRi or MLFS was 90% and 92.5%, respectively. In all, after a median follow-up of 13.7 months, the probabilities of overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM) at 1 year were 63.7%, 59.3%, 28.5%, and 12.2%, respectively. In addition, the cumulative incidences of grade II–IV acute graft-versus-host disease (GVHD) and moderate–severe chronic GVHD at 1 year were 28.4% and 37.4%, respectively. In multivariate analysis, the factors associated with a statistically significant impact on OS were VEN-HMA cycle (p = 0.021), ELN risk group (p = 0.041), and the response to VEN-HMA therapy before allo-HCT (p = 0.003). Although 80% of our patients had R/R-AML and 30% underwent a second allo-HCT, our data still suggest that allo-HCT following VEN-HMA therapy is a safe and effective treatment option.

Venetoclax with decitabine versus decitabine monotherapy in elderly acute myeloid leukemia: a propensity score-matched analysis

Venetoclax (VEN) combined with azacitidine (AZA) or decitabine (DEC) has been approved for older adults with acute myeloid leukemia (AML) unfit for intensive chemotherapy based on the pivotal VIALE-A trial. However, this trial only compared AZA + VEN with AZA monotherapy. Therefore, we compared the outcomes of consecutive older adults (65 years or older) with newly diagnosed AML who received DEC (n = 230) or DEC + VEN (n = 74) after propensity score matching to construct a one-to-one matched cohort by the nearest neighbor algorithm. The median overall survival was longer in the DEC + VEN group than in the DEC group (13.4 months vs. 8.3 months, p = 0.01). The median event-free survivals were 8.6 and 5.8 months in the DEC + VEN and DEC groups, respectively (p = 0.02). The response rate (complete response, complete response with incomplete hematologic recovery, and morphologic leukemia-free state) was significantly higher in the DEC + VEN group than in the DEC group (70.3% vs. 24.3%, p < 0.01). The 30-day (2.7% vs. 9.5%, p = 0.17) and 60-day (9.5% vs. 18.9%, p = 0.16) mortality rates did not differ between the two groups, nor did the median hospitalization and transfusion rates (hospitalization: 23 days vs. 21 days, p = 0.20; red blood cells: 3.2 units/month vs. 3.5 units/month, p = 0.73; platelets: 2.7 units/month vs. 2.3 units/months, p = 0.48). Of those who received DEC + VEN and became leukemia-free, 29% underwent allogeneic stem cell transplantation and had excellent survival outcomes (one-year survival: 79.4%; one-year non-relapse mortality: 13.3%). This study is the first to provide real-world evidence that DEC + VEN has superior outcomes to DEC monotherapy.