Updates in biology, classification, and management of acute myeloid leukemia with antecedent hematologic disorder and therapy related acute myeloid leukemia.

Acute myeloid leukemia with antecedent hematologic disorder (AHD-AML) and therapy related AML (t-AML) constitute a heterogenous disease with inferior outcomes. It is often characterized by high-risk cytogenetic and molecular alterations associated with AHD or prior cancer therapy. Historically, the standard of care treatment has been intensive induction with "7 + 3", with an improved overall response rate and survival with CPX-351. Results from large registry-based studies suggested that allogeneic hematopoietic stem cell transplant is preferable to consolidation chemotherapy alone for achieving long-term survival in patients with AHD-AML. Prevalence of high-risk genetic features and advanced age and comorbidities in patients make AHD-AML and t-AML clinically challenging subgroups to treat with intensive approaches. Recent reports on less intensive treatment options, particularly the hypomethylating agent-venetoclax combination, have shown encouraging response rates in these patients. However, emerging resistance mechanisms compromise duration of response and overall survival. Several novel agents targeting apoptotic machinery, signaling pathways, and immune checkpoints are under clinical investigation, with an aim to truly improve overall outcomes in this subgroup. We reviewed updates in biology, classification, and clinical data comparing safety and efficacy of intensive and less intensive treatment options, and summarized ongoing studies with promising novel therapies in AHD-AML and t-AML.

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.

Less is more: An analysis of venetoclax and hypomethylating agent post-induction treatment modifications in AML.

Venetoclax (Ven) combined with a hypomethylating agent (HMA) enhances survival in elderly/unfit acute myeloid leukemia (AML) patients, yet often necessitates regimen modifications due to intolerance. However, it is unclear how these modifications affect patient outcome. This retrospective cohort study evaluates the impact of post-induction HMA/Ven regimen modifications on disease progression and survival. This study reviewed 142 AML patients treated with HMA/Ven within the Northwell Health System from January 2019 to December 2022. To assess the impact of post-induction regimen modifications, patients were grouped according to median days between cycles (≤34 or ≥35 days cycle intervals) and median Ven days per cycle (≤14 or ≥15 days/cycle) based on only cycle 3 and beyond. Kaplan-Meier and Cox proportional hazard regression analyses were employed for univariate and multivariate assessments, respectively. There was no significant difference in median progression-free survival (mPFS)(11.6 vs 11.8 months, p = 0.73) or median overall survival (mOS)(15.1 vs 21.8 months, p = 0.16) between cycle interval groups. However, there was a clinically and statistically significant advantage in mPFS (15.8 vs 8.7 months, p = 0.01) and mOS (24.7 vs 11.3 months, p = 0.006) for patients with a median of ≤14 Ven days/cycle compared to ≥15 Ven days/cycle. Multivariate analysis demonstrated that ≤14 days of Ven for cycle 3 and beyond was an independent predictor of decreased mortality (HR 0.18, CI 0.07-0.48, p = 0.0007). Extended cycle intervals did not adversely affect mortality while reduced Ven duration per cycle post-induction was associated with improved survival in elderly AML patients.

Efficacy of venetoclax and rituximab in the treatment of concurrent acute myeloid leukemia and untreated chronic lymphocytic leukemia: A case report and literature review.

To date, few cases of concurrent acute myeloid leukemia (AML) and untreated chronic lymphocytic leukemia (CLL) have been reported. Due to the complexity of the pathogenesis and the absence of a uniform treatment regimen, the associated prognosis remains poor. The present study reports the case of a 58-year-old male with asymptomatic leukocytosis, who was previously healthy with no malignancies. Flow cytometry analysis revealed protocytosis, monocytosis and monoclonal B lymphocytosis in a bone marrow specimen. Results of a gene rearrangement assay demonstrated positive immunoglobulin heavy-chain variable region gene status in monoclonal B lymphocytes. Thus, the patient was diagnosed with AML with maturation (AML-M2) that co-existed with untreated CLL. The normative daunorubicin (40 mg/m2 on days 1-3) and cytarabine (80 mg/m2 on days 1-7) regimen combined with venetoclax (400 mg on days 1-7) and rituximab (375 mg/m2 on day 0) was used as induction chemotherapy. The patient achieved morphological complete remission in both AML and CLL following the first course of chemotherapy. In addition, the present study retrospectively analyzed the data of 22 patients with concurrent AML and untreated CLL, and the results demonstrated that the median age at the time of AML diagnosis was 69 years (range, 52-86 years). Moreover, the male:female ratio was 6.33:1 and AML-M2 was the most frequent subtype at diagnosis. The presence of a complex karyotype was associated with the poorest prognosis, and patients who received venetoclax often exhibited an improved prognosis. In conclusion, the combination of venetoclax and rituximab improves the prognosis of patients with concurrent AML and untreated CLL.

Outcomes of venetoclax-based therapy in patients with t(11;14) light chain amyloidosis after failure of daratumumab-based therapy.

BACKGROUND: Daratumumab's incorporation in the upfront treatment of light chain (AL) amyloidosis has led to daratumumab (dara) refractoriness early in disease course. Patients who experience relapse or have suboptimal response to dara-based-therapy, have limited options. OBJECTIVE: This study aimed to evaluate the outcomes of venetoclax-based therapy in t(11;14) positive AL patients who previously failed dara. METHODS: Thirty-one patients with AL were included in this bi-institutional retrospective analysis. RESULTS: Dara failure was due to inadequate response in 20 (65%) patients, haematologic relapse in 7 (22%), and both haematologic plus organ relapse in 4 (13%). Overall haematologic response rate to venetoclax-based therapy was 97%, with ≥ VGPR being 91%. Of the 19 evaluable patients with cardiac involvement, 14 (74%) achieved organ response. Of the 13 evaluable patients with renal involvement, 6 (46%) achieved organ response. With a median follow-up of 22 months, median time-to-next-treatment (TTNT) and overall survival (OS) were not reached. The 12- and 24-month TTNT rates were 74% and 56%, respectively. At data-cut-off, four patients had died, all from AL-related organ complications. The 12- and 24-month OS rates were 89% and 85%, respectively. Grade ≥3 adverse events occurred in 26% of patients, with 6% due to infections. CONCLUSION: These findings are encouraging for the use of venetoclax as salvage therapy post-dara failure.

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.

Three years follow-up of Venetoclax in advanced-stage, relapsed or refractory AL amyloidosis with cardiac involvement and t(11;14) with BCL2 expression.

Further line treatment of patients with advanced stage AL amyloidosis with cardiac involvement is challenging. Venetoclax is a promising option, especially in t(11;14) and BCL2 expression.In our multicentre observational study, we report the 3-year follow-up of Venetoclax treatment in 9 patients with advanced, relapsed or refractory AL amyloidosis with t(11;14) and BCL-2 expression in > 50% of plasma cells. At baseline, all patients had been previously treated with daratumumab, all had cardiac involvement with revised Mayo stage III or IV/ European modification of Mayo 2004 IIIA or IIIB (1/9 unclassified due to missing troponin T), 5/9 patients had renal involvement.After a median of 35 months (range 25-49) since the start of Venetoclax, 8/9 patients were still alive (OS 89%). First and best hematological responses were observed after a median of 26 days (11-125) and 106 days (35-659), overall response rate was 100% (7/9 CR, 2/9 VGPR). Where observed, organ response was documented within the first 6 months of therapy, including cardiac (6/9) and renal (3/5) improvements. Venetoclax was discontinued in 6/9 patients after a median of 15 months (11-48) due to toxicity (2/9), disease progression (2/9), fixed treatment duration (1/9), or safety concerns (1/9).In conclusion, Venetoclax induces a rapid and deep hematologic response with consistent improvement in organ function with an acceptable safety profile in patients with pretreated, advanced stage AL amyloidosis with cardiac involvement and BCL2 expression with and potentially without detected t(11:14), which warrants further investigation.

Real-world effectiveness of first-line azacitidine or decitabine with or without venetoclax in acute myeloid leukemia patients unfit for intensive therapy.

BACKGROUND: First-line treatment in patients with acute myeloid leukemia (AML) unfit for intensive therapy is the combination of a hypomethylating agent (HMA) with venetoclax (VEN). However, retrospective data confirming the benefits of this regimen outside of clinical trials have shown conflicting results. METHODS: We performed a multicenter retrospective analysis of outcomes with first-line HMA-VEN versus HMA in AML patients unfit for intensive chemotherapy. RESULTS: A total of 213 patients were included from three German hospitals (125 HMA-VEN, 88 HMA). Median overall survival in the HMA-VEN cohort was 7.9 months (95% confidence interval [CI], 5.1-14.7) versus 4.9 months (3.1-7.1) with HMA. After 1 year, 42% (95% CI, 33-54) and 19% (12-30) of patients were alive, respectively (hazard ratio [HR] for death, 0.64; 95% CI, 0.46-0.88). After adjusting for clinical and molecular baseline characteristics, treatment with HMA-VEN remained significantly associated with both prolonged survival (HR, 0.48; 95% CI, 0.29-0.77) and time to next treatment (HR, 0.63; 95% CI, 0.47-0.85). Patients who achieved recovery of peripheral blood counts had a favorable prognosis (HR for death, 0.52; 95% CI, 0.33-0.84). DISCUSSION: These data align with findings from the pivotal VIALE-A trial and support the use of HMA-VEN in patients unfit for intensive therapy.

Identifying Targetable Vulnerabilities to Circumvent or Overcome Venetoclax Resistance in Diffuse Large B-Cell Lymphoma.

Clinical trials with single-agent venetoclax/ABT-199 (anti-apoptotic BCL2 inhibitor) revealed that diffuse large B-cell lymphoma (DLBCL) is not solely dependent on BCL2 for survival. Gaining insight into pathways/proteins that increase venetoclax sensitivity or unique vulnerabilities in venetoclax-resistant DLBCL would provide new potential treatment avenues. Therefore, we generated acquired venetoclax-resistant DLBCL cells and evaluated these together with intrinsically venetoclax-resistant and -sensitive DLBCL lines. We identified resistance mechanisms, including alterations in BCL2 family members that differed between intrinsic and acquired venetoclax resistance and increased dependencies on specific pathways. Although combination treatments with BCL2 family member inhibitors may overcome venetoclax resistance, RNA-sequencing and drug/compound screens revealed that venetoclax-resistant DLBCL cells, including those with TP53 mutation, had a preferential dependency on oxidative phosphorylation. Mitochondrial electron transport chain complex I inhibition induced venetoclax-resistant, but not venetoclax-sensitive, DLBCL cell death. Inhibition of IDH2 (mitochondrial redox regulator) synergistically overcame venetoclax resistance. Additionally, both acquired and intrinsic venetoclax-resistant DLBCL cells were similarly sensitive to inhibitors of transcription, B-cell receptor signaling, and class I histone deacetylases. These approaches were also effective in DLBCL, follicular, and marginal zone lymphoma patient samples. Our results reveal there are multiple ways to circumvent or overcome the diverse venetoclax resistance mechanisms in DLBCL and other B-cell lymphomas and identify critical targetable pathways for future clinical investigations.

Application of omics in the diagnosis, prognosis, and treatment of acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most frequent leukemia in adults with a high mortality rate. Current diagnostic criteria and selections of therapeutic strategies are generally based on gene mutations and cytogenetic abnormalities. Chemotherapy, targeted therapies, and hematopoietic stem cell transplantation (HSCT) are the major therapeutic strategies for AML. Two dilemmas in the clinical management of AML are related to its poor prognosis. One is the inaccurate risk stratification at diagnosis, leading to incorrect treatment selections. The other is the frequent resistance to chemotherapy and/or targeted therapies. Genomic features have been the focus of AML studies. However, the DNA-level aberrations do not always predict the expression levels of genes and proteins and the latter is more closely linked to disease phenotypes. With the development of high-throughput sequencing and mass spectrometry technologies, studying downstream effectors including RNA, proteins, and metabolites becomes possible. Transcriptomics can reveal gene expression and regulatory networks, proteomics can discover protein expression and signaling pathways intimately associated with the disease, and metabolomics can reflect precise changes in metabolites during disease progression. Moreover, omics profiling at the single-cell level enables studying cellular components and hierarchies of the AML microenvironment. The abundance of data from different omics layers enables the better risk stratification of AML by identifying prognosis-related biomarkers, and has the prospective application in identifying drug targets, therefore potentially discovering solutions to the two dilemmas. In this review, we summarize the existing AML studies using omics methods, both separately and combined, covering research fields of disease diagnosis, risk stratification, prognosis prediction, chemotherapy, as well as targeted therapy. Finally, we discuss the directions and challenges in the application of multi-omics in precision medicine of AML. Our review may inspire both omics researchers and clinical physicians to study AML from a different angle.

Treatment Sequencing in Chronic Lymphocytic Leukemia in 2024: Where We Are and Where We Are Headed.

As treatments with BTK inhibitors and BCL2 inhibitors have replaced the use of chemoimmunotherapy in CLL in both first-line and relapsed patients, it becomes critical to rationalize their use and exploit the full potential of each drug. Despite their proven, robust, and manifest efficacy, BTKis and BCL2is fail to provide long-term disease control in some categories of patients, and to date this is an unmet clinical need that is critical to recognize and address. Ongoing clinical trials are evaluating new treatment algorithms and new molecules to progressively thin this population. In this review for each category of patients we explicate the different possible patterns of treatment sequencing based on currently available evidence, starting from the frontline to currently ongoing trials, in order to optimize therapies as much as possible.

Population Pharmacokinetic Models of Venetoclax in Hematologic Malignancies: A Systematic Review.

Several population pharmacokinetic (PPK) models of B cell lymphoma-2 (BCL-2) venetoclax (VEN) have been developed and published to characterize the influencing factors of pharmacokinetics in hematologic malignancies. This review described PPK models of VEN examining the magnitude and types of covariate effects in PK parameters, as well as identified areas that require further investigation in order to facilitate their use. Currently, there are six analyses on PPK models of VEN summarized in this review. Most analyses described the pharmacokinetics of VEN with a two-compartment model and all covariates are categorical. The median estimated apparent clearance (CL/F) was 446 L/Day and apparent volume of distribution of the central compartment (V2/F) was 114.5 L. The median IIV of CL/F reported was 39.5% and V2/F was 46.7%. Most commonly, CYP3A inhibitors, OATP1B3 inhibitors and rituximab co-administration were found to be significant covariates on CL/F. In addition, sex and population were influential covariates on V2/F. A detailed description of the characteristics of PPK models of VEN is provided in this review, as well as the effects of covariates on the PK parameters. For future development of the VEN PPK model, CYP3A inhibitors, rituximab co-administration, OATP1B1 transporter inhibitors, sex, population, and food might be considered. Further research and comprehensive investigations should be undertaken to explore reference ranges for therapeutic drug monitoring, define the potential role of patients with cerebrospinal fluid complications, and assess new or potential covariates. These endeavors will facilitate the development of personalized VEN therapy.

Targeted inhibition of DHODH is synergistic with BCL2 blockade in HGBCL with concurrent MYC and BCL2 rearrangement.

High-grade B-cell lymphoma (HGBCL), the subtype of non-Hodgkin lymphoma, to be relapsed or refractory in patients after initial therapy or salvage chemotherapy. Dual dysregulation of MYC and BCL2 is one of the important pathogenic mechanisms. Thus, combined targeting of MYC and BCL2 appears to be a promising strategy. Dihydroorotate dehydrogenase (DHODH) is the fourth rate-limiting enzyme for the de novo biosynthesis of pyrimidine. It has been shown to be a potential therapeutic target for multiple diseases. In this study, the DHODH inhibitor brequinar exhibited growth inhibition, cell cycle blockade, and apoptosis promotion in HGBCL cell lines with MYC and BCL2 rearrangements. The combination of brequinar and BCL2 inhibitors venetoclax had a synergistic inhibitory effect on the survival of DHL cells through different pathways. Venetoclax could upregulate MCL-1 and MYC expression, which has been reported as a resistance mechanism of BCL2 inhibitors. Brequinar downregulated MCL-1 and MYC, which could potentially overcome drug resistance to venetoclax in HGBCL cells. Furthermore, brequinar could downregulate a broad range of genes, including ribosome biosynthesis genes, which might contribute to its anti-tumor effects. In vivo studies demonstrated synergetic tumor growth inhibition in xenograft models with brequinar and venetoclax combination treatment. These results provide preliminary evidence for the rational combination of DHODH and BCL2 blockade in HGBCL with abnormal MYC and BCL2.

Cytoplasmic TP53INP2 acts as an apoptosis partner in TRAIL treatment: the synergistic effect of TRAIL with venetoclax in TP53INP2-positive acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a hematopoietic malignancy with poor outcomes, especially in older AML patients. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is considered a promising anticancer drug because it selectively induces the extrinsic apoptosis of tumor cells without affecting normal cells. However, clinical trials have shown that the responses of patients to TRAIL are significantly heterogeneous. It is necessary to explore predictable biomarkers for the preselection of AML patients with better responsiveness to TRAIL. Here, we investigated the critical role of tumor protein p53 inducible nuclear protein 2 (TP53INP2) in the AML cell response to TRAIL treatment. METHODS: First, the relationship between TP53INP2 and the sensitivity of AML cells to TRAIL was determined by bioinformatics analysis of Cancer Cell Line Encyclopedia datasets, Cell Counting Kit-8 assays, flow cytometry (FCM) and cell line-derived xenograft (CDX) mouse models. Second, the mechanisms by which TP53INP2 participates in the response to TRAIL were analyzed by Western blot, ubiquitination, coimmunoprecipitation and immunofluorescence assays. Finally, the effect of TRAIL alone or in combination with the BCL-2 inhibitor venetoclax (VEN) on cell survival was explored using colony formation and FCM assays, and the effect on leukemogenesis was further investigated in a patient-derived xenograft (PDX) mouse model. RESULTS: AML cells with high TP53INP2 expression were more sensitive to TRAIL in vitro and in vivo. Gain- and loss-of-function studies demonstrated that TP53INP2 significantly enhanced TRAIL-induced apoptosis, especially in AML cells with nucleophosmin 1 (NPM1) mutations. Mechanistically, cytoplasmic TP53INP2 maintained by mutant NPM1 functions as a scaffold bridging the ubiquitin ligase TRAF6 to caspase-8 (CASP 8), thereby promoting the ubiquitination and activation of the CASP 8 pathway. More importantly, simultaneously stimulating extrinsic and intrinsic apoptosis signaling pathways with TRAIL and VEN showed strong synergistic antileukemic activity in AML cells with high levels of TP53INP2. CONCLUSION: Our findings revealed that TP53INP2 is a predictor of responsiveness to TRAIL treatment and supported a potentially individualized therapeutic strategy for TP53INP2-positive AML patients.

Monocytic Differentiation in Acute Myeloid Leukemia Cells: Diagnostic Criteria, Biological Heterogeneity, Mitochondrial Metabolism, Resistance to and Induction by Targeted Therapies.

We review the importance of monocytic differentiation and differentiation induction in non-APL (acute promyelocytic leukemia) variants of acute myeloid leukemia (AML), a malignancy characterized by proliferation of immature myeloid cells. Even though the cellular differentiation block is a fundamental characteristic, the AML cells can show limited signs of differentiation. According to the French-American-British (FAB-M4/M5 subset) and the World Health Organization (WHO) 2016 classifications, monocytic differentiation is characterized by morphological signs and the expression of specific molecular markers involved in cellular communication and adhesion. Furthermore, monocytic FAB-M4/M5 patients are heterogeneous with regards to cytogenetic and molecular genetic abnormalities, and monocytic differentiation does not have any major prognostic impact for these patients when receiving conventional intensive cytotoxic therapy. In contrast, FAB-M4/M5 patients have decreased susceptibility to the Bcl-2 inhibitor venetoclax, and this seems to be due to common molecular characteristics involving mitochondrial regulation of the cellular metabolism and survival, including decreased dependency on Bcl-2 compared to other AML patients. Thus, the susceptibility to Bcl-2 inhibition does not only depend on general resistance/susceptibility mechanisms known from conventional AML therapy but also specific mechanisms involving the molecular target itself or the molecular context of the target. AML cell differentiation status is also associated with susceptibility to other targeted therapies (e.g., CDK2/4/6 and bromodomain inhibition), and differentiation induction seems to be a part of the antileukemic effect for several targeted anti-AML therapies. Differentiation-associated molecular mechanisms may thus become important in the future implementation of targeted therapies in human AML.

Synergistic Effect of Venetoclax and Bendamustine in Early T-cell Precursor Acute Lymphoblastic Leukemia.

BACKGROUND/AIM: To date, therapeutic options for T-cell acute lymphoblastic leukemia (T-ALL) remain very limited. This study evaluated the efficacy of monotherapies and combination therapies including a selective BCL-2 inhibitor for T-ALL cell lines, namely Jurkat, CCRF-CEM, and Loucy. MATERIALS AND METHODS: Loucy is an early T-precursor ALL (ETP-ALL) cell line characterized by an immature phenotype, whereas Jurkat and CCRF-CEM are late T-cell progenitor ALL (LTP-ALL) cell lines. Monotherapy was conducted with venetoclax, cytarabine, bendamustine, or azacytidine, whereas combination therapy was performed with venetoclax plus cytarabine, venetoclax plus bendamustine, or venetoclax plus azacytidine. Cell viability assay was conducted after 48 h using Trypan blue and the 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS). Statistical analysis for evaluating synergistic interactions between anticancer drugs was performed by using the SynergyFinder Plus and drc R package. RESULTS: Adding venetoclax to cytarabine, bendamustine, or azacitidine achieved an additive effect, with Loewe synergic scores ranging from -10 to 10 in Jurkat and CCRF-CEM. Conversely, the combination of venetoclax and cytarabine displayed an additive effect (Loewe synergic score: 8.45 and 5.82 with MTS and Trypan blue assays, respectively), whereas venetoclax plus bendamustine or azacitidine exhibited a synergistic effect (Loewe synergic score >10 with MTS assay) in Loucy. Remarkably, the Bliss/Loewe score revealed that the combination of venetoclax and bendamustine was the most synergistic, yielding a score of 13.832±0.55. CONCLUSION: The combination of venetoclax and bendamustine demonstrated the greatest synergistic effect in suppressing ETP-ALL cell proliferation. Further studies are warranted to determine the mechanisms for the synergism between venetoclax and bendamustine in high-risk T-ALL.

Plasma Venetoclax Concentrations in Patients with Acute Myeloid Leukemia Treated with CYP3A4 Inhibitors.

Venetoclax (VEN) is used in patients with acute myeloid leukemia (AML) and is primarily metabolized by CYP3A4, a major drug-metabolizing enzyme. Patients with AML simultaneously administered VEN and CYP3A4 inhibitors require a more appropriate management of drug-drug interactions (DDIs). Here, we report two cases of patients with AML (54-year-old man and 22-year-old woman) administrated VEN and CYP3A4 inhibitors, such as posaconazole, cyclosporine, or danazol. In the first case, we evaluated the appropriateness of timing for adjusting VEN dosage subsequent to the cessation of posaconazole. Consequently, modifying the VEN dosage in conjunction with the cessation of Posaconazole simultaneously may result in elevated plasma VEN levels. In the second case, plasma VEN concentrations were markedly elevated when co-administered with several CYP3A4 inhibitors. Additionally, in vitro assays were conducted for reverse translational studies to analyze CYP3A4 inhibition. CYP3A4 inhibition by combinatorial administration of cyclosporine A and danazol was demonstrated in vitro, which potentially explains the increasing plasma VEN concentrations observed in clinical settings. Although the acquisition of therapeutic effects is a major priority for patients, frequent therapeutic drug monitoring and dosage adjustments considering DDIs would be important factors in chemotherapy.

Reverse Phase Proteomic Array Profiling of Asparagine Synthetase Expression in Newly Diagnosed Acute Myeloid Leukemia.

Asparaginase-based therapy is a cornerstone in acute lymphoblastic leukemia (ALL) treatment, capitalizing on the methylation status of the asparagine synthetase (ASNS) gene, which renders ALL cells reliant on extracellular asparagine. Contrastingly, ASNS expression in acute myeloid leukemia (AML) has not been thoroughly investigated, despite studies suggesting that AML with chromosome 7/7q deletions might have reduced ASNS levels. Here, we leverage reverse phase protein arrays to measure ASNS expression in 810 AML patients and assess its impact on outcomes. We find that AML with inv(16) has the lowest overall ASNS expression. While AML with deletion 7/7q had ASNS levels slightly lower than those of AML without deletion 7/7q, this observation was not significant. Low ASNS expression correlated with improved overall survival (46 versus 54 weeks, respectively, p = 0.011), whereas higher ASNS levels were associated with better response to venetoclax-based therapy. Protein correlation analysis demonstrated association between ASNS and proteins involved in methylation and DNA repair. In conclusion, while ASNS expression was not lower in patients with deletion 7/7q as initially predicted, ASNS levels were highly variable across AML patients. Further studies are needed to assess whether patients with low ASNS expression are susceptible to asparaginase-based therapy due to their inability to augment compensatory ASNS expression upon asparagine depletion.