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.

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.

Efficacy and safety of venetoclax-based combination therapy for previously untreated acute myeloid leukemia: a meta-analysis.

PURPOSE: To explore the efficacy and safety of venetoclax-based combination therapy for older patients with newly diagnosed acute myeloid leukemia (AML). METHODS: We performed a systematic review and meta-analysis of clinical trials comparing venetoclax plus hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) with mono-HMAs or LDAC. The random or fixed effects model was applied to the studies based on heterogeneity. Dichotomous data were summarized using the risk ratio (RR) and 95% confidence interval (CI). Continuous variable data were reported as weighted mean differences (WMDs). RESULTS: Nine studies, including a total of 1232 patients, were included in this meta-analysis. Thec complete remission (CR)/complete remission with incomplete hematological recovery (CRi) rate of the venetoclax (Ven) + azacytidine (Aza) group was significantly greater than that of the Aza monotherapy group (RR: 2.42; 95% CI: 1.85-3.15; P < 0.001). Similarly, the CR/CRi rate of the Ven + LDAC group was also significantly greater than that of the LDAC monotherapy group (RR: 2.57; 95% CI: 1.58-4.17; P = 0.00). The same results were observed for OS among these groups. However, the incidence of febrile neutropenia was greater in the Ven + Aza group than in the Ven + Decitabine (Dec) or monotherapy Aza group (RR: 0.69; 95% CI: 0.53-0.90; P = 0.006 and RR: 2.19; 95% CI: 1.58-3.03; P < 0.001, respectively). In addition, the Ven + LDAC group had significantly greater rates of constipation, diarrhea, nausea, and vomiting than the LDAC monotherapy group, with RRs and CIs of 0.61 (95% CI 0.44-0.83, P = 0.002), 1.81 (95% CI 1.22-2.67, P = 0.003), 1.39 (95% CI 1.06-1.82, P = 0.016), and 1.80 (95% CI 1.19-2.72, P = 0.005), respectively. CONCLUSION: Venetoclax combined with azacitidine, decitabine, or LDAC significantly improved the CR/CRi and OS of patients with previously untreated AML. However, venetoclax plus azacitidine or LDAC was more likely to lead to increased febrile neutropenia and gastrointestinal toxicity.

[Efficacy and safety of venetoclax combined with hypomethylating agents in the treatment of 83 patients with higher-risk myelodysplastic syndromes].

Objective: This study aimed to evaluate the efficacy and safety of venetoclax (VEN) combined with hypomethylating agents (HMA) in the treatment of higher-risk myelodysplastic syndromes (HR-MDS) and analyze the factors influencing their therapeutic effect. Methods: The clinical data of 83 patients with HR-MDS who were diagnosed at the First Affiliated Hospital of Zhengzhou University between November 2019 and May 2023 were retrospectively analyzed. All patients were treated with VEN combined with HMA. The Kaplan-Meier method was used to depict the survival curves, and the log-rank test was used to compare survival between the groups. Results: The median age was 57 (15-82) years old, and 51 patients (61.4%) were male. Forty-five patients (54.2%) were initially treated with HMA, 23 (27.7%) received ≤4 cycles of HMA, and 15 (18.1%) demonstrated HMA failure. At the median follow-up of 10.3 (0.6-34.4) months, the overall response rate (ORR) was 62.7% (52/83), including 18 patients (21.7%) with a complete response (CR), 14 (16.9%) with a bone marrow CR (mCR) with hematological improvement, and 20 (24.1%) with a mCR. The ORR of patients with initial treatment, ≤4 HMA cycles, and HMA failure were 66.7%, 60.9%, and 53.3%, respectively (P=0.641). The median overall survival time was 14.6 (95% CI 7.2-22.0) months, and the median progression-free survival time was 8.9 (95% CI 6.7-11.1) months. The multivariate analysis showed that serum alkaline phosphatase (ALP) ≥90 U/L (OR=14.574, 95% CI 3.036-69.951, P=0.001), TP53 mutation (OR=13.052, 95% CI 1.982-85.932, P=0.008), and U2AF1 mutation (OR=7.720, 95% CI 1.540-38.698, P=0.013) were independent risk factors for poor efficacy of VEN combined with HMA. Hematological toxicity occurred in all patients, and the incidence of treatment-induced grade 3-4 leukopenia was 48.2% (40/83). Infection was the most common non-hematological adverse event, mainly pulmonary infection (31.3%) . Conclusion: VEN combined with HMA had a high response rate in patients with HR-MDS, both at initial treatment and with HMA failure. ALP ≥ 90 U/L, TP53 mutation, and U2AF1 mutation were independent risk factors for non-response to treatment.

Cell selective BCL-2 inhibition enabled by lipid nanoparticles alleviates lung fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a high mortality rate due to limited treatment options. Current therapies cannot effectively reverse the damage caused by IPF. Research suggests that promoting programmed cell death (apoptosis) in myofibroblasts, the key cells driving fibrosis, could be a promising strategy. However, inducing apoptosis in healthy cells like epithelial and endothelial cells can cause unwanted side effects. This project addresses this challenge by developing a targeted approach to induce apoptosis specifically in myofibroblasts. We designed liposomes (LPS) decorated with peptides that recognize VCAM-1, a protein highly expressed on myofibroblasts in fibrotic lungs. These VCAM1-targeted LPS encapsulate Venetoclax (VNT), a small molecule drug that inhibits BCL-2, an anti-apoptotic protein. By delivering VNT directly to myofibroblasts, we hypothesize that VCAM1-VNT-LPS can selectively induce apoptosis in these cells, leading to reduced fibrosis and improved lung function. We successfully characterized VCAM1-VNT-LPS for size, surface charge, and drug loading efficiency. Additionally, we evaluated their stability over three months at different temperatures. In vitro and in vivo studies using a bleomycin-induced mouse model of lung fibrosis demonstrated the therapeutic potential of VCAM1-VNT-LPS. These studies showed a reduction in fibrosis-associated proteins (collagen, α-SMA, VCAM1) and BCL-2, while simultaneously increasing apoptosis in myofibroblasts. These findings suggest that VCAM1-targeted delivery of BCL-2 inhibitors using liposomes presents a promising and potentially selective therapeutic approach for IPF.

Exploring the prognostic role of complex karyotype in chronic lymphocytic leukaemia patients treated with venetoclax-based regimens.

Although the unfavourable prognostic role of complex karyotype (CK) in chronic lymphocytic leukaemia (CLL) patients treated with chemoimmunotherapy has been clarified, its impact on the outcome of patients being treated with novel targeted agents, and especially with venetoclax-based regimens, remains to be resolved. In fact, only few studies, utilizing data derived from clinical trials (e.g. MURANO, CLL14, GAIA-CLL13), specifically focus on this topic while real-word evidence is missing. In our real-life retrospective study conducted on 61 patients with CLL and treated with venetoclax-based regimens in any therapeutic line, we documented a remarkable lower progression-free survival in patients harbouring both CK and high CK, while overall response rate (including complete remissions and partial remissions) and overall survival are not affected by CK in our population.

A phase 3b study of venetoclax and azacitidine or decitabine in an outpatient setting in patients with acute myeloid leukemia.

Venetoclax, a highly selective BCL-2 inhibitor, combined with hypomethylating agents (HMAs) azacitidine or decitabine, is approved for the treatment of newly diagnosed acute myeloid leukemia (ND AML) in patients who are ineligible to receive intensive chemotherapy. Previous clinical studies initiated venetoclax plus HMA in an inpatient setting owing to concerns of tumor lysis syndrome (TLS). This study (NCT03941964) evaluated the efficacy and safety of venetoclax plus HMA in a United States community-based outpatient setting in patients with ND AML (N = 60) who were treatment naïve for AML, ineligible to receive intensive chemotherapy, had no evidence of spontaneous TLS at screening, and were deemed as appropriate candidates for outpatient initiation of venetoclax plus HMA by the investigator. Patients received venetoclax in combination with azacitidine (75 mg/m2) or decitabine (20 mg/m2) for up to 6 cycles during the study. With a median time on study of 18.3 weeks, the best response rate of composite complete remission was 66.7%, and the overall post-baseline red blood cell (RBC) and platelet transfusion independence rate was 55.0%, consistent with results of studies in which treatment was initiated in an inpatient setting. Key adverse events included nausea, anemia, thrombocytopenia, neutropenia, and white blood cell count decrease of any grade (≥50% of patients). The observed safety profile was generally consistent with that of venetoclax plus HMA observed in inpatient AML studies. With close monitoring, 2 cases of TLS were identified, appropriately managed, and the patients were able to continue study treatment. CLINICAL TRIALS REGISTRATION: This study is registered at ClinicalTrials.gov. The registration identification number is NCT03941964.

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

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.

A real-world experience of venetoclax combined with hypomethylating agents vs. monotherapy hypomethylating agents in patients with myelodysplastic syndromes and chronic myelomonocytic leukemia patients.

Introduction: Current clinical research has reported the effectiveness and safety of venetoclax in combination with hypomethylating agents (VEN-HMA) in patients with myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). Thus, this study aimed to examine the effectiveness and safety of VEN-HMA therapy in patients with MDS and CMML and compared its short-term and long-term therapeutic effects with HMA monotherapy. Method: We analyzed data from our center, comprising 19 patients with MDS and CMML who received VEN-HMA therapy, compared to 32 patients treated with HMA monotherapy. Results: The overall response rate (ORR) in the VEN-HMA group was 73.7%, compared to 59.4% in the HMA group. The survival analysis revealed that the median overall survival (mOS) time in the VEN-HMA group was 16 months, with a median progression-free survival (mPFS) time of 9 months, both of which were longer than those observed in the HMA group (p < 0.05). Key adverse events (AEs) included grade 3-4 neutropenia (89.5% in VEN-HMA group vs. 87.5% in HMA group), grade 3-4 thrombocytopenia (73.7% vs. 71.9%), and anemia (73.7% vs. 90.6%). Infection of grade 3 or higher occurred in 63.2% of patients in the VEN-HMA group and 65.6% of patients in the HMA group. Discussion: Our study has confirmed the effectiveness and safety of the combined treatment of HMAs and venetoclax, which offers significant advantages to patients due to the relatively high and rapid response rates.

Gilteritinib with or without venetoclax for relapsed/refractory FLT3-mutated acute myeloid leukaemia.

Patients with FLT3-mutated acute myeloid leukaemia (AML) that relapse or are refractory (R/R) to intensive induction have poor outcomes. Gilteritinib has recently become standard-of-care for patients with R/R FLT3-mutated AML. We investigated whether adding venetoclax to gilteritinib (gilt-ven) improves outcomes as compared with gilteritinib monotherapy. We included patients treated with gilteritinib (n = 19) and gilt-ven (n = 17) for R/R AML after intensive chemotherapy. Gilteritinib and gilt-ven groups did not differ in terms of mCRc rates (53% and 65%, p = 0.51) and realization of allogeneic haematopoietic stem-cell transplantation (HSCT, 47% and 35%, p = 0.5). Overall survival (OS) was comparable between groups, although a trend towards better OS was seen with gilt-ven (12-month OS 58.8% [95% CI 39.5%-87.6%]) versus gilteritinib (42.1% [95% CI 24.9%-71.3%] for gilteritinib). Early salvage with gilt-ven versus any other gilteritinib-based approach was associated with the best outcome (p = 0.031). Combination therapy was associated with increased haematological toxicity. In summary, gilt-ven did not improve remissions or HSCT-realization rates in patients with R/R FLT3-mutated AML as compared with gilteritinib and was associated with increased haematological toxicity. Although OS did not differ, a trend towards better survival was suggested with gilt-ven and a survival benefit was shown for gilt-ven approach when sequenced early for salvage.

Venetoclax Clinical Pharmacokinetics After Administration of Crushed, Ground or Whole Tablets.

PURPOSE: Venetoclax is a potent, orally bioavailable BCL-2 inhibitor used in the treatment of some hematological malignancies. Crushing tablets may be necessary to help with the administration of venetoclax to patients with swallowing difficulties or patients requiring nasogastric tube feeding. The study was conducted to assess the bioavailability of crushed and finely ground venetoclax tablets relative to whole tablets. METHODS: An open-label, randomized, 3-way, crossover study in 15 healthy adult females was conducted. Venetoclax tablets were administered orally in a crushed, ground or intact form on Day 1 of each period with water following a high-fat breakfast. Pharmacokinetic samples were collected up to 72 hours postdosing. FINDINGS: The crushed and ground tablets met the bioequivalence criteria (0.80-1.25) relative to the intact tablets with respect to area under the concentration-time curve to time of the last measurable concentration (AUCt) and to infinite time (AUCinf) but exhibited a slightly lower maximum plasma concentration (Cmax). This was not considered clinically significant as only venetoclax overall exposure (AUC) has been shown to correlate with clinical efficacy. There was no change in the physical appearance and the evaluated physicochemical properties of crushed and ground venetoclax tablets after 72 hours of storage at 25°C/60% relative humidity. IMPLICATIONS: Crushing or grinding venetoclax tablets before administration could be considered as a viable alternative method of administration for patients who have difficulty swallowing whole venetoclax tablets or patients requiring nasogastric tube feeding. GOV IDENTIFIERS: NCT05909553, registered June 12, 2023.

Overexposure to venetoclax is associated with prolonged-duration of neutropenia during venetoclax and azacitidine therapy in Japanese patients with acute myeloid leukemia.

PURPOSE: An observational study was conducted to evaluate the pharmacokinetics of venetoclax and its impact on the efficacy and safety for Japanese patients with acute myeloid leukemia (AML) treated with venetoclax and azacitidine therapy. METHODS: The association between the plasma concentration, after the first cycle of azacitidine and venetoclax therapy, and the efficacy and safety was evaluated in 33 patients with untreated or relapsed/refractory AML. RESULTS: Full dose of venetoclax was administered to all patients. Venetoclax treatment was 28 day long in 82% of patients; the relative dose intensity of azacitidine was 82%. Trough concentration was significantly higher among patients with complete remission (CR) and CR with incomplete hematologic recovery (CRi) than those with the morphologic leukemia-free state and partial remission, and no response groups (P = 0.01). Median duration of grade 3 neutropenia was 28 days (range 8-46 days). Area under the concentration-time curve (AUC0-24) was significantly higher among patients with protracted grade 3 neutropenia (≥ 28 days) than those with a shorter duration (< 28 days) (P = 0.03); multivariate analysis revealed that a higher AUC0-24 was a significant predictor of a longer duration of neutropenia (odds ratio 54.3, P = 0.007). CONCLUSION: Plasma concentrations of venetoclax were variable in Japanese patients with AML. Higher plasma concentrations were associated with CR/CRi and protracted grade 3 neutropenia. Therefore, it is essential to adjust the duration of venetoclax administration based on individual pharmacokinetic data to limit total drug exposure, reduce severe neutropenia, and achieve higher efficacy.

Lower intensity therapy with cladribine/low dose cytarabine/venetoclax in older patients with acute myeloid leukemia compares favorably with intensive chemotherapy among patients undergoing allogeneic stem cell transplantation.

BACKGROUND: Allogeneic stem cell transplantation (SCT) remains the best consolidative modality in most patients with acute myeloid leukemia (AML). Along with factors directly pertaining to SCT, pretransplantation disease control, performance status, and prior treatment-related complications are important factors that affect posttransplantation survival outcomes. METHODS: The authors compared the survival outcomes of patients ≥60 years of age treated on the phase 2 clinical trial of venetoclax (Ven) added to cladribine (CLAD) and low dose cytarabine (LDAC) alternating with azacitidine (CLAD/LDAC/Ven arm) (NCT03586609) who underwent allogeneic SCT in first remission to a retrospective cohort of patients ≥60 years of age who underwent SCT after intensive chemotherapy. Intensive chemotherapy was defined as the use of cytarabine >1 g/m2 and anthracyclines during induction/consolidation. RESULTS: Thirty-five patients at median age of 68 years in the CLAD/LDAC/Ven arm were compared to 42 patients at a median age of 62 years in the intensive therapy arm. The 2-year relapse-free survival was superior with CLAD/LDAC/Ven versus intensive chemotherapy (88% vs. 65%; p = .03) whereas the 2-year overall survival (OS) was comparable (84% vs. 70%; p = .14). On a competing event analysis, the 2-year cumulative incidence of relapse (CIR) was significantly lower with CLAD/LDAC/Ven versus intensive chemotherapy (2.9% vs. 17.2%, Gray's p = .049) whereas nonrelapse mortality was comparable (16.2% vs. 17.1%; p = .486). CONCLUSION: In conclusion, treatment with CLAD/LDAC/Ven was associated with favorable outcomes in older patients who underwent subsequent allogeneic SCT. The OS was comparable to that with intensive chemotherapy followed by allogeneic SCT, but the CIR rate was significantly lower.

Transformation of marginal zone lymphoma into high-grade B-cell lymphoma expressing terminal deoxynucleotidyl transferase: A case report.

BACKGROUND: High-grade B-cell lymphoma (HGBL) is an unusual malignancy that includes myelocytomatosis viral oncogene (MYC), B-cell lymphoma-2 (BCL-2), and/or BCL-6 rearrangements, termed double-hit or triple-hit lymphomas, and HGBL-not otherwise specific (HGBL-NOS), which are morphologically characteristic of HGBL but lack MYC, BCL-2, or BCL-6 rearrangements. HGBL is partially transformed by follicular lymphoma and other indolent lymphoma, with few cases of marginal zone lymphoma (MZL) transformation. HGBL often has a poor prognosis and intensive therapy is currently mainly advocated, but there is no good treatment for these patients who cannot tolerate chemotherapy. CASE SUMMARY: We reported a case of MZL transformed into HGBL-NOS with TP53 mutation and terminal deoxynucleotidyl transferase expression. Gene analysis revealed the gene expression profile was identical in the pre- and post-transformed tissues, suggesting that the two diseases are homologous, not secondary tumors. The chemotherapy was ineffective and the side effect was severe, so we tried combination therapy including venetoclax and obinutuzumab. The patient tolerated treatment well, and reached partial response. The patient had recurrence of hepatocellular carcinoma and died of multifunctional organ failure. He survived for 12 months after diagnosis. CONCLUSION: Venetoclax combined with obinutuzumab might improve the survival in some HGBL patients, who are unsuitable for chemotherapy.

Rationalizing Counterion Selection for the Development of Lipophilic Salts: A Case Study with Venetoclax.

The use of lipid-based formulations (LBFs) can be hindered by low dose loading due to solubility limitations of candidate drugs in lipid vehicles. Formation of lipophilic salts through pairing these drugs with a lipophilic counterion has been demonstrated as a potential means to enhance dose loading in LBFs. This study investigated the screening of appropriate counterions to form lipophilic salts of the BCS class IV drug venetoclax. The physical properties, lipid solubility, and in vitro performance of the salts were analyzed. This study illustrated the versatility of alkyl sulfates and sulfonates as suitable counterions in lipophilic salt synthesis with up to ∼9-fold higher solubility in medium- and long-chain LBFs when compared to that of the free base form of venetoclax. All salts formulated as LBFs displayed superior in vitro performance when compared to the free base form of the drug due to the higher initial drug loadings in LBFs and increased affinity for colloidal species. Further, in vitro studies confirmed that venetoclax lipophilic salt forms using alkyl chain counterions demonstrated comparable in vitro performance to venetoclax docusate, thus reducing the potential for laxative effects related to docusate administration. High levels of the initial dose loading of venetoclax lipophilic salts were retained in a molecularly dispersed state during dispersion and digestion of the formulation, while also demonstrating increased levels of saturation in biorelevant media. The findings of this study suggest that alkyl chain sulfates and sulfonates can act as a suitable alternative counterion to docusate, facilitating the selection of counterions that can unlock the potential to formulate venetoclax as an LBF.

Selective eradication of venetoclax-resistant monocytic acute myeloid leukemia with iron oxide nanozymes.

The clinical treatment of human acute myeloid leukemia (AML) is rapidly progressing from chemotherapy to targeted therapies led by the BCL-2 inhibitor venetoclax (VEN). Despite its unprecedented success, VEN still encounters clinical resistance. Thus, uncovering the biological vulnerability of VEN-resistant AML disease and identifying effective therapies to treat them are urgently needed. We have previously demonstrated that iron oxide nanozymes (IONE) are capable of overcoming chemoresistance in AML. The current study reports a new activity of IONE in overcoming VEN resistance. Specifically, we revealed an aberrant redox balance with excessive intracellular reactive oxygen species (ROS) in VEN-resistant monocytic AML. Treatment with IONE potently induced ROS-dependent cell death in monocytic AML in both cell lines and primary AML models. In primary AML with developmental heterogeneity containing primitive and monocytic subpopulations, IONE selectively eradicated the VEN-resistant ROS-high monocytic subpopulation, successfully resolving the challenge of developmental heterogeneity faced by VEN. Overall, our study revealed an aberrant redox balance as a therapeutic target for monocytic AML and identified a candidate IONE that could selectively and potently eradicate VEN-resistant monocytic disease.

Current Therapeutic Sequencing in Chronic Lymphocytic Leukemia.

The treatment landscape of chronic lymphocytic leukemia (CLL), the most frequent leukemia in adults, is constantly changing. CLL patients can be divided into three risk categories, based on their IGHV mutational status and the occurrence of TP53 disruption and/or complex karyotype. For the first-line treatment of low- and intermediate-risk CLL, both the BCL2 inhibitor venetoclax plus obinutuzumab and the second generation BTK inhibitors (BTKi), namely acalabrutinib and zanubrutinib, are valuable and effective options. Conversely, venetoclax-based fixed duration therapies have not shown remarkable results in high-risk CLL patients, while continuous treatment with acalabrutinib and zanubrutinib displayed favorable outcomes, similar to those obtained in TP53 wild-type patients. The development of acquired resistance to pathway inhibitors is still a clinical challenge, and the optimal treatment sequencing of relapsed/refractory CLL is not completely established. Covalent BTKi-refractory patients should be treated with venetoclax plus rituximab, whereas venetoclax-refractory CLL may be treated with second generation BTKi in the case of early relapse, while venetoclax plus rituximab might be used if late relapse has occurred. On these grounds, here we provide an overview of the current state-of-the-art therapeutic algorithms for treatment-naïve patients, as well as for relapsed/refractory disease.

Venetoclax acts as an immunometabolic modulator to potentiate adoptive NK cell immunotherapy against leukemia.

Natural killer (NK) cell-based immunotherapy holds promise for cancer treatment; however, its efficacy remains limited, necessitating the development of alternative strategies. Here, we report that venetoclax, an FDA-approved BCL-2 inhibitor, directly activates NK cells, enhancing their cytotoxicity against acute myeloid leukemia (AML) both in vitro and in vivo, likely independent of BCL-2 inhibition. Through comprehensive approaches, including bulk and single-cell RNA sequencing, avidity measurement, and functional assays, we demonstrate that venetoclax increases the avidity of NK cells to AML cells and promotes lytic granule polarization during immunological synapse (IS) formation. Notably, we identify a distinct CD161lowCD218b+ NK cell subpopulation that exhibits remarkable sensitivity to venetoclax treatment. Furthermore, venetoclax promotes mitochondrial respiration and ATP synthesis via the NF-κB pathway, thereby facilitating IS formation in NK cells. Collectively, our findings establish venetoclax as a multifaceted immunometabolic modulator of NK cell function and provide a promising strategy for augmenting NK cell-based cancer immunotherapy.

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.

Design, synthesis, and evaluation of BCL-2 targeting PROTACs.

BCL-2, a member of the BCL-2 protein family, is an antiapoptotic factor that regulates the intrinsic pathway of apoptosis. Due to its aberrant activity, it is frequently implicated in haematopoietic cancers and represents an attractive target for the development of therapeutics that antagonize its activity. A selective BCL-2 inhibitor, venetoclax, was approved for treating chronic lymphocytic leukaemia, acute myeloid leukemia, and other hematologic malignancies, validating BCL-2 as an anticancer target. Since then, alternative therapeutic approaches to modulate the activity of BCL-2 have been explored, such as antibody-drug conjugates and proteolysis-targeting chimeras. Despite numerous research groups focusing on developing degraders of BCL-2 family member proteins, selective BCL-2 PROTACs remain elusive, as disclosed compounds only show dual BCL-xL/BCL-2 degradation. Herein, we report our efforts to develop BCL-2 degraders by incorporating two BCL-2 binding moieties into chimeric compounds that aim to hijack one of three E3 ligases: CRBN, VHL, and IAPs. Even though our project did not result in obtaining a potent and selective BCL-2 PROTAC, our research will aid in understanding the narrow chemical space of BCL-2 degraders.