A phase 1b study of venetoclax and alvocidib in patients with relapsed/refractory acute myeloid leukemia

Relapsed/refractory (R/R) Acute Myeloid Leukemia (AML) is a genetically complex and heterogeneous disease with a poor prognosis and limited treatment options. Thus, there is an urgent need to develop therapeutic combinations to overcome drug resistance in AML. This open-label, multicenter, international, phase 1b study evaluated the safety, efficacy, and pharmacokinetics of venetoclax in combination with alvocidib in patients with R/R AML. Patients were treated with escalating doses of venetoclax (400, 600, and 800 mg QD, orally, days 1-28) and alvocidib (45 and 60 mg/m2 , intravenously, days 1-3) in 28-day cycles. The combination was found to be safe and tolerable, with no maximum tolerated dose reached. Drug-related Grade ≥3 adverse events were reported in 23 (65.7%) for venetoclax and 24 (68.6%) for alvocidib. No drug-related AEs were fatal. Gastrointestinal toxicities, including diarrhea, nausea, and vomiting were notable and frequent; otherwise, the toxicities reported were consistent with the safety profile of both agents. The response rate was modest (complete remission [CR] + incomplete CR [CRi], 11.4%; CR + CRi + partial response rate + morphologic leukemia-free state, 20%). There was no change in alvocidib pharmacokinetics with increasing doses of venetoclax. However, when venetoclax was administered with alvocidib, AUC24 and Cmax decreased by 18% and 19%, respectively. A recommended phase 2 dose was not established due to lack of meaningful increase in efficacy across all cohorts compared to what was previously observed with each agent alone. Future studies could consider the role of the sequence, dosing, and the use of a more selective MCL1 inhibitor for the R/R AML population.

Development of a scoring system for predicting primary resistance to venetoclax plus hypomethylating agents (HMAs) in acute myeloid leukemia patients

In recent years, one of the most promising advances in the treatment of acute myeloid leukemia (AML) is the combination of a hypomethylating agent (HMA) with the BCL2 inhibitor venetoclax (VEN). To better understand the key factors associated with the response of VEN plus HMA, 212 consecutive AML patients were retrospectively recruited to establish and validate a scoring system for predicting the primary resistance to VEN-based induced therapy. All AML patients were divided randomly into a training set (n = 155) and a validation set (n = 57). Factors were selected using a multivariate logistic regression model, including FAB-M5, myelodysplastic syndrome-secondary acute myeloid leukemia (MDS-sAML), RUNX1-RUNX1T1 and FLT3-ITD mutation (FLT3-ITDm). A nomogram was then constructed including all these four predictors. The nomogram both presented a good performance of discrimination and calibration, with a C-index of 0.770 and 0.733 in the training and validation set. Decision curve analysis also indicated that the nomogram was feasible to make beneficial decisions. Eventually a total scoring system of 8 points was developed, which was divided into three risk groups: low-risk (score 0-2), medium-risk (score 3-4), and high-risk (score 5-8). There was a significant difference in the nonremission (NR) rate of these three risk groups (22.8% vs. 60.0% vs. 77.8%, p < 0.001). After adjustment of the other variables, patients in medium- or high-risk groups also presented a worse event-free survival (EFS) than that in the low-risk group (hazard ratio [HR] = 1.62, p = 0.03). In conclusion, we highlighted the response determinants of AML patients receiving a combination therapy of VEN plus HMAs. The scoring system can be used to predict the resistance of VEN, providing better guidance for clinical treatment.

Acquired resistance to venetoclax plus azacitidine in acute myeloid leukemia: In vitro models and mechanisms

The combination of venetoclax (VEN) and azacitidine (AZA) has become the standard of care for acute myeloid leukemia (AML) patients who are ≥ 75 years or unfit for intensive chemotherapy. Though initially promising, resistance to the combination therapy is an issue and VEN + AZA-relapsed/refractory patients have dismal outcomes. To better understand the mechanisms of resistance, we developed VEN + AZA-resistant AML cell lines, MV4-11/VEN + AZA-R and ML-2/VEN + AZA-R, which show > 300-fold persistent resistance compared to the parental lines. We demonstrate that these cells have unique metabolic profiles, including significantly increased levels of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP), changes in fatty acid and amino acid metabolism and increased utilization and reliance on glycolysis. Furthermore, fatty acid transporter CD36 is increased in the resistant cells compared to the parental cells. Inhibition of glycolysis with 2-Deoxy-D-glucose re-sensitized the resistant cells to VEN + AZA. In addition, the VEN + AZA-R cells have increased levels of the antiapoptotic protein Mcl-1 and decreased levels of the pro-apoptotic protein Bax. Overexpression of Mcl-1 or knockdown of Bax result in resistance to VEN + AZA. Our results provide insight into the molecular mechanisms contributing to VEN + AZA resistance and assist in the development of novel therapeutics to overcome this resistance in AML patients.

Limited Efficacy of Venetoclax Combination Regimens in Acute Myeloid Leukemia with Extramedullary Relapse

The recently approved BCL2 inhibitor venetoclax (VEN) has achieved promising outcomes in new and relapsed/refractory (R/R) acute myeloid leukemia (AML). Although its use is not well established in R/R AML with extramedullary disease (EMD), some reports have shown promising outcomes. We retrospectively analyzed 11 patients of R/R AML with EMD (with (n = 4) or without (n = 7) concurrent marrow involvement), who were treated with VEN plus decitabine (n = 9) or low-dose cytarabine (n = 2) between May 2020 and October 2020 in Seoul St. Mary's Hospital. The median number of prior treatment lines was 3 (1-6), and most (n = 9, 81.8%) had multiple sites of EMD. Nine patients (81.8%) received concurrent therapy for extramedullary (EM) involvement sites with radiotherapy (RT) (n = 4), surgery (n = 1), and both of them (n = 4). Among 11 patients, 4 patients (36.4%) had either marrow or EM responses to VEN combination; EM response was seen in 1 patient (9.1%, partial response) who had received concurrent RT (25 Gy, 10 fx) during the 1st cycle of VEN combination, and other 3 patients showed marrow response without EM response. After median follow-up of 27.0 months, the median overall survival was estimated to be 5.4 months. To conclude, VEN combination regimens have shown only modest efficacy in EM recurrence of AML with little impact on eliciting EM response.

Venetoclax, alone and in combination with the BH3 mimetic S63845, depletes HIV-1 latently infected cells and delays rebound in humanized mice

HIV-1 persists indefinitely in people living with HIV (PLWH) on antiretroviral therapy (ART). If ART is stopped, the virus rapidly rebounds from long-lived latently infected cells. Using a humanized mouse model of HIV-1 infection and CD4+ T cells from PLWH on ART, we investigate whether antagonizing host pro-survival proteins can prime latent cells to die and facilitate HIV-1 clearance. Venetoclax, a pro-apoptotic inhibitor of Bcl-2, depletes total and intact HIV-1 DNA in CD4+ T cells from PLWH ex vivo. This venetoclax-sensitive population is enriched for cells with transcriptionally higher levels of pro-apoptotic BH3-only proteins. Furthermore, venetoclax delays viral rebound in a mouse model of persistent HIV-1 infection, and the combination of venetoclax with the Mcl-1 inhibitor S63845 achieves a longer delay in rebound compared with either intervention alone. Thus, selective inhibition of pro-survival proteins can induce death of HIV-1-infected cells that persist on ART, extending time to viral rebound.

Longitudinal efficacy of Ertugliflozin in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

INTRODUCTION

Ertugliflozin, a sodium-glucose cotransporter-2 inhibitor, seems to improve glycemic control in type 2 diabetes mellitus (T2DM). We aim to evaluate the efficacy of Ertugliflozin across multiple time intervals (18, 26, and 52 weeks) in T2DM patients.

METHODS

A literature search was conducted on electronic databases. Data was extracted from eligible studies at both 5 mg and 15 mg doses in monotherapy and as add-on therapy. Cochrane RevMan was used to perform the meta-analysis.

RESULTS

Ertugliflozin, at both 5 mg and 15 mg doses, demonstrated a significant improvement in HbA1c levels at 18 weeks 5 mg [P = 0.00001], 15 mg [P = 0.05], and at 26 weeks in monotherapy 5 mg [P = 0.006], monotherapy 15 mg [P = 0.006], 5 mg as add-on therapy [P = 0.00001], 15 mg add-on therapy [P = 0.00001] respectively. At 52 weeks, the reduction in HbA1c was significant in 15 mg add-on therapy [P = 0.0001]. Additionally, ertugliflozin as an add-on therapy also led to a significant reduction in FPG, body weight, and systolic blood pressure.

CONCLUSION

Ertugliflozin showed clinical efficacy in improving glycemic control, fasting plasma glucose, body weight, and systolic blood pressure in T2DM patients over the studied time intervals compared to placebo.

Metformin sensitizes AML cells to venetoclax through endoplasmic reticulum stress-CHOP pathway

Venetoclax inhibits acute myeloid leukaemia by inhibiting BCL-2 targeting, and a combination regimen with venetoclax has been explored. Although these regimens produce better clinical results, the vast majority of patients still suffer from disease recurrence or primary drug resistance. Metformin has been demonstrated to induce apoptosis in cancer cells. However, whether it can synergize with venetoclax and the underlying mechanisms of metformin-induced apoptosis are not fully understood. In this study, we investigated the effect of metformin and venetoclax on the growth of AML cells in vitro and in vivo. In both Molm13 and THP-1 cell lines, metformin and venetoclax synergistically inhibited the proliferation and induced apoptosis of leukaemia cells. Most importantly, the combination of metformin and venetoclax treatment significantly increased the expression levels of the endoplasmic reticulum (ER) stress-related marker CHOP, for example, in AML cell lines. Knockdown of CHOP markedly attenuated the metformin- and venetoclax-induced cell apoptosis. Moreover, the combination of metformin and venetoclax demonstrated prominent anti-leukaemia effects in xenograft models and bone marrow samples from AML patients. In summary, the combination of metformin and venetoclax showed enhanced anti-leukaemia activity with acceptable safety in AML patients, representing a new combinatorial strategy worth further clinical investigation to treat AML.

High-Throughput Drug Screen for Potential Combinations With Venetoclax Guides the Treatment of Transformed Follicular Lymphoma

Transformed follicular lymphoma (t-FL) is an aggressive malignancy that is refractory and rapidly progressing with poor prognosis. There is currently no effective treatment. High-throughput screening (HTS) platforms are used to profile the sensitivity or toxicity of hundreds of drug molecules, and this approach is applied to identify potential effective treatments for t-FL. We randomly selected a compound panel from the School of Pharmaceutical Sciences Xiamen University, tested the effects of the panel on the activity of t-FL cell lines using HTS and the CCK-8 assay, and identified compounds showing synergistic anti-proliferative activity with the Bcl-2 inhibitor venetoclax (ABT-199). Bioinformatics tools were used to analyze the potential synergistic mechanisms. The single-concentration compound library demonstrated varying degrees of activity across the t-FL cell lines evaluated, of which the Karpas422 cells were the most sensitive, but it was the cell line with the least synergy with ABT-199. We computationally identified 30 drugs with synergistic effects in all cell lines. Molecularly, we found that the targets of these 30 drugs didn't directly regulate Bcl-2 and identified 13 medications with high evidence value above .9 of coordination with ABT-199, further confirming TP53 may play the largest role in the synergistic effect. Collectively, these findings identified the combined regimens of ABT-199 and further suggested that the mechanism is far from directly targeting Bcl-2, but rather through the regulation and synergistic action of p53 and Bcl-2. This study intended to reveal the best synergistic scheme of ABT-199 through HTS to more quickly inform the treatment of t-FL.

[Clinical efficacy and safety of venetoclax combined with multidrug chemotherapy in the treatment of 15 patients with relapsed or refractory early T-cell precursor acute lymphoblastic leukemia]

Objective: To explore the efficacy and safety of Venetoclax combined with multidrug chemotherapy in patients with relapsed or refractory early T-cell precursor acute lymphoblastic leukemia (R/R ETP-ALL) . Methods: This study retrospectively analyzed 15 patients with R/R ETP-ALL who received Venetoclax combined with multidrug chemotherapy from December 2018 to February 2022. Among them, eight cases were combined with demethylated drugs, four cases were combined with demethylated drugs and HAAG chemotherapy regimen, two cases were combined with demethylated drugs and CAG regimen, and one case was combined with Cladribine. Specific usage and dosage of Venetoclax: 100 mg on day 1, 200 mg on day 2, 400 mg on day 3-28, orally; when combined with azole antifungal drugs, dosage was reduced to 100 mg/d. Results: Fifteen patients (10 males and 5 females) with R/R ETP-ALL were treated with Venetoclax and multidrug chemotherapy with a median age of 35 (12-42) years old. Of 4 refractory and 11 relapsed patients, the efficacy was evaluated on the 21th day following combined chemotherapy: the overall response rate, the complete response (CR) rate, and the CR with incomplete hematological recovery (CRi) rate were 67.7% (10/15), 60.0% (9/15), and 6.7% (1/15), respectively. For the overall study population, the 12-month overall survival (OS) rate was 60.0%, and the median OS was 17.7 months. The disease-free survival (DFS) rate of all CR patients at 12 months was 60.0%, and the median DFS did not reach. About 14 patients had Ⅲ-Ⅳ hematological toxicity, but these adverse reactions were all controllable. No adverse reaction in the nervous system and tumor lysis syndrome occurred in this study, and no adverse reaction of organs above grade Ⅲ occurred. Conclusion: Venetoclax combined with multidrug chemotherapy may be a safe and promising treatment option for patients with R/R ETP-ALL.

High karyotypic complexity is an independent prognostic factor in patients with CLL treated with venetoclax combinations

Complex karyotypes have been associated with inferior outcomes in chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy (CIT), whereas their prognostic impact in the context of venetoclax-based treatments is still debated. In this prospective analysis on karyotype complexity in CLL, we evaluated the impact of complex (≥3 chromosomal aberrations [CAs], CKTs) and highly complex karyotypes (≥5 CAs; hCKTs) as well as specific aberrations in previously untreated patients without TP53 aberrations undergoing either CIT or time-limited venetoclax-based therapies in the phase 3 GAIA/CLL13 trial. Karyotype analyses were available for 895 of 926 patients (96.7%), of whom 153 (17%) had a CKT and 43 (5%) hCKT. In the CIT arm, CKT was associated with shorter progression-free survival (PFS) (hazard ratio [HR] 2.58; 95% confidence interval [95% CI], 1.54-4.32; P < .001) and overall survival (HR, 3.25; 95% CI, 1.03-10.26; P = .044). In the pooled venetoclax arms, a multivariable analysis identified hCKTs (HR, 1.96; 95% CI, 1.03-3.72; P = .041), but not CKTs, as independent adverse prognosticators for PFS. The presence of translocations (unbalanced and/or balanced) was also independently associated with shorter PFSs in the venetoclax arms. CIT led to the acquisition of additional CAs (mean CAs, 2.0-3.4; from baseline to CLL progression), whereas karyotype complexity remained stable after venetoclax-based treatments (2.0, both time points). This analysis establishes highly complex karyotypes and translocations as adverse prognostic factors in the context of venetoclax-based combination treatments. The findings of this study support the incorporation of karyotyping into the standard diagnostic workup of CLL, because it identifies patients at high risk of poor treatment outcomes and thereby improves prognostication. This trial was registered at www.clinicaltrials.gov as #NCT02950051.

The ribosomal protein S6 kinase alpha-1 (RPS6KA1) induces resistance to venetoclax/azacitidine in acute myeloid leukemia

Venetoclax/azacitidine combination therapy is effective in acute myeloid leukemia (AML) and tolerable for older, multimorbid patients. Despite promising response rates, many patients do not achieve sustained remission or are upfront refractory. Identification of resistance mechanisms and additional therapeutic targets represent unmet clinical needs. By using a genome-wide CRISPR/Cas9 library screen targeting 18,053 protein- coding genes in a human AML cell line, various genes conferring resistance to combined venetoclax/azacitidine treatment were identified. The ribosomal protein S6 kinase A1 (RPS6KA1) was among the most significantly depleted sgRNA-genes in venetoclax/azacitidine- treated AML cells. Addition of the RPS6KA1 inhibitor BI-D1870 to venetoclax/azacitidine decreased proliferation and colony forming potential compared to venetoclax/azacitidine alone. Furthermore, BI-D1870 was able to completely restore the sensitivity of OCI-AML2 cells with acquired resistance to venetoclax/azacitidine. Analysis of cell surface markers revealed that RPS6KA1 inhibition efficiently targeted monocytic blast subclones as a potential source of relapse upon venetoclax/azacitidine treatment. Taken together, our results suggest RPS6KA1 as mediator of resistance towards venetoclax/azacitidine and additional RPS6KA1 inhibition as strategy to prevent or overcome resistance.

Venetoclax is safe and tolerable as post-transplant maintenance therapy for AML patients at high risk for relapse

Relapse is the most common cause of mortality in acute myeloid leukemia (AML) patients after allogeneic stem cell transplant (SCT). Post-SCT maintenance strategies that prevent relapse are desirable but must be well tolerated and convenient to administer. We hypothesized single agent venetoclax (ven) may be an effective maintenance therapy among high relapse risk patients. Between February 2019 and December 2021, we administered post-SCT ven maintenance to 49 AML patients at high-risk for relapse as a prospectively defined off-label practice at our institution. Ven was planned to be administered until 1-year post-SCT. While temporary interruptions were common (67.3% of all patients), of those with >1 year follow up, 22/25 (88%) completed the full year of planned therapy. Cytopenias (40.8%) and gastrointestinal adverse events (34.7%) were the most common toxicities. At 1-year post-SCT, overall survival (OS) and relapse-free survival (RFS) were 70% and 67% respectively. Our experience demonstrates single agent ven is a safe, tolerable, and feasible maintenance therapy that may improve RFS and OS in high relapse risk post-SCT patients.

Posttranslational splicing modifications as a key mechanism in cytarabine resistance in acute myeloid leukemia

Despite the approval of several drugs for AML, cytarabine is still widely used as a therapeutic approach. However, 85% of patients show resistance and only 10% overcome the disease. Using RNA-seq and phosphoproteomics, we show that RNA splicing and serine-arginine-rich (SR) proteins phosphorylation were altered during cytarabine resistance. Moreover, phosphorylation of SR proteins at diagnosis were significantly lower in responder than non-responder patients, pointing to their utility to predict response. These changes correlated with altered transcriptomic profiles of SR protein target genes. Notably, splicing inhibitors were therapeutically effective in treating sensitive and resistant AML cells as monotherapy or combination with other approved drugs. H3B-8800 and venetoclax combination showed the best efficacy in vitro, demonstrating synergistic effects in patient samples and no toxicity in healthy hematopoietic progenitors. Our results establish that RNA splicing inhibition, alone or combined with venetoclax, could be useful for the treatment of newly diagnosed or relapsed/refractory AML.

Outcomes in Patients with High-Risk Features after Fixed-Duration Ibrutinib plus Venetoclax: Phase II CAPTIVATE Study in First-Line Chronic Lymphocytic Leukemia

PURPOSE

The CAPTIVATE study investigated first-line ibrutinib plus venetoclax for chronic lymphocytic leukemia in 2 cohorts: minimal residual disease (MRD)-guided randomized discontinuation (MRD cohort) and Fixed Duration (FD cohort). We report outcomes of fixed-duration ibrutinib plus venetoclax in patients with high-risk genomic features [del(17p), TP53 mutation, and/or unmutated immunoglobulin heavy chain (IGHV)] in CAPTIVATE.

PATIENTS AND METHODS

Patients received three cycles of ibrutinib 420 mg/day then 12 cycles of ibrutinib plus venetoclax (5-week ramp-up to 400 mg/day). FD cohort patients (n = 159) received no further treatment. Forty-three MRD cohort patients with confirmed undetectable MRD (uMRD) after 12 cycles of ibrutinib plus venetoclax received randomized placebo treatment.

RESULTS

Of 195 patients with known status of genomic risk features at baseline, 129 (66%) had ≥1 high-risk feature. Overall response rates were >95% regardless of high-risk features. In patients with and without high-risk features, respectively, complete response (CR) rates were 61% and 53%; best uMRD rates: 88% and 70% (peripheral blood) and 72% and 61% (bone marrow); 36-month progression-free survival (PFS) rates: 88% and 92%. In subsets with del(17p)/TP53 mutation (n = 29) and unmutated IGHV without del(17p)/TP53 mutation (n = 100), respectively, CR rates were 52% and 64%; uMRD rates: 83% and 90% (peripheral blood) and 45% and 80% (bone marrow); 36-month PFS rates: 81% and 90%. Thirty-six-month overall survival (OS) rates were >95% regardless of high-risk features.

CONCLUSIONS

Deep, durable responses and sustained PFS seen with fixed-duration ibrutinib plus venetoclax are maintained in patients with high-risk genomic features, with similar PFS and OS to those without high-risk features. See related commentary by Rogers, p. 2561.

A multicenter analysis of the outcomes with venetoclax in patients with relapsed mantle cell lymphoma

To report the activity of venetoclax in patients with relapsed mantle cell lymphoma (MCL), we identified 81 patients treated with venetoclax monotherapy (n = 50, 62%) or in combination with a Bruton tyrosine kinase inhibitor (BTKi) (n = 16, 20%), an anti-CD20 monoclonal antibody (n = 11, 14%), or other active agents at 12 US academic medical centers. Patients had high-risk disease features including Ki67 >30% (61%), blastoid/pleomorphic histology (29%), complex karyotype (34%), and TP53 alterations (49%), and received a median of 3 prior treatments including BTKis in 91%. Venetoclax alone or in combination resulted in an overall response rate (ORR) of 40% and median progression-free (PFS) and overall survival (OS) of 3.7 and 12.5 months, respectively. The receipt of ≤3 prior treatments was associated with higher odds of response to venetoclax in a univariable analysis. In a multivariable analysis, having a high-risk Mantle Cell Lymphoma International Prognostic Index score before receiving venetoclax and disease relapse or progression within 24 months of diagnosis were associated with inferior OS whereas the use of venetoclax in combination was associated with superior OS. Although most patients (61%) had low risk for tumor lysis syndrome (TLS), 12.3% of patients developed TLS despite the implementation of several mitigation strategies. In conclusion, venetoclax resulted in good ORR but short PFS in patients with MCL who are at high risk, and may have a better role in earlier lines of treatment and/or in conation with other active agents. TLS remains an important risk in patients with MCL who initiate treatment with venetoclax.