Venetoclax as monotherapy and in combination with hypomethylating agents or low dose cytarabine in relapsed and treatment refractory acute myeloid leukemia: a systematic review and meta-analysis

HMA/VEN treatment modifications and associated outcomes in IDH-mutant AML

Hypomethylating agents (HMA) and venetoclax (VEN) are commonly used in patients with IDH-mutated (IDHm) acute myeloid leukemia (AML) ineligible for induction chemotherapy. While prior studies demonstrated high response and survival rates with HMA/VEN in IDHm AML, the impact of treatment modifications in real-world settings is unclear. We retrospectively reviewed 89 IDHm AML patients treated with HMA/VEN from January 2018 to June 2023. CR/CRi rates were 76% in newly diagnosed (ND) and 55% in relapsed/refractory (R/R) patients, and median overall survival was 29.2 months (ND) and 17.1 months (R/R), respectively. Treatment modifications were common. Early VEN reductions were associated with lower response rates but not worse survival. Prolonged cycles were not associated with worse response rates or survival. Significant neutropenia and ED visits or unplanned hospitalizations were considerable before and after CR/CRi, though febrile neutropenia decreased afterward. HMA/VEN is efficacious, with treatment modifications not affecting survival, though long-term toxicities are notable.

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.

Novel insights and therapeutic approaches in secondary AML

Secondary acute myeloid leukemia (sAML) presents as a complex and multifaceted ensemble of disorders, positioning itself as both a challenge and an intriguing frontier within hematologic oncology. Its origins are diverse, stemming from antecedent hematologic conditions, germline predisposing mutations, or the sequelae of cytotoxic therapies, and its development is driven by intricate genetic and epigenetic modifications. This complexity necessitates a diverse array of therapeutic strategies, each meticulously tailored to address the distinctive challenges sAML introduces. Such strategies require a personalized approach, considering the variegated clinical backgrounds of patients and the inherent intricacies of the disease. Allogeneic stem cell transplantation stands as a cornerstone, offering the potential for curative outcomes. This is complemented by the emergence of innovative treatments such as CPX-351, venetoclax, and glasdegib, which have demonstrated promising results in enhancing prognosis. The evolving landscape of sAML treatment underscores the importance of continued research and innovation in the field, aiming not only to improve patient outcomes but also to deepen our understanding of the disease's biological underpinnings, thereby illuminating pathways toward more effective and individualized therapies.

Construction of an immune-related prognostic signature and lncRNA-miRNA-mRNA ceRNA network in acute myeloid leukemia

The progression of acute myeloid leukemia (AML) is influenced by the immune microenvironment in the bone marrow and dysregulated intracellular competing endogenous RNA (ceRNA) networks. Our study utilized data from UCSC Xena, The Cancer Genome Atlas Program, the Gene Expression Omnibus, and the Immunology Database and Analysis Portal. Using Cox regression analysis, we identified an immune-related prognostic signature. Genomic analysis of prognostic messenger RNA (mRNA) was conducted through Gene Set Cancer Analysis (GSCA), and a prognostic ceRNA network was constructed using the Encyclopedia of RNA Interactomes. Correlations between signature mRNAs and immune cell infiltration, checkpoints, and drug sensitivity were assessed using R software, gene expression profiling interactive analysis (GEPIA), and CellMiner, respectively. Adhering to the ceRNA hypothesis, we established a potential long noncoding RNA (lncRNA)/microRNA (miRNA)/mRNA regulatory axis. Our findings pinpointed 9 immune-related prognostic mRNAs (KIR2DL1, CSRP1, APOBEC3G, CKLF, PLXNC1, PNOC, ANGPT1, IL1R2, and IL3RA). GSCA analysis revealed the impact of copy number variations and methylation on AML. The ceRNA network comprised 14 prognostic differentially expressed lncRNAs (DE-lncRNAs), 6 prognostic DE-miRNAs, and 3 prognostic immune-related DE-mRNAs. Correlation analyses linked these mRNAs' expression to 22 immune cell types and 6 immune checkpoints, with potential sensitivity to 27 antitumor drugs. Finally, we identified a potential LINC00963/hsa-miR-431-5p/CSRP1 axis. This study offers innovative insights for AML diagnosis and treatment through a novel immune-related signature and ceRNA axis. Identified novel biomarkers, including 2 mRNAs (CKLF, PNOC), 1 miRNA (hsa-miR-323a-3p), and 10 lncRNAs (SNHG25, LINC01857, AL390728.6, AC127024.5, Z83843.1, AP002884.1, AC007038.1, AC112512, AC020659.1, AC005921.3) present promising candidates as potential targets for precision medicine, contributing to the ongoing advancements in the field.

Venetoclax plus cytarabine and azacitidine in relapsed/refractory AML: An open-label, single-arm, phase 2 study

BACKGROUND

The outcome of relapsed/refractory (R/R) acute myeloid leukemia (AML) remains extremely poor. Venetoclax (VEN)-based regimens have shown promise in treating R/R AML.

OBJECTIVE

This phase 2 study aimed to systematically evaluate the efficacy and safety of the VAA regimen (VEN plus Cytarabine and Azacitidine) in R/R AML patients.

METHODS

Thirty R/R AML patients were enrolled. The study adopted a stepwise ramp-up of VEN dosing, starting with 100 mg on day 1, escalating to 200 mg on day 2, and reaching 400 mg from day 3 to day 9. Cytarabine (10 mg/m2, q12h) was administered intravenously twice daily from days 1 to 10, and Azacitidine (75 mg/m2) was administered via subcutaneous injection once daily from days 1-7. The primary efficacy endpoint was the composite complete remission rate (CRc), including complete response (CR) and complete response with incomplete blood count recovery (CRi). Secondary endpoints included overall survival (OS), duration of response (DOR), and safety analysis.

RESULTS

The CRc rate was 63.3% (19/30), with CR in 36.7% of patients and CRi in 26.7%. Notably, 14 (73.7%) of 19 patients achieving CRc showed undetectable measurable residual disease by flow cytometry. With a median follow-up of 10.7 months, the median OS had not been reached, and the median DOR was 18.3 months. The most common grade 3-4 adverse events (AEs) were neutropenia (100%), anemia (96.7%), thrombocytopenia (90.0%), and leukopenia (90.0%). Infections, with pneumonia being the most prevalent (43.3%), were observed, including one fatal case of Pseudomonas aeruginosa septicemia. There were no treatment-related deaths.

CONCLUSION

The VAA regimen is an effective and safe option for patients with R/R AML, demonstrating a high CRc rate and manageable safety profile.

Advances in molecular targeted drugs in combination with CAR-T cell therapy for hematologic malignancies

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.

Meta‑analysis of the efficacy of venetoclax and azacitidine combination therapy and azacitidine monotherapy for treating acute myeloid leukemia

The present study aimed to compare the efficacy of combination therapy with venetoclax and azacitidine with that of azacytidine monotherapy in the treatment of acute myeloid leukemia (AML). The Web of Science, PubMed, Embase, The Cochrane Library, Weipu Database, Wanfang Digital Periodicals, Sinomed, China National Knowledge Infrastructure, ProQuest Dissertations and Theses and Cumulative Index to Nursing and Allied Health Literature were searched for publications on the treatment of AML with venetoclax combined with azacitidine or with azacitidine monotherapy. A total of 5,271 relevant studies were retrieved, of which 10 were included. Literature quality was evaluated according to the Cochrane systematic review methodology, and data were extracted for meta-analysis using Review Manager 5.4. The combination of venetoclax and azacitidine demonstrated greater overall efficacy than azacitidine monotherapy for AML treatment. Notably, combination therapy resulted in a higher frequency of complete remission. By contrast, combined treatment and monotherapy showed no significant differences in partial remission, whereas there was a statistically significant decrease in the frequency of no remission in the combination therapy group compared with in the monotherapy group. The results also revealed a significantly higher incidence of adverse reactions when venetoclax and azacitidine were combined in the treatment of AML compared with the observed rates in response to azacitidine monotherapy. Moreover, subgroup analyses showed that no statistically significant differences were observed between the two groups regarding adverse events, including hypokalemia and liver insufficiency. In conclusion, the combination of venetoclax and azacitidine was more effective than azacitidine alone, and had a good clinical application value in the treatment of AML. Although some adverse reactions occurred in response to the combination therapy, they did not significantly affect the prognosis of AML. To better evaluate the efficacy and safety of this treatment regimen, multicenter clinical studies with larger sample sizes are required.

Risk of infectious adverse events of venetoclax therapy for hematologic malignancies: a systematic review and meta-analysis of RCTs

ABSTRACT

Venetoclax is a small molecule inhibitor of BCL-2 used in the treatment of acute myelogenous leukemia (AML) and chronic lymphocytic leukemia (CLL). Recent postmarketing studies of ibrutinib, another small molecule inhibitor, suggested that these agents may predispose to opportunistic infections. We sought to systematically review the randomized controlled trial (RCT) evidence of venetoclax to assess whether it predisposes patients to infectious adverse events (IAEs) and neutropenia. We systematically reviewed RCTs comparing venetoclax therapy with active or placebo controls for patients with hematologic malignancies. Data on IAEs and neutropenia were pooled by Bayesian meta-analysis, and we computed the probability of any increased risk (P[risk ratio (RR) > 1]) of IAEs or neutropenic complications. Seven RCTs were included, comprising 2067 patients. In CLL (n = 1032), there was a low probability of increased risk of high-grade (P[RR > 1] = 71.2%) and fatal IAEs (P[RR > 1] = 64.5%) and high-grade neutropenia (P[RR > 1] = 63.4%). There were insufficient data to perform a meta-analysis of IAEs in AML; however, 1 trial suggested an increased risk of IAEs with venetoclax. Furthermore, in AML (n = 642), venetoclax was associated with a high probability of increased risk of high-grade neutropenia (P[RR > 1] = 94.6%) and febrile neutropenia (P[RR > 1] = 90.6%). Our results suggest that venetoclax has a low probability of increased risk of IAEs or neutropenia in CLL. By contrast, there is likely increased risk of high-grade neutropenia and febrile neutropenia in AML. Importantly, our analyses did not identify any specific IAEs that would benefit from routine antimicrobial prophylaxis or pre-emptive testing.

Venetoclax-based therapy in treatment-naïve and relapsed/refractory acute myeloid leukemia

Combining venetoclax with the hypomethylating agents azacitidine or decitabine has shown high complete response rates (60-70 %) in newly diagnosed (ND) acute myeloid leukemia (AML). However, studies addressing the efficacy of this approach in relapsed/refractory (R/R) AML remain limited. We conducted a retrospective analysis on patients treated with venetoclax-based therapy at a single institution. Objective response rates (ORR) and overall survival (OS) were assessed using logistic regression and Cox regression models, respectively. The total study population exhibited an ORR of 64 % with a complete remission at 34 %, complete remission with incomplete count recovery at 19%, and morphologic leukemia free state at 11 %. Patients with ND AML had a better ORR (71 %) compared to R/R AML (55 %), but the difference was not statistically significant. Median OS for the overall population was 14.4 months (range: 2-26 months). In the ND group, patients had a longer 6-month OS (82 % vs. 55 % in R/R AML), while both cohorts showed similar 12- and 24-month OS. Factors such as the hypomethylating agent chosen, adverse cytogenetics, TP53 mutations, prior hypomethylating agent use, and stem cell transplant status did not significantly affect ORR or OS. These findings support the effectiveness of venetoclax-based treatments in ND and R/R AML.

Venetoclax combined with hypomethylating agents and the CAG regimen in relapsed/refractory AML: a single-center clinical trial

Objective

This study aimed to evaluate the efficacy and safety of venetoclax in combination with hypomethylating agents and CAG (VEN-DCAG) regimens in patients with relapsed/refractory acute myeloid leukemia (R/R AML).

Methods

The treatment response was analyzed by retrospective methods in R/R AML patients treated with the VEN-DCAG regimen at our institution. This included, but was not limited to, CR/CRi (complete remission/complete remission with incomplete hematologic recovery) rate, measurable residual disease (MRD) negative rate, and overall survival (OS).

Results

20 patients with R/R AML were recruited, with a median age of 40 years (10-70), 11 of whom were male (55%), and a median follow-up of 10.4 months (0.7-21.8). The overall response rate (ORR) after receiving 1 course of VEN-DCAG was 90% (18/20), with 17 (85%) CR/CRi (10 MRD-CR), 1 (5%) PR, and 2 (10%) NR. Subsequently, 12 patients (7 MRD-CR, 4 MRD+CR, 1 NR) were treated with the VEN-DCAG regimen, and 3 MRD+CR patients turned negative, and 13 patients finally achieved MRD-CR. Among them, 7 patients were in the relapse group, all achieving CR/CRi (6 MRD-CR), and 13 patients in the refractory group, with 10 CR/CRi (7 MRD-CR). The ORR for patients in the relapse and refractory groups was 100% (7/7) and 84.6% (11/13), respectively. Further, all patients experienced adverse events (AEs) of varying degrees of severity, with hematologic AEs primarily consisting of myelosuppression, while non-hematologic AEs were more common in the form of fever, gastrointestinal distress, and infections. 11 patients were followed up with bridging allogeneic hematopoietic stem cell transplantation (allo-HSCT) therapy. At the last follow-up, 11 patients (7 MRD-CR, 4 MRD+CR) who received allo-HSCT, 1 (MRD+CR) died, and 9 patients (6 MRD-CR, 1 PR, 2 NR) who did not receive allo-HSCT, 5 (2 MRD-CR, 1 PR, 2 NR) died as well.

Conclusion

The VEN-DCAG regimen may be an effective treatment option for R/R AML patients, with high ORR and MRD negative remission rates in both the relapsed and refractory groups. It is recommend that patients should be bridged to allo-HSCT as soon as possible after induction to CR by the VEN-DCAG regimen, which can lead to a significant long-term survival benefit.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2300075985.

Spliceosome mutations are associated with clinical response in a phase 1b/2 study of the PLK1 inhibitor onvansertib in combination with decitabine in relapsed or refractory acute myeloid leukemia

PLK1 is overexpressed in acute myeloid leukemia (AML). A phase 1b trial of the PLK1 inhibitor onvansertib (ONV) combined with decitabine (DAC) demonstrated initial safety and efficacy in patients with relapsed/refractory (R/R) AML. The current study aimed to identify molecular predictors of response to ONV + DAC in R/R AML patients. A total of 44 R/R AML patients were treated with ONV + DAC and considered evaluable for efficacy. Bone marrow (BM) samples were collected at baseline for genomic and transcriptomic analysis (n = 32). A 10-gene expression signature, predictive of response to ONV + DAC, was derived from the leading-edge genes of gene set enrichment analyses (GSEA). The gene signature was evaluated in independent datasets and used to identify associated mutated genes. Twenty percent of the patients achieved complete remission, with or without hematologic count recovery (CR/CRi), and 32% exhibited a ≥50% reduction in bone marrow blasts. Patients who responded to treatment had elevated mitochondrial function and OXPHOS. The gene signature was not associated with response to DAC alone in an independent dataset. By applying the signature to the BeatAML cohort (n = 399), we identified a positive association between predicted ONV + DAC response and mutations in splicing factors (SF). In the phase 1b/2 trial, patients with SF mutations (SRSF2, SF3B1) had a higher CR/CRi rate (50%) compared to those without SF mutations (9%). PLK1 inhibition with ONV in combination with DAC could be a potential therapy in R/R AML patients, particularly those with high OXPHOS gene expression and SF mutations.

A small molecule BCL6 inhibitor as chemosensitizers in acute myeloid leukemia

BCL6 is a transcriptional repressor that regulates multiple genes involved in immune cell differentiation, DNA damage repair, cell cycle, and apoptosis, and is a carcinogenic factor in acute myeloid leukemia (AML). AML is one of the four major types of leukemia with the 5-year survival rate of patients is less than 20% and chemotherapy resistance remains the major obstacle to the treatment failure of AML. We identified WK499, a small molecule compound that can bind to BCL6BTB structure. Treatment with WK499 hinders the interactions between BCL6 with its corepressor proteins, resulting in a remarkable change of BCL6 downstream genes and anti-proliferative effects in AML cells, and inducing cell cycle arrest and apoptosis. We verified that AraC and DOXo could induce BCL6 expression in AML cells, and found that WK499 had a synergistic effect when combined with chemotherapeutic drugs. We further proved that WK499 and AraC could achieve a better result of inhibiting the growth of AML in vivo. These findings indicate that WK499, a small molecule inhibitor of BCL6, not only inhibits the proliferation of AML, but also provides an effective therapeutic strategy for increasing AML sensitivity to chemotherapy.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

AVALON: The Italian cohort study on real-life efficacy of hypomethylating agents plus venetoclax in newly diagnosed or relapsed/refractory patients with acute myeloid leukemia

BACKGROUND

Venetoclax in combination with hypomethylating agents (HMA) is revolutionizing the therapy of acute myeloid leukemia (AML). However, evidence on large sets of patients is lacking, especially in relapsed or refractory leukemia.

METHODS

AVALON is a multicentric cohort study that was conducted in Italy on patients with AML who received venetoclax-based therapies from 2015 to 2020. The study was approved by the ethics committee of the participating institution and was conducted in accordance with the Declaration of Helsinki. The effectiveness and toxicity of venetoclax + HMA in 190 (43 newly diagnosed, 68 refractory, and 79 relapsed) patients with AML are reported here.

RESULTS

In the newly diagnosed AML, the overall response rate and survival confirmed the brilliant results demonstrated in VIALE-A. In the relapsed or refractory AML, the combination demonstrated a surprisingly complete remission rate (44.1% in refractory and 39.7% in relapsed evaluable patients) and conferred to treated patients a good expectation of survival. Toxicities were overall manageable, and most incidents occurred in the first 60 days of therapy. Infections were confirmed as the most common nonhematologic adverse event.

CONCLUSIONS

Real-life data show that the combination of venetoclax and HMA offers an expectation of remission and long-term survival to elderly, newly diagnosed patients, and to relapsed or chemoresistant AML, increasing the chance of cure through a different mechanism of action. The venetoclax + HMA combination is expected to constitute the base for triplet combinations and integration of target therapies. Our data contribute to ameliorate the understanding of venetoclax + HMA effectiveness and toxicities in real life.

Real-life monocentric experience of venetoclax-based regimens for acute myeloid leukemia

Introduction

Combination of venetoclax and hypomethylating agents (HMAs) has become a standard of care in acute myeloid leukemia (AML) aged >75 years or who have comorbidities that preclude intensive induction chemotherapy.

Methods

We conducted a monocentric retrospective analysis on adult patients affected by treatment-naïve AML not eligible for standard induction therapy or refractory/relapsed (R/R) AML treated with venetoclax combinations outside clinical trials. Venetoclax was administered at the dose of 400 mg/daily after a short ramp-up and reduced in case of concomitant CYP3A4 inhibitors.

Results

Sixty consecutive AML were identified. Twenty-three patients (38%) were affected by treatment-naïve AML and 37 (62%) by R/R AML. Median age was 70 years. Among R/R AML 30% had received a prior allogeneic stem cell transplantation (allo-HSCT). In combination with venetoclax, 50 patients (83%) received azacitidine. Antifungal prophylaxis was performed in 33 patients (55%).

Overall response rate was 60%, with 53% of complete remission (CR; 78% for treatment-naïve and 49% for R/R, p 0.017). Median overall survival was 130 days for R/R patients and 269 days for treatment-naïve patients; median event free survival was 145 days for R/R cohort and 199 days for treatment-naïve AML.

Measurable residual disease was negative in 26% of evaluable patients in CR/CR with incomplete hematologic recovery after 2 cycles and in 50% after 4 cycles, with no significant association with survival.

Eleven patients (18%) received an allo-HSCT after venetoclax combinations. Most common grade 3/4 adverse events were infectious (51% of the patients), or hematological without infections (25% of the patients). Use of CYP3A4 inhibitors was associated with a trend to shorter cytopenias and with a lower rate of infections. Invasive fungal infections were less frequent among patients receiving azole prophylaxis (6% vs 26%; p 0.0659).

Discussion

Venetoclax-based regimens are a viable option for AML considered not eligible for standard induction therapy and a valid rescue therapy in the R/R setting.

Azole prophylaxis did not significantly affect response and it was associated with a lower rate of invasive fungal infections. Despite a limited number of patients, the association of venetoclax and HMAs proved to be also a feasible bridging therapy to transplantation.

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

BACKGROUND

The heterogeneity of relapsed or refractory (R/R) acute myeloid leukemia (AML) leads to no response to venetoclax (VEN)-based therapy in more than half of the patients. Genetic characteristics are considered important predictors for response to treatment in adults with AML. However, the association of genetic characteristics with outcomes receiving VEN-based therapy is incompletely understood in R/R AML.

OBJECTIVE

To evaluate the efficacy of VEN combined with hypomethylating agents (HMA) and identify the potential genetic predictors of response in R/R AML.

METHODS

A total of 150 R/R AML patients treated with VEN combined with HMA were enrolled in this retrospective study. Outcomes of the response and overall survival (OS) were analyzed. The predictors of response and OS were analyzed by logistic regression or Cox proportional hazards model.

RESULTS

With a median of two (range, 1-4) cycles of therapy, the overall response rate was 56.2%, including 22.0% complete remission (CR), 21.3% CR with incomplete hematologic recovery, 2.0% morphologic leukemia-free state, and 10.7% partial remission, in which 25 patients achieved measurable residual disease (MRD)-negative response. With a median follow-up of 11.2 [95% confidence interval (CI), 7.2-14.8] months, 1- and 2-year OS were 46.9% (95% CI, 37.8%-58.1%) and 38.9% (95% CI, 28.7%-52.9%), respectively. Adverse cytogenetics and European Leukemia Net (ELN) risk predicted inferior response to VEN-based therapy. Mutations in IDH1/2, NPM1, ASXL1, and chromatin-cohesin genes predicted superior response to VEN-based therapy, whereas mutations in active signaling genes such as FLT3-ITD and K/NRAS predicted inferior response.

CONCLUSION

VEN combined with HMA was effective with R/R AML patients, and the response to treatment was associated with genetic characteristics.

Venetoclax-based salvage therapy in patients with relapsed/refractory acute myeloid leukemia previously treated with FLT3 or IDH1/2 inhibitors

FLT3, IDH1 and IDH2 inhibitors as well as venetoclax in combination with hypomethylating agents or low-dose cytarabine have expanded treatment options for patients with acute myeloid leukemia (AML). However, little data exist on the efficacy of venetoclax-based therapies in AML patients previously treated with FLT3 or IDH1/2 inhibitors. In this multicenter, retrospective cohort study, we included 44 patients who received venetoclax-based therapy after FLT3, IDH1 or IDH2 inhibitors. The overall response rate (ORR; composite of complete remission [CR]/CR with incomplete count recovery, partial remission, and morphologic leukemia free state) was 56.8% (18.2% CR) and a median overall survival of 9.2 months. While 6 out of 7 patients with IDH1 mutations who had previously been treated with ivosidenib responded to venetoclax-based therapy, FLT3-ITD mutations were associated with a lower response rate. Our data suggest that venetoclax can be an effective salvage therapy in patients previously treated with IDH1/2 or FLT3 inhibitors.

Venetoclax plus hypomethylating agents versus intensive chemotherapy for hematological relapse of myeloid malignancies after allo-HSCT

Introduction

Since allogeneic stem cell transplantation (allo-HSCT) is considered one of the curative treatments for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), hematological relapse following allo-HSCT remained a crucial concern for patients' survival.

Methods

We retrospectively compared patients who received venetoclax plus hypomethylating agents (VEN+HMA, n=23) or intensive chemotherapy (IC, n=42) for hematological relapse of myeloid malignancies after allo-HSCT. HMA selection included decitabine (n=2) and azacitidine (n=21), and combined donor lymphocyte infusion was administered to 21 and 42 patients in VEN+HMA and IC groups, respectively.

Results

Median age of all patients was 39 (16-64) years old. Overall response rates, including complete response (CR), CR with incomplete recovery of normal neutrophil or platelet counts (CRi) and partial response (PR), were not significantly different between VEN+HMA and IC groups (60.1% versus 64.3%, P=0.785). CR/CRi rate was 52.2% in VEN+HMA and 59.5% in IC group (P=0.567). The rate of relapse after response was 66.7% in VEN+HMA group and 40.7% in IC group (P=0.176). Median overall survival was 209.0 (95%CI 130.9-287.1) days for VEN+HMA group versus 211.0 (95%CI 28.7-393.3) days for IC group (P=0.491). The incidence of lung infection (17.4% versus 50.0%, P=0.010), thrombocytopenia (73.9% versus 95.2%, P=0.035) and acute graft-versus-host disease (aGvHD) (50.0% versus 13.0%, P=0.003) was significantly higher in IC group.

Discussion

In conclusion, VEN+HMA is not inferior to IC regimen in terms of improving response and survival, and is associated with a lower incidence of adverse events and aGvHD. However, further research is required to enhance long-term survival.

Hitting the brakes on accelerated and blast-phase myeloproliferative neoplasms: current and emerging concepts

The BCR-ABL-negative myeloproliferative neoplasms (MPNs) have a variable risk of progressing to accelerated- or blast-phase MPN (MPN-AP/MPN-BP), defined by the presence of 10% to 19% and more than or equal to 20% myeloid blasts in the peripheral blood or bone marrow, respectively. The molecular processes underlying the progression to MPN-AP/MPN-BP are becoming increasingly understood with the acquisition of additional mutations in epigenetic modifiers (eg, ASXL1, EZH2, TET2), TP53, the Ras pathway, or splicing factors (eg, SRSF2, U2AF1), having been described as important steps in this evolutionary process. At least partially driven by the enrichment of these high-risk molecular features, the prognosis of patients with MPN-BP remains inferior to other patients with acute myeloid leukemia, with a median overall survival of 3 to 6 months. Allogeneic hematopoietic cell transplantation remains the only potentially curative therapeutic modality, but only a minority of patients are eligible. In the absence of curative intent, therapeutic strategies or palliative treatment with hypomethylating agents as monotherapy or in combination with ruxolitinib or venetoclax can be considered. Several novel agents are in various stages of clinical development but are not available for routine use at this point, highlighting the need for ongoing research and the prioritization of clinical trial enrollment when feasible.

Retrospective, real‐life study of venetoclax plus azacitidine or low‐dose cytarabine in French patients with acute myeloid leukemia ineligible for intensive chemotherapy

BACKGROUND

Recently, the combination of venetoclax plus a hypomethylating agent (HMA; azacitidine ordecitabine) or low-dose cytarabine (LDAC) showed promise in Phase III trials in previously untreated AML. In France at the time of this study, venetoclax was not yet approved for AML and there were therefore no formal usage recommendations. Here we report the first study in a French cohort that assessed venetoclax in combination with existing treatments for AML under real-life conditions.

METHOD

This retrospective, real-life study collected data on venetoclax use and management in a French cohort with acute myeloid leukemia (AML) ineligible for intensive chemotherapy.

RESULT

Of 118 patients, 81 were in second line/beyond (71.6% also hypomethylating agent [HMA]; 23.5% lowdose cytarabine [LDAC]) and 37 in first line. For venetoclax initiation, 57.3% underwent ramp up and 74.6% were hospitalized. Median venetoclax duration was 2.5 months (range 0.03-16.2). With all treatment lines and regimens, most common grade 3/4 adverse events were hematologic (overall 96.4% of patients) and infections (57.1%). Dosage adjustments for drug interactions and safety varied between centers. In second-line/beyond, median progression-free survival was 4.0 months (95% confidence interval [CI] 2.7-12.8) with venetoclax-HMA and 3.4 months (1.3-8.9) with venetoclax-LDAC; overall response rate was 51.9% and 41.2%, respectively. Thus, we showed that venetoclax-based treatment yields promising findings in patients with AML, but to address treatment complexity, practice harmonization is needed.

Real-world clinical outcomes with enasidenib in relapsed or refractory acute myeloid leukemia

Enasidenib was approved by the Food and Drug Administration in 2017 for the treatment of patients with relapsed or refractory (RR) acute myeloid leukemia (AML) with an isocitrate dehydrogenase-2 (IDH2) mutation. Given limited data in clinical practice, this study assessed real-world clinical outcomes and healthcare resource use in patients with RR AML. Physicians performed chart abstraction of patients with RR IDH2-mutated AML treated with enasidenib (between 1/2018 and 6/2019) or other first-line (1 L) RR therapy (between 1/2016 and 7/2017). Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method, and adjusted risk of progression and death were estimated by multivariable Cox proportional hazard models. Among 124 patients treated with enasidenib and 76 patients treated with other 1 L RR therapy, overall response rate was higher among patients treated with enasidenib vs. other 1 L RR therapies (77% vs. 52%, p < 0.01). After a median follow-up of 9 and 6 months, median PFS was 8 months in enasidenib-treated patients and 5 months in patients receiving other 1 L RR therapy, respectively (adjusted HR=0.36, 95% CI: 0.23-0.57, p < 0.01). Median OS was 11 and 6 months in enasidenib-treated patients and patients receiving other 1 L RR therapy, respectively (adjusted HR=0.37, 95% CI: 0.22-0.60, p < 0.01). Fewer enasidenib-treated patients were hospitalized during 1 L RR therapy vs. those receiving other therapies (14% vs. 46%, p < 0.01). Results from this real-world study confirm the effectiveness of enasidenib among patients with IDH2-mutated RR AML and demonstrate that hospitalizations were significantly lower vs. other 1 L RR treatment in clinical practice.

Targeting Acute Myeloid Leukemia with Venetoclax; Biomarkers for Sensitivity and Rationale for Venetoclax-Based Combination Therapies

Simple Summary

Venetoclax has proven to be a promising therapy for newly diagnosed, relapsed and refractory AML patients ineligible for induction chemotherapy. Current ongoing clinical trials are evaluating its effectivity as frontline therapy for all acute myeloid leukemia (AML) patients. However, response rates vary wildly, depending on patient characteristics and mutational profiles. This review elaborates on the efficacy and safety of venetoclax compared to conventional chemotherapy for treatment of AML patients, comparing the response rates, overall survival and adverse events. Moreover, it gives an overview of genetic and epigenetic AML cell characteristics that give enhanced or decreased response to venetoclax and offers insights into the pathogenesis of venetoclax sensitivity and resistance. Additionally, it suggests possible treatment combinations predicted to be successful based on identified mechanisms influencing venetoclax sensitivity of AML cells.

Abstract

Venetoclax is a BCL-2 inhibitor that effectively improves clinical outcomes in newly diagnosed, relapsed and refractory acute myeloid leukemia (AML) patients, with complete response rates (with and without complete blood count recovery) ranging between 34–90% and 21–33%, respectively. Here, we aim to give an overview of the efficacy of venetoclax-based therapy for AML patients, as compared to standard chemotherapy, and on factors and mechanisms involved in venetoclax sensitivity and resistance in AML (stem) cells, with the aim to obtain a perspective of response biomarkers and combination therapies that could enhance the sensitivity of AML cells to venetoclax. The presence of molecular aberrancies can predict responses to venetoclax, with a higher response in NPM1-, IDH1/2-, TET2- and relapsed or refractory RUNX1-mutated AML. Decreased sensitivity to venetoclax was observed in patients harboring FLT3-ITD, TP53, K/NRAS or PTPN11 mutations. Moreover, resistance to venetoclax was observed in AML with a monocytic phenotype and patients pre-treated with hypomethylating agents. Resistance to venetoclax can arise due to mutations in BCL-2 or pro-apoptotic proteins, an increased dependency on MCL-1, and usage of additional/alternative sources for energy metabolism, such as glycolysis and fatty acid metabolism. Clinical studies are testing combination therapies that may circumvent resistance, including venetoclax combined with FLT3- and MCL-1 inhibitors, to enhance venetoclax-induced cell death. Other treatments that can potentially synergize with venetoclax, including MEK1/2 and mitochondrial complex inhibitors, need to be evaluated in a clinical setting.

No time to die? Intrinsic apoptosis signaling in hematopoietic stem and progenitor cells and therapeutic implications

PURPOSE OF REVIEW

Dysregulated apoptosis contributes to the pathogenesis of many hematologic malignancies. BH3-mimetics, antagonists of antiapoptotic BCL-2 proteins, represent novel, and promising cancer drugs. While the acute myelosuppressive effects of Venetoclax, the first Food and Drug Administration approved BCL-2 inhibitor, are fairly well described, little is known about side effects of novel BH3-mimetics and effects of chronic Venetoclax treatment.

RECENT FINDINGS

Highly relevant publications focused on the effects of acute and chronic Venetoclax therapy, with focus on cell-type specific adaptive mechanisms, the emergence of clonal hematopoiesis, and the selection of BAX-mutated hematopoietic cells in patients treated with Venetoclax for a long period. Important advances were made in understanding primary and secondary Venetoclax resistance and prediction of Venetoclax response. Combination therapies of BH3-mimetics targeting different BCL-2 proteins are highly anticipated. However, human stem and progenitors require both MCL-1 and BCL-XL for survival, and serious myelosuppressive effects of combined MCL-1/BCL-XL inhibition can be expected.

SUMMARY

Long-term studies are indispensable to profile the chronic side effects of Venetoclax and novel BH3-mimetics and better balance their risk vs. benefit in cancer therapy. Combination therapies will be powerful, but potentially limited by severe myelosuppression. For precision medicine, a better knowledge of BCL-2 proteins in the healthy and diseased hematopoietic system is required.

Impact of infectious comorbidity and overall time of hospitalization in total outpatient management of acute myeloid leukemia patients following venetoclax and hypomethylating agents

Venetoclax (VEN) and hypomethylating agent (HMAs) regimens are emerging as the standard of care for unfit for chemotherapy acute myeloid leukemia (AML) patients, but the safety and feasibility of a total outpatient management have not been fully investigated. Fifty‐nine AML patients with active disease received VEN and HMAs. Nineteen out of 59 (32.2%) patients received the first cycle as inpatients, whereas 40/59 (67.8%) patients were treated in the outpatient setting. No significant differences were observed with regard to incidence of adverse events (AEs), including tumor lysis syndrome (TLS), and the 30‐day and 60‐day mortality was comparable. Notably, an infectious prophylaxis inspired to that adopted during intensive chemotherapy resulted in a low infection rate with a reduced bacterial infections incidence in out‐ versus hospitalized patients (p < .0001). The overall time of hospitalization was significantly shorter in patients who received a total outpatient treatment as compared to those who received the first cycle as inpatients (5.9 vs. 39.7 days, p < .0001). Despite the adopted differences in treatment management, the efficacy was similar. These data indicate that a total outpatient management of VEN and HMAs is feasible in AML patients without negatively impacting on treatment efficacy and may yield pharmacoeconomic and quality‐of‐life benefits.

A randomised phase II study of azacitidine (AZA) alone or with Lenalidomide (LEN), Valproic acid (VPA) or Idarubicin (IDA) in higher-Risk MDS or low blast AML: GFM's "pick a winner" trial, with the impact of somatic mutations

In order to improve the outcome observed with azacitidine (AZA) in higher-risk Myelodysplastic syndrome (MDS), its combination with other drugs in MDS must be evaluated. So far, no combination has not been shown to be more effective than AZA alone. AZA-PLUS was a phase II trial that, in a "pick a winner" approach, randomly assigned patients with higher-risk MDS, CMML and low blast count AML to: AZA; AZA plus lenalidomide; AZA plus Valproic Acid or AZA plus Idarubicin. 322 patients were included. After six cycles, 69 (21.4%) CR + PR were observed with no benefit from any combination. Median EFS and OS were 17.2 and 19.7 months in the whole cohort, respectively, with no difference across randomised arms. Infection and rates of hospitalisation during the first six cycles were higher in the AZA-LEN And AZA-IDA arm, related to increased myelosuppression. Factors associated with better response were IPSS, favourable or intermediate karyotype, haemoglobin, lower circulating blast count, fibrinogen level and lower LDH, while poorer survival was seen in therapy-related MDS and, in the case of TP53, PTPN11 or CSF3R mutation. The combinations used did not improve the outcome obtained with AZA alone. However, our "pick a winner" randomised strategy may remain useful with potentially more active drugs to be tested in combination with AZA.

Azacitidine plus Venetoclax for the Treatment of Relapsed and Newly Diagnosed Acute Myeloid Leukemia Patients

Venetoclax (VEN) belongs the BH3-mimetic class that selectively targets BCL-2, activating apoptosis. The combination of VEN and azacitidine (AZA) has changed the paradigm of treatment of newly diagnosed (ND) acute myeloid leukemia (AML) patients ineligible for intensive chemotherapy. There is scarce evidence for the use of VEN–AZA for relapsed or refractory (R/R) AML. We compared the outcome of 39 R/R AML and 38 ND AML patients treated between 01/20 and 12/21. The median age was 69 (22–86) and 73 (61–81) in the R/R and ND groups, respectively. Adverse cytogenetics were found in 36% of patients in the R/R group and 59% of patients in the ND group. Overall response rate was 37% in R/R AML, including 13% CR, 8% CRi, 3% PR and 13% MLFS, and 58% in the ND AML, including 32% CR, 13% CRi and 13% MLFS. Adverse cytogenetics was associated with treatment failure in the R/R group (Relative Risk = 0.13, p = 0.005). Median overall survival (OS) was 5.9 months in the R/R group and 9.4 months in the ND group. Median OS was 2.2 months in the adverse cytogenetics group versus 8.7 months in the intermediate cytogenetics group in the R/R group (p = 0.02). Median leukemia-free survival was not different between the two groups (9.4 months and 10.3 months), indicating that VEN–AZA can be an efficient salvage treatment for selected R/R AML patients. In conclusion, VEN–AZA is a promising treatment for ND AML and for selected R/R AML patients.

Combination of Venetoclax and Midostaurin Efficiently Suppressed Relapsed t(8;21)Acute Myeloid Leukemia With Mutant KIT After Failure of Venetoclax Plus Azacitidine Treatment

Acute myeloid leukemia (AML) with t(8;21) is categorized as favorable-risk AML, but KIT mutations show a significantly poor prognostic impact in such patients. Persistent vulnerability to relapse is a major challenge in the treatment of this subtype of patients. Venetoclax is a BCL-2 selective inhibitor. The venetoclax+HMA strategy is also a notable salvage regimen that achieves good clinical outcomes in the treatment of relapsed or refractory (R/R) AML. However, in our clinical practice, we found that disease progressed rapidly even after venetoclax+azacitidine (AZA) therapy in two relapsed t(8;21) AML patients with KIT mutations. We report for the first time the therapeutic potential of venetoclax+midostaurin as a new combination therapy for relapsed t(8;21) AMLs with KIT mutations showing resistance to venetoclax+AZA therapy. Our ex vivo study also showed that midostaurin alone could inhibit proliferation and induce apoptosis of Kasumi-1 cells (e.g. Midostaurin induced G2 phase cell arrest, down-regulated p-KIT and BCL-2, while Bax protein levels were up-regulated) and observed a synergistic anti effect when the two drugs were combined. Our study shows that the venetoclax+midostaurin regimen may be a promising treatment option for R/R t(8;21) AML with KIT mutations.

Venetoclax-based combinations for acute myeloid leukemia: optimizing their use in Latin-America

Objectives: Venetoclax combinations are a new standard for patients with acute myeloid leukemia (AML). We aimed to evaluate the safety and efficacy of these combinations in a period of accelerated approval in Latin-America.Methods: This observational study evaluated adults with acute myeloid leukemia who received venetoclax-based therapy in 11 public or private centers in Mexico and Peru for both newly diagnosed or relapsed and refractory AML.Results: Fifty patients were included; 28 with newly diagnosed (ND) AML and 22 with relapsed/refractory (RR) disease. ND patients were older (64 vs. 40 years; p < 0.001) with a lower functional capacity (ECOG ≥2 64.3% vs 9%; p < 0.001). Venetoclax was frequently combined with azacytidine (60%) and prophylactic azoles (82%) with a median maximum dose of 200 mg (range, 100-600 mg). Hematologic toxicities were common. Complete response rates including patients with incomplete hematopoietic recovery were 78.6% in ND and 45.5% in RR patients, with a median overall survival of 9.6 (95% CI 3.7-15.5) and 8 months (95% CI 4.8-11.2).Discussion: Our study showed a preferred use of venetoclax plus azacytidine over cyatrabine. Patients in the first-line setting were similar to those in the landmark studies, while most patients with relapsed disease had received prior intensive therapies. Responses were favorable, with a median survival in agreement to other reports, albeit shorter than that observed in the randomized phase-3 trials.Conclusion: Venetoclax-based therapy in AML was effective despite dose reductions and prophylactic antifungals in two middle-income countries outside of a clinical trial setting.

Venetoclax enhances NK cell killing sensitivity of AML cells through the NKG2D/NKG2DL activation pathway

BACKGROUND

Venetoclax, a selective B-cell lymphoma-2 (BCL2) inhibitor, has a potential therapeutic effect when combined with demethylating agents in the first-line setting of unfit elderly patients with acute myeloid leukaemia (AML); however, efficacy is still limited in refractory/recurrent AML. Therefore, exploration of a suitable novel treatment scheme is urgently needed.However, combining venetoclax with NK cell-based immunotherapy has not been studied.

METHODS

The cytotoxicity of NK cell combined with venetoclax was assessed in vitro using flow cytometry. Venetoclax-induced natural killer group 2 member D (NKG2D) ligand (NKG2DL) expression was detected by flow cytometry and western blotting. Mechanisms underlying venetoclax-induced NKG2DL expression were found by GSE127200 analysis and investigated using real-time PCR (Q-PCR) and western blotting.

RESULTS

Flow cytometric analysis showed that combining venetoclax with NK cells produced synergistic anti-leukaemia effects similar to those of venetoclax + azacitidine. Venetoclax could render AML cell lines and primary AML cells sensitive to NK cell killing by promoting NK cell degranulation, NK-AML cell recognition and NK cell secretion of interferon (IFN)-γ and granzyme B. The synergistic effect resulted from venetoclax-induced NKG2DL upregulation in AML cells and could be undermined by blocking NKG2D on NK cells. This finding suggests that venetoclax enhances NK cell killing activity by activating the NKG2D/NKG2DL ligand-receptor pathway. Furthermore, the nuclear factor-kappa-B (NFKB) signalling pathway was involved in venetoclax-induced NKG2DL upregulation.

CONCLUSIONS

Collectively, our data confirm that venetoclax combined with NK cells induces synergistic AML cell cytolysis and preliminarily revealed that venetoclax could selectively induce NKG2DLs on AML cells via NFKB signalling pathway.

How We Incorporate Venetoclax in Treatment Regimens for Acute Myeloid Leukemia

ABSTRACT

Venetoclax has transformed the therapeutic landscape of acute myeloid leukemia (AML). Hypomethylating agents with venetoclax (HMA-VEN) have significantly improved outcomes and have become the standard therapy for older/unfit patients with newly diagnosed AML and are comparable to intensive chemotherapy in salvage setting. Venetoclax with intensive chemotherapy have shown high response rates in both frontline and salvage setting in younger patients, and triplet combinations with HMA-VEN and FLT3 inhibitors have shown encouraging results in FLT3mut AML. While patients with NPM1mut, IDH1/2mut experience favorable outcomes, those with TP53mut and secondary AML may experience minimal benefit from the addition of venetoclax. Despite improved outcomes, severe cytopenias and infectious complications are common with venetoclax-based regimens. Early response evaluation, dose reductions, venetoclax interruptions, use of growth factors, and prophylactic antimicrobials may minimize such myelosuppression and risk of infections. Outcomes after failure of frontline HMA-VEN are dismal, and novel approaches are needed to abrogate primary and acquired resistance.

Older Patients with Acute Myeloid Leukemia Deserve Individualized Treatment

PURPOSE OF REVIEW

Treatment of elderly patients with acute myeloid leukemia is a known challenge for hematologists due to patient diversity, heterogeneous disease biology, and a rapidly evolving treatment landscape. Here, we highlight the importance of determining fitness, review the latest therapeutic developments, and discuss clinical scenarios to provide guidance on individualized treatment for older AML patients.

RECENT FINDINGS

Several factors, like age, performance status, and comorbidities, play a role in fitness and are associated with outcome. Comorbidity scoring systems and geriatric assessments are tools to help physicians select the most appropriate treatment for each patient. The addition of venetoclax, targeted therapy with IDH1/2 and FLT3 inhibitors, and enhanced formulas of existing drugs like CPX-351 and oral azacitidine have improved responses and outcomes. New drugs and combination therapies have increased the therapeutic options for elderly AML patients but determination of fitness and disease biology is essential to select patient-tailored treatments.

Venetoclax in Relapsed/Refractory Acute Myeloid Leukemia: Are Supporting Evidences Enough?

Simple Summary

Venetoclax (VEN) is a potent oral inhibitor of the anti-apoptotic molecule BCL2, approved for adults with chronic lymphocytic leukemia (CLL), and recently for naïve acute myeloid leukemia (AML) unfit for intensive chemotherapy. Therefore, VEN is not approved for relapsed/refractory (R/R) AML patients; consequently, this use falls within the so-called off-label use. This review provides evidence of the role of VEN-based therapy in R/R AML patients, including data from clinical trials and from retrospective studies.

Abstract

Despite the progress in the development of new therapeutic strategies, relapsed/refractory (R/R) acute myeloid leukemia (AML) still represents a high unmet medical need. Treatment options in this setting include enrollment into clinical trials, allogeneic stem cell transplantation and/or targeted therapy. Nevertheless, it is associated with poor outcomes. Thus, the development of new treatments, which could ameliorate the prognosis of these patients with a good safety profile are highly demanded. Recently, venetoclax (VEN) has been approved for naïve AML patients unfit for intensive chemotherapy. In this regard, regimens including VEN could represent a valuable treatment option even in those with R/R disease and several studies have been conducted to demonstrate its role in this clinical setting. This review aims to summarize the current evidence on the use of VEN regimens in the treatment of R/R AML.

Keeping up with venetoclax for leukemic malignancies: key findings, optimal regimens and clinical considerations

INTRODUCTION

Venetoclax has transformed the treatment landscape in hematologic malignancies, especially in elderly population. With high rates of remission, deep and durable responses, and safe toxicity profile, venetoclax in combination therapy has been extremely effective, garnering accelerated approval and becoming standard of care in lymphoid and myeloid malignancies.

AREAS COVERED

The role of venetoclax in the intrinsic apoptotic pathway is covered. This includes preclinical and clinical experience of venetoclax monotherapy and combination therapy in relapsed/refractory and frontline CLL, AML, ALL and high-risk MDS, with an emphasis on key clinical trials and efficacy of combination regimens in distinct mutational landscapes. Strategies to mitigate myelosuppression, manage dose adjustments and infectious complications are addressed.

EXPERT OPINION

Targeting BCL-2 offers a safe and highly effective adjunct to available therapies in hematologic malignancies. Despite success and frequent utilization of venetoclax, several resistance mechanisms have been elucidated, prompting development of novel combinatorial strategies. Further, on-target myelosuppression of venetoclax is a key obstacle in clinical practice, requiring diligent monitoring and practice-based knowledge of dose modifications. Despite these limitations, venetoclax has gained tremendous popularity in hematologic-oncology, becoming an integral component of numerous combination regimes, with ongoing plethora of clinical trials encompassing standard chemotherapy, targeted agents and immune-based approaches.

The changing landscape for patients with relapsed/refractory acute myeloid leukaemia

PURPOSE OF REVIEW

The treatment of patients with relapsed or refractory (R/R) acute myeloid leukaemia (AML) has been an unequal challenge for many decades. Although significant progress has been made in the discovery of the mechanisms underlying the molecular pathogenesis of the disease, more than 50% of AML patients still die, mostly from relapsed disease. Currently, the only potential curative option for patients with R/R AML remains allogeneic bone marrow transplantation in second complete remission, which is far being easy to achieve, mainly for patients with primary induction failure or older than 65 years. The purpose of this review is to discuss recent advances in the management of patients with R/R AML, with particular emphasis to new therapeutic options that are replacing conventional salvage chemotherapy.

RECENT FINDINGS

The development of new agents selectively targeting molecular abnormalities offer more effective and less toxic alternative to chemotherapy, potentially useful as a bridge to allogeneic stem cell transplantation in second complete remission.

SUMMARY

The recent approval of new drugs for R/R is transforming the paradigm of care we have relied on for the past 50 years. Ongoing clinical trials will tell us how bright is the future for R/R AML patients.

Immunotherapy for Acute Myeloid Leukemia: Allogeneic hematopoietic cell transplantation is here to stay

Acute Myeloid Leukemia (AML) represents 1 % of all new cancer diagnosis made annually in the US and has a five-year survival of 30 %. Traditional treatment includes aggressive induction therapy followed by consolidation therapy that may include a hematopoietic stem cell transplant (HSCT). Thus far, HSCT remains the only potentially curative therapy for many patients with AML owing to the graft-versus-leukemia effect elicited by this treatment. The use of novel therapies, specifically immunotherapy, in the treatment of AML has been limited by the lack of appropriate target antigens, therapy associated toxicities and variable success with treatment. Antigenic variability on leukemia cells and the sharing of antigens by malignant and non-malignant cells makes the identification of appropriate antigens problematic. While studies with immunotherapeutic agents are underway, prior investigations have demonstrated a mixed response with some studies prematurely discontinued due to associated toxicities. This review presents a discussion of the envisioned role of immunotherapy in the treatment of AML in the setting of mixed therapeutic success and potentially lethal toxicities.

Management Approach to Acute Myeloid Leukemia Leveraging the Available Resources in View of the Latest Evidence: Consensus of the Saudi Society of Blood and Marrow Transplantation

Acute myeloid leukemia (AML) is the most prevalent acute leukemia in adults and is responsible for the majority of cancer-related mortality. In Saudi Arabia, leukemia is ranked the fifth most prevalent type of malignancy in adults. Our aim is to review existing epidemiologic data in Saudi Arabia and develop consensus guidelines for management of AML.

Venetoclax-based salvage therapy followed by Venetoclax and DLI maintenance vs. FLAG-Ida for relapsed or refractory acute myeloid leukemia after allogeneic stem cell transplantation

We retrospectively compared the outcomes of 20 patients receiving Venetoclax + low-dose Cytarabine + Actinomycin D (ACTIVE) with 29 patients receiving FLAG-Ida as salvage therapy for relapsed or refractory AML (R/R AML) after alloSCT. The groups were statistically balanced according to age, performance status, cytogenetics, and previous treatment. The overall response rate (CR + CRp + MLFS) of ACTIVE was 75% (15/20) in comparison to 66% (19/29) in the FLAG-Ida group (p = 0.542). The cumulative CR + CRp rate was significantly higher in the ACTIVE group compared to FLAG-Ida (70% (14/20) vs. 34% (10/29), respectively, p = 0.02). All three patients failing previous Venetoclax therapy and five out of seven patients with previous FLAG-Ida exposure achieved a CR/CRp after ACTIVE induction. ACTIVE patients survived longer compared to FLAG-Ida patients (13.1 vs. 5.1 months, respectively, p = 0.032). The treatment-related mortality was 0% in the ACTIVE group and 34% (10/29) in the FLAG-Ida patients (p = 0.003). The cumulative incidence of relapse did not differ between the two treatment groups. ACTIVE appears to have comparable antileukemic activity and lower toxicity compared to FLAG-Ida resulting in improved survival. Patients with Venetoclax or FLAG-Ida exposure responded to ACTIVE.

Efficacy of Venetoclax Combined with Decitabine-Based Treatment for Heavily Pre-Treated Relapsed or Refractory AML Patients in a Real-World Setting

Purpose

We report the efficacy and safety of venetoclax plus decitabine-based treatment in heavily pre-treated relapsed or refractory acute myeloid leukaemia (RR-AML) in a real-world setting.

Patients and Methods

There were 22 patients in this study and the median age was 47.5 (12–84) years old, including 11 males and 11 females. Among them, 8 patients were relapsed AML including 2 patients relapsed after HSCT and 14 patients with primary refractory AML including 4 secondary AML. The median number of cycles of previous chemotherapy was 4 (range, 2–10).

Results

After a course of venetoclax plus decitabine-based treatment, 9 patients achieved complete remission (CR) and 1 patient achieved complete remission with incomplete haematological recovery (CRi). The overall response rate (ORR) was 45.5% and the CR rate was 40.9%, and the median time to reach CR/CRi was 21 (13–46) days. Four of the 10 CR/CRi patients relapsed again, and the median time of relapse was 5 (1.0–24) months. The one-year overall survival rate was 31.8%, and the median survival time was 6 months (95% CI, 1–9 months). The one-year overall survival rate of 10 CR/CRi patients was 59.1%, and the 12 NR patients was 10.4% (p=0.001). Nausea and vomiting occurred in 11 patients (50.0%). All patients had grade IV neutropenia and IV thrombocytopenia (100%). Pneumonia occurred in 14 patients (63.6%) and septicaemia occurred in 2 patients (9.0%). The cause of death in all patients was primary disease progression, and no patients died due to the side effects.

Conclusion

The efficacy of venetoclax plus decitabine-based treatment in the real-world treatment of heavily pre-treated RR-AML is similar to that in clinical trials, and the side effects are controllable.

Recent Clinical Update of Acute Myeloid Leukemia: Focus on Epigenetic Therapies

Acute myeloid leukemia (AML) is a complicated disease characterized by genetic heterogeneity and simultaneous alterations in multiple genes. For decades, its only curative method has been intensive induction chemotherapy with or without allogeneic hematopoietic stem cell transplantation, and this approach cannot be applied to elderly patients, who make up more than 50% of AML patients. Recent advances in genomics facilitated the elucidation of various mutations related to AML, and the most frequent mutations were discovered in epigenetic regulators. Alterations to epigenetic modifications that are essential for normal cell biology, including DNA methylation and histone acetylation, have been identified. As epigenetic dysregulation is an important carcinogenic mechanism and some epigenetic changes are reversible, these epigenetic alterations have become targets for novel drug development against AML. This review summarizes the recent advances in epigenetic therapies for AML and discusses future research directions.

Outcomes of Adults With Relapsed/Refractory Acute Myeloid Leukemia Treated With Venetoclax Plus Hypomethylating Agents at a Comprehensive Cancer Center

Relapsed/refractory acute myeloid leukemia (AML) is a devastating disease with a poor prognosis and represents a major unmet medical need. We report on a real-world academic center experience of treating 25 patients with relapsed/refractory AML using venetoclax in combination with decitabine or azacitidine, which is not otherwise widely evaluated in the current literature. Our patients come from a large, socioeconomically and geographically diverse area including the majority of Northern California. Most had ELN Adverse Risk (52%) or Intermediate Risk (44%) AML, and most had an ECOG Performance Status of 1 (64%). Over half (52%) had prior hypomethylating agent exposure, and 40% had Secondary AML. We observed an overall response rate of 52%, with eight patients (32%) achieving composite complete remission. Median overall survival was 5.5 months, and for patients achieving composite complete remission this was 21.6 months. One-year estimated overall survival was 38%. Three patients were able to proceed directly to stem cell transplant for consolidation, and all three were alive at last follow-up, ranging 13.8–24.0 months. We found venetoclax in combination with hypomethylating agents to be well tolerated and potentially efficacious in securing long-term remissions for patients with relapsed/refractory AML.