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

Safety and Efficacy: Clinical Experience of Venetoclax in Combination With Hypomethylating Agents in Both Newly Diagnosed and Relapsed/Refractory Advanced Myeloid Malignancies

Hypomethylating agents (HMAs) in combination with venetoclax have been widely adopted as the standard of care for patients who cannot tolerate induction chemotherapy and for patients who have relapsed/refractory (R/R) acute myeloid leukemia (AML). This study retrospectively analyzed the outcomes of all patients with AML (n = 65) or myelodysplastic syndrome (n = 7) who received the combination of HMA and venetoclax at our institution. Outcomes measured included complete remission (CR) and CR with incomplete hematologic recovery (CRi) rates, duration of response (DOR), and overall survival (OS). Patient mutational profiles and transfusion requirements were also assessed. Of 26 newly diagnosed AML patients, the CR/CRi rate was 53.8%. The median DOR and OS were 6.9 months and not reached, respectively. Of 39 R/R AML patients, the CR/CRi rate was 38.5%. The median DOR and OS were both 8.1 months. Responders to HMA and venetoclax were enriched for TET2, IDH1, and IDH2 mutations, while nonresponders were associated with FLT3 and RAS mutations. Adaptive resistance was observed through various mechanisms including acquired RAS pathway mutations. Of transfusion-dependent patients, 12.2% and 15.2% achieved red blood cell (RBC) and platelet transfusion independence, respectively, while 44.8% and 35.1% of RBC and platelet transfusion independent patients, respectively, became transfusion dependent. In total 59.1% of patients developed a ≥grade 3 infection and 46.5% neutropenic fever. HMA + venetoclax can lead to impressive response rates with moderately durable remissions and survival. However, the benefits of this combination are diminished by the significant toxicities from infection, persistent cytopenias, and transfusion requirements.

Improving awareness of several combination therapies for acute myeloid leukemia among oncology and hematology team members in Colorado, USA

INTRODUCTION

Although several combination therapies for acute myeloid leukemia (AML) have emerged recently, there has been a lack of published surveys and educational projects focused on these important treatment options. We aimed to improve the oncology team members' knowledge and awareness of several FDA approved combination therapies for AML, including glasdegib (DAURISMO®), venetoclax (VENCLEXTA®), GO (MYOLOTARG®),CPX-351 (VYXEOS®), and midostaurin (RYDAPT®). Additionally, we aimed to examine these teams' perspectives, views, and attitudes towards these topics and finally identify barriers to the implementationof such therapies in clinical practice.

METHOD

Initially, we developed booklets and then distributed them to each participating oncology and hematology office. Subsequently, all participating oncology and hematology team members were asked to complete an anonymous online survey to test their knowledge of and attitudes toward the subjects.

MAIN RESULTS

There was a total of 52 survey respondents. The correct answer regarding various combination therapies for AML was identified by nearly 70% or more of survey takers. The level of awareness of project subjects significantly improved after reading our printing materials. Many survey respondents were motivated to learn more about combination therapies for AML as well as discuss these topics with others.

CONCLUSIONS

Our booklets effectively improved understanding and awareness of combination therapies for AML. Future studies should explore awareness, knowledge, and perception of other new and emerging combination therapies for AML among oncology and hematology team members in other areas.

The efficacy and adverse events of venetoclax in combination with hypomethylating agents treatment for patients with acute myeloid leukemia and myelodysplastic syndrome: a systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy and adverse effects of venetoclax(VEN) in combination with hypomethylating agents(HMAs) in acute myeloid leukemia(AML) or myelodysplastic syndrome(MDS).

METHODS

Clinical studies were identified from the Cochrane Library, PubMed, Embase, Google Scholar, and ClinicalTrials.gov. Overall complete remission (CR) and overall response rate (ORR) were used to evaluate the efficacy of VEN in combination with HMAs for AML/MDS, the incidence of the 4 most common grade 3-4 adverse events was used to evaluate safety.

RESULTS

We identified 13 studies that included a total of 1059 patients. 7 cohort studies and 5 non-randomized controlled trials(NRCTs) were analyzed by random-effects model, and subgroup analyses showed the pooled overall CR rate of 62% (95% CI 57-67%, I² = 3%) for the new-diagnosed(ND) AML group, 39% (95% CI 30-48%, I² = 28%) for relapsed/refractory(R/R)-AML, and 61% (95% CI 50-71%, I² = 25%) for MDS, respectively. There was only one randomized controlled trial(RCT) that showed a CR rate of 66.4% in the patients who received azacitidine(AZA) plus VEN. A total of 8 studies reported adverse events, with cytopenia and infection being the most common grade 3-4 adverse events.

CONCLUSIONS

The addition of VEN to HMAs may provide significant clinical benefit for AML/MDS patients, where response rates are better in MDS and ND-AML than in R/R-AML, but attention should be paid to the possible increased risk of febrile neutropenia.

A review of FDA-approved acute myeloid leukemia therapies beyond '7 + 3'

Introduction: The standard anthracycline and cytarabine-based chemotherapy for acute myeloid leukemia (AML) has changed relatively little since the 1970s and produces unsatisfactory outcomes in many patients. In the past two decades, a better understanding of the pathophysiology and heterogeneity of this disease has led to promising new therapies, resulting in a flurry of new drug approvals.Areas covered: The MEDLINE database, ClinicalTrials.gov and conference proceedings were reviewed for the most salient literature concerning FDA-approved drugs for AML beyond standard chemotherapy: gemtuzumab ozogamicin, hypomethylating agents, Fms-like tyrosine kinase 3 (FLT3) inhibitors, isocitrate dehydrogenase (IDH) inhibitors, venetoclax, liposomal cytarabine and daunorubicin (CPX-351), and hedgehog pathway inhibitors. Key evidence for their efficacy is discussed. For each drug category, indications, typical usage and responses, major toxicities, and future directions for research are highlighted.Expert opinion: The treatment paradigm for AML is rapidly evolving. Promising new drugs targeting driver mutations have improved outcomes in specific AML subgroups. In parallel, advances in low-intensity therapies have allowed patients unfit for standard induction chemotherapy to achieve meaningful disease control. Further work is ongoing to identify synergistic drug combinations as well as optimal treatment selection guided by individual patient and disease features.

Acute Myeloid Leukemia in Children: Emerging Paradigms in Genetics and New Approaches to Therapy

PURPOSE OF REVIEW

Acute myeloid leukemia (AML) in children remains a challenging disease to cure with suboptimal outcomes particularly when compared to the more common lymphoid leukemias. Recent advances in the genetic characterization of AML have enhanced understanding of individualized patient risk, which has also led to the development of new therapeutic strategies. Here, we review key cytogenetic and molecular features of pediatric AML and how new therapies are being used to improve outcomes.

RECENT FINDINGS

Recent studies have revealed an increasing number of mutations, including WT1, CBFA2T3-GLIS2, and KAT6A fusions, DEK-NUP214 and NUP98 fusions, and specific KMT2A rearrangements, which are associated with poor outcomes. However, outcomes are starting to improve with the addition of therapies such as gemtuzumab ozogamicin and FLT3 inhibitors, initially developed in adult AML. The combination of advanced risk stratification and ongoing improvements and innovations in treatment strategy will undoubtedly lead to better outcomes for children with AML.

Optimizing management of acute leukemia in community centers and when to refer

Treatment of acute leukemia has been delivered predominantly in academic and larger leukemia treatment centers with the infrastructure and staff needed to manage patients receiving complex therapeutic regimens and supportive care. However, in recent years, several oral agents and less-myelosuppressive regimens were approved, making it possible for these patients to receive therapy in smaller community hospitals and oncology office practices. In this review, we discuss the optimum community setting, type of patient who can be treated, agents that can be applied, and an appropriate clinical circumstance in which a referral to a tertiary center should be made.

Venetoclax and hypomethylating agents in acute myeloid leukemia: Mayo Clinic series on 86 patients

Venetoclax and hypomethylating agent (HMA) combination therapy is FDA-approved for elderly or unfit acute myeloid leukemia (AML) patients unable to withstand intensive chemotherapy. The primary objective of the current study was to impart our institutional experience with the above regimen, outlining response, survival outcomes, and its determinants amongst 86 treatment- naïve and relapsed/refractory AML patients. A total of 44 treatment-naïve AML patients, median age 73.5 years, enriched with secondary, therapy related and ELN adverse risk disease (n = 27) were studied. The CR/CRi rates of 50% (22 of 44 patients) were superior to 23% in a matched AML cohort treated with HMA alone (P = .005). Response rates were similar with TP53, FLT3, NPM1 and IDH mutations (P = .31). Moreover, CEPBA mutations (P = .03) and neutropenia (P = .05) emerged as predictors of complete response. Survivalwas prolonged in patients achieving CR/CRi (17 vs 3 months without CR/CRi, P < .001; conversely adverse ELN risk portended inferior survival. Amongst 42 relapsed/refractory AML patients, half received ≥2 prior therapies excluding transplant, and 15 (35.7%) had received HMA. A group of 14 patients (33.3%) attained CR/CRi; age > 65 years, AML with myelodysplasia, JAK2, DNMT3A, and BCOR mutations predicted complete response. Survival distinctions were based on CR/CRi (median survival 15 vs 3 months with/without CR/CRi; P < .001), and TP53 mutation status (P = .04). In summary, we corroborate existing reports demonstrating superior response and prolonged survival with venetoclax and HMA in treatment -naïve and relapsed/refractory AML patients regardless of genotype. Additionally, we identify unique predictors of response to therapy which require validation.

Venetoclax-based chemotherapy in acute and chronic myeloid neoplasms: literature survey and practice points

Venetoclax (VEN), a small-molecule inhibitor of B cell leukemia/lymphoma-2, is now FDA approved (November 2018) for use in acute myeloid leukemia (AML), specific to newly diagnosed elderly or unfit patients, in combination with a hypomethylating agent (HMA; including azacitidine or decitabine) or low-dose cytarabine. A recent phase-3 study compared VEN combined with either azacitidine or placebo, in the aforementioned study population; the complete remission (CR) and CR with incomplete count recovery (CRi) rates were 28.3% and 66.4%, respectively, and an improvement in overall survival was also demonstrated. VEN-based chemotherapy has also shown activity in relapsed/refractory AML (CR/CRi rates of 33-46%), high-risk myelodysplastic syndromes (CR 39% in treatment naïve, 5-14% in HMA failure), and blast-phase myeloproliferative neoplasm (CR 25%); in all instances, an additional fraction of patients met less stringent criteria for overall response. Regardless, venetoclax-induced remissions were often short-lived (less than a year) but long enough to allow some patients transition to allogeneic stem cell transplant. Herein, we review the current literature on the use of VEN-based combination therapy in both acute and chronic myeloid malignancies and also provide an outline of procedures we follow at our institution for drug administration, monitoring of adverse events and dose adjustments.

Venetoclax and Decitabine for T/Myeloid Mixed-Phenotype Acute Leukemia Not Otherwise Specified (MPAL NOS)

T/myeloid mixed-phenotype acute leukemia not otherwise specified (MPAL NOS) is an uncommon and aggressive leukemia without well-established treatment guidelines, particularly when relapsed. Venetoclax plus a hypomethylating agent offers a promising option in this situation since studies support its use in both acute myeloid and, albeit with fewer data to date, acute T-cell-lymphoblastic leukemias. We report the successful eradication of T/myeloid MPAL NOS relapsed after allogeneic stem cell transplant with venetoclax plus decitabine. A consolidative allogeneic stem cell transplant from a second donor was subsequently performed, and the patient remained without evidence of disease more than one year later. Further investigation is indicated to evaluate venetoclax combined with hypomethylating agents and/or other therapies for the management of T/myeloid MPAL NOS.

Interferon Therapy in Myelofibrosis: Systematic Review and Meta-analysis

BACKGROUND

Myelofibrosis (MF) is a Philadelphia chromosome-negative myeloproliferative neoplasm characterized by progressive bone marrow failure, increased risk of progression to acute myeloid leukemia, and constitutional symptoms. For over 3 decades, various formulations of interferon (IFN) have been used for the treatment of MF, with variable results, and the role of IFN in the treatment of MF is evolving.

PATIENTS AND METHODS

For this systematic review and meta-analysis, Medline and Embase via Ovid, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science were searched from inception through March 2019 for studies of pegylated IFN (peg-IFN) and non-peg-IFN in MF patients. The primary outcome of overall response rate was defined as a composite of complete response, partial response, complete hematologic response, and partial hematologic response. Random-effects models were used to pool overall response rate, and metaregression analyses were performed to compare peg-IFN and non--peg-IFN formulations.

RESULTS

Among the 10 studies with 141 MF patients included, the overall response rate was 49.9% (95% confidence interval [CI], 30.4-69.3), and there was no statistically significant difference (P = .99) between peg-IFN (50.0%; 95% CI, 26.2-73.9; I2 = 76.9%) and non-peg-IFN (49.6%; 95% CI, 20.5-79.0; I2 = 56.7%). Treatment discontinuation resulting from adverse events was common with non-peg-IFN at 35.8% (95% CI, 3.5-68.1) per year, and less in the one study on peg-IFN (0.5% per year).

CONCLUSION

IFN can lead to hematologic improvements in a subset of MF patients, but study quality is limited and heterogenous. Biomarkers predicting response to IFN and formulations with improved tolerability are needed.

Sequential treatment with FLAG-IDA/treosulfan conditioning regimen for patients with active acute myeloid leukemia

Sequential protocols combining salvage chemotherapy with reduced intensity conditioning (RIC) and allogeneic hematopoietic cell transplantation (alloHCT) for high-risk acute myeloid leukemia (AML) have been studied more than a decade. Purpose of this retrospective analysis was to evaluate the anti-leukemic efficacy and toxicity of FLAG-IDA protocol (fludarabine, cytarabine, and idarubicin) followed by treosulfan-based conditioning for patients with active AML. From January 2014 to November 2019, a total of 29 active AML patients [median age, 64 years (range, 23-73)] were treated. All patients completed protocol regimen and were transplanted. Five patients (17%) had grade 3-4 toxicities; therefore, treosulfan was substituted with total body irradiation (TBI) non-myeloablative conditioning. Six (20%) patients died within 30 post-transplant days, all from infectious complications. Out of 23 evaluable patients on day 30, 22 (96%) achieved complete hematologic remission with full donor chimerism. Non-relapse mortality (NRM) rates at 1 and 3 years were 22% and 49%, respectively. Median overall survival (OS) was 12 (95% CI, 4-20) months. OS and disease-free survival were 50% and 46% at 1 year and 28% and 17% at 2 years, respectively. Age, gender, disease burden, number of previous lines, and comorbidity score did not predict survival. Sequential strategy combining FLAG-IDA and treosulfan may offer a salvage option for few selected patients with active AML; however, high NRM presents a major obstacle to treatment success. Future efforts should focus on reducing NRM by moderating regimen intensity and by better selection of patients.

Fast Rescoring Protocols to Improve the Performance of Structure-Based Virtual Screening Performed on Protein-Protein Interfaces

Protein-protein interactions (PPIs) are attractive targets for drug design because of their essential role in numerous cellular processes and disease pathways. However, in general, PPIs display exposed binding pockets at the interface, and as such, have been largely unexploited for therapeutic interventions with low-molecular weight compounds. Here, we used docking and various rescoring strategies in an attempt to recover PPI inhibitors from a set of active and inactive molecules for 11 targets collected in ChEMBL and PubChem. Our focus is on the screening power of the various developed protocols and on using fast approaches so as to be able to apply such a strategy to the screening of ultralarge libraries in the future. First, we docked compounds into each target using the fast "pscreen" mode of the structure-based virtual screening (VS) package Surflex. Subsequently, the docking poses were postprocessed to derive a set of 3D topological descriptors: (i) shape similarity and (ii) interaction fingerprint similarity with a co-crystallized inhibitor, (iii) solvent-accessible surface area, and (iv) extent of deviation from the geometric center of a reference inhibitor. The derivatized descriptors, together with descriptor-scaled scoring functions, were utilized to investigate possible impacts on VS performance metrics. Moreover, four standalone scoring functions, RF-Score-VS (machine-learning), DLIGAND2 (knowledge-based), Vinardo (empirical), and X-SCORE (empirical), were employed to rescore the PPI compounds. Collectively, the results indicate that the topological scoring algorithms could be valuable both at a global level, with up to 79% increase in areas under the receiver operating characteristic curve for some targets, and in early stages, with up to a 4-fold increase in enrichment factors at 1% of the screened collections. Outstandingly, DLIGAND2 emerged as the best scoring function on this data set, outperforming all rescoring techniques in terms of VS metrics. The described methodology could help in the rational design of small-molecule PPI inhibitors and has direct applications in many therapeutic areas, including cancer, CNS, and infectious diseases such as COVID-19.

An acylhydroquinone derivative produces OXPHOS uncoupling and sensitization to BH3 mimetic ABT-199 (Venetoclax) in human promyelocytic leukemia cells

Since cancer cells have different mitochondrial bioenergetic requirements than non-cancerous cells, therapeutic inhibition of its mitochondrial functionality continues to be an important target for anticancer drug discovery. In this study, a series of acylhydroquinones with different acyl-chain length, and their chlorinated derivatives, in the aromatic ring, synthesized by Fries rearrangement under microwave irradiation, were evaluated for their anticancer activity in two leukemia cell lines. Findings from the primary and secondary screening of the 18 acylhydroquinones, tested at 5 µM on acute promyelocytic leukemia HL-60 and acute lymphoblastic leukemia CEM cells lines, identified an acylchlorohydroquinone (12) with a highly selective anti-proliferative effect toward HL-60 cells. This compound induced S-phase arrest in the cell cycle progression of HL-60 cells with insignificant toxicity on leukemic CEM cells and non-cancerous Hs27 cells. In HL-60 leukemic cells, 12 triggered increased mitochondrial NADH oxidation, increased respiration in presence of oligomycin (state 4o), mitochondrial depolarization, and ROS production, suggesting an uncoupling of OXPHOS. This provoked a metabolic adaptation dependent on AMPK/ACC/autophagy axis, having the mitochondrial β-oxidation a pro-survival role since the combination of 12 and etomoxir, a carnitine palmitoyl-transferase (CPT) inhibitor promoted extensive HL-60 cell death. Finally, 12-induced metabolic stress sensitized to HL-60 cells to cell death by the FDA-approved anti-leukemic drug ABT-199, a BH3 mimetic. Therefore, our results suggest that acylchlorohydroquinone is a promising scaffold in anti-promyelocytic leukemia drug research.