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40 result(s) for "Pollyea, Daniel A."
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Methylation-dependent loss of RIP3 expression in cancer represses programmed necrosis in response to chemotherapeutics
Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is an essential part of the cellular machinery that executes "programmed" or "regulated" necrosis. Here we show that programmed necrosis is activated in response to many chemotherapeutic agents and contributes to chemotherapy-induced cell death. However, we show that RIP3 expres- sion is often silenced in cancer cells due to genomic methylation near its transcriptional start site, thus RIP3-depen- dent activation of MLKL and downstream programmed necrosis during chemotherapeutic death is largely repressed. Nevertheless, treatment with hypomethylating agents restores RIP3 expression, and thereby promotes sensitivity to chemotherapeutics in a RIP3-dependent manner. RIP3 expression is reduced in tumors compared to normal tissue in 85% of breast cancer patients, suggesting that RIP3 deficiency is positively selected during tumor growth/develop- ment. Since hypomethylating agents are reasonably well-tolerated in patients, we propose that RIP3-deficient cancer patients may benefit from receiving hypomethylating agents to induce RIP3 expression prior to treatment with con- ventional chemotherapeutics.
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.
Characterization and targeting of malignant stem cells in patients with advanced myelodysplastic syndromes
Myelodysplastic syndrome (MDS) is a chronic hematologic disorder that frequently evolves to more aggressive stages and in some cases leads to acute myeloid leukemia (AML). MDS arises from mutations in hematopoietic stem cells (HSCs). Thus, to define optimal therapies, it is essential to understand molecular events driving HSC pathogenesis. In this study, we report that during evolution of MDS, malignant HSCs activate distinct cellular programs that render such cells susceptible to therapeutic intervention. Specifically, metabolic analyses of the MDS stem cell compartment show a profound activation of protein synthesis machinery and increased oxidative phosphorylation. Pharmacological targeting of protein synthesis and oxidative phosphorylation demonstrated potent and selective eradication of MDS stem cells in primary human patient specimens. Taken together, our findings indicate that MDS stem cells are reliant on specific metabolic events and that such properties can be targeted prior to the onset of clinically significant AML, during antecedent MDS. Myelodysplastic syndrome (MDS) arises from mutations in hematopoietic stem cells (HSCs). Here, the authors demonstrate that HSCs in higher-risk MDS express the surface marker CD123 and are characterized by activation of protein synthesis machinery and increased oxidative phosphorylation.
ATM/G6PD-driven redox metabolism promotes FLT3 inhibitor resistance in acute myeloid leukemia
Activating mutations in FMS-like tyrosine kinase 3 (FLT3) are common in acute myeloid leukemia (AML) and drive leukemic cell growth and survival. Although FLT3 inhibitors have shown considerable promise for the treatment of AML, they ultimately fail to achieve long-term remissions as monotherapy. To identify genetic targets that can sensitize AML cells to killing by FLT3 inhibitors, we performed a genome-wide RNA interference (RNAi)-based screen that identified ATM (ataxia telangiectasia mutated) as being synthetic lethal with FLT3 inhibitor therapy. We found that inactivating ATM or its downstream effector glucose 6-phosphate dehydrogenase (G6PD) sensitizes AML cells to FLT3 inhibitor induced apoptosis. Examination of the cellular metabolome showed that FLT3 inhibition by itself causes profound alterations in central carbon metabolism, resulting in impaired production of the antioxidant factor glutathione, which was further impaired by ATM or G6PD inactivation. Moreover, FLT3 inhibition elicited severe mitochondrial oxidative stress that is causative in apoptosis and is exacerbated by ATM/G6PD inhibition. The use of an agent that intensifies mitochondrial oxidative stress in combination with a FLT3 inhibitor augmented elimination of AML cells in vitro and in vivo, revealing a therapeutic strategy for the improved treatment of FLT3 mutated AML.
How we use venetoclax with hypomethylating agents for the treatment of newly diagnosed patients with acute myeloid leukemia
Acute myeloid leukemia (AML) is associated with poor outcomes, especially in older patients in whom the disease is most common. B-cell lymphoma 2 (BCL-2) is an antiapoptotic protein involved in the survival and maintenance of AML, and it is overexpressed in the leukemia stem cell population. Venetoclax is an oral BCL-2 protein inhibitor recently approved by the United States Food and Drug Administration (FDA) for use in combination with a hypomethylating agent (HMA) (azacitidine or decitabine) or low-dose cytarabine for front-line treatment of AML in older patients or those unfit for induction chemotherapy. Given that its mechanism of action is unique, it is not surprising that this widely effective therapy presents unique challenges, including but not limited to the rapidity of responses, the rate and depth of cytopenias, and issues related to drug–drug interactions. With the recent FDA approval and increasingly widespread use, we aim here to summarize, based on evidence and experience, emerging management strategies for the combination of HMAs and venetoclax in the treatment of AML.
Survival outcomes and clinical benefit in patients with acute myeloid leukemia treated with glasdegib and low-dose cytarabine according to response to therapy
Background The phase 2 BRIGHT AML 1003 trial evaluated efficacy and safety of glasdegib + low-dose cytarabine (LDAC) in patients with acute myeloid leukemia ineligible for intensive chemotherapy. The multicenter, open-label study randomized patients to receive glasdegib + LDAC ( n = 78) or LDAC alone ( n = 38). The rate of complete remission (CR) was 19.2% in the glasdegib + LDAC arm versus 2.6% in the LDAC arm ( P = 0.015). Methods This post hoc analysis determines whether the clinical benefits of glasdegib are restricted to patients who achieve CR, or if they extend to those who do not achieve CR. Results In patients who did not achieve CR, the addition of glasdegib to LDAC improved overall survival (OS) versus LDAC alone (hazard ratio = 0.63 [95% confidence interval, 0.41–0.98]; P = 0.0182; median OS, 5.0 vs 4.1 months). Additionally, more patients receiving glasdegib + LDAC achieved durable recovery of absolute neutrophil count (≥ 1000/μl, 45.6% vs 35.5%), hemoglobin (≥ 9 g/dl, 54.4% vs 38.7%), and platelets (≥ 100,000/μl, 29.8% vs 9.7%). Transfusion independence was achieved by 15.0% and 2.9% of patients receiving glasdegib + LDAC and LDAC alone, respectively. Conclusions Collectively, these data suggest that there are clinical benefits with glasdegib in the absence of CR. Trial registration ClinicalTrials.gov NCT01546038 (March 7, 2012)
Randomized comparison of low dose cytarabine with or without glasdegib in patients with newly diagnosed acute myeloid leukemia or high-risk myelodysplastic syndrome
Glasdegib is a Hedgehog pathway inhibitor. This phase II, randomized, open-label, multicenter study (ClinicalTrials.gov, NCT01546038) evaluated the efficacy of glasdegib plus low-dose cytarabine (LDAC) in patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome unsuitable for intensive chemotherapy. Glasdegib 100 mg (oral, QD) was administered continuously in 28-day cycles; LDAC 20 mg (subcutaneous, BID) was administered for 10 per 28 days. Patients (stratified by cytogenetic risk) were randomized (2:1) to receive glasdegib/LDAC or LDAC. The primary endpoint was overall survival. Eighty-eight and 44 patients were randomized to glasdegib/LDAC and LDAC, respectively. Median (80% confidence interval [CI]) overall survival was 8.8 (6.9–9.9) months with glasdegib/LDAC and 4.9 (3.5–6.0) months with LDAC (hazard ratio, 0.51; 80% CI, 0.39–0.67, P = 0.0004). Fifteen (17.0%) and 1 (2.3%) patients in the glasdegib/LDAC and LDAC arms, respectively, achieved complete remission (P < 0.05). Nonhematologic grade 3/4 all-causality adverse events included pneumonia (16.7%) and fatigue (14.3%) with glasdegib/LDAC and pneumonia (14.6%) with LDAC. Clinical efficacy was evident across patients with diverse mutational profiles. Glasdegib plus LDAC has a favorable benefit–risk profile and may be a promising option for AML patients unsuitable for intensive chemotherapy.
Venetoclax with azacitidine disrupts energy metabolism and targets leukemia stem cells in patients with acute myeloid leukemia
Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Leukemia stem cells (LSCs) drive the initiation and perpetuation of AML, are quantifiably associated with worse clinical outcomes, and often persist after conventional chemotherapy resulting in relapse 1 – 5 . In this report, we show that treatment of older patients with AML with the B cell lymphoma 2 (BCL-2) inhibitor venetoclax in combination with azacitidine results in deep and durable remissions and is superior to conventional treatments. We hypothesized that these promising clinical results were due to targeting LSCs. Analysis of LSCs from patients undergoing treatment with venetoclax + azacitidine showed disruption of the tricarboxylic acid (TCA) cycle manifested by decreased α-ketoglutarate and increased succinate levels, suggesting inhibition of electron transport chain complex II. In vitro modeling confirmed inhibition of complex II via reduced glutathionylation of succinate dehydrogenase. These metabolic perturbations suppress oxidative phosphorylation (OXPHOS), which efficiently and selectively targets LSCs. Our findings show for the first time that a therapeutic intervention can eradicate LSCs in patients with AML by disrupting the metabolic machinery driving energy metabolism, resulting in promising clinical activity in a patient population with historically poor outcomes. Targeting of mitochondrial metabolism in combination with BCL-2 inhibition eradicates leukemia stem cells and induces long-lasting responses in patients with acute myeloid leukemia.
Safety and preliminary efficacy of venetoclax with decitabine or azacitidine in elderly patients with previously untreated acute myeloid leukaemia: a non-randomised, open-label, phase 1b study
Elderly patients (aged ≥65 years) with acute myeloid leukaemia have poor outcomes and no effective standard-of-care therapy exists. Treatment with hypomethylating agents such as azacitidine and decitabine is common, but responses are modest and typically short-lived. The oral anti-apoptotic B-cell lymphoma 2 protein inhibitor, venetoclax, has shown promising single-agent activity in patients with relapsed or refractory acute myeloid leukaemia and preclinical data suggested synergy between hypomethylating agents and venetoclax, which led to this combination phase 1b study. Previously untreated patients aged 65 years and over with acute myeloid leukaemia who were ineligible for standard induction therapy were enrolled into this non-randomised, open-label, phase 1b study. Patients were required to have an Eastern Cooperative Oncology Group performance status of 0–2 and either intermediate-risk or poor-risk cytogenetics. Patients were enrolled into one of three groups for the dose-escalation phase of this study: group A (venetoclax and intravenous decitabine 20 mg/m2 [days 1–5 of each 28-day cycle]), group B (venetoclax and subcutaneous or intravenous azacitidine 75 mg/m2 [days 1–7 of each 28-day cycle]), and group C (a venetoclax and decitabine substudy with the oral CYP3A inhibitor posaconazole, 300 mg twice on cycle 1, day 21, and 300 mg once daily from cycle 1, days 22–28, to assess its effect on venetoclax pharmacokinetics). Dose escalation followed a standard 3 + 3 design with at least three evaluable patients enrolled per cohort; daily target doses of venetoclax for groups A and B were 400 mg (cohort 1), 800 mg (cohorts 2 and 3), and 1200 mg (cohort 4), and 400 mg for group C. The primary endpoints were the safety and pharmacokinetics of venetoclax plus decitabine or azacitidine, and to determine the maximum tolerated dose and recommended phase 2 dose. Secondary endpoints included the preliminary anti-leukaemic activity of venetoclax with decitabine or azacitidine through the analysis of overall response, duration of response, and overall survival. We analysed safety, pharmacokinetics, and anti-leukaemic activity in all patients who received one or more venetoclax doses. The expansion phase of the study is ongoing but is closed to accrual. This trial is registered with ClinicalTrials.gov, number NCT02203773. 57 patients were enrolled in the study. 23 patients in group A and 22 patients in group B were enrolled between Nov 19, 2014, and Dec 15, 2015, and 12 patients in group C were enrolled between June 14, 2015, and Jan 16, 2016. As of data cutoff on June 15, 2016, the most common grade 3–4 treatment-emergent adverse events were thrombocytopenia (27 [47%] of 57 patients; nine in group A, 13 in group B, and five in group C), febrile neutropenia (24 [42%] of 57; 11 in group A, ten in group B, and three in group C), and neutropenia (23 [40%] of 57; 12 in group A, eight in group B, and three in group C). The most common serious treatment-emergent adverse event in groups A and B was febrile neutropenia (seven [30%] of 23 patients vs seven [32%] of 22), whereas in group C it was lung infection (four [33%] of 12 patients). 49 (86%) of 57 patients had treatment-related adverse events; the most common in groups A and B included nausea (12 [52%] patients vs seven [32%] patients), fatigue (six [26%] patients vs seven [32%]), and decreased neutrophil count (six [26%] patients vs six [27%]), whereas in group C the most common were nausea (seven [58%] of 12 patients), leucopenia (six [50%]), vomiting (five [42%]), and decreased platelet count (five [42%]). The maximum tolerated dose was not reached. The recommended phase 2 dose was 400 mg once a day or 800 mg with an interrupted dosing schedule (safety expansion). In total, four (7%) of 57 patients had died within 30 days of the first venetoclax dose caused by sepsis (group B), bacteraemia (group A), lung infection (group C), and respiratory failure (group A). Tumour lysis syndrome was not observed. Decitabine and azacitidine did not substantially affect venetoclax exposures. Overall, 35 (61%; 95% CI 47·6–74·0) of 57 patients achieved complete remission or complete remission with incomplete marrow recovery. In groups A and B, 27 (60%; 95% CI 44·3–74·3) of 45 patients had complete remission or complete remission with incomplete marrow recovery. Venetoclax plus hypomethylating agent therapy seems to be a novel, well-tolerated regimen with promising activity in this underserved patient population. Evaluation of expansion cohorts is ongoing at 400 mg and 800 mg doses using both hypomethylating agent combinations. AbbVie and Genentech.
Venetoclax and azacitidine followed by allogeneic transplant results in excellent outcomes and may improve outcomes versus maintenance therapy among newly diagnosed AML patients older than 60
The combination of venetoclax (ven) and azacitidine (aza) has resulted in high response rates in the upfront treatment of AML in patients age > 75 and patients unfit for intensive chemotherapy. Given the poor historical outcomes in patients age ≥ 60 treated with induction chemotherapy, ven/aza has become our institutional preference for the initial treatment of non-core binding factor (CBF) AML patients age ≥ 60. The benefit of allogeneic stem cell transplant (SCT) in patients who achieve response to ven/aza is uncertain. We report outcomes of SCT-eligible patients treated at our center. Between 1/2015 and 1/2020, 119 newly diagnosed non-CBF AML patients age ≥ 60 received ven/aza as initial therapy. 21 patients underwent SCT; 31 additional patients were potentially SCT eligible but deferred SCT. Overall survival (OS) was significantly greater among SCT patients (median survival not reached) versus potentially SCT eligible patients not undergoing SCT (median 518 days) (p = 0.01). Our data suggest that ven/aza followed by SCT in newly diagnosed AML patients older than ≥ 60 results in excellent outcomes and likely improves outcomes over maintenance therapy. Ongoing investigation will further refine the optimal timing of and selection of patients for SCT based on prognostic disease features and response assessments.