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20 result(s) for "Frattini, Mark G"
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Enasidenib plus azacitidine versus azacitidine alone in patients with newly diagnosed, mutant-IDH2 acute myeloid leukaemia (AG221-AML-005): a single-arm, phase 1b and randomised, phase 2 trial
Enasidenib is an oral inhibitor of mutant isocitrate dehydrogenase-2 (IDH2) proteins. We evaluated the safety and activity of enasidenib plus azacitidine versus azacitidine alone in patients with newly diagnosed, mutant-IDH2 acute myeloid leukaemia ineligible for intensive chemotherapy. This open-label, phase 1b/2 trial was done at 43 clinical sites in 12 countries (the USA, Germany, Canada, the UK, France, Spain, Australia, Italy, the Netherlands, Portugal, Switzerland, and South Korea). Eligible patients were aged 18 years or older and had newly diagnosed, mutant-IDH2 acute myeloid leukaemia, and an Eastern Cooperative Oncology Group performance status of 0–2. In the phase 1b dose-finding portion, patients received oral enasidenib 100 mg/day or 200 mg/day in continuous 28-day cycles, plus subcutaneous azacitidine 75 mg/m2 per day for 7 days of each cycle. In phase 2, patients were randomly assigned (2:1) via an interactive web response system to enasidenib plus azacitidine or azacitidine-only, stratified by acute myeloid leukaemia subtype (de novo or secondary). The primary endpoint in the phase 2 portion was the overall response rate in the intention-to-treat population at a prespecified interim analysis (Aug 20, 2019) when all patients had at least 1 year of follow-up. Safety was assessed in all patients who received at least one dose of study drug. The trial is registered with ClinicalTrials.gov, NCT02677922, and is ongoing. Between June 3, 2016, and Aug 2, 2018, 322 patients were screened and 107 patients with mutant-IDH2 acute myeloid leukaemia were enrolled. At data cutoff for the interim analysis, 24 patients (including two from the phase 1 portion) were still receiving their assigned treatment. Six patients were enrolled in the phase 1b dose-finding portion of the trial and received enasidenib 100 mg (n=3) or 200 mg (n=3) in combination with azacitidine. No dose-limiting toxicities occurred and the enasidenib 100 mg dose was selected for phase 2. In phase 2, 101 patients were randomly assigned to enasidenib plus azacitidine (n=68) or azacitidine only (n=33). Median age was 75 years (IQR 71–78). 50 (74%; 95% CI 61–84) patients in the enasidenib plus azacitidine combination group and 12 (36%; 20–55) patients in the azacitidine monotherapy group achieved an overall response (odds ratio 4·9 [95% CI 2·0–11·9]; p=0·0003). Common treatment-related grade 3 or 4 adverse events with enasidenib plus azacitidine were thrombocytopenia (25 [37%] of 68 vs six [19%] of 32 in the azacitidine-only group), neutropenia (25 [37%] vs eight [25%]), anaemia (13 [19%] vs seven [22%]), and febrile neutropenia (11 [16%] vs five [16%]). Serious treatment-related adverse events were reported in 29 (43%) patients in the combination group and 14 (44%) patients in the azacitidine-only group; serious treatment-related adverse events occurring in more than 5% of patients in either group were febrile neutropenia (nine [13%] in the combination group vs five [16%] in the azacitidine-only group), differentiation syndrome (seven [10%] vs none), and pneumonia (three [4%] vs two [6%]). No treatment-related deaths were reported. Combination enasidenib plus azacitidine was well tolerated and significantly improved overall response rates compared with azacitidine monotherapy, suggesting that this regimen can improve outcomes for patients with newly diagnosed, mutant-IDH2 acute myeloid leukaemia. Bristol Myers Squibb.
Kinase-dead ATR differs from ATR loss by limiting the dynamic exchange of ATR and RPA
ATR kinase is activated by RPA-coated single-stranded DNA (ssDNA) to orchestrate DNA damage responses. Here we show that ATR inhibition differs from ATR loss. Mouse model expressing kinase-dead ATR ( Atr +/KD ), but not loss of ATR ( Atr +/− ), displays ssDNA-dependent defects at the non-homologous region of X-Y chromosomes during male meiosis leading to sterility, and at telomeres, rDNA, and fragile sites during mitosis leading to lymphocytopenia. Mechanistically, we find that ATR kinase activity is necessary for the rapid exchange of ATR at DNA-damage-sites, which in turn promotes CHK1-phosphorylation. ATR-KD, but not loss of ATR, traps a subset of ATR and RPA on chromatin, where RPA is hyper-phosphorylated by ATM/DNA-PKcs and prevents downstream repair. Consequently, Atr +/KD cells have shorter inter-origin distances and are vulnerable to induced fork collapses, genome instability and mitotic catastrophe. These results reveal mechanistic differences between ATR inhibition and ATR loss, with implications for ATR signaling and cancer therapy. ATR kinase is a key regulator of chromosome integrity. Here the authors by analysing the phenotype of a mouse model expressing a kinase-dead ATR, reveal the effect of ATR inhibition compared to ATR loss and its consequences for meiosis, DNA replication, checkpoint activation and genome instability .
Clonal diversity predicts adverse outcome in chronic lymphocytic leukemia
Genomic analyses of chronic lymphocytic leukemia (CLL) identified somatic mutations and associations of clonal diversity with adverse outcomes. Clonal evolution likely has therapeutic implications but its dynamic is less well studied. We studied clonal composition and prognostic value of seven recurrently mutated driver genes using targeted next-generation sequencing in 643 CLL patients and found higher frequencies of mutations in TP53 (35 vs. 12%, p < 0.001) and SF3B1 (20 vs. 11%, p < 0.05) and increased number of (sub)clonal (p < 0.0001) mutations in treated patients. We next performed an in-depth evaluation of clonal evolution on untreated CLL patients (50 “progressors” and 17 matched “non-progressors”) using a 404 gene-sequencing panel and identified novel mutated genes such as AXIN1, SDHA, SUZ12, and FOXO3. Progressors carried more mutations at initial presentation (2.5 vs. 1, p < 0.0001). Mutations in specific genes were associated with increased (SF3B1, ATM, and FBXW7) or decreased progression risk (AXIN1 and MYD88). Mutations affecting specific signaling pathways, such as Notch and MAP kinase pathway were enriched in progressive relative to non-progressive patients. These data extend earlier findings that specific genomic alterations and diversity of subclones are associated with disease progression and persistence of disease in CLL and identify novel recurrently mutated genes and associated outcomes.
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.
Enasidenib, an inhibitor of mutant IDH2 proteins, induces durable remissions in older patients with newly diagnosed acute myeloid leukemia
Older adults with acute myeloid leukemia (AML) who are not fit for standard chemotherapy historically have poor outcomes. Approximately 12–15% of older patients with AML harbor isocitrate dehydrogenase 2 (IDH2) gene mutations. Enasidenib is an oral inhibitor of mutant IDH2 proteins. Among 39 patients with newly diagnosed mutant-IDH2 AML who received enasidenib monotherapy in this phase I/II trial, median age was 77 years (range 58–87) and 23 patients (59%) had had an antecedent hematologic disorder. The median number of enasidenib treatment cycles was 6.0 (range 1–35). The most common treatment-related adverse events were indirect hyperbilirubinemia (31%), nausea (23%), and fatigue, decreased appetite, and rash (18% each). Treatment-related grade 3–4 cytopenias were reported for eight patients (21%); there was no treatment-related grade 3–4 infections. Twelve patients achieved a response (overall response rate 30.8% [95% CI 17.0%, 47.6%]), including seven patients (18%) who attained complete remission. At a median follow-up of 8.4 months, the median duration of any response was not reached (NR). Median overall survival for all patients was 11.3 months (95% CI 5.7, 15.1), and was NR for responders. Oral, outpatient targeted treatment with enasidenib may benefit older adults with newly diagnosed mutant-IDH2 AML who are not candidates for cytotoxic regimens.
Improved survival with enasidenib versus standard of care in relapsed/refractory acute myeloid leukemia associated with IDH2 mutations using historical data and propensity score matching analysis
Background The present study evaluated the relative survival benefits associated with enasidenib and current standard of care (SoC) therapies for patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) and an isocitrate dehydrogenase 2 (IDH2) mutation who are ineligible for hematopoietic stem cell transplantation (HSCT). Methods Propensity score matching (PSM) analysis compared survival outcomes observed with enasidenib 100 mg daily in the phase I/II AG221‐C‐001 trial and SoC outcomes obtained from a real‐world chart review of patients in France. Results Before matching, enasidenib (n = 195) was associated with numerically improved overall survival (OS) relative to SoC (n = 80; hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.61–1.11). After matching and adjusting for covariates (n = 78 per group), mortality risk was significantly lower with enasidenib than with SoC (HR, 0.67; 95% CI, 0.47–0.97). The median OS was 9.26 months for enasidenib (95% CI, 7.72–13.24) and 4.76 months for SoC (95% CI, 3.81–8.21). Results remained robust across all sensitivity analyses conducted. Conclusions PSM analyses indicate that enasidenib significantly prolongs survival relative to SoC among patients with R/R AML and an IDH2 mutation who are ineligible for HSCT. Future prospective studies are needed to validate these findings using other data sources and to assess the comparative efficacy of enasidenib for other treatment outcomes. Overall survival was improved with enasidenib compared with SoC. Enasidenib may be an important advance in treatment for patients with R/R acute myeloid leukemia associated with IDH2 mutations who are ineligible for hematopoietic stem cell transplantation.
A phase 1 study of IDH305 in patients with IDH1R132-mutant acute myeloid leukemia or myelodysplastic syndrome
Purpose Isocitrate dehydrogenase enzyme 1 (IDH1) mutations at 132nd amino acid residue (R132*) result in the cellular accumulation of the oncometabolite, 2-hydroxyglutarate (2-HG). IDH305 is an orally bioavailable, brain-penetrant, mutant-selective allosteric IDH1 inhibitor demonstrating target engagement in preclinical models. This first-in human study was designed to identify the recommended dose for expansion/maximum tolerated dose of IDH305 in patients with IDH1 R132 -mutant acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Methods IDH305 was given at doses 75–750 mg twice daily in 41 patients with IDH1 R132 -mutant AML/MDS. Dose escalation was designed using Bayesian hierarchical model with overdose control principle and relationship with dose-limiting toxicity. Results IDH305 exhibited rapid absorption with mean T 1/2 approximately 4–10 h across doses. Interpatient variability was moderate and exposure increased with dose in a less than dose proportional manner. Most patients (35/41) demonstrated target engagement with reduction in 2-HG concentration at all doses. Complete remission (CR) or CR with incomplete count recovery occurred in 10/37 (27%) patients with AML and 1/ 4 patients with MDS. Adverse events (AEs) suspected to be related to study drug were reported in 53.7% of patients: increased blood bilirubin (14.6%), nausea (14.6%), increased alanine aminotransferase and aspartate aminotransferase (12.2%, each); most frequent grade 3 or 4 AEs were differentiation syndrome and tumor lysis syndrome ( n  = 3; 7.3%, each). Hepatotoxicity was manageable with dose modification. Conclusion Due to potentially narrow therapeutic window, the study was prematurely halted and recommended phase 2 dose could not be declared. Trial registration Clinicaltrials.gov identifier: NCT02381886.
An exo-cell assay for examining real-time γ-secretase activity and inhibition
γ-Secretase is an aspartyl protease that cleaves multiple substrates that are involved in broad biological processes ranging from stem cell development to neurodegeneration. The investigation of γ-secretase has been limited by currently available assays that require genetic or biochemical manipulation in the form of substrate transfection or membrane preparation. Here we report an exo-cell assay that is capable of characterizing γ-secretase activity in any cellular system without limitation. Using a highly active, recombinant substrate this assay can quickly and easily ascertain the status of γ-secretase activity in cell systems and patient samples. We have applied this method to determine the activity of γ-secretase in primary cell samples where transfection and/or membrane isolation are not viable options. Importantly, it allows for the detection of real time γ-secretase activity after inhibitor or drug treatment. The application of this assay to determine the role of γ-secretase in physiological and pathological conditions will greatly facilitate our characterization of this complex protease and help in the development and evaluation of γ-secretase-targeted therapies in Alzheimer's disease or a variety of neoplasms.
Biosynthesis of Human Papillomavirus from a Continuous Cell Line Upon Epithelial Differentiation
The study of the human pathogen papillomaviruses (HPVs) has been hampered by the inability to propagate the virus in tissue culture. The addition of 12-O-tetradecanoyl phorbol-13-acetate to the media of organotypic (raft) cultures increased expression of physiological markers of keratinocyte differentiation and concomitantly induced production of virions. Capsid production was detected in differentiated suprabasal cells. Virions approximately 54 nanometers in size were observed by electron microscopy in raft tissue cross sections in the suprabasal layers. Virions purified through isopycnic gradients were found to contain type 31b DNA and exhibited an icosahedral shape similar to that of papillomaviruses found in clinical samples.
An exo-cell assay for examining real-time gamma-secretase activity and inhibition
[gamma]-Secretase is an aspartyl protease that cleaves multiple substrates that are involved in broad biological processes ranging from stem cell development to neurodegeneration. The investigation of [gamma]-secretase has been limited by currently available assays that require genetic or biochemical manipulation in the form of substrate transfection or membrane preparation. Here we report an exo-cell assay that is capable of characterizing [gamma]-secretase activity in any cellular system without limitation. Using a highly active, recombinant substrate this assay can quickly and easily ascertain the status of [gamma]-secretase activity in cell systems and patient samples. We have applied this method to determine the activity of [gamma]-secretase in primary cell samples where transfection and/or membrane isolation are not viable options. Importantly, it allows for the detection of real time [gamma]-secretase activity after inhibitor or drug treatment. The application of this assay to determine the role of [gamma]-secretase in physiological and pathological conditions will greatly facilitate our characterization of this complex protease and help in the development and evaluation of [gamma]-secretase-targeted therapies in Alzheimer's disease or a variety of neoplasms.