1,022 research outputs found

    New Cepheid variables in the young open clusters Berkeley 51 and Berkeley 55

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    As part of a wider investigation of evolved massive stars in Galactic open clusters, we have spectroscopically identified three candidate classical Cepheids in the little-studied clusters Berkeley 51, Berkeley 55 and NGC 6603. Using new multi-epoch photometry, we confirm that Be 51 #162 and Be 55 #107 are bona fide Cepheids, with pulsation periods of 9.83±0.01 d and 5.850±0.005 d respectively, while NGC 6603 star W2249 does not show significant photometric variability. Using the period-luminosity relationship for Cepheid variables, we determine a distance to Be 51 of 5.3 +1.0 −0.8 kpc and an age of 44 +9 −8 Myr, placing it in a sparsely-attested region of the Perseus arm. For Be 55, we find a distance of 2.2±0.3 kpc and age of 63 +12 −11 Myr, locating the cluster in the Local arm. Taken together with our recent discovery of a long-period Cepheid in the starburst cluster VdBH222, these represent an important increase in the number of young, massive Cepheids known in Galactic open clusters. We also consider new Gaia (data release 2) parallaxes and proper motions for members of Be 51 and Be 55; the uncertainties on the parallaxes do not allow us to refine our distance estimates to these clusters, but the well-constrained proper motion measurements furnish further confirmation of cluster membership. However, future final Gaia parallaxes for such objects should provide valuable independent distance measurements, improving the calibration of the period-luminosity relationship, with implications for the distance ladder out to cosmological scales

    Silicoaluminates as “support activator” systems in olefin polymerization processes

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    In this work we report the polymerization behaviour of natural clays (montmorillonites, MMT) as activating supports. These materials have been modified by treatment with different aluminium compounds in order to obtain enriched aluminium clays and to modify the global Brönsted/Lewis acidity. As a consequence, the intrinsic structural properties of the starting materials have been changed. These changes were studied and these new materials used for ethylene polymerization using a zirconocene complex as catalyst. All the systems were shown to be active in ethylene polymerization. The catalyst activity and the dependence on acid strength and textural properties have been also studied. The behaviour of an artificial silica (SBA 15) modified with an aluminium compound to obtain a silicoaluminate has been studied, but no ethylene polymerization activity has been found yet

    Clinical and exploratory biomarker findings from the MODUL trial (Cohorts 1, 3 and 4) of biomarker-driven maintenance therapy for metastatic colorectal cancer

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    Biomarkers; Colorectal cancer; Maintenance therapyBiomarcadors; Càncer colorectal; Teràpia de mantenimentBiomarcadores; Cáncer colorrectal; Terapia de mantenimientoPurpose MODUL is an adaptable, signal-seeking trial of biomarker-driven maintenance therapy following first-line induction treatment in patients with metastatic colorectal cancer (mCRC). We report findings from Cohorts 1 (BRAFmut), 3 (human epidermal growth factor 2 [HER2]+) and 4 (HER2‒/high microsatellite instability, HER2‒/microsatellite stable [MSS]/BRAFwt or HER2‒/MSS/BRAFmut/RASmut). Methods Patients with unresectable, previously untreated mCRC without disease progression following standard induction treatment (5-fluorouracil/leucovorin [5-FU/LV] plus oxaliplatin plus bevacizumab) were randomly assigned to control (fluoropyrimidine plus bevacizumab) or cohort-specific experimental maintenance therapy (Cohort 1: vemurafenib plus cetuximab plus 5-FU/LV; Cohort 3: capecitabine plus trastuzumab plus pertuzumab; Cohort 4: cobimetinib plus atezolizumab). The primary efficacy end-point was progression-free survival (PFS). Results Cohorts 1, 3 and 4 did not reach target sample size because of early study closure. In Cohort 1 (n = 60), PFS did not differ between treatment arms (hazard ratio, 0.95; 95% confidence intervals 0.50–1.82; P = 0.872). However, Cohort 1 exploratory biomarker data showed preferential selection for mitogen-activated protein kinase (MAPK) pathway mutations (mainly KRAS, NRAS, MAP2K1 or BRAF) in the experimental arm but not the control arm. In Cohort 3 (n = 5), PFS ranged from 3.6 to 14.7 months versus 4.0 to 5.4 months in the experimental and control arms, respectively. In Cohort 4 (n = 99), PFS was shorter in the experimental arm (hazard ratio, 1.44; 95% confidence intervals 0.90–2.29; P = 0.128). Conclusions Vemurafenib plus cetuximab plus 5-FU/LV warrants further investigation as first-line maintenance treatment for BRAFmut mCRC. MAPK-pathway emergent genomic alterations may offer novel therapeutic opportunities in BRAFmut mCRC. Cobimetinib plus atezolizumab had an unfavourable benefit:risk ratio in HER2‒/MSS/BRAFwt mCRC. New strategies are required to increase the susceptibility of MSS mCRC to immunotherapy.This work was supported by F. Hoffmann-La Roche Ltd

    MODUL cohort 2: an adaptable, randomized, signal-seeking trial of fluoropyrimidine plus bevacizumab with or without atezolizumab maintenance therapy for BRAFwt metastatic colorectal cancer

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    Atezolizumab; Bevacizumab; Metastatic colorectal cancerAtezolizumab; Bevacizumab; Cáncer colorrectal metastásicoAtezolizumab; Bevacizumab; Càncer colorectal metastàticBackground MODUL is an adaptable, signal-seeking trial designed to test novel agents in predefined patient subgroups in first-line metastatic colorectal cancer (mCRC). Patients and methods Patients with measurable, unresectable, previously untreated mCRC received induction with ≤8 cycles of FOLFOX + bevacizumab followed by randomization to maintenance treatment comprising control [fluoropyrimidine (FP)/bevacizumab: 5-fluorouracil 1600-2400 mg/m2 46-h intravenous (i.v.) infusion day 1 q2 weeks plus leucovorin 400 mg/m2 2-h infusion i.v. day 1 q2 weeks or capecitabine 1000 mg/m2 b.i.d. orally days 1-14 every 21 days; bevacizumab 5 mg/kg 15-30-min i.v. infusion q2 weeks] or experimental treatment in one of four biomarker-driven cohorts. In patients with BRAF wild-type (BRAFwt) tumors (cohort 2), experimental treatment was FP/bevacizumab + atezolizumab (800 mg 60-min i.v. infusion q2 weeks). Primary efficacy endpoint was progression-free survival (PFS; intent-to-treat population). Enrollment is complete; efficacy and safety findings from cohort 2 are presented. Results Four hundred and forty-five patients with BRAFwt mCRC were randomized (2 : 1) to maintenance in cohort 2. At a median follow-up of 10.5 months, PFS outcome hypothesis was not met [hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.72-1.17; P = 0.48]; overall survival (OS) was immature. At a median follow-up of 20.3 months (2-year survival follow-up), PFS benefit was also not met (HR 0.95; 95% CI 0.77-1.18; P = 0.666); OS HR with nearly two-thirds of patients with events was 0.83 (95% CI 0.65-1.05; P = 0.117). No new safety signals were identified. The most common grade ≥3 treatment-emergent adverse events (TEAEs) for experimental versus control arms were hypertension (6.1% versus 4.2%), diarrhea (3.1% versus 2.1%), and palmar-plantar erythrodysesthesia syndrome (1.0% versus 2.5%). Four patients experienced TEAEs with fatal outcome, two were study treatment-related: hepatic failure (experimental arm) and large intestine perforation (control arm; bevacizumab-related). Conclusions Adding atezolizumab to FP/bevacizumab as first-line maintenance treatment after FOLFOX + bevacizumab induction for BRAFwt mCRC did not improve efficacy outcomes.This work was supported by F. Hoffmann-La Roche Ltd (no grant number). The sponsor was involved in the study design and was responsible for the overall study management (monitoring), drug supply, data management, statistical analysis, and drug safety process. The Trial Master Files are maintained electronically by the sponsor. The sponsor was involved in the writing of this report, alongside the authors, all of whom had access to the raw data. The corresponding author had full access to all of the data and the final responsibility for submitting the article for publication on behalf of all authors

    The impact of COVID-19 on cancer care and oncology clinical research: an experts’ perspective

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    COVID-19; Cancer care; Clinical researchCOVID-19; Cura del càncer; Recerca clínicaCOVID-19; Cuidado del cancer; Investigación clínicaThe coronavirus disease-19 (COVID-19) pandemic promises to have lasting impacts on cancer clinical trials that could lead to faster patient access to new treatments. In this article, an international panel of oncology experts discusses the lasting impacts of the pandemic on oncology clinical trials and proposes solutions for clinical trial stakeholders, with the support of recent data on worldwide clinical trials collected by IQVIA. These lasting impacts and proposed solutions encompass three topic areas. Firstly, acceleration and implementation of new operational approaches to oncology trials with patient-centric, fully decentralized virtual approaches that include remote assessments via telemedicine and remote devices. Geographical differences in the uptake of remote technology, including telemedicine, are discussed in the article, focusing on the impact of the local adoption of new operational approaches. Secondly, innovative clinical trials. The pandemic has highlighted the need for new trial designs that accelerate research and limit risks and burden for patients while driving optimization of clinical trial objectives and endpoints, while testing is being minimized. Areas of considerations for clinical trial stakeholders are discussed in detail. In addition, the COVID-19 pandemic has exposed the underrepresentation of minority groups in clinical trials; the approach for oncology clinical trials to improve generalizability of efficacy and outcomes data is discussed. Thirdly, a new problem-focused collaborative framework between oncology trial stakeholders, including decision makers, to leverage and further accelerate the innovative approaches in clinical research developed during the COVID-19 pandemic. This could shorten timelines for patient access to new treatments by addressing the cultural and technological barriers to adopting new operational approaches and innovative clinical trials. The role of the different stakeholders is described, with the aim of making COVID-19 a catalyst for positive change in oncology clinical research and eventually in cancer care

    Effect of lurbinectedin on the QTc interval in patients with advanced solid tumors: an exposure–response analysis

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    Cardiac repolarization; Lurbinectedin; Plasma concentrationRepolarización cardíaca; Lurbinectedina; Concentración plasmáticaRepolarització cardíaca; Lurbinectedina; Concentració plasmàticaPurpose This study assessed the effect of lurbinectedin, a highly selective inhibitor of oncogenic transcription, on the change from baseline in Fridericia’s corrected QT interval (∆QTcF) and electrocardiography (ECG) morphological patterns, and lurbinectedin concentration–∆QTcF (C-∆QTcF) relationship, in patients with advanced solid tumors. Methods Patients with QTcF ≤ 500 ms, QRS < 110 ms, PR < 200 ms, and normal cardiac conduction and function received lurbinectedin 3.2 mg/m2 as a 1-h intravenous infusion every 3 weeks. ECGs were collected in triplicate via 12-lead digital recorder in treatment cycle 1 and 2 and analyzed centrally. ECG collection time-matched blood samples were drawn to measure lurbinectedin plasma concentration. No effect on QTc interval was concluded if the upper bound (UB) of the least square (LS) mean two-sided 90% confidence intervals (CI) for ΔQTcF at each time point was < 20 ms. C-∆QTcF was explored using linear mixed-effects analysis. Results A total of 1707 ECGs were collected from 39 patients (females, 22; median age, 56 years). The largest UB of the 90% CI of ΔQTcF was 9.6 ms, thus lower than the more conservative 10 ms threshold established at the ICH E14 guideline for QT studies in healthy volunteers. C-∆QTcF was better fit by an effect compartment model, and the 90% CI of predicted ΔQTcF at Cmax was 7.81 ms, also below the 10 ms threshold of clinical concern. Conclusions ECG parameters and C-ΔQTcF modelling in this prospective study indicate that lurbinectedin was not associated with a clinically relevant effect on cardiac repolarization.This study was funded by Pharma Mar S.A. and partially funded by the Industrial and Technological Development Center–CDTI (IDI-20150006)

    A New Paradigm for KIM-PTP Drug Discovery: Identification of Allosteric Sites with Potential for Selective Inhibition Using Virtual Screening and LEI Analysis

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    From MDPI via Jisc Publications RouterHistory: accepted 2021-11-06, pub-electronic 2021-11-11Publication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Grant(s): Doctoral Training Partnership PhD studentshipFunder: University of Manchester; Grant(s): Presidential PhD awardFunder: Medical Research Council; Grant(s): Doctoral Training Partnership PhD studentshipFunder: Society for Chemical Industry; Grant(s): scholarshipThe kinase interaction motif protein tyrosine phosphatases (KIM-PTPs), HePTP, PTPSL and STEP, are involved in the negative regulation of mitogen-activated protein kinase (MAPK) signalling pathways and are important therapeutic targets for a number of diseases. We have used VSpipe, a virtual screening pipeline, to identify a ligand cluster distribution that is unique to this subfamily of PTPs. Several clusters map onto KIM-PTP specific sequence motifs in contrast to the cluster distribution obtained for PTP1B, a classic PTP that mapped to general PTP motifs. Importantly, the ligand clusters coincide with previously reported functional and substrate binding sites in KIM-PTPs. Assessment of the KIM-PTP specific clusters, using ligand efficiency index (LEI) plots generated by the VSpipe, ascertained that the binders in these clusters reside in a more drug-like chemical–biological space than those at the active site. LEI analysis showed differences between clusters across all KIM-PTPs, highlighting a distinct and specific profile for each phosphatase. The most druggable cluster sites are unexplored allosteric functional sites unique to each target. Exploiting these sites may facilitate the delivery of inhibitors with improved drug-like properties, with selectivity amongst the KIM-PTPs and over other classical PTPs

    Trifluridine/tipiracil in combination with oxaliplatin and either bevacizumab or nivolumab in metastatic colorectal cancer: a dose-expansion, phase I study

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    Càncer colorectal metastàtic; Oxaliplatina; Trifluridina/TipiracilCáncer colorrectal metastásico; Oxaliplatino; Trifluridina/TipiracilMetastatic colorectal cancer; Oxaliplatin; Trifluridine/tipiracilBackground In preclinical studies trifluridine/tipiracil (FTD/TPI) plus oxaliplatin (Industriestrasse, Holzkirchen, Germany) sensitised microsatellite stable (MSS) metastatic colorectal cancer (mCRC) to anti-programmed cell death protein-1; the addition of oxaliplatin or bevacizumab (F Hoffmann- la ROCHE AG, Kaiseraugst, Switzerland) enhanced the antitumour effects of FTD/TPI. This study aimed to investigate the safety and efficacy of FTD/TPI plus oxaliplatin and either bevacizumab or nivolumab (Uxbridge business Park, Uxbridge, United Kingdom) in patients with mCRC who had progressed after at least one prior line of treatment. Patients and methods In 14-day cycles, patients received FTD/TPI 35 mg/m2 (twice daily, days 1-5) plus oxaliplatin 85 mg/m2 (day 1), and, on day 1, either bevacizumab 5 mg/kg (cohort A) or nivolumab 3 mg/kg (cohort B). Patients in Cohort B had confirmed MSS status. Results In total, 54 patients were enrolled: 37 in cohort A and 17 in cohort B. Recruitment in cohort B was stopped early due to the low response rate (RR) observed at interim analyses of efficacy. The most common adverse events (AEs) in cohort A were neutropenia/decreased neutrophils (75.7%), nausea (59.5%), vomiting (40.5%), diarrhoea (37.8%), peripheral sensory neuropathy (37.8%), fatigue (35.1%) and decreased appetite (35.1%). In cohort B, the most common AEs were neutropenia/decreased neutrophils (70.6%), diarrhoea (58.8%), nausea (47.1%), vomiting (47.1%), fatigue (47.1%), asthenia (41.2%), paraesthesia (41.2%), thrombocytopenia/decreased platelets (35.3%) and decreased appetite (35.3%). Confirmed objective RR was 17.1% in cohort A and 7.1% in cohort B; the corresponding values for median progression-free survival in the two cohorts were 6.3 and 6.0 months. Conclusion FTD/TPI plus oxaliplatin and bevacizumab or nivolumab had an acceptable safety profile and demonstrated antitumour activity in previously treated patients with mCRC.The study was funded jointly by Servier, France and Taiho Pharmaceutical, Japan
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