33 research outputs found

    Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

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    Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

    Efficacy and safety of oral semaglutide with flexible dose adjustment versus sitagliptin in type 2 diabetes (PIONEER 7): a multicentre, open-label, randomised, phase 3a trial

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    Background: Oral semaglutide is the first oral formulation of a glucagon-like peptide-1 (GLP-1) receptor agonist developed for the treatment of type 2 diabetes. We aimed to compare the efficacy and safety of flexible dose adjustments of oral semaglutide with sitagliptin 100 mg. Methods: In this 52-week, multicentre, randomised, open-label, phase 3a trial, we recruited patients with type 2 diabetes from 81 sites in ten countries. Patients were eligible if they were aged 18 years or older (19 years or older in South Korea), had type 2 diabetes (diagnosed ≥90 days before screening), HbA1c of 7·5–9·5% (58–80 mmol/mol), and were inadequately controlled on stable daily doses of one or two oral glucose-lowering drugs (for 90 days or more before screening). Participants were randomly assigned (1:1) by use of an interactive web-response system, stratified by background glucose-lowering medication at screening, to oral semaglutide with flexible dose adjustments to 3, 7, or 14 mg once daily or sitagliptin 100 mg once daily. To approximate treatment individualisation in clinical practice, oral semaglutide dose could be adjusted on the basis of prespecified HbA1c and tolerability criteria. Two efficacy-related estimands were prespecified: treatment policy (regardless of treatment discontinuation or use of rescue medication) and trial product (on treatment and without use of rescue medication) for participants randomly assigned to treatment. The primary endpoint was achievement of HbA1c of less than 7% (53 mmol/mol) at week 52 and the confirmatory secondary efficacy endpoint was change in bodyweight from baseline to week 52. Safety was assessed in all participants who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT02849080, and European Clinical Trials Database, EudraCT number 2015-005593-38, and an open-label extension is ongoing. Findings: Between Sept 20, 2016, and Feb 7, 2017, of 804 patients assessed for eligibility, 504 were eligible and randomly assigned to oral semaglutide (n=253) or sitagliptin (n=251). Most participants were male (285 [57%] of 504) with a mean age of 57·4 years (SD 9·9). All participants were given at least one dose of their allocated study drug except for one participant in the sitagliptin group. From a mean baseline HbA1c of 8·3% (SD 0·6%; 67 mmol/mol [SD 6·4]), a greater proportion of participants achieved an HbA1c of less than 7% with oral semaglutide than did with sitagliptin (treatment policy estimand: 58% [134 of 230] vs 25% [60 of 238]; and trial product estimand: 63% [123 of 196] vs 28% [52 of 184]). The odds of achieving an HbA1c of less than 7% was significantly better with oral semaglutide than sitagliptin (treatment policy estimand: odds ratio [OR] 4·40, 95% CI 2·89–6·70, p<0·0001; and trial product estimand: 5·54, 3·54–8·68, p<0·0001). The odds of decreasing mean bodyweight from baseline to week 52 were higher with oral semaglutide than with sitagliptin (estimated mean change in bodyweight, treatment policy estimand: −2·6 kg [SE 0·3] vs −0·7 kg [SE 0·2], estimated treatment difference [ETD] −1·9 kg, 95% CI −2·6 to −1·2; p<0·0001; and trial product estimand: −2·9 kg [SE 0·3] vs −0·8 kg [SE 0·3], ETD −2·2 kg, −2·9 to −1·5; p<0·0001). Adverse events occurred in 197 (78%) of 253 participants in the oral semaglutide group versus 172 (69%) of 250 in the sitagliptin group, and nausea was the most common adverse event with oral semaglutide (53 [21%]). Two deaths occurred in the sitagliptin group during the trial. Interpretation: Oral semaglutide, with flexible dose adjustment, based on efficacy and tolerability, provided superior glycaemic control and weight loss compared with sitagliptin, and with a safety profile consistent with subcutaneous GLP-1 receptor agonists. Funding: Novo Nordisk A/S

    The economic and clinical burden of early versus late initiation of celecoxib among patients with osteoarthritis

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    Ahmed Shelbaya,1,2 Caitlyn T Solem,3 Chris Walker,4 Yin Wan,3 Courtney Johnson,3 Joseph C Cappelleri1 1Pfizer Inc., New York, NY, 2Columbia School of Public Health, New York, NY, 3Pharmerit International, Bethesda, MD, USA; 4Pfizer Ltd., Tadworth, Surrey, UK Objective: This study aimed to evaluate the characteristics associated with early versus late initiation of celecoxib treatment after osteoarthritis (OA) diagnosis and whether economic and safety outcomes differ between patients with early versus late initiation of celecoxib.Methods: Adults (≥18 years) with a confirmed OA diagnosis (International Classification of Diseases, 9th Edition, Clinical Modifications code: 715.XX), ≥12 months of continuous pre- and post-index enrollment, and ≥1 post-index claim for celecoxib were included from the MarketScan® Commercial Claims and Encounter Database (2009–2013). Index date was defined as initial OA diagnosis. Patients were categorized as initiating celecoxib early (within 6 months of index date) or late (≥6 months after index date). Logistic regressions were used to assess characteristics associated with early versus late celecoxib initiation. Key outcomes included health care resource utilization (HCRU) and costs post-index, and adverse event incidence post-celecoxib initiation. Unadjusted and adjusted comparisons (using generalized linear models with a gamma distribution for costs and Poisson distribution for event and resource utilization) were made between early and late celecoxib initiators.Results: Of the 62,434 OA patients identified, 27,402 were early and 35,032 were late initiators. Post-index hospital admissions and length of stay did not differ statistically between early versus late initiators after controlling for pre-index event rates and covariates, but early patients had significantly fewer outpatient (incidence rate ratio [IRR]: 0.96; 95% confidence interval [CI]: 0.95, 0.97) and emergency room visits (IRR: 0.89; 95% CI: 0.84, 0.95). After adjustment for key covariates, early initiators (versus late initiators) had lower all-cause (US12,909versusUS12,909 versus US13,781, P<0.001) and OA-related (US4,988versusUS4,988 versus US5,178, P=0.015) costs per person-year. Early initiators had no statistically significant difference in the incidence of post-celecoxib cardiovascular (IRR: 0.92; 95% CI: 0.73, 1.14), gastrointestinal (IRR: 1.25; 95% CI: 0.81, 1.92), or renal (IRR: 1.19; 95% CI: 0.65, 2.18) events, controlling for pre-index event rates and covariates when compared to late initiators.Conclusion: In this real-world cohort, patients initiated on celecoxib early (versus late) had significantly lower costs and HCRU; this may warrant consideration when making treatment decisions for OA patients. Keywords: osteoarthritis, celecoxib, nonsteroidal anti-inflammatory drug, economic burden, health care resource use&nbsp

    Economic burden of inpatient and outpatient antibiotic treatment for methicillin-resistant Staphylococcus aureus complicated skin and soft-tissue infections: a comparison of linezolid, vancomycin, and daptomycin

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    Jennifer M Stephens,1 Xin Gao,1 Dipen A Patel,1 Bram G Verheggen,2 Ahmed Shelbaya,3,5 Seema Haider4 1Pharmerit North America, Bethesda, MD, USA; 2Pharmerit Europe, Rotterdam, The Netherlands; 3Pfizer Inc, New York, NY, USA; 4Pfizer Inc, Groton, CT, USA; 5Mailman School of Public Health, Columbia University, NY, USA Background: Previous economic analyses evaluating treatment of methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft-tissue infections (cSSTI) failed to include all direct treatment costs such as outpatient parenteral antibiotic therapy (OPAT). Our objective was to develop an economic model from a US payer perspective that includes all direct inpatient and outpatient costs incurred by patients with MRSA cSSTI receiving linezolid, vancomycin, or daptomycin. Methods: A 4-week decision model was developed for this economic analysis. Published literature and database analyses with validation by experts provided clinical, resource use, and cost inputs on data such as efficacy rate, length of stay, adverse events, and OPAT services. Base-case analysis assumed equal efficacy and equal length of stay for treatments. We conducted several sensitivity analyses where assumptions on resource use or efficacy were varied. Costs were reported in year-end 2011 US dollars. Results: Total treatment costs in the base-case were lower for linezolid (10,571)thanvancomycin(10,571) than vancomycin (11,096), and daptomycin (13,612).Inpatienttreatmentcostswere13,612). Inpatient treatment costs were 740 more, but outpatient costs, 1,266lesswithlinezolidthanvancomycintherapyduetoaswitchtoorallinezolidwhenthepatientwasdischarged.Comparedwithdaptomycin,bothinpatientandoutpatienttreatmentcostswerelowerwithlinezolidby1,266 less with linezolid than vancomycin therapy due to a switch to oral linezolid when the patient was discharged. Compared with daptomycin, both inpatient and outpatient treatment costs were lower with linezolid by 87 and 2,954respectively.Insensitivityanalyses,linezolidhadlowercostscomparedwithvancomycinanddaptomycinwhenusingdifferentiallengthofstaydatafromaclinicaltrial,andusingsuccessratesfromameta−analysis.Inascenariowithoutperipherallyinsertedcentralcatheterlinecosts,linezolidbecameslightlymoreexpensivethanvancomycin(by2,954 respectively. In sensitivity analyses, linezolid had lower costs compared with vancomycin and daptomycin when using differential length of stay data from a clinical trial, and using success rates from a meta-analysis. In a scenario without peripherally inserted central catheter line costs, linezolid became slightly more expensive than vancomycin (by 285), but remained less costly than daptomycin (by $2,316). Conclusion: Outpatient costs of managing MRSA cSSTI may be reduced by 30%–50% with oral linezolid compared with vancomycin or daptomycin. Results from this analysis support potential economic benefit and cost savings of using linezolid versus traditional OPAT when total inpatient and outpatient medical costs are evaluated. Keywords: economic model, OPAT, cos
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