scholarly journals Development and validation of a methotrexate adherence assay

2019 ◽  
Vol 78 (9) ◽  
pp. 1192-1197 ◽  
Author(s):  
James Bluett ◽  
Isabel Riba-Garcia ◽  
Suzanne M M Verstappen ◽  
Thierry Wendling ◽  
Kayode Ogungbenro ◽  
...  

BackgroundThe first-line therapy for rheumatoid arthritis (RA) is weekly oral methotrexate (MTX) at low dosages (7.5–25 mg/week). However, ~40% of patients are non-adherent which may explain why some do not respond and need to start more expensive biological therapies. To monitor adherence more accurately and develop strategies to improve it, a validated objective MTX adherence test is required.ObjectiveTo develop and validate the diagnostic accuracy of a novel MTX adherence assay using high-performance liquid chromatography–selected reaction monitoring– mass spectrometry (HPLC-SRM-MS) based biochemical analysis of drug levels.Methods20 patients with RA underwent MTX pharmacokinetic assessment using HPLC-SRM-MS MTX plasma concentration analysis over a 6-day period. Directly observed therapy was the reference standard. Pharmacokinetic model validation was performed using independent plasma samples from real-world patients (n=50) with self-reported times of drug administration. Following assay optimisation, the sensitivity of the assay to detect adherence was established using samples from an observational cohort study (n=138).ResultsA two-compartment pharmacokinetic model was developed and validated. Simulations described the sensitivity required for MTX detection over 7 days; subsequent assay optimisation and retesting of samples confirmed that all patients were correctly identified as MTX adherers. Using real-world samples, the assays sensitivity was 95%.ConclusionNon-adherence to MTX is common and can have a significant effect on disease activity. HPLC-SRM-MS plasma analysis accurately detects MTX adherence. The validated objective test could easily be used in clinic to identify patients requiring adherence support.

Author(s):  
Bo Li ◽  
Jin Wang ◽  
Xinyao Dou ◽  
Xinjie Zhang ◽  
Xianbei Xue ◽  
...  

Aim and Objective:: An analytical method for the determination of mobocertinib, an investigational tyrosine kinase inhibitor, was developed and optimized by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) in rat plasma. Materials and Methods:: Plasma samples were pretreated by the protein precipitation method with a methanol solution of osimertinib as the internal standard (IS). Chromatographic separation was performed using an Inertsil ODS-3 column (50 mm × 4.6 mm, I.D. 5 μm) column with the temperature maintained at 40 °C. The mobile phase consisted of water (containing 0.1% formic acid) and methanol in a gradient mode at a flow rate of 0.5 mL/min. Mass spectrometric detection was carried out in the selected reaction monitoring (SRM) mode with positive electrospray ionization, and the mass transitions of mobocertinib and osimertinib were m/z 587.01 → 71.88 and m/z 499.80 → 71.94, respectively. The method was validated in terms of selectivity, linearity, accuracy and precision, extraction recovery and matrix effect, stability and carryover as per the guidelines for bioanalytical method validation (FDA, 2018). The method was applied to the pharmacokinetic study of mobocertinib in rats by oral gavage at the doses of 2, 6, and 18 mg/kg. A total of 216 plasma samples from 18 rats were analyzed. Results:: It showed good linearity over the range of 1-1000 ng/mL (R2 = 0.9957). The intra-batch accuracy was within 94.65-102.59% and the precision was within 5.49-10.46%. The inter-batch accuracy was within 97.08-102.25% with a precision of 7.54-10.13%. The extraction recovery and matrix factor were acceptable for the bioanalysis of mobocertinib. Additionally, mobocertinib was found to be stable under the detected conditions. Mobocertinib showed linear pharmacokinetic characteristics following oral administration to rats at 2.0-18.0 mg/kg. Conclusion:: The developed and validated method was successfully employed in the pharmacokinetic study in rats following oral administration of mobocertinib at the doses of 2, 6, and 18 mg/kg.


BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Toby Page ◽  
Rajan Veeratterapillay ◽  
Kim Keltie ◽  
Julie Burn ◽  
Andrew Sims

Abstract Background To determine real-world outcomes of prostatic urethral lift (UroLift) procedures conducted in hospitals across England. Methods A retrospective observational cohort was identified from Hospital Episode Statistics data including men undergoing UroLift in hospitals in England between 2017 and 2020. Procedure uptake, patient demographics, inpatient complications, 30-day accident and emergency re-attendance rate, requirement for further treatment and catheterization were captured. Kaplan–Meier and hazard analysis were used to analyse time to re-treatment. Results 2942 index UroLift procedures from 80 hospital trusts were analysed; 85.3% conducted as day-case surgery (admitted to hospital for a planned surgical procedure and returning home on the same day). In-hospital complication rate was 3.4%. 93% of men were catheter-free at 30 days. The acute accident and emergency attendance rate within 30 days was 12.0%. Results of Kaplan Meier analysis for subsequent re-treatment (including additional UroLift and endoscopic intervention) at 1 and 2 years were 5.2% [95% CI 4.2 to 6.1] and 11.9% [10.1 to 13.6] respectively. Conclusions This real-world analysis of UroLift shows that it can be delivered safely in a day-case setting with minimal morbidity. However, hospital resource usage for catheterization and emergency hospital attendance in the first 30 days was substantial, and 12% required re-treatment at 2 years.


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