Pharmacokinetics and brain σ1 receptor occupancy of MR309, a selective σ1 receptor antagonist.

AIMS: Preclinical studies of MR309, a selective sigma-1 receptor (σ1R) antagonist, support a potential role in treating neuropathic pain. We report 2 studies that provide insight into the pharmacokinetics (PK) and brain σ1R binding of MR309. METHODS: Steady-state PK of MR309 (400 mg once daily and 200 mg twice-daily [BID] for 10 days; EudraCT 2015-001818-99 [PK study]) and the relationship between MR309 plasma exposure and brain σ1R occupancy (EudraCT 2017-000670-11 [positron emission tomography study]) were investigated in healthy volunteers. Positron emission tomography using the σ1R ligand [11 C]SA4503 was conducted at baseline, and 2 and 8 hours after a single dose of MR309 (200-800 mg). The relationship between brain σ1R occupancy and MR309 exposure was explored using data-driven model fitting. RESULTS: MR309 was well tolerated, brain σ1R occupancy ranged between 30.5 and 74.9% following single-dose MR309 (n = 7). MR309 BID provided a plasma PK profile with less fluctuation than once daily dosing (n = 16). MR309 200 mg BID yielded average steady state plasma concentrations between 2000 and 4000 ng/mL in the PK study, which corresponded to an estimated brain σ1R occupancy of 59-74%. CONCLUSION: MR309 200 mg BID dose was below the 75% σ1R occupancy threshold expected to elicit maximal antinociceptive effect as observed in neuropathic pain models. Further investigations of MR309 for neuropathic pain will require higher brain σ1R occupancy, and establish the optimal dose by elucidating the clinical impact of a broad range of brain σ1R occupancy across different neuropathic pain indications.

Pharmacokinetics of Tramadol and Celecoxib in Japanese and Caucasian Subjects Following Administration of Co-Crystal of Tramadol-Celecoxib (CTC): A Randomised, Open-Label Study.

BACKGROUND AND OBJECTIVES: Co-Crystal of Tramadol-Celecoxib (CTC) is a first-in-class active pharmaceutical ingredient (API-API) co-crystal of rac-tramadol.HCl and celecoxib in a 1:1 molecular ratio (100 mg CTC: 44 mg rac-tramadol.HCl and 56 mg celecoxib). Tramadol and celecoxib pharmacokinetics are modified after CTC administration versus administration of reference products. This randomised, open-label, crossover, phase 1 study assessed CTC pharmacokinetics, dose proportionality, safety and tolerability in Japanese and Caucasian subjects. METHODS: CTC (100, 150 and 200 mg) was administered orally to healthy Japanese/Caucasian subjects. Tramadol, O-desmethyltramadol and celecoxib plasma concentrations were determined pre-dose and up to 48 h post-dose. Maximum observed plasma concentration (Cmax), and area under the plasma concentration-time curve from dosing to last measurable concentration (AUCt) and from dosing extrapolated to infinity (AUC∞) were evaluated. Dose proportionality was assessed in a dose-adjusted bioavailability analysis of variance and in a power model. Inter-cohort comparability of pharmacokinetic exposure was confirmed if the ratio (Japanese cohort/Caucasian cohort) of geometric least-squares means and corresponding 90% confidence intervals were 80-125%. Post hoc weight-adjusted comparability analyses were performed. Safety was assessed throughout. RESULTS: Sixty subjects (21 males/9 females per cohort) were randomised; 57 completed the study. Cohorts were age and BMI matched; there were expected inter-cohort weight differences. Exposure to each analyte increased in both cohorts with increasing CTC dose. Tramadol's pharmacokinetic exposure was comparable between cohorts after adjusting for body weight; the pharmacokinetic exposure of O-desmethyltramadol and celecoxib was increased in Japanese subjects. CONCLUSIONS: Differences in pharmacokinetics were not sufficient to suggest that CTC dose adjustment is required in Japanese subjects. CLINICAL TRIAL REGISTRATION: EudraCT: 2015-003071-29.

Non-interventional study of the safety and effectiveness of fluticasone propionate/formoterol fumarate in real-world asthma management.

INTRODUCTION: In recognition of the value of long-term real-world data, a postauthorization safety study of the inhaled corticosteroid (ICS) fluticasone propionate and long-acting ß2-agonist (LABA) formoterol fumarate (fluticasone/formoterol; Flutiform®) was conducted. METHODS: This was a 12-month observational study of outpatients with asthma aged ⩾ 12 years in eight European countries. Patients were prescribed fluticasone/formoterol according to the licensed indication, and independently of their subsequent enrolment in the study. They were then treated according to local standard practice. The study objectives were to evaluate the safety and effectiveness of fluticasone/formoterol under real-world conditions. RESULTS: The safety population for this study comprised 2539 patients (mean age 47.7 years; 94.3% aged ⩾ 18 years; 63.4% female). Most patients (1538/2539, 60.6%) had switched to fluticasone/formoterol from another ICS/LABA, primarily due to lack of efficacy (1150/2539, 45.3%). Three quarters (77.4%) of patients were treated for 12 months, and 80.6% continued fluticasone/formoterol treatment after the study. Adverse events (AEs) occurred in 60.0% patients, and 10.2% had AEs considered possibly related to fluticasone/formoterol [most commonly asthma exacerbation (2.0% patients), dysphonia (1.8%) and cough (1.1%)]. Thirty-six severe AEs, but no serious AEs, were considered possibly related to fluticasone/formoterol. The proportion of patients with controlled asthma (based on Asthma Control Test score ⩾ 20) increased from 29.4% at baseline to 67.4% at study end (last observation carried forward). The proportion of patients experiencing at least one severe exacerbation decreased from 35.8% in the year prior to enrolment to 9.8% during the study. Improvements from baseline to study end were also observed in Asthma Quality of Life scores and physician/patient reports of satisfaction with treatment. CONCLUSION: In this real-world postauthorization safety study, fluticasone/formoterol demonstrated a safety profile consistent with that seen in controlled clinical trials, with effectiveness in improving asthma control.

Pediatric oncology clinical trial participation where the geography is vast: Development of a clinical research system for tertiary and satellite centers in Ontario, Canada.

Opportunities for participation in clinical trials are a core component of the care of children with cancer. In Ontario, many pediatric patients live long distances from their cancer center. This paper describes the work that was done in order to allow patients participating in Children's Oncology Group trials to receive care, including research protocol related care, jointly between the tertiary pediatric cancer center and the closer-to-home satellite center. The system is a pragmatic risk-based model, supporting excellence in care while ensuring good conduct of the research in compliance with applicable regulations and guidelines, including ethics oversight.