This was a double-blind, randomised, placebo-controlled study to investigate the pharmacokinetics and safety of trans-resveratrol. In four groups of ten healthy adult subjects (five males and five females), two subjects were randomized to receive placebo and eight subjects to receive trans-resveratrol 25, 50, 100 or 150 mg, six times/day, for thirteen doses. Peak plasma concentrations of trans-resveratrol were reached at 0.8-1.5 h postdose. Following the 13th dose of trans-resveratrol 25, 50, 100 and 150 mg, mean peak plasma concentration (C(max)) was 3.89, 7.39, 23.1 and 63.8 ng/mL and mean area under the plasma concentration-time curve (AUC(0-tau)) was 3.1, 11.2, 33.0 and 78.9 ng.h/mL. Interindividual variability was high, with coefficients of variation >40%. Trans-resveratrol half-life was 1-3 h following single-doses and 2-5 h following repeated dosing. Trough (C(min)) concentrations were < or = 1 ng/mL following 25 and 50 mg, 3 ng/mL following 100 mg and < 10 ng/mL following 150 mg. Trans-resveratrol pharmacokinetics showed circadian variation. Adverse events were mild in severity and similar between all groups. In conclusion, repeated administration was well-tolerated but produced relatively low plasma concentrations of trans-resveratrol, despite the high doses and short dosing interval used. Bioavailability was higher after morning administration.
ObjectiveTo evaluate the efficacy and safety of adjunctive eslicarbazepine acetate (ESL) in patients with refractory partial-onset seizures.MethodsThis randomized, placebo-controlled, double-blind, parallel-group, phase III study was conducted at 173 centers in 19 countries, including the United States and Canada. Eligible patients were aged ≥16 years and had uncontrolled partial-onset seizures despite treatment with 1–2 antiepileptic drugs (AEDs). After an 8-week baseline period, patients were randomized to once-daily placebo (n = 226), ESL 800 mg (n = 216), or ESL 1,200 mg (n = 211). Following a 2-week titration period, patients received ESL 800 or 1,200 mg once-daily for 12 weeks. Seizure data were captured and documented using event-entry or daily entry diaries.ResultsStandardized seizure frequency (SSF) during the maintenance period (primary end point) was reduced with ESL 1,200 mg (p = 0.004), and there was a trend toward improvement with ESL 800 mg (p = 0.06), compared with placebo. When data for titration and maintenance periods were combined, ESL 800 mg (p = 0.001) and 1,200 mg (p < 0.001) both reduced SSF. There were no statistically significant interactions between treatment response and geographical region (p = 0.38) or diary version (p = 0.76). Responder rate (≥50% reduction in SSF) was significantly higher with ESL 1,200 mg (42.6%, p < 0.001) but not ESL 800 mg (30.5%, p = 0.07) than placebo (23.1%). Incidence of treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation increased with ESL dose. The most common TEAEs were dizziness, somnolence, nausea, headache, and diplopia.SignificanceAdjunctive ESL 1,200 mg once-daily was more efficacious than placebo in adult patients with refractory partial-onset seizures. The once-daily 800 mg dose showed a marginal effect on SSF, but did not reach statistical significance. Both doses were well tolerated. Efficacy assessment was not affected by diary format used.
Opicapone was well-tolerated and presented dose-proportional kinetics. Opicapone demonstrated marked and sustained inhibition of erythrocyte soluble COMT activity. Based on the observation that the half-life of COMT inhibition is independent of the dose and that it reflects an underlying kinetic process that is consistent with the k(off) value of the COMT-opicapone complex, we propose that the sustained COMT inhibition, far beyond the observable point of clearance of circulating drug, is due to the long residence time of the reversible complex formed between COMT and opicapone. Globally, these promising results provide a basis for further clinical development of opicapone.
AIMSThe aim of this study was to assess the tolerability, pharmacokinetics and inhibitory effect on erythrocyte soluble catechol-O-methyltransferase (S-COMT) activity following repeated doses of opicapone.
METHODSThis randomized, placebo-controlled, double-blind study enrolled healthy male subjects who received either once daily placebo or opicapone 5, 10, 20 or 30 mg for 8 days.
RESULTSOpicapone was well tolerated. Its systemic exposure increased in an approximately dose-proportional manner with an apparent terminal half-life of 1.0 to 1.4 h. Sulphation was the main metabolic pathway. Opicapone metabolites recovered in urine accounted for less than 3% of the amount of opicapone administered suggesting that bile is likely the main route of excretion. Maximum S-COMT inhibition (Emax) ranged from 69.9% to 98.0% following the last dose of opicapone. The opicapone-induced S-COMT inhibition showed a half-life in excess of 100 h, which was dose-independent and much longer than plasma drug exposure. Such a half-life translates into a putative underlying rate constant that is comparable with the estimated dissociation rate constant of the COMT-opicapone complex.
CONCLUSIONDespite its short elimination half-life, opicapone markedly and sustainably inhibited erythrocyte S-COMT activity making it suitable for a once daily regimen.
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Currently available catechol-O-methyltransferase (COMT) inhibitors used as adjunctive therapy in levodopa-treated Parkinson's disease patients have clinical limitations. Due to liver toxicity, the use of tolcapone requires liver function monitoring. Entacapone is considered to be safe, but its efficacy is limited and it requires frequent dosing. Opicapone is a novel third generation COMT inhibitor designed to provide high COMT inhibitory potency and avoid cell toxicity.
WHAT THIS STUDY ADDS• Based on the observation that the duration of COMT inhibition after opicapone administration is dose-independent and that it reflects an underlying kinetic process that is consistent with the dissociation rate constant of the COMT-opicapone complex, we propose that the sustained COMT inhibition, far beyond the observable point of clearance of circulating drug, is due to the long residence time of the reversible COMT-opicapone complex. The results clearly suggest that opicapone has a unique pharmacodynamic profile adequate for a once daily regimen, which in the treatment of Parkinson's disease patients could represent an advantage over entacapone and tolcapone.
SUMMARYPurpose: To evaluate the efficacy and safety profile of eslicarbazepine acetate (ESL) added to stable antiepileptic therapy in adults with partial-onset seizures. Methods: Data from 1,049 patients enrolled from 125 centers, in 23 countries, in three phase III double-blind, randomized, placebo-controlled studies were pooled and analyzed. Following a 2-week titration period, ESL was administered at 400 mg, 800 mg, and 1,200 mg once-daily doses for 12 weeks. Key Findings: Seizure frequency was significantly reduced with ESL 800 mg (p < 0.0001) and 1,200 mg (p < 0.0001) compared to placebo. Median relative reduction in seizure frequency was, respectively, 35% and 39% (placebo 15%) and responder rate was 36% and 44% (placebo 22%). ESL was more efficacious than placebo regardless of gender, geographic region, epilepsy duration, age at time of diagnosis, seizure type, and number and type of concomitant antiepileptic drugs (AEDs). Incidence of adverse events (AEs) and AEs leading to discontinuation were dose dependent. AEs occurred mainly during the first weeks of treatment, with no difference between groups after 6 weeks. Most common AEs (>10% patients) were dizziness, somnolence, and headache. The incidence of AEs in ESL groups compared to placebo was generally consistent among different subpopulations. Significance: Once-daily ESL 800 mg and 1,200 mg showed consistent results across all efficacy and safety end points. Results were independent of study population characteristics and type and number of concomitant AEDs.
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