Effect of zamicastat on blood pressure and heart rate response to cold pressor test: A double-blind, randomized, placebo-controlled study in healthy subjects.

AIMS: Dopamine beta-hydroxylase (DßH) inhibitors, like zamicastat, hold promise for treating pulmonary arterial hypertension. This study aimed to validate the mechanism of action of zamicastat by studying its effect on the overdrive of the sympathetic nervous system (SNS). METHODS: A single-centre, prospective, double-blind, randomized, placebo-controlled, crossover study evaluated the effect of 400 mg zamicastat in 22 healthy male subjects. Cold pressor test (CPT) was performed at screening and each treatment period on Days -1 and 10. Plasma and 24 h-urine levels of dopamine (DA), epinephrine (EPI) and norepinephrine (NE), and plasma DßH activity, were measured. RESULTS: Compared to placebo, zamicastat showed a - 4.62 mmHg decrease in systolic blood pressure during the cold stimulus vs. rest phases on Day 10 of CPT (P = .020). Zamicastat decreased mean arterial pressure response to cold stimulus during CPT (-2.62 mmHg; P = .025). At Day 10, zamicastat significantly increased plasma DA, before CPT (12.63 ng/L; P = .040) and after CPT (19.22 ng/L; P = .001) as well as the estimated plasma EPI change from baseline after CPT (P = .040). Inhibition of plasma DßH activity ranged from 19.8% to 25.0%. At Day 10, significant reductions in 24-h urinary excretion of EPI (P = .002) and NE (P = .001) were observed. Zamicastat Cτ geometric mean ± GSD ranged from 45.86 ± 1.46 ng/mL on Day 3 to 58.64 ± 1.52 ng/mL on Day 10, with moderate inter-individual variability (CV: 32.6%-36.6%). Steady state was already achieved on Day 6. CONCLUSIONS: Our results demonstrated the effect of zamicastat on the overdrive sympathetic response to cold stimulus, confirming its potential as SNS modulator.

Drug-Drug Interaction between Oral Zamicastat and Continuous Epoprostenol Infusion at Steady-State Conditions in Healthy Subjects.

This study intended to evaluate the interactions between zamicastat and epoprostenol in healthy human subjects. This was a single-center, open-label, two-period study. In period 1, epoprostenol 8 ng/kg/min was administered alone. In period 2, epoprostenol 8 ng/kg/min was administered following an 8-day treatment with zamicastat. Since the initial dose of epoprostenol showed to be insufficiently tolerated, it was decreased to 6 ng/kg/min. Blood samples were collected to determine the metabolites of epoprostenol and concentrations of zamicastat and its metabolites. A total of 54 subjects were enrolled and data from 28 subjects were available for pharmacokinetic analysis. The epoprostenol plus zamicastat-to-epoprostenol geometric means ratio (GMR) and corresponding 90% confidence interval (CI) for Cav,ss and area under the plasma concentration-time curve from time 0 up to 16 h at steady state (AUC0-16,ss) of the metabolites of epoprostenol were within the acceptance bioequivalence range (80.00%-125.00%). The intrasubject coefficient of variation (ISCV) was below 10% for both parameters, on both metabolites. For zamicastat AUC0-τ,ss, the zamicastat plus epoprostenol-to-zamicastat GMR and corresponding 90% CI were within the bioequivalence acceptance range, while for zamicastat Cmax,ss, the lower limit of the 90% CI was slightly below the acceptance range. For zamicastat metabolites, Cmax,ss and AUC0-τ,ss and the zamicastat plus epoprostenol-to-zamicastat GMR were below the acceptance bioequivalence range. ISCV was between 30% and 41% for Cmax,ss and between 21% and 41% for AUC0-τ,ss, for zamicastat and both metabolites. This study showed that the administration of zamicastat did not significantly modify the cardiovascular effects of epoprostenol and that the interactions between zamicastat and epoprostenol are not expected to be clinically relevant.

Cellular and Mitochondrial Toxicity of Tolcapone, Entacapone, and New Nitrocatechol Derivatives.

Nitrocatechols are the standard pharmacophore to develop potent tight-binding inhibitors of catechol O-methyltransferase (COMT), which can be used as coadjuvant drugs to manage Parkinson's disease. Tolcapone is the most potent drug of this class, but it has raised safety concerns due to its potential to induce liver damage. Tolcapone-induced hepatotoxicity has been attributed to the nitrocatechol moiety; however, other nitrocatechol-based COMT inhibitors, such as entacapone, are safe and do not damage the liver. There is a knowledge gap concerning which mechanisms and chemical properties govern the toxicity of nitrocatechol-based COMT inhibitors. Using a vast array of cell-based assays, we found that tolcapone-induced toxicity is caused by direct interference with mitochondria that does not depend on bioactivation by P450. Our findings also suggest that (a) lipophilicity is a key property in the toxic potential of nitrocatechols; (b) the presence of a carbonyl group directly attached to the nitrocatechol ring seems to increase the reactivity of the molecule, and (c) the presence of cyano moiety in double bond stabilizes the reactivity decreasing the cytotoxicity. Altogether, the fine balance between lipophilicity and the chemical nature of the C1 substituents of the nitrocatechol ring may explain the difference in the toxicological behavior observed between tolcapone and entacapone.

OFF-times before, during, and after nighttime sleep periods in Parkinson's disease patients with motor fluctuations and the effects of opicapone: A post hoc analysis of diary data from BIPARK-1 and -2.

INTRODUCTION: In BIPARK-1 and BIPARK-2, addition of once-daily opicapone to levodopa/carbidopa significantly reduced daily "OFF"-time relative to placebo in adults with Parkinson's disease (PD) and motor fluctuations. Diary data from these studies were pooled and analyzed post hoc to characterize "OFF"-times around nighttime sleep and to explore the effects of opicapone 50 mg. METHODS: "OFF" before sleep (OBS), "OFF during the nighttime sleep period" (ODNSP), early morning "OFF" (EMO), and duration of nighttime sleep and awake periods were analyzed descriptively at baseline. Mean changes from baseline to Week 14/15 (end of double-blind treatment) were analyzed using two-sided t-tests in participants with data for both visits. RESULTS: At baseline, 88.3 % (454/514) of participants reported having OBS (34.0 %), ODNSP (17.1 %), or EMO (79.6 %). Those with ODNSP had substantially shorter mean duration of uninterrupted sleep (4.4 h) than the overall pooled population (7.1 h). At Week 14/15, mean decrease from baseline in ODNSP duration was significantly greater with opicapone than with placebo (-0.9 vs. -0.4 h, P < 0.05). In participants with ODNSP at baseline, the decrease in total time spent awake during the night-time sleep period was significantly greater with opicapone than with placebo (-1.0 vs. -0.4 h, P < 0.05), as was the reduction in percent time spent awake during the night-time sleep period (-12.8 % vs. -4.5 %, P < 0.05). CONCLUSION: "OFF"-times around nighttime sleep were common in BIPARK-1 and BIPARK-2. Opicapone may improve sleep by decreasing the amount of time spent awake during the night in patients with PD who have night-time sleep period "OFF" episodes.

Antiepileptogenesis after stroke-trials and tribulations: Methodological challenges and recruitment results of a Phase II study with eslicarbazepine acetate.

There is currently no evidence to support the use of antiseizure medications to prevent unprovoked seizures following stroke. Experimental animal models suggested a potential antiepileptogenic effect for eslicarbazepine acetate (ESL), and a Phase II, multicenter, randomized, double-blind, placebo-controlled study was designed to test this hypothesis and assess whether ESL treatment for 1 month can prevent unprovoked seizures following stroke. We outline the design and status of this antiepileptogenesis study, and discuss the challenges encountered in its execution to date. Patients at high risk of developing unprovoked seizures after acute intracerebral hemorrhage or acute ischemic stroke were randomized to receive ESL 800 mg/d or placebo, initiated within 120 hours after primary stroke occurrence. Treatment continued until Day 30, then tapered off. Patients could receive all necessary therapies for stroke treatment according to clinical practice guidelines and standard of care, and are being followed up for 18 months. The primary efficacy endpoint is the occurrence of a first unprovoked seizure within 6 months after randomization ("failure rate"). Secondary efficacy assessments include the occurrence of a first unprovoked seizure during 12 months after randomization and during the entire study; functional outcomes (Barthel Index original 10-item version; National Institutes of Health Stroke Scale); post-stroke depression (Patient Health Questionnaire-9; PHQ-9); and overall survival. Safety assessments include the evaluation of treatment-emergent adverse events; laboratory parameters; vital signs; electrocardiogram; suicidal ideation and behavior (PHQ-9 question 9). The protocol aimed to randomize approximately 200 patients (1:1), recruited from 21 sites in seven European countries and Israel. Despite the challenges encountered, particularly during the COVID-19 pandemic, the study progressed and included a remarkable number of patients, with 129 screened and 125 randomized. Recruitment was stopped after 30 months, the first patient entered in May 2019, and the study is ongoing and following up on patients according to the Clinical Trial Protocol.

Long-term effect of Toll-like receptor-2, -4, -5, -7 and NOD2 stimulation on Na+,K+-ATPase activity and expression in intestinal epithelial cells.

Inappropriate activation of Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NOD) is involved in many chronic disorders, including inflammatory bowel disease (IBD). Altered function and/or expression of Na+,K+-ATPase (NKA) and epithelial ion channels are the main cause of electrolyte absorption imbalance in patients with IBD, leading to diarrhea. We aimed to evaluate the effect of TLRs and NOD2 stimulation upon NKA activity and expression in human intestinal epithelial cells (IECs) using RT-qPCR, Western blot, and electrophysiology techniques. TLR2, TLR4, and TLR7 activation inhibited NKA activity [(means ± SE) -20.0 ± 1.2%, -34.0 ± 1.5%, and -24.5 ± 2.0% in T84 cells; and -21.6 ± 7.4%, -37.7 ± 3.5%, and -11.0 ± 2.3% in Caco-2 cells]. On the other hand, activation of TLR5 increased NKA activity (16.2 ± 2.9% in T84 and 36.8 ± 5.2% in Caco-2 cells) and ß1-NKA mRNA levels (21.8 ± 7.8% in T84 cells). The TLR4 agonist synthetic monophosphoryl lipid A (MPLAs) reduced α1-NKA mRNA levels in both T84 and Caco-2 cells (-28.5 ± 3.6% and -18.7 ± 2.8%), and this was accompanied by a decrease in α1-NKA protein expression (-33.4 ± 11.8% and -39.4 ± 11.2%). NOD2 activation upregulated NKA activity (12.2 ± 5.1%) and α1-NKA mRNA levels (6.8 ± 1.6%) in Caco-2 cells. In summary, TLR2, TLR4, and TLR7 activation induce downregulation of NKA in IECs, whereas TLR5 and NOD2 activation has the opposite effect. A comprehensive understanding of the cross talk between TLRs, NOD2, and NKA is of utmost relevance for developing better IBD treatments.

Voltage-clamp evidence of GABAA receptor subunit-specific effects: pharmacodynamic fingerprint of chlornordiazepam, the major active metabolite of mexazolam, as compared to alprazolam, bromazepam, and zolpidem.

BACKGROUND: Anxiolytic benzodiazepines, due to their clinical effectiveness, are one of the most prescribed drugs worldwide, despite being associated with sedative effects and impaired psychomotor and cognitive performance. Not every GABAA receptor functions in the same manner. Those containing α1 subunits are associated with sleep regulation and have a greater effect on the sedative-hypnotic benzodiazepines, whereas those containing α2 and/or α3 subunits are associated with anxiety phenomena and have a greater effect on the anxiolytic benzodiazepines. Therefore, characterization of the selectivity profile of anxiolytic drugs could translate into a significant clinical impact. METHODS: The present study pharmacodynamically evaluated chlornordiazepam, the main active metabolite of mexazolam, upon GABAA receptors containing α2 and/or α3, anxiety-related, and those containing an α1 subunit, associated with sleep modulation. RESULTS: As shown by whole-cell patch-clamp data, chlornordiazepam potentiated GABA-evoked current amplitude in α2 and α3 containing receptors without changing the current amplitude in α1 containing receptors. However, current decay time increased, particularly in GABAA receptors containing α1 subunits. In contrast, other anxiolytic benzodiazepines such as alprazolam, bromazepam, and zolpidem, all increased currents associated with GABAA receptors containing the α1 subunit. CONCLUSIONS: This novel evidence demonstrates that mexazolam (through its main metabolite chlornordiazepam) has a "pharmacodynamic fingerprint" that correlates better with an anxiolytic profile and fewer sedative effects, when compared to alprazolam, bromazepam and zolpidem, explaining clinical trial outcomes with these drugs. This also highlights the relevance of the pharmacological selectivity over GABAA receptor subtypes in the selection of benzodiazepines, in addition to their clinical performance and pharmacokinetic characteristics.

Boosting caffeic acid performance as antioxidant and monoamine oxidase B/catechol-O-methyltransferase inhibitor.

Increased oxidative stress (OS) and depletion of nigrostriatal dopamine (DA) are closely linked to the neurodegeneration observed in Parkinson's Disease (PD). Caffeic acid (CA)-based antioxidants were developed, and their inhibitory activities towards monoamine oxidases (MAOs) and catechol O-methyltransferases (COMT) were screened. The results showed that the incorporation of an extra double bond maintained or even boosted the antioxidant properties of CA. α-CN derivatives displayed redox potentials (Ep) similar to CA (1) and inhibited hMAO-B with low µM IC50 values. Moreover, catechol amides acted as MB-COMT inhibitors, showing IC50 values within the low µM range. In general, CA derivatives presented safe cytotoxicity profiles at concentrations up to 10 µM. The formation of reactive oxygen species (ROS) induced by CA derivatives may be underlying the cytotoxic effects observed at higher concentrations. Catechol amides 3-6, 8-11 at 10 µM protected cells against oxidative damage. Compounds 3 and 8 were predicted to cross the blood-brain barrier (BBB) by passive diffusion. In summary, we report for the first time BBB-permeant CA-based multitarget lead compounds that may restore DAergic neurotransmission (dual hMAO-B/MB-COMT inhibition) and prevent oxidative damage. The data represents a groundbreaking advancement towards the discovery of the next generation of new drugs for PD.

Effect of Opicapone on Levodopa Pharmacokinetics in Patients with Fluctuating Parkinson's Disease.

BACKGROUND: Inhibiting catechol-O-methyltransferase extends the plasma half-life of levodopa, potentially allowing physicians to optimize the levodopa regimen in patients with Parkinson's disease (PD) experiencing motor fluctuations. OBJECTIVES: To evaluate the effects of once-daily opicapone on levodopa plasma pharmacokinetics and motor response when added to two different levodopa dosing regimens. METHODS: A total of 24 patients with PD and motor fluctuations were enrolled in an exploratory, open-label, modified cross-over trial. Participants first received levodopa/carbidopa 500/125 mg (five intakes) for 2 weeks and were then randomly assigned (1:1) to levodopa/carbidopa 400/100 mg given over either four or five daily intakes plus opicapone 50 mg for an additional 2 weeks. Levodopa 12-hour pharmacokinetics was the primary outcome (ie, excluding the effect of last/evening levodopa/carbidopa intake), with motor complications evaluated as secondary outcomes. RESULTS: Over 12-hour pharmacokinetics and compared with five-intake levodopa/carbidopa 500/125 mg without opicapone, maximal levodopa concentrations were similar or nonsignificantly higher on both levodopa/carbidopa 400/100 mg regimens plus opicapone. Despite a 100 mg lower total levodopa/carbidopa daily dose, adding opicapone 50 mg at least doubled the levodopa plasma half-life and minimal concentrations, with a significant ≈30% increase in total exposure. The levodopa fluctuation index was only significantly lower for the five intakes plus opicapone regimen (difference of -71.8%; P < 0.0001). Modifications to levodopa pharmacokinetics were associated with decreased off time and increased on time. CONCLUSIONS: Combining opicapone 50 mg with a 100 mg lower daily dose of levodopa provides higher levodopa bioavailability with avoidance of trough levels. Despite the lower levodopa dose, modifying the levodopa pharmacokinetic profile with opicapone was associated with decreased off time and increased on time. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The safety/tolerability of opicapone when used early in Parkinson's disease patients with levodopa-induced motor fluctuations: A post-hoc analysis of BIPARK-I and II.

Introduction: Post-hoc analyses of the BIPARK-I and II trials previously demonstrated that opicapone (OPC) 50 mg was efficacious over the whole trajectory of motor fluctuation evolution in patients with Parkinson's disease (PD) and end-of-dose motor fluctuations, with enhanced efficacy in patients who were earlier vs. later in their disease course and levodopa treatment pathway. Complementary post-hoc analyses were performed to evaluate the safety/tolerability of OPC following the same pre-defined segmentation of the wide spectrum of duration of both PD and levodopa therapy, as well as of motor fluctuation history, in this patient population. Materials and methods: Data from matching treatment arms in BIPARK-I and II were combined for the placebo (PLC) and OPC 50 mg groups and exploratory post-hoc analyses were performed to investigate the safety/tolerability of OPC 50 mg and PLC in 22 subgroups of patients who were in "earlier" vs. "later" stages of both their disease course (e.g., duration of PD <6 years vs. ≥6 years) and levodopa treatment pathway (e.g., levodopa treatment duration <4 vs. ≥4 years). Safety/tolerability assessments included evaluation of treatment-emergent adverse events (TEAEs). Results: The Safety Set included 522 patients (PLC, n = 257; OPC 50 mg, n = 265). For OPC 50 mg, incidences of TEAEs, related TEAEs, related serious TEAEs, and related TEAEs leading to discontinuation were lower for patients in earlier vs. later stages of their disease course and levodopa treatment pathway in 86.4, 86.4, 63.6, and 68.2% of the 22 pairwise comparisons conducted, respectively (compared with 63.6, 77.3, 18.2, and 45.5%, respectively, in the 22 corresponding PLC comparisons). Conclusion: OPC 50 mg was generally well-tolerated when used to treat patients with PD with end-of-dose fluctuations, with an even more favorable tolerability profile in patients who were earlier, as opposed to later, in their disease course and levodopa treatment pathway, further supporting its use as an early adjunct to levodopa in PD.

Effect of Toll-like receptor-2, -4, -5, -7, and NOD2 stimulation on potassium channel conductance in intestinal epithelial cells.

Disproportionate activation of pattern recognition receptors plays a role in inflammatory bowel disease (IBD) pathophysiology. Diarrhea is a hallmark symptom of IBD, resulting at least in part from an electrolyte imbalance that may be caused by changes in potassium channel activity. We evaluated the impact of Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain 2 (NOD2) stimulation on potassium conductance of the basolateral membrane in human intestinal epithelial cells (IECs) and the role of potassium channels through electrophysiological assays under short-circuit current in Ussing chambers. TLRs and NOD2 were stimulated using specific agonists, and potassium channels were selectively blocked using triarylmethane-34 (TRAM-34), adenylyl-imidodiphosphate (AMP-PNP), and BaCl2. Potassium conductance of the basolateral membrane decreased upon activation of TLR2, TLR4, and TLR7 in T84 cells (means ± SE, -11.2 ± 4.5, -40.4 ± 7.2, and -19.4 ± 5.9, respectively) and in Caco-2 cells (-13.1 ± 5.7, -55.7 ± 7.4, and -29.1 ± 7.2, respectively). In contrast, activation of TLR5 and NOD2 increased basolateral potassium conductance, both in T84 cells (18.0 ± 4.1 and 18.4 ± 2.8, respectively) and in Caco-2 cells (21.2 ± 8.4 and 16.0 ± 3.6, respectively). TRAM-34 and AMP-PNP induced a decrease in basolateral potassium conductance upon TLR4 stimulation in both cell lines. Both KCa3.1- and Kir6-channels appear to be important mediators of this effect in IECs and could be potential targets for therapeutic agent development.NEW & NOTEWORTHY This study highlights that PRRs stimulation directly influences K+-channel conductance in IECs. TLR-2, -4, -7 stimulation decreased K+ conductance, whereas TLR5 and NOD2 stimulation had the opposite effect, leading to an increase of it instead. This study reports for the first time that KCa3.1- and Kir6-channels play a role in K+ transport pathways triggered by TLR4 stimulation. These findings suggest that KCa3.1- and Kir6-channels modulation may be a potential target for new therapeutic agents in IBD.

Inactivation Mechanism of the Fatty Acid Amide Hydrolase Inhibitor BIA 10-2474.

BIA 10-2474 is a time-dependent inhibitor of fatty acid amide hydrolase (FAAH) that was under clinical development for the treatment of neurological conditions when the program was terminated after one subject died and four were hospitalized with neurological symptoms during a first-in-human clinical study. The present work describes the mechanism of FAAH inhibition by BIA 10-2474 as a target-specific covalent inhibition, supported by quantum mechanics and molecular modelling studies. The inhibitor incorporates a weakly reactive electrophile which, upon specific binding to the enzyme's active site, is positioned to react readily with the catalytic residues. The reactivity is enhanced on-site by the increased molarity at the reaction site and by specific inductive interactions with FAAH. In the second stage, the inhibitor reacts with the enzyme's catalytic nucleophile to form a covalent enzyme-inhibitor adduct. The hydrolysis of this adduct is shown to be unlikely under physiological conditions, therefore leading to irreversible inactivation of FAAH. The results also reveal the important role played by FAAH Thr236 in the reaction with BIA 10-2474, which is specific to FAAH and is not present in other serine hydrolases. It forms a hydrogen bond with the imidazole nitrogen of the inhibitor and helps lowering the activation free energy of the first step of the reaction, by pre-orienting and stabilizing the inhibitor in a near-reactive configuration. In the second step, Thr236 can also serve as a mechanistic alternative to protonate the leaving group.

Salt-inducible kinases: new players in pulmonary arterial hypertension?

Salt-inducible kinases (SIKs) are serine/threonine kinases belonging to the AMP-activated protein kinase (AMPK) family. Accumulating evidence indicates that SIKs phosphorylate multiple targets, including histone deacetylases (HDACs) and cAMP response element-binding protein (CREB)-regulated transcriptional coactivators (CRTCs), to coordinate signaling pathways implicated in metabolism, cell growth, proliferation, apoptosis, and inflammation. These pathways downstream of SIKs are altered not only in pathologies like cancer, systemic hypertension, and inflammatory diseases, but also in pulmonary arterial hypertension (PAH), a multifactorial disease characterized by pulmonary vasoconstriction, inflammation and remodeling of pulmonary arteries owing to endothelial dysfunction and aberrant proliferation of smooth muscle cells (SMCs). In this opinion article, we present evidence of SIKs as modulators of key signaling pathways involved in PAH pathophysiology and discuss the potential of SIKs as therapeutic targets for PAH, emphasizing the need for deeper molecular insights on PAH.

Opicapone as an Add-on to Levodopa in Patients with Parkinson's Disease Without Motor Fluctuations: Rationale and Design of the Phase III, Double-Blind, Randomised, Placebo-Controlled EPSILON Trial.

INTRODUCTION: Levodopa remains the cornerstone treatment for Parkinson's disease (PD) but its use is associated with the development of 'wearing-off' fluctuations and other motor and non-motor complications over time. Adding a catechol-O-methyltransferase (COMT) inhibitor to levodopa/dopa decarboxylase (DDC) inhibitor therapy reduces fluctuations in the profile of plasma levodopa levels following oral dosing, and can therefore be beneficial for the management of motor complications. The objective of the EPSILON study is to investigate the efficacy of opicapone (OPC; a third-generation, once-daily COMT inhibitor) in enhancing the clinical benefit of levodopa in patients in earlier stages of PD, without end-of-dose motor fluctuations. METHODS: EPSILON is a phase III, double-blind, randomised, placebo-controlled and parallel-group study, designed to evaluate the efficacy and safety of OPC as add-on to levodopa/DDC inhibitor therapy in patients with early PD who do not exhibit signs of motor complications. Eligible patients will be randomised (1:1) to receive OPC 50 mg or placebo, in addition to their existing levodopa/DDC inhibitor therapy, over a 24-week, double-blind treatment period, after which they will have the option of entering an additional 1-year, open-label extension period, during which all patients will receive OPC 50 mg. PLANNED OUTCOMES: The primary efficacy endpoints are change in Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III total score from baseline to the end of the double-blind period (double-blind phase) and change in MDS-UPDRS Part IV total score from open-label baseline to the end of the open-label period (open-label phase). Secondary outcomes during the double-blind phase will include other measures of PD symptoms, including quality of life, non-motor symptoms, and development of motor fluctuations. Safety assessments will include evaluation of treatment-emergent adverse events, laboratory safety parameters, suicidality and impulse control disorders. TRIAL REGISTRATION: European Union Drug Regulating Authorities Clinical Trials Database (number 2020-005011-52).

Absorption, metabolism and excretion of opicapone in human healthy volunteers.

AIMS: The absorption, metabolism and excretion of opicapone (2,5-dichloro-3-(5-[3,4-dihydroxy-5-nitrophenyl]-1,2,4-oxadiazol-3-yl)-4,6-dimethylpyridine 1-oxide), a selective catechol-O-methyltransferase inhibitor, were investigated. METHODS: Plasma, urine and faeces were collected from healthy male subjects following a single oral dose of 100 mg [14 C]-opicapone. The mass balance of [14 C]-opicapone and metabolic profile were evaluated. RESULTS: The recovery of total administered radioactivity averaged >90% after 144 hours. Faeces were the major route of elimination, representing 70% of the administered dose; 5% and 20% were excreted in urine and expired air, respectively. The Cmax of total radioactivity matched that of unchanged opicapone, whereas the total radioactivity remained quantifiable for a longer period, attributed to the contribution of opicapone metabolites, involving primarily 3-O-sulfate conjugation (58.6% of total circulating radioactivity) at the nitrocatechol ring. Other circulating metabolites, accounting for <10% of the radioactivity exposure, were formed by glucuronidation, methylation, N-oxide reduction and gluthatione conjugation. Additionally, various other metabolites resulting from combinations with the opicapone N-oxide reduced form at the 2,5-dichloro-4,6-dimethylpyridine 1-oxide moiety, including nitro reduction and N-acetylation, reductive opening and cleavage of the 1,2,4-oxadiazole ring and the subsequent hydrolysis products were identified, but only in faeces, suggesting the involvement of gut bacteria. CONCLUSION: [14 C]-opicapone was fully excreted through multiple metabolic pathways. The main route of excretion was in faeces, where opicapone may be further metabolized via reductive metabolism involving the 1,2,4-oxadiazole ring-opening and subsequent hydrolysis.

Opicapone Use in Clinical Practice across Germany: A Sub-Analysis of the OPTIPARK Study in Parkinson's Disease Patients with Motor Fluctuations.

INTRODUCTION: The OPTIPARK study confirmed the effectiveness and safety of opicapone as adjunct therapy to levodopa in patients with Parkinson's disease (PD) and motor fluctuations under real-world conditions. The aim of this sub-analysis was to evaluate opicapone in the German patient cohort of OPTIPARK in order to provide country-specific data. METHODS: OPTIPARK was an open-label, single-arm study conducted in routine clinical practice across Germany and the UK. Patients with PD and motor fluctuations received once-daily opicapone 50 mg for 3 months in addition to levodopa. The primary endpoint was Clinicians' Global Impression of Change (CGI-C). Secondary assessments included Patients' Global Impressions of Change (PGI-C), Unified Parkinson's Disease Rating Scale (UPDRS) I-IV, Parkinson's Disease Questionnaire (PDQ-8), and Non-Motor Symptoms Scale (NMSS). This sub-analysis reports outcomes from the German patients only. RESULTS: Overall, 363 (97.6%) of the 372 patients included in the German cohort received ≥1 dose of opicapone and 291 (80.2%) completed the study. Improvements on CGI-C and PGI-C were reported by 70.8% and 76.3% of patients, respectively. UPDRS scores improved for activities of daily living during OFF time by -3.3 ± 4.5 points and motor scores during ON time by -5.3 ± 7.9 points. PDQ-8 and NMSS scores also demonstrated improvements. Treatment emergent adverse events considered at least possibly related to opicapone occurred in 37.7% of patients, with most being of mild or moderate intensity. CONCLUSION: Opicapone added to levodopa in patients with PD and motor fluctuations was effective and generally well tolerated in routine clinical practice across Germany.

Opicapone versus placebo in the treatment of Parkinson's disease patients with end-of-dose motor fluctuation-associated pain: rationale and design of the randomised, double-blind OCEAN (OpiCapone Effect on motor fluctuations and pAiN) trial.

BACKGROUND: Optimisation of dopaminergic therapy may alleviate fluctuation-related pain in Parkinson's disease (PD). Opicapone (OPC) is a third-generation, once-daily catechol-O-methyltransferase inhibitor shown to be generally well tolerated and efficacious in reducing OFF-time in two pivotal trials in patients with PD and end-of-dose motor fluctuations. The OpiCapone Effect on motor fluctuations and pAiN (OCEAN) trial aims to investigate the efficacy of OPC 50 mg in PD patients with end-of-dose motor fluctuations and associated pain, when administered as adjunctive therapy to existing treatment with levodopa/dopa decarboxylase inhibitor (DDCi). METHODS: OCEAN is a Phase IV, international, multicentre, randomised, double-blind, placebo-controlled, parallel-group, interventional trial in PD patients with end-of-dose motor fluctuations and associated pain. It consists of a 1-week screening period, 24-week double-blind treatment period and 2-week follow-up period. Eligible patients will be randomised 1:1 to OPC 50 mg or placebo once daily while continuing current treatment with levodopa/DDCi and other chronic, stable anti-PD and/or analgesic treatments. The primary efficacy endpoint is change from baseline in Domain 3 (fluctuation-related pain) of the King's Parkinson's disease Pain Scale (KPPS). The key secondary efficacy endpoint is change from baseline in Domain B (anxiety) of the Movement Disorder Society-sponsored Non-Motor rating Scale (MDS-NMS). Additional secondary efficacy assessments include other domains and total scores of the KPPS and MDS-NMS, the Parkinson's Disease Questionnaire (PDQ-8), the MDS-sponsored Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts III and IV, Clinical and Patient's Global Impressions of Change, and change in functional status via Hauser's diary. Safety assessments include the incidence of treatment-emergent adverse events. The study will be conducted in approximately 140 patients from 50 clinical sites in Germany, Italy, Portugal, Spain and the United Kingdom. Recruitment started in February 2021 and the last patient is expected to complete the study by late 2022. DISCUSSION: The OCEAN trial will help determine whether the use of adjunctive OPC 50 mg treatment can improve fluctuation-associated pain in PD patients with end-of-dose motor fluctuations. The robust design of OCEAN will address the current lack of reliable evidence for dopaminergic-based therapy in the treatment of PD-associated pain. TRIAL REGISTRATION: EudraCT number 2020-001175-32 ; registered on 2020-08-07.

Opicapone in UK clinical practice: effectiveness, safety and cost analysis in patients with Parkinson's disease.

Aim: This subanalysis of the OPTIPARK study aimed to confirm the effectiveness and safety of opicapone in patients with Parkinson's disease and motor fluctuations in clinical practice specifically in the UK and to assess the impact of opicapone on treatment costs. Methods: Patients received opicapone added to levodopa for 6 months. Clinical outcomes were assessed at 3 and 6 months and treatment costs at 6 months. Results: Most patients' general condition improved at 3 months, with sustained improvements reported at 6 months. Opicapone improved motor and non-motor symptoms at both timepoints, was generally well tolerated and reduced total treatment costs by GBP 3719. Conclusion: Opicapone added to levodopa resulted in clinical improvements and reduced treatment costs across UK clinical practice.

Patients with Parkinson's disease (PD) often experience motor fluctuations (reduced and variable response to medication) following prolonged treatment with levodopa, which is currently the most effective treatment for the symptoms of PD. Opicapone has been developed for use in combination with levodopa to reduce the occurrence of motor fluctuations and was shown to be effective in two large clinical trials. This study describes the effectiveness, safety and cost-saving impact of opicapone when used to treat patients with PD and motor fluctuations across everyday clinical practice in the UK. Six months' treatment with opicapone was generally well tolerated, resulted in an improvement of the patients' overall PD condition and reduced treatment costs. Clinical trial registration: Registered in July 2016 at NCT02847442 (ClinicalTrial.gov).

Safety, Tolerability, and Pharmacokinetics of FAAH Inhibitor BIA 10-2474: A Double-Blind, Randomized, Placebo-Controlled Study in Healthy Volunteers.

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of BIA 10-2474, a fatty acid amide hydrolase (FAAH) inhibitor, after first administration to healthy male and female participants. Participants (n = 116) were recruited into this phase I, double-blind, randomized, placebo-controlled, single ascending dose and multiple ascending dose (10-day) study. The primary outcome was the safety and tolerability of BIA 10-2474. Secondary outcomes were pharmacokinetics of BIA 10-2474 and pharmacodynamics, considering plasma concentrations of anandamide and three other fatty acid amides (FAAs) and leukocyte FAAH activity. Single oral doses of 0.25-100 mg and repeated oral doses of 2.5-50 mg were evaluated. BIA 10-2474 was well tolerated up to 100 mg as a single dose and up to 20 mg once daily for 10 days. In the cohort receiving repeated administrations of 50 mg, there were central nervous system adverse events in five of six participants, one with fatal outcome, which led to early termination of the study. BIA 10-2474 showed a linear relationship between dose and area under plasma concentration-time curve (AUC) across the entire dose range and reached steady state within 5-6 days of administration, with an accumulation ratio, based on AUC0-24h , of <2 on Day 10. BIA 10-2474 was rapidly absorbed with a mean terminal elimination half-life of 8-10 hours (Day 10). BIA 10-2474 caused reversible, dose-related increases in plasma FAAs. In conclusion, we propose that these data, as well as the additional data generated since the clinical trial was stopped, do not provide a complete mechanistic explanation for the tragic fatality.

In vitro and in vivo anti-epileptic efficacy of eslicarbazepine acetate in a mouse model of KCNQ2-related self-limited epilepsy.

BACKGROUND AND PURPOSE: The KCNQ2 gene encodes for the Kv 7.2 subunit of non-inactivating potassium channels. KCNQ2-related diseases range from autosomal dominant neonatal self-limited epilepsy, often caused by KCNQ2 haploinsufficiency, to severe encephalopathies caused by KCNQ2 missense variants. In vivo and in vitro effects of the sodium channel blocker eslicarbazepine acetate (ESL) and eslicarbazepine metabolite (S-Lic) in a mouse model of self-limited neonatal epilepsy as a first attempt to assess the utility of ESL in the KCNQ2 disease spectrum was investigated. EXPERIMENTAL APPROACH: Effects of S-Lic on in vitro physiological and pathological hippocampal neuronal activity in slices from mice carrying a heterozygous deletion of Kcnq2 (Kcnq2+/- ) and Kcnq2+/+ mice were investigated. ESL in vivo efficacy was investigated in the 6-Hz psychomotor seizure model in both Kcnq2+/- and Kcnq2+/+ mice. KEY RESULTS: S-Lic increased the amplitude and decreased the incidence of physiological sharp wave-ripples in a concentration-dependent manner and slightly decreased gamma oscillations frequency. 4-Aminopyridine-evoked seizure-like events were blocked at high S-Lic concentrations and substantially reduced in incidence at lower concentrations. These results were not different in Kcnq2+/+ and Kcnq2+/- mice, although the EC50 estimation implicated higher efficacy in Kcnq2+/- animals. In vivo, Kcnq2+/- mice had a lower seizure threshold than Kcnq2+/+ mice. In both genotypes, ESL dose-dependently displayed protection against seizures. CONCLUSIONS AND IMPLICATIONS: S-Lic slightly modulates hippocampal oscillations and blocks epileptic activity in vitro and in vivo. Our results suggest that the increased excitability in Kcnq2+/- mice is effectively targeted by S-Lic high concentrations, presumably by blocking diverse sodium channel subtypes.