Objective assessment of the effects of opicapone in Parkinson's disease through kinematic analysis

BACKGROUND

Opicapone (OPC) is a third-generation, selective peripheral COMT inhibitor that improves peripheral L-DOPA bioavailability and reduces OFF time and end-of-dose motor fluctuations in Parkinson's disease (PD) patients.

OBJECTIVES

In this study, we objectively assessed the effects of adding OPC to L-DOPA on bradykinesia in PD through kinematic analysis of finger movements.

METHODS

We enrolled 20 treated patients with PD and motor fluctuations. Patients underwent two experimental sessions (L-DOPA, L-DOPA + OPC), separated by at least 1 week. In each session, patients were clinically evaluated and underwent kinematic movement analysis of repetitive finger movements at four time points: (i) before their usual morning dose of L-DOPA (T0), (ii) 30 min (T1), (iii) 1 h and 30 min (T2), and (iv) 3 h and 30 min after the L-DOPA intake (T3).

RESULTS

Movement velocity and amplitude of finger movements were higher in PD patients during the session with OPC compared to the session without OPC at all the time points tested. Importantly, the variability of finger movement velocity and amplitude across T0-T3 was significantly lower in the L-DOPA + OPC than L-DOPA session.

CONCLUSIONS

This study is the first objective assessment of the effects of adding OPC to L-DOPA on bradykinesia in patients with PD and motor fluctuations. OPC, in addition to the standard dopaminergic therapy, leads to significant improvements in bradykinesia during clinically relevant periods associated with peripheral L-DOPA dynamics, i.e., the OFF state in the morning, delayed-ON, and wearing-OFF periods.

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.

Opicapone to Treat Early Wearing-off in Parkinson's Disease Patients: The Korean ADOPTION Trial

BACKGROUND

Increasing levodopa (L-dopa)/dopa decarboxylase inhibitor (DDCI) daily dose or adding a catechol-O-methyltransferase (COMT) inhibitor to levodopa/DDCI therapy are strategies used to manage wearing-off symptoms in Parkinson's disease (PD) patients.

OBJECTIVES

To evaluate the COMT inhibitor opicapone versus an additional dose of levodopa to treat early wearing-off in PD patients.

METHODS

ADOPTION was a randomized, parallel-group, open-label, Phase 4 study conducted in Korea. At baseline, eligible patients were randomized (1:1) to opicapone 50 mg (n = 87) or L-dopa 100 mg (n = 81) (added to current L-dopa/DDCI therapy) for 4 weeks. The main efficacy endpoint was change from baseline to end of study in absolute off time. Other endpoints included changes in on time, in Movement Disorder Society-Unified Parkinson's Disease Rating Scale and 8-item PD Questionnaire scores, and the Clinical and Patient Global Impression of Improvement/Change.

RESULTS

The adjusted mean in absolute off time was significantly greater for opicapone 50 mg than for L-dopa 100 mg (-62.1 vs. -16.7 minutes; P = 0.0015). Opicapone-treated patients also reported a greater reduction in the percentage of off time (P = 0.0015), a greater increase in absolute on time (P = 0.0338) and a greater increase in the percentage of on time (P = 0.0015). There were no significant differences in other secondary endpoints. The L-dopa equivalent daily dose was significantly higher in the opicapone group (750.9 vs. 690.0 mg; P = 0.0247), when a 0.5 conversion factor is applied.

CONCLUSIONS

Opicapone 50 mg was more effective than an additional 100 mg L-dopa dose at decreasing off time in patients with PD and early wearing-off.

Effectiveness and safety of different catechol-o-methyl transferase inhibitors for patients with parkinson's disease: Systematic review and network meta-analysis

BACKGROUND

Levodopa treatment requires the addition of other drugs, such as catechol-O-methyl transferase (COMT) inhibitors, to alleviate motor fluctuations in advanced parkinson's disease (PD). However, the optimal strategy, including the type and dose of COMT inhibitors remains unknown. This systematic review and network meta-analysis aimed to assess the efficacy and safety of different COMT inhibitors and for treating PD patients.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were screened up to November 20, 2022. Randomized controlled trials (RCTs) of COMT inhibitors (entacapone, opicapone, tolcapone) for PD patients were included. Eligible outcomes were total ON-time, rate of ON-time >1 h, total daily dose of levodopa therapy, mean change from baseline to final follow up in Unified Parkinson's Disease Rating Scale (UPDRS) part III scores, adverse events and dyskinesia. Network meta-analyses integrated direct and indirect evidence with placebo as a common comparator.

RESULTS

We identified 18 studies with 7564 patients. Opicapone, entacapone, and tolcapone could increase total ON-time when compared with placebo. However, opicapone (25 mg, MD 4.0, 95%CrI: 1.1-7.5) and opicapone (50 mg, MD 5.1, 95%CrI: 2.2-8.7) statistically significant increase the total ON-time. opicapone and entacapone could increase the rate of ON-time >1 h when compared with placebo. Only opicapone (5 mg) showed no statistically significant with placebo (OR 1.4, 95%CrI: 0.74-2.4). We found that opicapone (50 mg, SURCA, 0.796) is the best option compared with other treatments. TOL (200 mg) was ranked highest in the rank probability test for total daily dose of levodopa therapy, followed by OPI (50 mg), TOL (400 mg) and TOL (100 mg) in order. SUCRA rankings identified TOL (200 mg) as the most likely therapy for increasing adverse events (SUCRA 27.19%), followed by TOL (400 mg, SUCRA 27.20%) and OPI (5 mg, SUCRA 30.81%). The SUCRA probabilities were 91.6%, 75.2%, 67.9%, 59.3%, 45.6%, 41.1%, 35.1%, 24.6% and 9.4% for PLA, TOL (400 mg), ENT (100 mg), ENT (200 mg), OPI (5 mg), TOL (100 mg), OPI (25 mg), OPI (50 mg), and TOL (200 mg) respectively.

CONCLUSION

In conclusion, opicapone (50 mg) may be a better choice for treatment PD when compared with other COMT inhibitors.

Efficacy and safety of adjunctive oral therapy in Parkinson's disease with motor complications: a systematic review and network meta-analysis

Background

The aim of this manuscript is to review the evidence and compare the efficacy and safety of catechol-O-methyltransferase inhibitors (COMT-Is), dopamine receptor agonists (DRAs) and monoamine-oxidase B inhibitors (MAOB-Is) as adjunctive treatment to levodopa in patients with Parkinson's disease (PD) experiencing motor complications.

Methods

In this systematic review and network meta-analysis, literature searches were performed in MEDLINE and Embase to identify eligible randomised controlled trials (RCTs) with a minimal follow-up of at least 4 weeks published in English between 1980 and 2021. RCTs were included if either a COMT-I, DRA or MAOB-I was evaluated as an adjunctive therapy to levodopa in patients with PD experiencing motor complications and dyskinesia. The main outcomes included daily off-medication time, motor and non-motor examination scales, and adverse events including dyskinesia.

Results

74 RCTs reporting on 18 693 patients were included. All three studied drug classes decreased daily off-medication time compared with placebo (COMT-Is mean -0.8 hours (95% CI -1.0 to -0.6), DRAs -1.1 hours (95% CI -1.4 to -0.8), MAOB-Is -0.9 hours (95% CI -1.2 to -0.6)). Safety analysis showed an increased risk of dyskinesia for all three drug classes (COMT-Is OR 3.3 (95% CI 2.7 to 4.0), DRAs 3.0 (95% CI 2.5 to 3.5), MAOB-Is 1.6 (95% CI 1.2 to 2.2)). According to surface under the cumulative ranking curve scores, pramipexole IR was associated with the most favourable benefit-risk profile.

Conclusions

COMT-Is, DRAs and MAOB-Is effectively reduce motor complications and increase incidence of dyskinesia. In the network meta-analysis, adjunctive use of DRAs appeared most effective.

The Effects of Safinamide in Chinese and Non-Chinese Patients with Parkinson's Disease

INTRODUCTION

Ethnicity differences are an important determinant in the clinical manifestation of Parkinson's disease (PD), but they are not yet widely recognized, particularly regarding the response to dopaminergic medications. The aim of this paper is to analyze the efficacy and safety of safinamide in Chinese patients with PD in the pivotal studies SETTLE and XINDI compared to the non-Chinese population of the SETTLE trial.

METHODS

SETTLE (NCT00627640) and XINDI (NCT03881371) were phase III, randomized, double-blind, placebo-controlled, multicenter trials. Patients received safinamide or placebo as add-on to levodopa. The primary efficacy endpoint was the change in the mean total daily OFF time. Secondary efficacy endpoints included total daily ON time, ON time with no/non-troublesome dyskinesia, Unified Parkinson's Disease Rating Scale, and Parkinson's Disease Questionnaire-39 items. Safety was evaluated through the frequency of adverse events. Data from 440 non-Chinese and 109 Chinese patients in the SETTLE study, and 305 Chinese patients in the XINDI trial were considered for this post hoc analysis.

RESULTS

Significant positive results were seen in favor of safinamide in all populations for the primary and secondary endpoints, with no differences in terms of magnitude. No "treatment by ethnicity" interaction was detected for any parameters, confirming the homogeneity of treatment effects between different populations. The safety and tolerability of safinamide in Chinese patients were similar to those in the other ethnic groups, without unexpected adverse reactions.

CONCLUSIONS

Safinamide was shown to improve PD symptoms and quality of life in different ethnic populations, without any treatment by race interaction. Further studies are warranted to investigate potential differences in a real-life situation.

TRIAL REGISTRATION NUMBER

SETTLE (NCT00627640) and XINDI (NCT03881371).

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

A 12-month prospective real-life study of opicapone efficacy and tolerability in Emirati and non-White subjects with Parkinson's disease based in United Arab Emirates

Parkinson's disease (PD) is the second most common neurodegenerative disorder, and the condition is complicated by the emergence of wearing off/motor fluctuations with levodopa treatment after a variable period. COMT inhibitors when used as adjunct therapy to levodopa tend to smoothen out these wearing off fluctuations by enhancing delivery of levodopa and increasing its bioavailability to the brain. The study was conducted to investigate the motor and nonmotor effect, safety and tolerability of the third generation once-daily COMT inhibitor (opicapone), as add-on, adjuvant therapy to levodopa and at 6 and 12 months follow-up in a real-life cohort of consecutive Emirati and non-White PD patients. A real-life observational analysis using tolerability parameters as used previously by Rizos et al. and Shulman et al. based on clinical database of cases rat Kings College Hospital Dubai Parkinson care database. This was a prospective, single-arm follow-up clinical evaluation study that evaluated the effectiveness of opicapone 50 mg once-daily regime in 50 patients diagnosed with idiopathic neurodegenerative disorder. All patients were assessed with scales used in clinical pathway and include motor Unified Parkinson's Disease Rating Scale (UPDRS), nonmotor symptom scale (NMSS), quality of life (PDQ8) Parkinson's fatigue scale (PFS16) and King's Parkinson's Pain Scale (KIPS). Out of 50 patients treated with opicapone (72% male, mean age 66.9 years (SD 9.9, range 41-82 years) and mean duration of disease 5.7 years (SD 2.5 range (2-11), there was significant statistical improvements shown in motor function-UPDRS part 3: baseline 40.64 ± 2.7, at 6 months 32.12 ± 3.14 and after 12 months 33.72 ± 3.76. Nonmotor burden NMSS: 107.00 ± 21.86, at 6 months 100.78 ± 17.28 and 12 months 96.88 ± 16.11. Reduction in dyskinesias (UPDRS part 4): baseline 8.78 ± 1.07, at 6 months 7.4 ± 0.81 and 12 months 6.82 ± 0.75. Opicapone provides beneficial motor and nonmotor effects in Emirati and other non-White Parkinson's patients, resident in UAE, proving its efficacy across different racial groups as COMT activity may vary between races.

Management of OFF condition in Parkinson disease

Parkinson disease (PD) impacts nearly 1 million individuals in the United States. Nearly every patient with PD will require therapy with dopamine in the form of levodopa as the disease progresses. In more advanced stages of the disease, patients will experience motor fluctuations and require adjustment to their medication regimens to maintain good control of their symptoms. During the last 10 years, several new therapeutic treatment options have come to the market to treat motor fluctuations and improve patient quality of life. Some of these agents represent additional options to previously available drug classes, such as the catechol-O-methyl transferase (COMT) inhibitor, opicapone, and monoamine-oxidase B-inhibitor (MAO-B inhibitor), safinamide, as well as new dosage forms for available therapeutics. One new agent, istradefylline, has a novel mechanism in the treatment of PD. The place in therapy for these newer therapeutic options will be explored through a series of patient cases. This article focuses on evidence-based recommendations for the use of these newer options in the management of patients experiencing OFF episodes.

Comparative efficacy and safety of adjunctive drugs to levodopa for fluctuating Parkinson's disease - network meta-analysis

It remains unclear which adjunctive drug for Parkinson's disease (PD) in combination with levodopa is more effective, tolerable, and safe. We aimed to compare the efficacy, tolerability, and safety among anti-PD drugs from several classes in patients with fluctuating PD who received levodopa through network meta-analysis (NMA). Twelve anti-PD drugs belonging to 4 different drug classes (dopamine agonists, monoamine oxidase type B inhibitors, catechol-O-methyl transferase inhibitors, and an adenosine A2A receptor antagonist) were selected. We systematically searched PubMed, Embase, and the Cochrane Library for eligible randomized controlled trials (RCTs) comparing placebo with anti-PD drug or among anti-PD drugs in patients with PD who experienced motor fluctuations or wearing-off and received levodopa. We included 54 RCTs in the analysis. The NMA was performed under a frequentist framework using a random-effects model. The efficacy outcome was change in daily off-time, and the tolerability outcome was discontinuation due to all causes. Safety outcomes included discontinuation due to adverse events (AEs) and the incidence of AEs, dyskinesia, hallucination, and orthostatic hypotension. According to the surface under the cumulative ranking curve (SUCRA) in the NMA, ropinirole transdermal patch (SUCRA, 0.861) ranked the highest in efficacy, followed by pramipexole (0.762), ropinirole extended release (ER) (0.750), and safinamide (0.691). In terms of tolerability, ropinirole (0.954) ranked the highest, followed by pramipexole (0.857), safinamide (0.717), and ropinirole ER (0.708). Each anti-PD drug had different SUCRA ranking profiles for the safety outcomes. These findings suggest that ropinirole, pramipexole, and safinamide are well-balanced anti-PD drugs that satisfy both efficacy and tolerability outcomes.

Opicapone versus entacapone: Head-to-head retrospective data-based comparison of healthcare resource utilization in people with Parkinson's disease new to catechol-O-methyltransferase (COMT) inhibitor treatment

BACKGROUND AND PURPOSE

Motor fluctuations are a significant driver of healthcare resource utilization (HCRU) in people with Parkinson's disease (pwPD). A common management strategy is to include catechol-O-methyltransferase (COMT) inhibition with either opicapone or entacapone in the levodopa regimen. However, to date, there has been a lack of head-to-head data comparing the two COMT inhibitors in real-world settings. The aim of this study was to evaluate changes in HCRU and effect on sleep medications when opicapone was initiated as first COMT inhibitor versus entacapone.

METHODS

In this retrospective cohort study, we assessed HCRU outcomes in pwPD naïve to COMT inhibition via UK electronic healthcare records (Clinical Practice Research Datalink and Hospital Episodes Statistics databases, June 2016 to December 2019). HCRU outcomes were assessed before (baseline) and after COMT inhibitor prescription at 0-6 months, 7-12 months and 13-18 months. Opicapone-treated pwPD were algorithm-matched (1:4) to entacapone-treated pwPD.

RESULTS

By 6 months, treatment with opicapone resulted in 18.5% fewer neurology outpatient visits compared to entacapone treatment; this effect was maintained until the last follow-up (18 months). In the opicapone group, the mean levodopa equivalent daily dose decreased over the first year and then stabilized, whereas the entacapone-treated group showed an initial decrease in the first 6 months followed by a dose increase between 7 and 18 months. Neither COMT inhibitor had a significant impact on sleep medication use.

CONCLUSIONS

This head-to-head study is the first to demonstrate, using 'real-world' data, that initiating COMT inhibition with opicapone is likely to decrease the need for post-treatment HCRU versus initiation of COMT inhibition with entacapone.

Clinical Use of On-Demand Therapies for Patients with Parkinson's Disease and OFF Periods

On-demand therapies for Parkinson's disease (PD) provide rapid, reliable relief for patients experiencing OFF periods; however, practical guidelines on the use of these therapies are not generally available. This paper reviews the use of on-demand treatments. Motor fluctuations occur in nearly all patients with PD after long-term use of levodopa. As the goal of PD treatment is to provide good ON time, on-demand treatments that have a more rapid reliable onset than the slower-acting oral medications provide rapid relief for OFF periods. All current on-demand treatments bypass the gastrointestinal tract, providing dopaminergic therapy directly into the blood stream by subcutaneous injection, through the buccal mucosa, or by inhalation into the pulmonary circulation. On-demand treatments are fast acting (10- to 20-min onset), with maximum, reliable, and significant responses reached within 30 min after administration. Oral medications pass through the gastrointestinal tract and thus have slower absorption owing to gastroparesis and competition with food. On-demand therapies, by providing fast-acting relief, can have a positive impact on a patient's quality of life when patients are experiencing OFF periods.

Safety review of current pharmacotherapies for levodopa-treated patients with Parkinson's disease

INTRODUCTION

Levodopa remains the gold standard for treatment of Parkinson's disease (PD). Patients develop complications with disease progression, necessitating adjunctive therapy to control fluctuations in motor and non-motor symptoms and dyskinesia. Knowledge of medication safety and tolerability is critical to ascertain the benefit-risk ratio and select an adjunctive therapy that provides the highest chance for medication adherence. Posing a challenge are the sheer abundance of options, stemming from the development of several new drugs in recent years, as well as differences in commercial drug availability worldwide.

AREAS COVERED

This review evaluates the efficacy, safety, and tolerability of current US FDA-approved pharmacotherapies for levodopa-treated PD patients, including dopamine agonists, monoamine oxidase type-B inhibitors, catechol-O-methyltransferase inhibitors, the N-methyl-D-aspartate receptor antagonist amantadine, and the adenosine receptor antagonist istradefylline. Data were taken from pivotal phase III randomized controlled and post-surveillance studies, when available, that directly led to FDA-approval.

EXPERT OPINION

No strong evidence exists to support use of a specific adjunctive treatment for improving Off time. Only one medication has demonstrated improvement in dyskinesia in levodopa-treated PD patients; however, every patient cannot tolerate it and therefore adjunctive therapy should be tailored to an individual's symptoms and risk for specific adverse effects.

Clinical benefit of MAO-B and COMT inhibition in Parkinson's disease: practical considerations

Inhibitors of monoamine oxidase B (MAO-B) and catechol-O-methyltransferase (COMT) are major strategies to reduce levodopa degradation and thus to increase and prolong its effect in striatal dopaminergic neurotransmission in Parkinson's disease patients. While selegiline/rasagiline and tolcapone/entacapone have been available on the market for more than one decade, safinamide and opicapone have been approved in 2015 and 2016, respectively. Meanwhile, comprehensive data from several post-authorization studies have described the use and specific characteristics of the individual substances in clinical practice under real-life conditions. Here, we summarize current knowledge on both medication classes, with a focus on the added clinical value in Parkinson's disease. Furthermore, we outline practical considerations in the treatment of motor fluctuations and provide an outlook on ongoing studies with MAO-B and COMT inhibitors.

The real-life effect of catechol-O-methyltransferase inhibition on non-motor symptoms in levodopa-treated Parkinson's disease: opicapone versus entacapone

OBJECTIVE

To evaluate the long-term, real-life effects on non-motor symptoms (NMS) of opicapone compared to entacapone in levodopa-treated people with Parkinson's disease (PwP).

METHODS

A retrospective data analysis, with pre- and post-opicapone initiation data of 17 PwP with motor fluctuations compared to a comparable group of 18 PwP introduced on entacapone. The primary outcome was changes in the NMS Scale (NMSS) total score after 1-year follow-up. Secondary outcomes included changes in the NMSS domains, and Parkinson's Disease Sleep Scale (PDSS) total and item scores after the same time span.

RESULTS

Groups were comparable for baseline demographics and Parkinson's-related features (p ≥ 0.314) as well as duration of follow-up (1.33 ± 0.66 years for PwP on opicapone and 1.23 ± 0.49 years for those on entacapone; p = 0.858). PwP who were introduced on opicapone showed no changes in NMSS and PDSS total scores after 1 year (p = 0.605 and p = 0.507, respectively), whereas PwP who were introduced on entacapone showed significant worsening of NMSS and PDSS total scores at follow-up (p = 0.005 and p = 0.001, respectively). In neither group changes in individual NMSS domains from baseline to follow-up were observed (p ≥ 0.288 for entacapone and p ≥ 0.816 for opicapone, respectively). In PwP on entacapone significant worsening was seen in the distressing dreams, hallucinations, and limb numbness items of the PDSS (p ≤ 0.05).

CONCLUSIONS

Introduction of opicapone in real-life PwP with motor fluctuations seems to stabilise NMS burden and aspects of sleep dysfunction, in contrast to entacapone where there was a worsening of NMS burden and PDSS scores over 1 year follow-up.

Sustained response in early responders to safinamide in patients with Parkinson's disease and motor fluctuations: A post hoc analysis of the SETTLE study

Safinamide is a selective, reversible, monoamine oxidase B inhibitor for the treatment of patients with Parkinson's disease (PD) and motor fluctuations. This was a post hoc analysis of the SETTLE study, in which patients with PD and motor fluctuations were randomly assigned to 24-week treatment with safinamide (50 mg/day for 2 weeks, increased to 100 mg/day if tolerated) or placebo. In the present analysis, responders were defined according to their treatment responses at Week 2 and Week 24 based on changes in ON-time without troublesome dyskinesia from baseline with cutoffs of 1 hour. It was found that 81% (103/127) of the responders at Week 2 maintained the response through Week 24 in the safinamide group. Other outcomes did not necessarily coincide with the ON-time response; however, “Early” responders who showed a treatment response at both Week 2 and Week 24 had substantial improvements from baseline in OFF-time, UPDRS Part II and III scores, and PDQ-39 summary index scores through Week 24. The safinamide group had a higher proportion of early responders than the placebo group (39% vs 20%, p &lt; 0.0001). At baseline, early responders in the safinamide group had significantly higher UPDRS Part II and III scores, shorter ON-time, and longer OFF-time than the other responder populations. In conclusion, the results of the present post hoc analysis suggest that patients with a short ON-time, severe motor symptoms, and highly compromised activities of daily living can benefit from safinamide early in treatment and over the long term.

Opicapone Pharmacokinetics and Effects on Catechol- O -Methyltransferase Activity and Levodopa Pharmacokinetics in Patients With Parkinson Disease Receiving Carbidopa/Levodopa

OBJECTIVES

Levodopa (LD) administered with dopa decarboxylase inhibitor is predominantly metabolized in the periphery by catechol- O -methyltransferase (COMT) to 3- O -methyldopa (3-OMD). Catechol- O -methyltransferase inhibition can improve treatment outcomes by decreasing variability in circulating LD concentrations. Opicapone is a once-daily COMT inhibitor approved in the US adjunctive to carbidopa (CD)/LD in patients with Parkinson disease experiencing "OFF" episodes. This study aimed to evaluate the pharmacokinetics and pharmacodynamics of once-daily opicapone 50 mg adjunctive to CD/LD in patients with stable Parkinson disease.

METHODS

Once-daily opicapone 50 mg was administered the evenings of days 1 to 14. Participants were randomized to receive CD/LD (25/100 mg) every 3 or 4 hours (Q3H or Q4H). Participants received Q3H or Q4H CD/LD on days 1, 2, and 15 and their usual CD/LD regimen on other days. Serial blood samples were collected to determine plasma opicapone, LD, and 3-OMD concentrations and erythrocyte soluble COMT (S-COMT) activity. The effects of opicapone on S-COMT, LD, and 3-OMD were assessed. Mean (SD) values are presented.

RESULTS

Sixteen participants were enrolled. At steady-state (day 14), opicapone Cmax (peak plasma concentration) and AUC 0-last (area under the curve-time curve) were 459 ± 252 ng/mL and 2022 ± 783 ng/mL·h, respectively. Maximum COMT inhibition was 83.4 ± 4.9% of baseline on day 14. After opicapone administration, LD total AUC, peak concentration, and trough concentration increased; peak-to-trough fluctuation index decreased. Correspondingly, 3-OMD total AUC, peak concentration, and trough concentration decreased.

CONCLUSIONS

Adding once-daily opicapone 50 mg to LD resulted in marked and extended COMT inhibition, which increased systemic exposure to LD. These changes translated into higher trough concentrations and decreased peak-to-trough fluctuations for LD.

Off-time Treatment Options for Parkinson's Disease

Motor fluctuations (MF) are deemed by patients with Parkinson's disease (PD) as the most troublesome disease feature resulting from the increasing impairment in responsiveness to dopaminergic drug treatments. MF are characterized by the loss of a stable response to levodopa over the nychthemeron with the reappearance of motor (and non-motor) parkinsonian clinical signs at various moments during the day and night. They normally appear after a few years of levodopa treatment and with a variable, though overall increasing severity, over the disease course. The armamentarium of first-line treatment options has widened in the last decade with new once-a-daily compounds, including a catechol O-methyltransferase inhibitor - Opicapone-, two MAO-B inhibitors plus channel blocker - Zonisamide and Safinamide and one amantadine extended-release formulation - ADS5012. In addition to apomorphine injection or oral levodopa dispersible tablets, which have been available for a long time, new on-demand therapies such as apomorphine sublingual or levodopa inhaled formulations have recently shown efficacy as rescue therapies for Off-time treatment. When the management of MF becomes difficult in spite of oral/on-demand options, more complex therapies should be considered, including surgical, i.e. deep brain stimulation, or device-aided therapies with pump systems delivering continuous subcutaneous or intestinal levodopa or subcutaneous apomorphine formulation. Older and less commonly used ablative techniques (radiofrequency pallidotomy) may also be effective while there is still scarce data regarding Off-time reduction using a new lesional approach, i.e. magnetic resonance-guided focused ultrasound. The choice between the different advanced therapies options is a shared decision that should consider physician opinion on contraindication/main target symptom, patients' preference, caregiver's availability together with public health systems and socio-economic environment. The choice of the right/first add-on treatment is still a matter of debate as well as the proper time for an advanced therapy to be considered. In this narrative review, we discuss all the above cited aspects of MF in patients with PD, including their phenomenology, management, by means of pharmacological and advanced therapies, on-going clinical trials and future research and treatment perspectives.

Adverse event profiles of adjuvant treatment with opicapone in Parkinson's disease: A systematic review and meta-analysis

Background: Opicapone, a novel third-generation catechol-O-methyltransferase inhibitor, has demonstrated efficacy in Parkinson's Disease (PD) patients with end-of-dose motor fluctuations. Objective: This study aimed to compare the short-term (<6 months) and long-term (≥6 months) tolerability of opicapone adjuvant treatment in PD patients. Method: Electronic databases including PubMed, Embase, Web of Science and Cochrane library were searched for randomized controlled trials (RCTs) and observational studies. The end points included any treatment-related adverse events (TEAEs), serious TEAEs (SAEs) and treatment discontinuation. A random-effects model was used to generate overall incidences of TEAE. Results: Three RCTs, three RCT extension studies and three open-label studies involving 2177 PD patients were evaluated. In the short-term studies, there were reports of TEAEs with an incidence of ≥5% in individuals treated with opicapone 50 mg, including dyskinesia (14.1%), elevated blood creatine phosphokinase levels (8.0%) and urinary tract infection (6.0%). Any TEAEs, SAEs and treatment discontinuation all occurred at rates of 62.9%, 4.8% and 9.3%, respectively. TEAEs with opicapone 50 mg that were reported by more than 5% of patients in long-term studies included dyskinesia (16.1%), dry mouth (12.1%), medication effect decreased (12.1%), PD exacerbated (7.8%), blood creatine phosphokinase level raised (7.4%), nausea (6.1%) and insomnia (5.1%). The incidence of any TEAEs, SAEs and treatment discontinuation were, correspondingly, 73.2%, 8.7% and 8.4%. Conclusion: These studies demonstrated that opicapone was generally well-tolerated and had a low risk of adverse events, suggesting that it could be a valuable therapeutic choice for people with 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 &lt; 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.

Opicapone as an add-on to levodopa for reducing end-of-dose motor fluctuations in Parkinson's disease: a systematic review and meta-analysis

Aim: To assess the clinical efficacy and safety profile of opicapone (25 and 50 mg once daily) versus placebo. Patients: Levodopa-treated adults with Parkinson's disease. Material & methods: A systematic review and meta-analysis were conducted. Results: Opicapone provided a greater reduction in the absolute OFF-time, increased the chances of ≥1-h reduction in the OFF-time and ≥1-h increase in the ON-time compared with placebo. Receiving opicapone more often facilitated levodopa dose reduction versus placebo. There were no differences in the occurrence of adverse events (severe and leading to drug discontinuation), but receiving opicapone increased the frequency of dyskinesia. Conclusion: Opicapone demonstrated superior clinical efficacy to placebo, with a comparable general safety profile.

Newly Approved and Investigational Drugs for Motor Symptom Control in Parkinson's Disease

Motor symptoms are a core feature of Parkinson’s disease (PD) and cause a significant burden on patients’ quality of life. Oral levodopa is still the most effective treatment, however, the motor benefits are countered by inherent pharmacologic limitations of the drug. Additionally, with disease progression, chronic levodopa leads to the appearance of motor complications including motor fluctuations and dyskinesia. Furthermore, several motor abnormalities of posture, balance, and gait may become less responsive to levodopa. With these unmet needs and our evolving understanding of the neuroanatomic and pathophysiologic underpinnings of PD, several advances have been made in defining new therapies for motor symptoms. These include newer levodopa formulations and drug delivery systems, refinements in adjunctive medications, and non-dopaminergic treatment strategies. Although some are in early stages of development, these novel treatments potentially widen the available options for the management of motor symptoms allowing clinicians to provide an individually tailored care for PD patients. Here, we review the existing and emerging interventions for PD with focus on newly approved and investigational drugs for motor symptoms, motor fluctuations, dyskinesia, and balance and gait dysfunction.

Opicapone, a Novel Catechol-O-methyl Transferase Inhibitor, for Treatment of Parkinson's Disease "Off" Episodes

Parkinson's Disease (PD) is a common neurodegenerative disorder and the leading cause of disability. It causes significant morbidity and disability through a plethora of symptoms, including movement disorders, sleep disturbances, and cognitive and psychiatric symptoms. The traditional pathogenesis theory of PD involves the loss of dopaminergic neurons in the substantia nigra (SN). Classically, treatment is pursued with an assortment of medications that are directed at overcoming this deficiency with levodopa being central to most treatment plans. Patients taking levodopa tend to experience "off episodes" with decreasing medication levels, causing large fluctuations in their symptoms. These off episodes are disturbing and a source of morbidity for these patients. Opicapone is a novel, peripherally acting Catechol-O-methyl transferase (COMT) inhibitor that is used as adjunctive therapy to carbidopa/levodopa for treatment and prevention of "off episodes." It has been approved for use as an adjunct to levodopa since 2016 in Europe and has recently (April 2020) gained FDA approval for use in the USA. By inhibiting COMT, opicapone slows levodopa metabolism and increases its availability. Several clinical studies demonstrated significant improvement in treatment efficacy and reduction in duration of "off episodes." The main side effect demonstrated was dyskinesia, mostly with the 100mg dose, which is higher than the approved, effective dose of 50mg. Post-marketing surveillance and analysis are required to further elucidate its safety profile and contribute to patient selection. This paper reviews the seminal and latest evidence in the treatment of PD "off episodes" with the novel drug Opicapone, including efficacy, safety, and clinical indications.

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).

Efficacy and Safety of Opicapone for Motor Fluctuations as an Adjuvant to Levodopa Therapy in Patients with Parkinson's Disease: A Systematic Review and Meta-Analysis

Background:

Long-term levodopa administration for treating Parkinson’s disease (PD) may shorten the duration of effect and cause dyskinesias, inducing the need for catechol-O-methyltransferase (COMT) inhibitors as adjuvant therapy.

Objective:

We provide pooled scientific evidence highlighting the efficacy and safety of opicapone, a newly approved COMT inhibitor, as an adjuvant to levodopa.

Methods:

We searched Ovid Medline, Embase, and Cochrane databases for relevant reports. Efficacy and safety were evaluated as off-time reduction and risk ratio (RR) of dyskinesia, respectively. Data were independently extracted using predefined criteria. Selected placebo-controlled trials were divided into double-blind and open-label periods. Using a random-effects model, the mean difference (MD) of the off-time reduction (efficacy), RR for the occurrence of dyskinesia, and on-time without/with troublesome dyskinesia (TD; safety assessment) were compared between opicapone and placebo groups.

Results:

Five studies from three randomized controlled trials were included, and a meta-analysis was performed with 407 patients receiving opicapone 50 mg and 402 patients receiving placebo. Compared with the placebo, opicapone (50 mg) reduced off-time by 49.91 min during the double-blind period (95% confidence intervals [CIs] = –71.39, –28.43; I² = 0%). The RR of dyskinesia was 3.43 times greater in the opicapone 50 mg group than in the placebo group (95% CI = 2.14, 5.51; I = 0%). Compared with the placebo, opicapone increased the on-time without TD by 44.62 min (95% CI = 22.60, 66.64; I² = 0%); the on-time increase with TD did not differ between treatments.

Conclusion:

Opicapone can play a positive role as an adjuvant to levodopa in patients with PD by reducing off-time and prolonging on-time without PD.

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.

Amantadine delayed release/extended release capsules significantly reduce OFF time in Parkinson's disease

Maintaining consistent levodopa benefits while simultaneously controlling dyskinesia can be difficult. Recently, an amantadine delayed release/extended release (DR/ER) formulation (Gocovri^®) indicated for dyskinesia received additional FDA approval as an adjunct to levodopa for the treatment of OFF episodes. We evaluated OFF time reductions with amantadine-DR/ER in a pooled analysis of two phase III amantadine-DR/ER trials (NCT02136914, NCT02274766) followed by a 2-year open-label extension trial (NCT02202551). OFF outcomes were analyzed for the mITT population, as well as stratified by baseline OFF time of ≥2.5 h/day or <2.5 h/day. At Week 12, mean placebo-subtracted treatment difference in OFF time was −1.00 [−1.57, −0.44] h in the mITT population (n = 196), −1.2 [−2.08, −0.32] h in the ≥2.5 h subgroup (n = 102) and −0.77 [−1.49, −0.06] in the <2.5 h subgroup (n = 94). Amantadine-DR/ER-treated participants showed reduced MDS-UPDRS Part IV motor fluctuation subscores by week 2 that were maintained below baseline to Week 100.

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 Improves Global Non-Motor Symptoms Burden in Parkinson's Disease: An Open-Label Prospective Study

Patients with Parkinson’s disease (PD) can improve some non-motor symptoms (NMS) after starting treatment with opicapone. The aim of this study was to analyze the effectiveness of opicapone on global NMS burden in PD. OPEN-PD (Opicapone Effectiveness on Non-motor symptoms in Parkinson’s Disease) is a prospective open-label single-arm study conducted in 5 centers from Spain. The primary efficacy outcome was the change from baseline (V0) to the end of the observational period (6 months ± 30 days) (V2) in the Non-Motor Symptoms Scale (NMSS) total score. Different scales were used for analyzing the change in motor, NMS, quality of life (QoL), and disability. Thirty-three patients were included between JUL/2019 and JUN/2021 (age 63.3 ± 7.91; 60.6% males; 7.48 ± 4.22 years from symptoms onset). At 6 months, 30 patients completed the follow-up (90.9%). The NMSS total score was reduced by 27.3% (from 71.67 ± 37.12 at V0 to 52.1 ± 34.76 at V2; Cohen’s effect size = −0.97; p = 0.002). By domains, improvement was observed in sleep/fatigue (−40.1%; p < 0.0001), mood/apathy (−46.6%; p = 0.001), gastrointestinal symptoms (−20.7%; p = 0.029), and miscellaneous (−44.94%; p = 0.021). QoL also improved with a 18.4% reduction in the 39-item Parkinson’s Disease Quality of Life Questionnaire Summary Index (from 26.67 ± 17.61 at V0 to 21.75 ± 14.9 at V2; p = 0.001). A total of 13 adverse events in 11 patients (33.3%) were reported, 1 of which was severe (not related to opicapone). Dyskinesias and nausea were the most frequent (6.1%). Opicapone is well tolerated and improves global NMS burden and QoL in PD patients at 6 months.

COMT Inhibitors in the Management of Parkinson's Disease

Levodopa treatment remains the gold standard for Parkinson's disease, but shortcomings related to the pharmacological profile, notably, oral administration and the consequent occurrence of motor complications, have led to the development of several add-on levodopa treatments or to research to improve the method of delivery. Motor fluctuations, and to a lesser extent non-motor fluctuations, concern half of the patients with Parkinson's disease after 5 years of disease and patients identified them as one of their most bothersome symptoms. Catechol-O-methyl transferase inhibitors (COMT-Is) are one of the recommended first-line levodopa add-on therapies for the amelioration of end-of dose motor fluctuations in patient with advanced Parkinson's disease. Currently, two peripheral COMT-Is are considered as first-line choices - entacapone (ENT), which was approved by the US Food and Drug Administration in 1999 and the European Committee in 1998; and opicapone (OPC), which was approved by the European Committee in 2016. A second-line COMT-I that requires regular hepatic monitoring, tolcapone (TOL), was approved by the Food and Drug Administration in 1998 and the European Committee in 1997. Of note, OPC also received Food and Drug Administration approval in 2021, but it is still only marketed in a few countries, including Germany, UK, Spain, Portugal, Italy, Japan, and USA, while ENT and TOL have a wider market. Our narrative review summarizes the pharmacokinetic/pharmacodynamic properties, clinical efficacy in terms of motor fluctuations, motor/non-motor symptoms, quality of life, and safety data of these three COMT-Is, as evidenced by randomized clinical trials, as well as by real-life observational studies. Overall, a phase III non-inferiority trial showed a similar effect between ENT and OPC on off-time (-60.8 min/day and -40.3 min/day, vs placebo, respectively), with a possible additional off-time reduction of 39 min/day, obtained when there is a switch from ENT to OPC. Concomitantly, TOL can reduce off-time by an average of 98 min/day. A significant though discrete concomitant reduction on the Unified Parkinson's Disease Rating Scale motor section (2-3 points) is obtained with all three drugs vs placebo. Data on quality of life are fewer and more heterogeneous, with positive results obtained especially in open-label studies. Effects on non-motor symptoms were investigated as secondary outcome only in a few studies, frequently by means of non-specific scales and a benefit was observed in open-label studies. Dopaminergic adverse effects were the most frequent, dyskinesia being the most common for the three drugs eventually requiring levodopa dose reductions. No urine discoloration and a very low incidence of diarrhea were found with OPC compared with ENT and TOL. Regular hepatic monitoring is needed only for TOL. A combination of COMT-Is with new formulations of levodopa, including the subcutaneous, intrajejunal, or new extended-release formulation, merits further exploration to improve the management of both mild and severe motor fluctuations.

Opicapone: Once-Daily COMT Inhibitor for the Treatment of Wearing Off in Parkinson's Disease

Objective To provide a review of opicapone as a treatment for end-of-dose wearing off associated with long-term levodopa therapy in patients with Parkinson's disease (PD). Data Sources PubMed, Web of Science, and Google Scholar were searched for relevant literature using the following terms: management, treatment, opicapone, BIA 9-1067, entacapone, and tolcapone. Current guidelines and the manufacturer's package inserts were also reviewed. Study Selection/Data Extraction Recent literature and published studies of opicapone in the management of wearing off. Data Synthesis Long-term use of levodopa is associated with known complications of motor fluctuations and dyskinesia. The addition of a drug with fewer daily administrations may reduce the complexity of the current medication regimen, improve adherence, and reduce the risk of adverse events in older people with PD. The Food and Drug Administration (FDA) approved a new catechol-O-methyltransferase (COMT) inhibitor opicapone in combination with levodopa/carbidopa to treat wearing off in PD patients on April 24, 2020. Conclusion Opicapone offers patients with PD a once-daily option with a favorable side effect profile, increased exposure to levodopa, and reduction in "off" time. It may be an appropriate second line option in patients who are intolerant or do not respond with entacapone.

[Relevance of COMT inhibitors in the treatment of motor fluctuations]

Catechol O‑methyltransferase (COMT) inhibitors have been established in the treatment of Parkinson's disease for more than 20 years. They are considered the medication of choice for treating motor fluctuations. The available COMT inhibitors, entacapone, opicapone and tolcapone, differ pharmacokinetically in terms of their half-lives with implications for the dose frequency, in their indication requirements and in their spectrum of side effects, including diarrhea and yellow discoloration of urine. Many patients with motor fluctuations are currently not treated with COMT inhibitors and are, therefore, unlikely to receive individually optimized drug treatment. This manuscript summarizes the results of a working group including several Parkinson's disease experts, in which the value of COMT inhibitors was critically discussed.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Opicapone in Healthy Chinese and Caucasian Subjects: An Open-Label, Single-Center, Phase 1 Study

INTRODUCTION

This study evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of single and multiple doses of opicapone (OPC) in healthy Chinese and Caucasian subjects.

METHODS

In this open-label, single-center, phase 1 study, eligible Chinese subjects received one of three OPC doses (25, 50, or 100 mg), and Caucasian subjects received either 25 or 50 mg of OPC. All subjects were administered a single dose of OPC, whereas subjects in the 50-mg OPC group continued to receive once-daily doses of 50 mg OPC for 10 days. The primary endpoint was to evaluate and compare the plasma concentrations and PK parameters of OPC and its main metabolite, and erythrocyte-soluble catechol-O-methyltransferase (S-COMT) activity in Chinese subjects with that of Caucasian subjects. The secondary endpoint was to evaluate the safety of OPC in Chinese subjects. The estimated results for geometric mean ratios (GMRs) were evaluated with the standard bioequivalence (BE) limits between 80% and 125% to evaluate the ethnic differences. All statistical analyses were performed using SAS version 9.4.

RESULTS

In total, 70 subjects (45 Chinese, 25 Caucasian) were enrolled; the majority of them were male (85.7%). The plasma exposure of both OPC and BIA 9-1103 increased in an approximately dose-proportional manner in both populations. Maximum S-COMT inhibition ranged from 79% to 95% after a single dose and was about 94% after a 10-day once-daily regimen in both populations. The point estimates of GMRs (Chinese/Caucasian) and 90% CI, except C_max in 25-mg and 50-mg OPC groups, for PK and PD parameters were within 80% to 125%. Furthermore, no new risks or safety concerns associated with OPC were identified, indicating a tolerable safety profile in healthy Chinese subjects.

CONCLUSION

Ethnicity had no significant impact on PK and PD parameters after single or multiple doses of OPC, and OPC was safe and tolerable in healthy Chinese subjects.

TRIAL REGISTRATION

ChiCTR number, CTR20192230.

Opicapone for the Treatment of Parkinson's Disease "Off" Episodes: Pharmacology and Clinical Considerations

Parkinson's disease (PD) is a common neurodegenerative disorder. It is also the fastest-growing neurodegenerative disorder and has more than doubled between 1990 and 2016. Parkinson's disease causes significant morbidity and disability from motor dysfunction, sleep disturbances, and cognitive and psychiatric symptoms. This paper reviews recent evidence in the treatment of PD "off" episodes with the novel drug opicapone, including its efficacy, safety, and clinical indications. Opicapone is a novel, peripherally acting catechol-O-methyl transferase (COMT) inhibitor used as adjunctive therapy to carbidopa/levodopa for treatment and prevention of "off" episodes. It has been approved for use as an adjunct to levodopa since 2016 in Europe and has recently (April 2020) gained FDA approval for use in the USA. By inhibiting COMT, opicapone slows levodopa metabolism and increases its availability. Several clinical studies demonstrated significant improvement in treatment efficacy and reduction in the duration of "off" episodes The main side effect demonstrated was dyskinesia, mostly with the 100 mg dose, which is higher than the approved, effective dose of 50 mg.

The Added Benefit 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: Opicapone (OPC) was efficacious in reducing OFF-time in two pivotal trials in patients with Parkinson's disease (PD) and end-of-dose motor fluctuations (BIPARK-I and -II). Post-hoc analyses of these trials evaluated the efficacy of OPC following pre-defined segmentation of the wide spectrum of motor fluctuations in PD.

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 efficacy of OPC 50 mg vs. PLC in 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., number of daily levodopa intakes <4 vs. ≥4). Efficacy variables included changes from baseline in absolute OFF-time and total ON-time.

Results: The Full Analysis Set included 517 patients (PLC, n = 255; OPC 50 mg, n = 262). OPC 50 mg was significantly more effective than PLC in reducing OFF-time and increasing ON-time in the majority of subgroup analyses (p < 0.05). Moreover, patients in “earlier” stages of both their disease course and levodopa treatment pathway experienced numerically greater efficacy when using OPC 50 mg, in comparison with those in “later” stages.

Conclusion: OPC 50 mg was efficacious over the whole trajectory of motor fluctuation evolution in PD patients. There was also a signal for enhanced efficacy in patients who were earlier vs. later in their disease course and levodopa treatment pathway.

Istradefylline Versus Opicapone for "Off" Episodes in Parkinson's Disease: A Systematic Review and Meta-Analysis

Background:

In recent times, the US-FDA approved istradefylline and opicapone as an adjunct to levodopa/carbidopa for managing the "off" episodes in Parkinson’s disease.

Purpose:

Current meta-analysis was performed to determine the safety and efficacy of these drugs in the management of “off” episodes and to recognize which among them would provide therapeutic benefits clinically.

Methods:

A thorough literature search was performed through the Cochrane Library, PubMed, and clinicaltrials.gov for a period from January 2003 to October 2020, with the following keywords: Istradefylline, KW-6002, opicapone, BIA 9-1067, and Parkinson’s disease. Those randomized, double-blind placebo/active comparator-controlled trials that analyzed the efficacy and safety of istradefylline and opicapone and that were published in the English language were included. In this analysis, the outcomes focused on the least square mean change in “off” time and Unified Parkinson’s Disability Rating Scale (UPDRS) III score from baseline to the end of the study, and the incidence of treatment-emergent adverse events (TEAEs) and dyskinesia.

Results:

Both drugs have shown significant reduction in “off” time duration (mean difference [MD] = –0.70; 95% CI [–1.11, –0.30]; P < 0.001 for istradefylline and MD = –0.85; 95% CI [–1.09, –0.61]; P < .001 for opicapone). Istradefylline showed significant improvement in UPDRS III (MD = –1.56; 95% CI [–2.71, –0.40]; P < .008), but the same was not observed with opicapone (MD = –0.63; 95% CI [–1.42, –0.15]; P < .12). The incidence of TEAEs and dyskinesia reportedly were higher in the intervention group rather than with the placebo, (risk ratio RR =1.11, 95% CI [1.02,1.20] for istradefylline and RR =1.12, 95% CI [1.00,1.25] for opicapone, and for dyskinesia particularly, the incidence was higher with opicapone as compared to istradefylline (RR = 3.47, 95% CI [2.17, 5.57], and RR = 1.77, 95% CI [1.29, 2.44], respectively).

Conclusions:

Both drugs were comparable in efficacy; however, istradefylline seemed to be better in reducing the UPDRS III score. Although the incidence of TEAEs and dyskinesia were higher with both the drugs, the incidence of dyskinesia was more in the opicapone group.

Different Catechol-O-Methyl Transferase Inhibitors in Parkinson's Disease: A Bayesian Network Meta-Analysis

Parkinson's disease (PD) is a common, chronic, progressive, debilitating neurodegenerative disease. The current levodopa treatment requires the addition of other drugs, such as catechol-O-methyl transferase (COMT) inhibitors, to alleviate motor fluctuations in advanced PD. Therefore, a theoretical reference for treatment is urgently needed. In this study, an appropriate search strategy was used to screen eligible studies on different drugs to treat patients with PD from the Embase, PubMed, and Cochrane Library. The publication dates were from January 1990 to June 2021. We integrated eligible randomized controlled trials, and statistical analysis was performed on three kinds of effectiveness outcomes and two types of safety outcomes. We assessed the average difference or odds ratio between each drug and placebo and summarized them as the average and 95% confidence interval (CI), respectively. In terms of efficacy, entacapone (mean difference [MD], 0.64 h; 95% CI, 0.29–1.0), opicapone (MD, 0.92 h; 95% CI, 0.35–1.5), and tolcapone (MD, 3.2 h; 95% CI, 2.1–4.2) increased patients' total ON-time compared to placebo. Tolcapone (MD, −100 mg; 95% CI −160 to −45) reduced the total daily dose of levodopa therapy. None of these three drugs was found to have statistical significance in mean change from baseline in UPDRS part III scores when compared with others. In terms of safety, tolcapone (MD, 3.8; 95% CI, 2.1–6.8), opicapone (MD, 3.7; 95% CI, 2–7.2), and entacapone (MD, 2.2; 95% CI, 1.5–3.3) increased the number of cases of dyskinesia compared to placebo. Entacapone (MD, 1.7; 95% CI, 1.3–2.2) and tolcapone (MD, 4.3; 95% CI, 1.3–15) were more likely to cause adverse events than placebo. In conclusion, opicapone showed higher efficiency and fewer safety problems in five indicators we selected when compared with the other two drugs.

Redefining the strategy for the use of COMT inhibitors in Parkinson's disease: the role of opicapone

INTRODUCTION

Levodopa remains the gold-standard Parkinson's disease (PD) treatment, but the inevitable development of motor complications has led to intense activity in pursuit of its optimal delivery.

AREAS COVERED

Peripheral inhibition of dopa-decarboxylase has long been considered an essential component of levodopa treatment at every stage of illness. In contrast, only relatively recently have catechol-O-methyltransferase (COMT) inhibitors been utilized to block the other major pathway of degradation and optimize levodopa delivery to the brain. First and second-generation COMT inhibitors were deficient because of toxicity, sub-optimal pharmacokinetics or a short duration of effect. As such, they have only been employed once 'wearing-off' has developed. However, the third-generation COMT inhibitor, opicapone has overcome these difficulties and exhibits long-lasting enzyme inhibition without the toxicity observed with previous generations of COMT inhibitors. In clinical trials and real-world PD studies opicapone improves the levodopa plasma profile and results in a significant improvement in ON time in 'fluctuating' disease, but it has not yet been included in the algorithm for early treatment.

EXPERT OPINION

This review argues for a shift in the positioning of COMT inhibition with opicapone in the PD algorithm and lays out a pathway for proving its effectiveness in early disease.

Opicapone and Levodopa-Carbidopa Intestinal Gel Infusion: The Way Forward Towards Cost Savings for Healthcare Systems?

Combined catechol-O-methyl-transferase-inhibition and Levodopa-Carbidopa intestinal gel (LCIG) infusion has the potential to reduce LCIG daily dose and the costs of this therapy. In this retrospective analysis, we report on Parkinson's disease (PD) patients on LCIG with concomitant Opicapone. In 11 patients, the introduction of Opicapone led to LCIG daily dose being reduced by 24.8% (p = 0.05) without any significant worsening of dyskinesia. Three patients withdrew from Opicapone due to side effects or inefficacy. LCIG daily dose reduction could lead to cost savings of £142,820.63/year in the United Kingdom while maintaining clinical care.

Implications of dopaminergic medication withdrawal in Parkinson's disease

The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan for dose adjustment is usually done as per drug information recommendations from the licensing bodies, but there are no clear guidelines with regards to the best practice regarding the tapering off schedule given sudden dose reductions of drugs such as dopamine agonists may have serious adverse consequences. A systematic literature search was, therefore, performed to derive recommendations and the data show that there are no controlled studies or evidence-based recommendations how to taper or discontinue PD medication in a systematic manner. Most of the data were available on the dopamine agonist withdrawal syndrome (DAWS) and we found only two instructions on how to reduce pramipexole and rotigotine published by the EMA. We suggest that based on the available data, levodopa, dopamine agonists (DA), and amantadine should not be discontinued abruptly. Abrupt or sudden reduction of DA or amantadine in particular can lead to severe life-threatening withdrawal symptoms. Tapering off levodopa, COMT inhibitors, and MAO-B inhibitors may worsen motor and non-motor symptoms. Based on our clinical experience, we have proposed how to reduce PD medication and this work will form the basis of a future Delphi panel to define the recommendations in a consensus.

An Update on Medical and Surgical Treatments of Parkinson's Disease

Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta and other neuronal populations. The worldwide prevalence of PD is over 7 million and has been increasing more rapidly than many other neurodegenerative disorders. PD symptoms can be broadly divided into motor (slowness, stiffness, tremor) and non-motor symptoms (such as depression, dementia, psychosis, orthostatic hypotension). Patients can also have prodromal symptoms of rapid eye movement sleep behavior disorder, hyposmia, and constipation. The diagnosis of PD is mainly clinical, but dopamine transporter single-photon emission computed tomography can improve the accuracy of the diagnosis. Dopamine based therapies are used for the treatment of motor symptoms. Non-motor symptoms are treated with other medications such as selective serotonin reuptake inhibitors (depression/anxiety), acetylcholinesterase inhibitors (dementia), and atypical antipsychotics (psychosis). Patients with motor fluctuations or uncontrolled tremor, benefit from deep brain stimulation. Levodopa-carbidopa intestinal gel is an alternative to deep brain stimulation for uncontrolled motor fluctuations. Rehabilitative therapies such as physical, occupational, and speech therapy are important during all stages of the disease. Management of PD is complex but there have been significant advancements in the treatment of motor and non-motor symptoms over the past few years. This review discusses the updates in the medical and surgical management of PD.

Clinical Utility of Opicapone in the Management of Parkinson's Disease: A Short Review on Emerging Data and Place in Therapy

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, and levodopa (L-dopa) remains the most efficacious drug treatment for PD and a gold-standard for symptom control. Nonetheless, a significant majority of PD patients develop motor fluctuations over their disease course, with a significant impact on quality-of-life, meaning control of such complications translates into a fundamental clinical need. Catechol-O-methyl transferase (COMT) inhibitors (COMT-i) are used as first-line adjuvant therapy to L-dopa for end-of-dose (EoD) motor fluctuations, since they increase L-dopa availability in the brain by inhibiting its peripheral metabolism. Opicapone (OPC), a once-daily, long-acting COMT-i, is the most recent and potent of its class, having been licensed in Europe in 2016 as an add-on to preparations of L-dopa/DOPA decarboxylase inhibitors in PD patients with EoD motor fluctuations. More recently, it has also received approval in the USA and Japan in 2020. Two high-quality positive efficacy studies (double-blind Phase III clinical trials) established OPC efficacy with significant reduction in OFF time (average 60 minutes vs placebo), without concomitant increase of distressing dyskinesias during ON time. These beneficial effects were sustained in open-label extension studies, without unexpected safety issues or adverse events, with dyskinesia having been the most frequent complaint. OPC also avoids liver toxicity and gastrointestinal issues compared with previous COMT-i. In this review, we aimed to cover OPC’s lifecycle (synthesis to commercialization), its clinical pharmacological data, safety, tolerability and pharmacovigilance evidence, and discuss its role in the management of motor fluctuations in PD as well as its emerging place in international recommendations.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2020

While the COVID-19 pandemic also affected the work of regulatory authorities, the US Food and Drug Administration approved a total of 53 new drugs in 2020, one of the highest numbers in the past decades. Most newly approved drugs related to oncology (34%) and neurology (15%). We discuss these new drugs by level of innovation they provide, i.e., first to treat a condition, first using a novel mechanisms of action, and "others." Six drugs were first in indication, 15 first using a novel mechanism of action, and 32 other. This includes many drugs for the treatment of orphan indications and some for the treatment of tropical diseases previously neglected for commercial reasons. Small molecules continue to dominate new drug approvals, followed by antibodies. Of note, newly approved drugs also included small-interfering RNAs and antisense oligonucleotides. These data show that the trend for declines in drug discovery and development has clearly been broken.

Opicapone for Parkinson's disease: clinical evidence and future perspectives

Since 2016, opicapone (OPC), a potent third-generation, long-acting, once-daily, peripheral catechol-O-methyltransferase inhibitor, is approved as an add-on to levodopa in Parkinson's disease patients with motor fluctuations. OPC 50 mg has showed to be able in reducing OFF time by an average of about 60 min daily compared with placebo, to further reduce OFF-time of about 39 min, when switched from ENT to OPC and to be safe. These beneficial effects of OPC were maintained for 1 year. Recently, several post hoc analysis and few pilot observational open-label studies, have suggested its efficacy and wider applicability for different phenotypes of motor complications and for Parkinson's disease stages. Here we review OPC applicability and perspectives, in the light of the more recently published analysis.

Long-term safety and efficacy of opicapone in Japanese Parkinson's patients with motor fluctuations

The double-blind part of the COMFORT-PD (COMt-inhibitor Findings from Opicapone Repeated Treatment for Parkinson’s Disease) study in Japanese levodopa-treated patients with Parkinson’s disease and motor fluctuations found that both opicapone 25 and 50 mg were significantly more effective than placebo. This 52-week open-label extension study evaluated the long-term safety and efficacy of opicapone 50 mg tablets in patients who completed the double-blind part of the COMFORT-PD study. Safety was monitored via adverse events, laboratory testing, and physical, cardiovascular and neurological examinations. Efficacy was primarily assessed by change in OFF-time. Secondary efficacy measures included: ON-time, percentage of OFF/ON-time responders, other outcomes from the double-blind part. 391/437 patients were transferred to the open-label extension period and included in the safety analysis set (full analysis set, n = 387; open-label completers, n = 316). Adverse events were frequently reported (n = 338, 86.4%), but < 50% were considered drug-related (39.9%) and few were considered serious (2.6%) or led to discontinuation (2.8%). Decreased OFF-time was consistently observed over the open-label period regardless of initial randomization. Change [LSM (SE)] in OFF-time from the open-label baseline to the last visit showed a persistent effect in patients initially randomized to opicapone 25 mg [− 0.37 (0.20) h, P = 0.0689] and opicapone 50 mg [− 0.07 (0.21) h, P = 0.6913] whereas opicapone 50 mg led to a statistically significant reduction in the previous placebo group [− 1.26 (0.19) h, P < 0.05]. Once-daily opicapone 50 mg was generally well tolerated and consistently reduced OFF-time over 52 weeks in Japanese levodopa-treated patients with motor fluctuations.

Trial registration JapicCTI-153112; date of registration: December 25, 2015.

New drug approvals for 2020: Synthesis and clinical applications

53 New drugs including 38 chemical entities and 15 biologics were approved by the U.S. Food and Drug Administration during 2020. Among the marketed drugs, 34 new small molecule drugs and 4 new diagnostic agents with privileged structures and novel clinical applications represent as promising leads for the development of new drugs with the similar indications and improved therapeutic efficacy. This review is mainly focused on the clinical applications and synthetic methods of 34 small-molecule drugs newly approved by the FDA in 2020.