Long-term efficacy of opicapone in fluctuating Parkinson's disease patients: a pooled analysis of data from two phase 3 clinical trials and their open-label extensions

BACKGROUND AND PURPOSE

The aim was to evaluate the efficacy of the catechol-O-methyltransferase inhibitor opicapone (25 and 50 mg) as adjunct therapy to levodopa in a pooled population of Parkinson's disease patients who participated in the pivotal double-blind trials of opicapone and their 1-year open-label extensions.

METHODS

Data (placebo, opicapone 25 mg and opicapone 50 mg) from the BIPARK-1 and BIPARK-2 double-blind and open-label studies were combined. The studies had similar designs, eligibility criteria and assessment methods. The primary efficacy variable in both double-blind studies was the change from baseline in absolute OFF time based on patient diaries.

RESULTS

Double-blind treatment with opicapone (25 and 50 mg) significantly reduced absolute daily OFF time from a baseline of 6.1-6.6 h. The mean (and 95% confidence interval) treatment effect versus placebo was -35.1 (-62.1, -8.2) min (P = 0.0106) for the 25 mg dose and -58.1 (-84.5, -31.7) min (P < 0.0001) for the 50 mg dose. Reductions in OFF time were mirrored by significant increases in ON time without troublesome dyskinesia (P < 0.05 and P < 0.0001 for the 25 and 50 mg doses, respectively). No significant differences were observed for ON time with troublesome dyskinesia. Patient diary results from the open-label phase indicated a maintenance of effect for patients previously treated with opicapone 50 mg. The group previously treated with the 25 mg dose benefitted with further optimization of therapy during the open-label phase, whilst switching from placebo to opicapone led to significant reductions in OFF time and increased ON time.

CONCLUSIONS

Over at least 1 year of open-label therapy, opicapone consistently reduced OFF time and increased ON time without increasing the frequency of troublesome dyskinesia.

Exposure-safety and efficacy response relationships and population pharmacokinetics of eslicarbazepine acetate

Objectives

Eslicarbazepine acetate (ESL) is a once‐daily (QD) oral antiepileptic drug (AED) for focal‐onset seizures (FOS). Pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to assess dose selection, identify significant AED drug interactions, and quantitate relationships between exposure and safety and efficacy outcomes from Phase 3 trials of adjunctive ESL.

Methods

Eslicarbazepine (the primary active metabolite of ESL) population PK was evaluated using data from 1351 subjects enrolled in 14 studies (11 Phase 1 and three Phase 3 studies) after multiple oral doses ranging from 400 to 1200 mg. Population PK and PD models related individual eslicarbazepine exposures to safety outcomes and efficacy responses.

Results

Eslicarbazepine PK was described by a one‐compartment model with linear absorption and elimination. The probability of a treatment‐emergent adverse event (TEAE; dizziness, headache, or somnolence) was higher with an initial dose of ESL 800 mg than with an initial dose of ESL 400 mg QD. Body weight, sex, region, and baseline use of carbamazepine (CBZ) or lamotrigine were also found to influence the probability of TEAEs. Eslicarbazepine exposure influenced serum sodium concentration, standardized seizure frequency, and probability of response; better efficacy outcomes were predicted in patients not from Western Europe (WE; vs WE patients) and those not taking CBZ (vs taking CBZ) at baseline.

Conclusions

Pharmacokinetic and PK/PD modeling were implemented during the development of ESL for adjunctive treatment of FOS in adults. This quantitative approach supported decision‐making during the development of ESL, and contributed to dosing recommendations and labeling information related to drug interactions.

Effectiveness of opicapone and switching from entacapone in fluctuating Parkinson disease

OBJECTIVE

To evaluate the effectiveness of opicapone as add-on to levodopa and the effects of switching from entacapone over 1 year of treatment in patients with fluctuating Parkinson disease.

METHODS

After completion of a placebo- and entacapone-controlled double-blind study of opicapone (5, 25, or 50 mg), 495 patients continued to a 1-year extension phase in which patients were treated with opicapone. Patients began with once-daily opicapone 25 mg for 1 week, followed by individually tailored levodopa and/or opicapone dose adjustments. The primary efficacy variable was the change from baseline in absolute "off" time based on patient diaries. Other outcomes included proportion of responders, scale-based assessments, and standard safety assessments.

RESULTS

One year of treatment with opicapone reduced "off" time by a half-hour (33.8 minutes) vs the open-label baseline and >2 hours (126.9 minutes) vs the double-blind baseline. Whereas patients who were originally treated with opicapone 50 mg in the double-blind phase maintained their efficacy, switching treatments led to further decreases in "off" time (-64.9, -39.3, -27.5, and -23.0 minutes for switching from placebo, entacapone, and opicapone 5 and 25 mg, respectively). Dyskinesia was the most frequently reported adverse event (14.5%) and was managed by adjustment of dopaminergic therapy. No new safety concerns were observed with long-term opicapone administration.

CONCLUSION

Long-term use of opicapone provided sustained efficacy over 1 year. Switching from entacapone to opicapone led to enhanced efficacy under the conditions of the study.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with Parkinson disease and end-of-dose motor fluctuations, long-term use (52 weeks) of opicapone is well tolerated and reduces "off" time.

Reliability of body-weight scalars on the assessment of propofol induction dose in obese patients

BACKGROUND

Obese patients require specific perioperative care when compared with non-obese patients. The present study aimed to analyse the ability of size descriptors to estimate propofol induction dose in class II and III obese patients.

METHODS

A cross-sectional study on adult patients with body mass index (BMI) equal to or greater than 35 kg/m² and on adult patients with BMI lower than 35 kg/m² was carried out. General anaesthesia was induced with remifentanil, propofol and rocuronium. Propofol infusion was started at 2000 mg/h until loss of consciousness. Bioelectrical impedance analysis and Brice modified interview was completed during pre- and post-operative evaluation, respectively. Measurements of propofol plasma concentration were performed using gas chromatography/ion trap-mass spectrometry.

RESULTS

Forty patients were enrolled in the study. The median values of fat free mass (FFM) in BMI < 35 kg/m² and BMI ≥ 35 kg/m² groups were 70% and 55% of total body weight, respectively. Our results did not demonstrate a strong correlation level between the studied size descriptors and propofol induction dose in both groups. Nevertheless, when propofol doses were normalized by FFM, an apparent convergence of the empirical cumulative distribution functions was observed.

CONCLUSION

None of the size descriptors was seen to be an effective predictor of the propofol induction dose in class II and III obese patients when a fixed infusion rate was used. Due to the observed variability between patients, guiding propofol induction dose against a clinical endpoint of unconsciousness appears more appropriate in order to avoid side effects related both with under or overdosing of propofol.

Effects of adjunctive eslicarbazepine acetate on neurocognitive functioning in children with refractory focal-onset seizures

PURPOSE

This was a phase-II, randomized, double-blind (DB), placebo-controlled study aimed to evaluate neurocognitive effects of eslicarbazepine acetate (ESL) as adjunctive therapy in pediatric patients with refractory focal-onset seizures (FOS).

METHODS

Children (6-16years old) with FOS were randomized (2:1) to ESL or placebo. Treatment started at 10mg/kg/day, was up-titrated up to 30mg/kg/day (target dose), and maintained for 8weeks, followed by one-year open-label follow-up. The primary endpoint was change from baseline to the end of maintenance period in the composite Power of Attention assessed with the Cognitive Drug Research (CDR) system. Behavioral and emotional functioning and quality of life (QOL), secondary endpoints, were assessed with Child Health Questionnaire-Parent Form 50 (CHQ-PF50), Child Behavior Checklist (CBCL), and Raven's Standard Progressive Matrices (SPM). Efficacy was evaluated through changes in standardized seizure frequency (SF), responder rate, and proportion of seizure-free patients. Safety was evaluated by the incidence of treatment-emergent adverse events (TEAEs).

RESULTS

One hundred and twenty-three patients were randomized. A noninferiority analysis failed to reject the null hypothesis that the change from baseline in the Power of Attention score in the ESL group was at least 121ms inferior to the placebo group for all age groups. The CDR scores showed no differences between placebo and ESL in Power of Attention (1868.0 vs 1759.5), Continuity of Attention (1.136 vs -1.786), Quality of Working Memory (-0.023 vs -0.024), and Speed of Memory (-263.4 vs -249.6). Nonsignificant differences between placebo and ESL were seen for CHQ-PF50, CBCL scores, and Raven's SPM. Episodic Memory Index showed significant negative effect on ESL. Efficacy results favored the ESL group (SF least square [LS] means 1.98 vs 4.29). The TEAEs had a similar incidence between treatment groups (41.0% vs 47.5%).

CONCLUSIONS

Overall ESL did not produce statistically significant effects on neurocognitive and behavioral functioning in patients with epilepsy aged 6 to 16years. Additionally, ESL was effective in reducing seizure frequency and was well-tolerated.

Abstract P477: Effect of Zamicastat on Blood Pressure and Heart Rate - Comparison Between Acute and Repeated Dosing in the SHR

The sympathetic nervous system (SNS) can alter blood pressure by modulation of cardiac output, peripheral vascular resistance and renal function. One strategy for the modulation of sympathetic nerve function is to reduce the biosynthesis of norepinephrine (NE) via inhibition of dopamine β-hydroxylase (DβH), the enzyme that catalyses the conversion of dopamine to NE in sympathetic nerves. Zamicastat is a new peripheral DβH inhibitor that decreases NE levels in sympathetically innervated tissues and slows down the drive of SNS. In order to compare the effect of zamicastat on blood pressure and heart rate after acute and repeated dosing in spontaneously hypertensive rats (SHR), male adult SHR were implanted with telemetry devices (TA11PA-C40, DSI). Zamicastat (30 mg/kg p.o.) was given either as a single dose (n=8) or once a day for five days (n=6). On day 1, the maximal effect (E max ) of zamicastat on systolic blood pressure (SBP) was attained 15h after dosing. E max was similar in the acute and repeated dosing groups: -21.1±3.9 and -22.0±8.2 mmHg, respectively. In the acute treatment group, a gradual return of the SBP to the high baseline levels was observed over time. On the other hand, in the repeat dosing group the E max were consistent across the five administrations -22.0±8.2, -25.2±7.9, -22.0±7.5, -20.0±6.0 and -16.1±2.8 mmHg, respectively day 1 to 5. On day 5, after reaching E max a gradual return of SBP to baseline levels was also observed. The effect of zamicastat on diastolic blood pressure was similar with an E max of -18.4±3.5 mmHg in the acute dosing group and -18.8±8.7, -19.2±7.2, -18.2±6.6, -19.6±6.6 and -15.7±4.7 mmHg over the five days of administration in the repeated dosing group. Zamicastat did not affect heart rate under each dosing regimen. In conclusion, there is no tachyphylaxis or sensitization to the cardiovascular effects of zamicastat in this model and blood pressure returns to basal levels after zamicastat treatment discontinuation.

Sustained high blood pressure reduction with etamicastat, a peripheral selective dopamine β-hydroxylase inhibitor

The aim of the present study was to evaluate the influence of chronic inhibition of dopamine ß-hydroxylase by etamicastat on the development of hypertension in the spontaneously hypertensive rat (SHR) and the sustainability of effects on the systolic and diastolic blood pressure in the SHR and the normotensive Wistar-Kyoto rat (WKY). WKY and SHR received etamicastat (10 mg/kg/d) from 5 weeks of age for 35 weeks in drinking water, and cardiovascular assessments were performed on a weekly basis. Etamicastat reduced systolic and diastolic blood pressure when SHRs reached the age of 16 weeks with mean decreases of 37 and 32 mm Hg, respectively, for the subsequent for 24 weeks of treatment, but did not prevent the increase in blood pressure (BP) aged between 5 and 11 week. The BP lowering effect of etamicastat in SHR was reversible on discontinuation and quickly resumed after reinstatement of therapy and was not accompanied by changes in heart rate. Etamicastat affected neither BP nor heart rate in WKY during 36 weeks of treatment. Etamicastat reduced urinary excretion of norepinephrine to a similar extent in WKY and SHR, accompanied by significant increases in urinary dopamine in SHR. Chronic administration of etamicastat did not adversely affected development of animals. Chronic dopamine ß-hydroxylase inhibition with etamicastat effectively decreases BP, although does not prevent the development of hypertension in the SHR.

SAFETY AND EFFICACY OF ESLICARBAZEPINE ACETATE IN ELDERLY PATIENTS

Purpose

To evaluate the safety/tolerability and efficacy of eslicarbazepine acetate (ESL) as adjunctive therapy in elderly patients with partial-onset seizures (POS).

Method

Phase III, multicentre, open-label, non-controlled study in patients aged ≥65 years with ≥2 POS during an 8-week baseline and treated with 1–2 antiepileptic drugs. Following baseline, patients entered a 26-week maintenance period. ESL was initiated at 400 mg once-daily and adjusted (400–1200 mg/day) based on individual response. Safety/tolerability evaluations included treatment-emergent adverse events (TEAEs), vital signs, 12-lead electrocardiogram and physical/neurological examinations. Efficacy evaluations included change in standardised seizure frequency (SSF; seizure frequency/4 weeks).

Results

Of the 72 patients included, 47 (65.3%) experienced 152 TEAEs; most commonly, dizziness (12.5%), somnolence (9.7%), fatigue (8.3%), convulsion (8.3%) and hyponatraemia (8.3%). Three patients died of cardiac failure, glioblastoma multiforme and ischaemic stroke (relationship unlikely/not related). Overall, 16 (22.2%) patients discontinued due to TEAEs. Incidence of clinically significant findings was low for vital signs, electrocardiogram and physical/neurological examinations. SSF decreased from 2.9 at baseline to 1.2 during the maintenance period (median relative change: –54.1%).

Conclusion

Once-daily ESL (400–1200 mg) as adjunctive therapy in elderly subjects with POS did not raise major safety concerns and was efficacious. Supported by Bial.

Distribution and pharmacokinetics of etamicastat and its N-acetylated metabolite (BIA 5-961) in dog and monkey

1. The disposition etamicastat was evaluated in the Cynomolgus monkey after intravenous and oral administration of [(14)C]-etamicastat. The pharmacokinetics of etamicastat and its N-acetylated metabolite BIA 5-961 were also evaluated in monkeys and dogs. 2. In the monkey, 7 days after intravenous and oral administration of [(14)C]-etamicastat, 76.6-91.1% of the etamicastat-related radioactivity had been excreted mainly in urine. The radioactivity peaked in plasma between 4- and 8-h post-dosing followed by a quick decline and a slow terminal phase (half-life of 68.7 h). The calculated oral bioavailability for etamicastat was 46.1%. Etamicastat was quickly absorbed in monkeys and dogs with a half-life ranging from 5.2 to 9.9 h in monkeys and 6.9 to 11.4 h in dogs over. 3. The N-acetylated metabolite of etamicastat, represented 4-7% of the extent of exposure of etamicastat in the monkey, but was not found detectable in dogs. Gender did not influence etamicastat exposure and the concentration versus time curves fitted a dose-dependent pharmacokinetics in the dog, but not in the monkey. 4. In conclusion, etamicastat is rapidly absorbed and primarily excreted via urine in monkeys. Similarly, to humans, monkeys, unlike dogs, N-acetylate etamicastat and evidence that etamicastat pharmacokinetics is less than dose proportional.