Arbaclofen extended-release tablets for spasticity in multiple sclerosis: open-label extension study.

Baclofen, a racemic γ-aminobutyric acid B receptor agonist, is commonly used for the management of multiple sclerosis-related spasticity but is associated with frequent dosing and poor tolerability. Arbaclofen, the active R-enantiomer of baclofen, exhibits 100- to 1000-fold greater specificity for the γ-aminobutyric acid B receptor compared with the S-enantiomer and ∼5-fold greater potency compared with racemic baclofen. Arbaclofen extended-release tablets allow a dosing interval of 12 h and have shown a favourable safety and efficacy profile in early clinical development. A 12-week, randomized, placebo-controlled Phase 3 trial in adults with multiple sclerosis-related spasticity demonstrated that arbaclofen extended-release 40 mg/day significantly reduced spasticity symptoms compared with placebo and was safe and well tolerated. The current study is an open-label extension of the Phase 3 trial designed to evaluate the long-term safety and efficacy of arbaclofen extended-release. In a 52-week, open-label, multicentre study, adults with a Total Numeric-transformed Modified Ashworth Scale score ≥2 in the most affected limb received oral arbaclofen extended-release titrated over 9 days up to 80 mg/day based on tolerability. The primary objective was assessment of arbaclofen extended-release safety and tolerability. Secondary objectives included an assessment of efficacy using the Total Numeric-transformed Modified Ashworth Scale-most affected limb, the Patient Global Impression of Change and Expanded Disability Status Scale. Of 323 patients enrolled, 218 (67.5%) completed 1 year of treatment. Most patients (74.0%) achieved an arbaclofen extended-release maintenance dose of 80 mg/day. At least one treatment-emergent adverse event was reported by 278 patients (86.1%). The most common adverse events were [n patients (%)]: urinary tract disorder [112 (34.7)], muscle weakness [77 (23.8)], asthenia [61 (18.9)], nausea [70 (21.7)], dizziness [52 (16.1)], somnolence [41 (12.7)], vomiting [29 (9.0)], headache [24 (7.4)] and gait disturbance [20 (6.2)]. Most adverse events were of mild-moderate severity. Twenty-eight serious adverse events were reported. One death occurred during the study, a myocardial infarction that was considered by investigators as unlikely to be related to treatment. Overall, 14.9% of patients discontinued due to adverse events, primarily muscle weakness, multiple sclerosis relapse, asthenia and nausea. Evidence of improvement in multiple sclerosis-related spasticity was observed across arbaclofen extended-release dosages. Arbaclofen extended-release treatment (up to 80 mg/day) was well tolerated and reduced symptoms of spasticity in adult patients with multiple sclerosis for 1 year. Clinical Trial Identifier: ClinicalTrials.gov, NCT03319732.

Arbaclofen extended-release tablets for spasticity in multiple sclerosis: randomized, controlled clinical trial.

Baclofen, a racemic GABA-B (GABAB) receptor agonist, is commonly used for the management of multiple sclerosis-related spasticity but is associated with frequent dosing and poor tolerability. Arbaclofen, the active R-enantiomer of baclofen, exhibits 100- to 1000-fold greater specificity for the GABAB receptor compared with the S-enantiomer and ∼5-fold greater potency compared with racemic baclofen. Arbaclofen extended-release tablets have a dosing interval of 12 hours and have shown a favourable safety and efficacy profile in early-phase clinical development. The current Phase 3 study was designed to evaluate the efficacy and safety of arbaclofen extended-release tablets in patients with multiple sclerosis-related spasticity. In this multicentre, double-blind, placebo-controlled study, adults with multiple sclerosis-related spasticity were randomized to arbaclofen extended-release 40 mg/day, arbaclofen extended-release 80 mg/day or placebo for 12 weeks. The co-primary end-points were the change from baseline to Week 12 in the Total Numeric-transformed Modified Ashworth Scale in the Most Affected Limb score and the Clinical Global Impression of Change score. A hierarchical testing procedure was used to evaluate the co-primary end-points; analyses for the 80 mg/day group were considered inferential only if the arbaclofen extended-release 40 mg/day and placebo groups demonstrated a statistically significant difference (P ≤ 0.05) for both end-points. Five hundred thirty-six patients were included in the study. At Week 12, the least squares mean change from baseline in Total Numeric-transformed Modified Ashworth Scale in the Most Affected Limb score was -1.67 (95% confidence interval: -1.97 to -1.36) and -1.28 (95% confidence interval: -1.57 to -0.99) in the arbaclofen extended-release 40 mg/day and placebo groups, respectively (least squares mean difference: -0.39; P < 0.048). Improvements were seen in the mean Clinical Global Impression of Change scores for both the arbaclofen extended-release 40 mg/day and placebo groups; however, no statistically significant difference was observed between them (least squares mean difference: -0.10; P = 0.43). Most adverse events were of mild-moderate severity. Arbaclofen extended-release 40 mg/day for 12 weeks significantly reduced multiple sclerosis-related spasticity compared with placebo and was safe and well tolerated over the 12-week treatment period. Although arbaclofen extended-release 40 mg/day improved Clinical Global Impression of Change scores, a significant difference from placebo was not observed.

Immediate-release/extended-release amantadine (OS320) to treat Parkinson's disease with levodopa-induced dyskinesia: Analysis of the randomized, controlled ALLAY-LID studies.

BACKGROUND: Immediate-release (IR) amantadine has been used for treatment of levodopa induced dyskinesia (LID). The immediate-release/extended-release (IR/ER) amantadine formulation OS320 (OSMOLEX ER®) contains an IR outer layer and ER core for once-daily dosing. OBJECTIVE: Report individual and pooled results for the similarly designed double-blind, placebo-controlled ALLAY-LID I and II trials, assessing IR/ER-amantadine for LID. METHODS: PD patients with LID were randomized to IR/ER-amantadine 193 mg, 258 mg, or placebo. Primary endpoint was Unified Dyskinesia Rating Scale (UDysRS) score change from baseline to Day 98. Secondary outcome was ON time without troublesome dyskinesia based on diaries. Exploratory outcomes were other diary states (including OFF), MDS-UPDRS Parts II + III and Fatigue Severity Scale. RESULTS: Overall, 222 individuals enrolled (N = 87 ALLAY-LID I, N = 135 ALLAY-LID II); both trials terminated early for sponsor's decision. While ALLAY-LID I did not meet its primary endpoint, a significant reduction in UDysRS scores versus placebo was observed in ALLAY-LID II for both 193 mg and 258 mg doses. In the pooled analysis, placebo-adjusted UDysRS score differences were -5.5 [-9.8, -1.2], p = 0.012 and -5.2 [-9.5, -0.9], p = 0.017, respectively. IR/ER-amantadine 258 mg significantly increased time spent ON without troublesome dyskinesia in ALLAY-LID II and pooled analysis. Reductions in ON time with dyskinesia supported the primary outcome. There was no effect on OFF time or other outcomes. Overall, 13.3% (193 mg), 18.7% (258 mg) and 11.1% (placebo) discontinued for adverse events, most commonly hallucinations (4.0%, 10.7%, and 1.4%, respectively). CONCLUSIONS: IR/ER-amantadine significantly reduced LID in ALLAY-LID II but not in ALLAY-LID I; post-hoc pooled data also indicated a positive treatment effect on LID.

Bioavailability and Pharmacokinetics of Once-Daily Amantadine Extended-Release Tablets in Healthy Volunteers: Results from Three Randomized, Crossover, Open-Label, Phase 1 Studies.

INTRODUCTION: In February 2018, OS320-an amantadine extended-release (ER) tablet formulation with once-daily morning administration-was approved for the treatment of Parkinson's disease and drug-induced extrapyramidal reactions in adults. The purpose of this study was to describe three phase 1 studies that assessed the pharmacokinetics (PK) and bioavailability of amantadine ER in healthy adult volunteers. METHODS: Study 1 was an open-label, four-treatment, single-dose, crossover study comparing amantadine ER 129, 193, and 258 mg tablets with an equivalent dose of immediate-release (IR) amantadine 40 mg/5 mL syrup. Study 2 was an open-label, single-dose, crossover food-effect study with amantadine ER 258 mg. Study 3 was an open-label, multiple-dose, crossover study comparing amantadine ER and amantadine IR syrup. RESULTS: Amantadine ER displayed a steady release of amantadine, with the peak amantadine concentration occurring at ~ 7.5 h postdose or in the middle of the day (following a morning dose) with steady-state administration. Administration of amantadine ER 258 mg with a high-fat meal did not affect amantadine bioavailability. Amantadine plasma exposure increased proportionally with increasing doses, and at steady state, amantadine exposure from an amantadine ER 258-mg tablet was bioequivalent to twice-daily 129-mg amantadine IR syrup. CONCLUSION: The PK profile of amantadine ER 129-mg, 193-mg, and 258-mg tablets allows for once-daily dosing in the morning; the 24-h average amantadine plasma concentration is equivalent to that for the same daily dose of IR amantadine administered twice daily. FUNDING: Osmotica Pharmaceutical US LLC.

Effects of Renal Impairment on the Pharmacokinetics of Once-Daily Amantadine Extended-Release Tablets.

BACKGROUND: An extended-release formulation of amantadine (Osmolex ER™, Osmotica Pharmaceutical US LLC) was approved in February 2018 to treat Parkinson's disease and drug-induced extrapyramidal reactions in adults. OBJECTIVES: To determine the pharmacokinetic profile of extended-release amantadine in subjects with varying degrees of renal impairment. METHODS: Adults with normal renal function (creatinine clearance > 89 mL/min/1.73 m2), moderate renal impairment (creatinine clearance 30-59 mL/min/1.73 m2), or severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m2) received a single 129-mg dose (160 mg amantadine hydrochloride) of extended-release amantadine. Blood and urine samples for pharmacokinetic analysis were taken at scheduled intervals. A two-compartment pharmacokinetic population model was employed to determine optimum extended-release amantadine dosing in subjects with renal impairment. RESULTS: Following a single oral dose of the 129-mg extended-release amantadine tablet, amantadine plasma concentration increased slowly, reaching a peak at approximately 11 h. Amantadine elimination was reduced in subjects with renal impairment. Renal clearance decreased from 10,965 to 2618 mL/h in subjects with severe renal impairment compared to those with normal renal function. Pharmacokinetic modeling and simulation methods were used to recommend the oral administration of 129-mg extended-release amantadine tablets at intervals of 24, 48, 72, 96, 120, or 168 h depending on the degree of renal function. CONCLUSIONS: Renal impairment was associated with reduced amantadine clearance. Based on pharmacokinetic modeling and simulations, dose regimens were recommended for subjects with impaired renal function to provide systemic amantadine exposure similar to subjects with normal renal function taking a once-daily extended-release amantadine tablet.

Pharmacokinetic Comparison of Once-Daily Topical Minocycline Foam 4% vs Oral Minocycline for Moderate-to-Severe Acne.

OBJECTIVE: To characterize minocycline pharmacokinetics and relative bioavailability following multiple-dose topical administration of minocycline hydrochloride (HCl) foam 4% (FMX101 4%) as compared with single-dose oral administration of minocycline HCl extended-release tablets (Solodyn®) in subjects with moderate-to-severe acne. METHODS: A Phase 1, single-center, nonrandomized, open-label, active-controlled, 2-period, 2-treatment crossover clinical study. The study included 30 healthy adults (mean age, 22.6 years; 90% white, and 60% females) who had moderate-to-severe acne. Subjects were assigned to first receive a single oral dose of a minocycline HCl extended-release tablet (approximately 1 mg/kg). At 10 days after the oral minocycline dose, topical minocycline foam 4% was applied, once daily for 21 days. Serial blood samples were obtained before and after administration of oral minocycline and each topical application of minocycline foam 4% on days 1, 12, and 21. RESULTS: Following oral administration of minocycline (approximately 1 mg/kg), plasma minocycline concentration increased until 3 hours, followed by a log-linear decrease over the remainder of the 96-hour sampling period. Following topical application of a 4-g maximal-use dose of minocycline foam 4% for 21 days, plasma minocycline concentration was very low, with geometric mean Cmax values ranging from 1.1 ng/mL to 1.5 ng/mL. Steady state was achieved by day 6. Overall, minocycline exposure with topical minocycline foam 4% was 730 to 765 times lower than that with oral minocycline. There was no evidence of minocycline accumulation over the 21 days of topical application of minocycline foam 4%. Topical minocycline foam 4% appeared to be safe and well tolerated, with no serious treatment-emergent adverse events (TEAEs), treatment-related TEAEs, or TEAEs that led to treatment discontinuation. CONCLUSION: Once-daily topical application of minocycline foam 4% did not lead to significant systemic exposure to minocycline. It appears to be a well-tolerated treatment option for individuals with moderate-to-severe acne.

J Drugs Dermatol. 2017;16(10):1022-1028.

Results of a phase I/II multi-center investigation of udenafil in adolescents after fontan palliation.

BACKGROUND: The Fontan operation results in a circulation that is dependent on low pulmonary vascular resistance to maintain an adequate cardiac output. Medical therapies that lower pulmonary vascular resistance may augment cardiac output and improve long-term outcomes. OBJECTIVES: This phase I/II clinical trial conducted by the Pediatric Heart Network was designed to evaluate short-term safety, pharmacokinetics (PK), and preliminary efficacy of udenafil in adolescents following Fontan. METHODS: A 5-day dose-escalation trial was conducted in five study cohorts of six subjects each (37.5, 87.5, and 125 mg daily, 37.5 and 87.5 mg by mouth twice daily). A control cohort with 6 subjects underwent exercise testing only. Adverse events (AEs) were recorded, PK samples were collected on study days six through eight, and clinical testing was performed at baseline and day five. RESULTS: The trial enrolled 36 subjects; mean age 15.8 years (58% male). There were no significant differences in subject characteristics between cohorts. No drug-related serious AEs were reported during the study period; 24 subjects had AEs possibly or probably related to study drug. Headache was the most common AE, occurring in 20 of 30 subjects. The 87.5 mg bid cohort was well tolerated, achieved the highest maximal concentration (506 ng/mL) and the highest average concentration over the dosing interval (279 ng/mL), and was associated with a suggestion of improvement in myocardial performance. Exercise performance did not improve in any of the dosing cohorts. CONCLUSIONS: Udenafil was well-tolerated at all dosing levels. The 87.5 mg bid cohort achieved the highest plasma drug level and was associated with a suggestion of improvement in myocardial performance. These data suggest that the 87.5 mg bid regimen may be the most appropriate for a Phase III clinical trial.