ADS-5102, FDA-approved as Gocovri, to treat dyskinesia in Parkinson’s disease, has a unique PK profile, such that once daily bedtime dosing provides higher amantadine concentrations from morning throughout the day and lower at night. Based on results from a 60-subject, 4-week, Phase-2 study, INROADS was designed to confirm benefit of ADS-5102 on walking in MS patients.
To evaluate the efficacy and safety of ADS-5102 (amantadine) extended release capsules in patients with multiple sclerosis with walking impairment.
INROADS comprised a 4-week placebo run-in, followed by a 12-week double-blind period. Five hundred ninety-four MS patients with walking impairment from the US or Canada enrolled, and 560 were randomized, 1:1:1, to 274 mg ADS-5102 (n=185), 137 mg ADS-5102 (n=187), or placebo (n=186). The primary endpoint was the proportion of responders (≥20% improvement from baseline measured in ft/sec) in timed 25-foot walk [T25FW] at Week 16, comparing 274 mg ADS-5012 versus placebo. Subjects who did not have a Week 16 assessment were counted as non-responders. Additional outcomes included timed up and go test, 2-minute walk test, and MS walking scale-12. Prespecified subgroups, including prior dalfampridine use, were analyzed.
Baseline characteristics were similar across treatment arms, with mean time since diagnosis 15.9 years, median EDSS 6.0, and mean T25FW 12.4 seconds; 52.5% reported prior dalfampridine use. At Week 16, 274 mg ADS-5102 demonstrated a statistically significantly greater response rate, 21.1% (P=.01) than placebo (11.3%); the response rate for 137 mg ADS-5102 was 17.6% (P=.08). For subjects who completed the study, the response rates were 28.3% (P< .001) for 274 mg, and 19.6% (P=.049) for 137 mg, vs. 11.9% for placebo. Response rates were consistent for subjects with (20.0%, 15.9%, vs. 11.0%) and without (22.5%, 19.2%, vs. 11.6%) prior dalfampridine use. The most commonly reported (>5%) adverse events (AEs) were peripheral edema, dry mouth, fall, constipation, UTI, and insomnia; AEs led to study drug discontinuation for 20.5% (274 mg), 6.4% (137 mg) and 3.8% (placebo) of subjects.
INROADS met its primary objective of showing clinically meaningful benefit in MS walking speed for 274 mg ADS-5102. A dose-response was seen for both efficacy and tolerability. AEs were consistent with the known safety profile of amantadine. Results suggest a role for ADS-5102 to improve walking in patients with MS, particularly those who have tried and discontinued dalfampridine.