GA Depot, a long-acting glatiramer acetate, vs placebo in patients with relapsing multiple sclerosis: A randomized phase 3 clinical trial.

BACKGROUND

GA Depot is a long-acting glatiramer acetate (GA)-based formulation designed to provide significantly extended dosing intervals compared to currently available GA formulations.

OBJECTIVE

To assess GA Depot efficacy, safety, and tolerability compared to placebo in patients with relapsing multiple sclerosis (RMS).

METHODS

A 52-week multi-center, double-blind, placebo-controlled phase 3 trial in RMS. Patients aged 18-55 with an Expanded Disability Status Scale (EDSS) score ⩽ 5.5 were enrolled and randomized (1:1) to intramuscular (IM) GA Depot 40 mg or matching placebo every 4 weeks. The primary endpoint was annualized relapse rate (ARR) at 52 weeks.

RESULTS

A total of 1016 patients were treated with GA Depot (n = 508) or placebo (n = 508). Adjusted ARR was lower in patients treated with GA Depot compared to placebo (0.18, 95% confidence interval [CI] = 0.14 to 0.3 vs 0.26, 95% CI = 0.21 to 0.32, 30.1% relative risk reduction, p = 0.0066). GA Depot significantly reduced the number of contrast-enhancing lesions (p = 0.0083). The most common adverse events were injection site reactions (46.1% with GA Depot vs 28.7% with placebo), primarily mild and self-limited.

CONCLUSION

GA Depot effectively reduced clinical and radiological activity compared to placebo in RMS patients, recapitulating the favorable profile of subcutaneous GA products with significantly less frequent injections.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04121221 (https://clinicaltrials.gov/study/NCT04121221).