FDA Accepts New Drug Application for Long-Acting Form of Glatiramer Acetate

Rajiv Malik

The FDA has accepted Viatris and Mapi Pharma’s new drug application (NDA) for its investigational agent GA Depot, a long-acting, once-monthly glatiramer acetate solution for the treatment of patients with relapsing forms of multiple sclerosis (MS). The agency is expected to have a decision on the therapy by March 8, 2024.¹

The NDA is supported by data from a phase 3, multinational, double-blind, placebo-controlled study (NCT04121221) in which treatment with GA Depot resulted in a 30% statistically significant reduction of annualized relapsing rate relative to placebo (P = .0066). The trial featured 1016 patients who were randomly assigned to 40 mg of GA Depot or placebo, via intramuscular injection, once every 4 weeks for a total of 13 doses. Findings from the study were strengthened by MRI end points as well.²

"The NDA filing acceptance for GA Depot is yet another example of our continuous commitment to look for opportunities to enhance existing therapies and innovation to support unmet medical needs,” Rajiv Malik, president at Viatris, said in a statement.¹ "Our application is backed by Phase III efficacy and safety data, and we believe, when approved, GA Depot could improve patient experience through fewer injections, greater tolerability and increased compliance. This milestone gives us further confidence in the strength of our GA Depot clinical program, and we look forward to continuing to work closely with FDA to bring access to this important complex medicine to patients."

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In addition to positive findings on the primary end point, treatment with GA Depot resulted in a 28.5% reduction in cumulative new enhancing T1 lesions (P = .0083) and a 17.3% reduction of cumulative number of new or newly enlarging hyperintense T2 lesions (P = .0305) over a 52-week treatment period. Mean Expanded Disability Status Scale scores were also consistently and statistically significantly (P = .0193) reduced in the GA Depot arm.²

GA Depot is composed of extended-release microspheres that are administered intramuscularly, typically every 28 days. In terms of safety, the phase 3 findings showed a higher incidence of treatment-emergent adverse events among those on GA Depot. The most common TEAEs were injection site reactions, though they were mostly mild. The compliance rate was approximately 99% for the total remaining patients in the study, with 93.4% of patients who continued on to the open-label study.

"We are confident that GA Depot, when approved, will represent an important advancement in MS care by offering a convenient once-monthly option for patients which may potentially improve compliance and adherence, and the medicine is well positioned to deliver on this important unmet need,” Ehud Maron, chief executive officer and chairman, Mapi Pharma, said in a statement.¹ "I commend the teams at Mapi and Viatris for the strong collaboration which has leveraged our collective expertise in complex products to deliver this novel medicine."

The therapy is also currently being investigated in a phase 2a study of patients with progressive MS, a form of the disease that has 1 approved therapy. At the 2022 Consortium of Multiple Sclerosis Centers Annual Meeting, 1-year interim data from the trial suggested that the agent is safe and effective for this patient population, based on the low rate of AEs detected and the stable EDSS for both men and women. Data showed that mean 9-hole peg test and timed 25-foot walk tests remained stabled, while no evidence of progression was observed in 69.2% of treated patients. Furthermore, at 6 months and 1 year, MRI volumetric analysis demonstrated changes of –0.89% and –0.34%, respectively, on brain volume.³

REFERENCES
1. Viatris and Mapi Pharma announce FDA acceptance of new drug application filing for GA Depot for the treatment of relapsing forms of multiple sclerosis. Viatris. August 7, 2023. Accessed August 7, 2023. https://www.prnewswire.com/news-releases/viatris-and-mapi-pharma-announce-fda-acceptance-of-new-drug-application-filing-for-ga-depot-for-the-treatment-of-relapsing-forms-of-multiple-sclerosis-301894145.html
2. Miller AE, Popper L, Berger JR, et al. Results of a Phase III, Multinational, Double Blind, Placebo-Controlled Study in Subjects with Relapsing Forms of Multiple Sclerosis to Assess the Efficacy, Safety and Tolerability of GA Depot, a Long-Acting IM Injection of Glatiramer Acetate, Administered Once Every Four Weeks. Presented at ACTRIMS Forum 2023; February 23-25; San Diego, California. Abstract P087.
3. Fletcher S, Kimelman NB, Danon U, et al. Glatiramer acetate depot (extended release) phase 2a study in patients with primary progressive multiple sclerosis: safety and efficacy 1 year interim snapshot analysis. Presented at: CMSC Annual Meeting; June 1-4, 2022; National Harbor, MD.