The U.S. Food and Drug Administration (FDA) has agreed to review Viatris and Mapi Pharma's application seeking approval of GA Depot for the treatment of relapsing forms of multiple sclerosis (MS). The medication is a long-acting formulation of glatiramer acetate, the active ingredient in the approved therapy Copaxone, which also is available in generic formulations. But while Copaxone and its generics are given as a subcutaneous (under-the-skin) therapy either three times per week or once per day, GA Depot is delivered intramuscularly (into the muscle) once a month. The regulatory agency now will review the companies' application for the 40 mg dose of GA Depot, with a decision expected by March 8, 2024. "We believe, when approved, GA Depot could improve patient experience through fewer injections, greater tolerability and increased compliance," Rajiv Malik, president of Viatris, said in a company press release. "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." GA Depot was first created by Mapi, which is now co-developing it with Viatris for relapsing forms of MS. It contains extended-release microspheres, tiny particles that release small amounts of glatiramer acetate over an extended period of time. This helps the therapy remain at therapeutic levels in the bloodstream for longer, enabling less frequent dosing than with Copaxone. Data from a Phase 3 clinical trial supported application. The application to the FDA was supported by data from a Mapi-sponsored Phase 3 clinical trial (NCT04121221) involving 1,016 people, ages 18-55, with relapsing-remitting MS or active secondary progressive MS. Participants who had experienced at least one relapse in the year prior to the study or two relapses in the previous two years were randomly assigned to receive 40 mg GA Depot or a placebo once per month for a year (13 injections). GA Depot reduced relapse rates by 30.1% compared with a placebo, meeting the trial's main goal. The effect of the therapy on relapses was similar to findings from previous trials of Copaxone. The treatment also was associated with reductions in inflammatory lesions and new and enlarging brain lesions, as well as a slowing of disability accumulation. Safety findings were similar to those seen with Copaxone and generics. The most common side effect was injection site reactions, most of which were mild. According to the companies, injection site reactions were fewer than with other glatiramer acetate products. Most participants (93.4%) then opted into an open-label extension phase, where all were treated with GA Depot for another year. "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," said Ehud Marom, CEO and chairman of Mapi. Meanwhile, GA Depot also is being investigated as a potential treatment for primary progressive MS (PPMS). An open-label Phase 2 clinical trial (NCT03362294) was launched in 2017 to evaluate GA Depot's safety, effects on disability progression, and changes in brain volume over about three years among 30 adults with PPMS, ages 18-65. Interim one-year trial results presented last year demonstrated that GA Depot was safe and patient disability was stable, with no evidence of disability progression in most treated after one year.