ACTRIMS 2026: GA Depot shot keeps disability stable for most PPMS patients
Three-year data show most participants experienced no disease progression
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- GA Depot, a monthly injection, shows promise for primary progressive multiple sclerosis (PPMS).
- A 3-year trial found GA Depot stabilized disability in most PPMS patients, with some mobility improvements.
- The 25 mg dose of GA Depot was safer and as effective as 40 mg for PPMS, supporting future trials.
A three-year study of GA Depot, a monthly injection for primary progressive multiple sclerosis (PPMS), found that most patients experienced no disability progression, with some even showing slight improvements in mobility.
These interim results from a Phase 2a clinical trial will be presented tomorrow by developer Mapi Pharma at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2026. The poster is titled “Glatiramer Acetate Depot (Extended-Release) Phase IIa Study in Patients with Primary Progressive Multiple Sclerosis: Safety and Efficacy.”
The data suggest that the experimental long-acting formulation of glatiramer acetate (the active ingredient in Copaxone) may offer a new lifeline to a patient population with very few treatment options.
“We are very excited to share these positive results for GA Depot in the treatment of PPMS, where there is a significant unmet medical need,” Ehud Marom, chairman and CEO of Mapi, said in a company press release. “The new clinical results we are sharing this week at ACTRIMS demonstrate that GA Depot can significantly impact disease progression.”
Addressing the challenges of PPMS
“We believe this product, if approved, has the potential to transform the treatment landscape for PPMS, and we look forward to further evaluating GA Depot in the clinic for this indication,” Marom added.
Most people with multiple sclerosis (MS) are initially diagnosed with relapsing-remitting MS, which is marked by relapses where symptoms suddenly worsen, followed by periods of remission where symptoms ease. But about 15% of MS patients instead develop PPMS, which is marked by a gradual worsening of symptoms independent of relapse activity right from the onset of disease.
PPMS is much harder to treat than relapsing forms of MS. Whereas more than 20 disease-modifying therapies are approved in the U.S. for relapsing MS types, only Ocrevus (ocrelizumab) and Ocrevus Zunovo (ocrelizumab and hyaluronidase-ocsq) are indicated for use in people with PPMS.
GA Depot is a long-acting formulation of glatiramer acetate, a compound that is already approved for relapsing forms of MS under the brand name Copaxone (generics are also available). Whereas available versions of glatiramer acetate are injected under the skin daily or three times per week, GA Depot is designed to be given into the muscle once per month.
An open-label Phase 2 clinical trial (NCT03362294) is investigating this glatiramer acetate formulation in 30 adults with PPMS. Among them, 10 are being treated with GA Depot at a low dose (25 mg), while the other 20 are getting a higher dose (40 mg). Treatment will be given for up to 148 weeks, or nearly three years.
The trial’s main goal is to evaluate the safety of GA Depot in people with PPMS. The interim analysis covered different treatment durations due to study termination, but some patients were treated for up to three years.
Safety data have been generally positive: most reported side effects were mild, and no unexpected side effects were reported. Still, one patient given the higher dose experienced a serious safety issue judged as possibly related to treatment. The researchers noted that safety issues were generally more common with the higher dose.
Stability and improvement in disability scores
Data also indicated that disability has remained largely stable over three years. One of the 30 patients has experienced 12-week confirmed disability progression — defined as an increase in Expanded Disability Status Scale (EDSS) scores that’s sustained for at least 12 weeks — since starting treatment.
Average EDSS scores decreased from 5.1 at the trial’s start to 4.5 at three years, which suggests disability has eased slightly, a notable contrast from the typical progression of PPMS, where disability worsens over time.
Other disability measures have also remained generally stable. Specifically, 89.7% of patients maintained stability on the nine-hole peg test, a measure of arm and hand dexterity, and 79.3% were stable on a test of walking speed.
Overall, 69% of patients had no confirmed progression on EDSS or other disability measures, and both tested doses showed comparable effects.
“Treatment with GA Depot was safe and associated with stable clinical disability,” the researchers concluded. “The 25 mg dose showed improved safety and tolerability compared with the 40 mg dose, while maintaining similar efficacy.”
The team added that these data provide support for evaluating this potential PPMS treatment in a Phase 3 clinical trial. Mapi plans to launch that trial this year, though the company has not shared details.
Mapi is also developing GA Depot in collaboration with Viatris as a potential treatment for relapsing forms of MS. The companies sought U.S. approval of the therapy for this indication in 2023, but the FDA decided not to approve it for reasons that have not been made public.
The Multiple Sclerosis News Today team is providing virtual coverage of the ACTRIMS Forum 2026 from Feb. 5-7. Go here to see the latest stories from the conference.
