Aro Biotherapeutics Reports Preliminary Efficacy for ABX1100, a Muscle-targeted GYS1 siRNA, in Patients with Late-Onset Pompe Disease (LOPD)

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PHILADELPHIA--(BUSINESS WIRE)--Feb 5, 2026--

Aro Biotherapeutics, a clinical-stage biotechnology company developing potent and tissue-targeted short-interfering RNA (siRNA) medicines, today announced interim data from a phase 1b study of ABX1100, a novel investigational therapy for the treatment of late-onset Pompe disease (LOPD). ABX1100 was well tolerated in the study of normal healthy volunteers (NHVs, n=29) and patients with LOPD (n=9). The data were presented in an oral session at the 22 nd annual WORLD Symposium in San Diego, California. (The session poster is available on Aro’s website, here.)

“The sustained knockdown of GYS1 mRNA in muscle, as demonstrated in this phase 1b trial in patients, and in the earlier phase 1 trial in healthy volunteers, provides proof of principle that GYS1 inhibition may be a viable therapeutic approach in patients with late-onset Pompe disease, and a source for hope for the Pompe community,” said Purnanand Sarma, Ph.D., chief executive officer of Aro Biotherapeutics. “We look forward to additional analyses from this ongoing trial as we continue our efforts to measure the clinical potential of GYS1 inhibition as an option for patients in need of new therapeutic approaches to Pompe disease.”

ABX1100 was administered, over a 20-minute infusion, on Days 1 and 29 with 20 weeks of follow-up. ABX1100 was administered as add-on to enzyme replacement therapy (ERT) in the nine patients with LOPD, whose mean age was 54 years at study initiation and 45 years at diagnosis; participants had been receiving ERT for a range of 1-15 years. Muscle biopsies were collected per protocol at Weeks 6 and 10 for the first four patients, and at Weeks 10 and 16 for the next five patients, to investigate persistence of glycogen synthase 1 ( GYS1 ) messenger RNA (mRNA) knockdown. ABX1100 was detected in the muscle tissue at 10 weeks in the first four patients tested so far. Interim data from these patients revealed robust and sustained GYS1 mRNA knockdown in the quadriceps muscle at Week 6 persisting through Week 10, similar to that observed in NHVs and achieving the targeted level of knockdown. These data suggest the potential for quarterly or less frequent dosing.

ABX1100 was generally well tolerated with no dose interruptions, no dosing discontinuations, no withdrawals, and no reports of serious adverse events (SAEs).

In addition to the safety and pharmacodynamic effect of ABX1100, the study assessed the drug’s effect on exploratory biomarkers. Interim biomarker data from the first four participants showed reductions in creatine kinase (CK, a biomarker for muscle damage) by Week 10, while three of the four experienced reductions in the Pompe disease biomarker Hex4 (glucose tetrasaccharide, or Glc4) by Week 10. Evaluation of the next five patients dosed is ongoing, with muscle biopsies obtained at later time periods to better understand the persistence of the mRNA knockdown observed to date.

“Many patients with Pompe disease endure a significant loss of strength and independence, a burden compounded by the limited muscle-specific uptake of enzyme replacement therapy, the current standard of care,” noted Ozlem Goker-Alpan, M.D., president of the Lysosomal and Rare Disorders Research and Treatment Center in Fairfax, Va., who presented the data at the WORLD Symposium. “Our study is the first to demonstrate the effect of a substrate reduction therapy in patients with late-onset Pompe disease. The favorable safety profile, predictable pharmacokinetics, GYS1 mRNA knockdown, and biomarker reductions support further development of ABX1100 as an addition or alternative to ERT in patients with late-onset Pompe disease.”

More information about the Phase 1b trial of ABX1100 is available at ClinicalTrials.gov, using the ID no. NCT06109948.

About ABX1100
ABX1100, an investigational treatment for Pompe disease, is comprised of a CD71 receptor-binding Centyrin conjugated to a short-interfering RNA (siRNA) that specifically interferes with expression of GYS1 messenger RNA (mRNA), thereby reducing levels and overall activity of GYS1, the enzyme responsible for glycogen production, in muscle tissues. ABX1100 has received Orphan Drug Designation and Rare Pediatric Disease status from the United States Food and Drug Administration.

About Pompe Disease
Pompe disease is a rare neuromuscular disorder caused by a genetic deficiency of the enzyme acid alpha-glucosidase (GAA), which leads to a toxic buildup of glycogen in the muscle. This buildup leads to progressive loss of muscle function, weakness, and disability that can eventually progress to death from respiratory failure. 1 Late-onset Pompe disease (LOPD) is a subtype of Pompe that has onset after the first year of life. The current standard of care for LOPD is enzyme replacement therapy (ERT), which aims to restore genetically deficient enzymes. Despite the availability of ERT, significant unmet need remains due to limited ERT efficacy and burden of care. ERT requires intravenous infusions that can last as long as 6 hours, multiple times a month.

About Aro Biotherapeutics
Aro Biotherapeutics is a biotechnology company working to develop potent and versatile tissue-targeted short-interfering RNA (siRNA) medicines for the treatment of immune-mediated diseases and diseases with high unmet medical need. The company is developing a wholly owned pipeline of therapeutic candidates for a diverse set of diseases, employing a proprietary protein technology called Centyrins, which are small proteins engineered for exceptional efficiency, versatility, and safety. For more information, visit https://www.AroBiotx.com/.

Reference

1. Pompe disease. MedlinePlus. U.S. Department of Health and Human Services, National Institutes of Health, National Library of Medicine; 2016. https://medlineplus.gov/genetics/condition/pompe-disease/. Accessed January 29, 2026.

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