Satellos submits SAT-3247 IND to FDA for phase 2 study in children with Duchenne muscular dystrophy | Image credit: Contemporary Pediatrics

On September 22, 2025, Satellos Bioscience submitted an Investigational New Drug (IND) application to the FDA to initiate a phase 2 clinical trial of SAT-3247 in ambulatory children with Duchenne muscular dystrophy (DMD), according to a press release from the company. Parallel regulatory submissions were also filed in the United Kingdom, Europe, Serbia, and Australia. The trial is designed to evaluate the safety, tolerability, and efficacy of SAT-3247, an oral small-molecule therapy aimed at restoring impaired muscle regeneration in DMD.¹

“Filing our Phase 2 clinical trial submissions in the US and globally marks a major milestone for Satellos in advancing SAT-3247’s potential to treat Duchenne in a novel way,” said Satellos Co-Founder and CEO Frank Gleeson. “Current therapies do not address the fundamental challenge in Duchenne, which we have identified — the body’s impaired muscle-repair process. With SAT-3247, our goal is to re-boot that regenerative cycle with the potential to restore muscle, improve functional outcomes, and truly change lives.”

SAT-3247 study design for children with DMD

The planned phase 2 trial will be a 3-month, randomized, placebo-controlled study enrolling ambulatory children with DMD in the United States, pending FDA clearance, and internationally, following additional regulatory approvals. Outcomes will include safety and tolerability assessments, pharmacokinetics, dosing, muscle biopsies, and measures of function in ambulatory children. A 9-month, open-label extension is also planned, allowing participants to continue receiving SAT-3247 beyond the controlled study period.

SAT-3247 is being developed as a dystrophin-independent therapy, making it potentially applicable across all exon mutation types. The therapy is designed to target the underlying defect in muscle regeneration observed in DMD. SAT-3247 aims to directly restore the body’s ability to regenerate muscle.

SAT-3247 data in adults

In a recently completed Phase 1b study involving 5 adults with DMD, SAT-3247 demonstrated safety and tolerability, with pharmacokinetics comparable to healthy volunteers.^1,2

Exploratory endpoints included grip strength, measured with the MyoGrip device. Across participants, grip strength approximately doubled over 28 days, rising from ~2 kg to ~4 kg on average. Other exploratory measures appeared stable during the study period. Investigators noted this finding aligns with preclinical results, where SAT-3247 increased muscle force in rodent and canine models of DMD.²

Based on these results, Satellos has launched an 11-month extension study in Australia, incorporating MRI assessments and quarterly grip strength measurements to determine whether improvements are durable.

“We have gained valuable insights from this study of SAT-3247, and we are deeply grateful to the participants,” said Gleeson at the time of the adult data announcement in May 2025. "Given the short 28-day treatment window, the severity and variability of disease in this population, who have limited remaining muscle, we are encouraged by these initial data—particularly, the apparent trend of improved grip strength. Improvements in muscle strength have consistently been an early signal of a possible drug effect in our preclinical studies, where treatment with SAT-3247 led to notable increases in muscle force in both rodent and canine models of DMD."

References:

1. Satellos announces IND submission to the US FDA and global regulatory filings to advance a phase 2 clinical trial of SAT-3247 in children with Duchenne muscular dystrophy. Satellos Bioscience. Press release. September 22, 2025. Accessed September 22, 2025. https://www.businesswire.com/news/home/20250922219476/en/Satellos-Announces-IND-Submission-to-the-U.S.-FDA-and-Global-Regulatory-Filings-to-Advance-a-Phase-2-Clinical-Trial-of-SAT-3247-in-Children-with-Duchenne-Muscular-Dystrophy
2. Satellos announces encouraging functional data from the 28-day phase 1b open-label trial of SAT-3247 in adults with Duchenne muscular dystrophy. Satellos Bioscience. Press release. May 22, 2025. Accessed September 22, 2025. https://ir.satellos.com/news/news-details/2025/Satellos-Announces-Encouraging-Functional-Data-from-the-28-day-Phase-1b-Open-Label-Trial-of-SAT-3247-in-Adults-with-Duchenne-Muscular-Dystrophy/default.aspx