Satellos Bioscience Inc.

TRAILHEAD Study

The TRAILHEAD study is designed to assess the long-term safety, tolerability and potential efficacy of a 60 mg dose of SAT-3247 with a weekday regimen in a 12-month, open-label study. There are two planned cohorts for the study, Cohort one consists of adult participants with DMD previously treated in the Phase 1b study noted above who will receive a 60 mg dose of SAT-3247 with a weekday regimen for 11-months (12-month total drug exposure). Cohort two will consist of participants with DMD between the ages of 16 and 25 years who have previously not been exposed to SAT-3247 who will receive a 60 mg dose of SAT-3247 with a weekday regimen for 12-months. The TRAILHEAD study will evaluate in both cohorts safety, strength measures, MRI fat fraction, SYSNAV physical effort and PUL 2.0.

Early in the second quarter of 2026, Satellos submitted the TRAILHEAD protocol to the FDAand following the statutory review period, Satellos began to engage with its planned clinical sites in the U.S. to identify participants with DMD aged 16 to 25 years. The Company plans to enroll up to 20 participants in the USA and up to 10 participants in Australia for a total of up to 30 participants.

As described above, on July 8, 2026, the Company announced six-month interim data from TRAILHEAD and the results, in four adults aged 21-28 who had previously completed the Phase 1a/b CL-101 study, showed reduced muscle fat fraction, increased total effort, stable strength, lower CK, and a safety and tolerability profile consistent with previously reported data.

The Company’s objective is to provide an update on the TRAILHEAD study in the fourth quarter of 2026.