Satellos Bioscience’s oral Duchenne muscular dystrophy (DMD) drug has increased upper limb activity in four patients in a Phase II trial.
In the TRAILHEAD study (NCT06867107), an open-label long-term follow-up study for those who participated in the Phase Ia/b CL-101 trial (NCT06565208), patients continued to receive SAT-3247, an oral small molecule which targets adapter-associated kinase 1 (AAK1).
Go deeper with GlobalData
Discover B2B Marketing That Performs
Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.
It is thought that by targeting AAK1, biochemical signalling can be modulated to allow muscle stem cells to divide properly and regenerate functional muscle.
Treatment continued for a further 11 months, making it a full 12-month dosing cycle, including the Phase Ia/Ib portion.
Six-month interim data from four patients enrolled in the ongoing TRAILHEAD trial has found reduced muscle fat fraction, increased total effort, stable strength, lower CK, and a safety and tolerability profile consistent with previously reported data.
All four patients showed a decline in muscle fat fraction as measured by MRI, with a mean improvement of 3.7% from 49.7% at TRAILHEAD baseline to 46.0% at month six, suggesting improved muscle composition.
An increase in TE99C, a measure of maximum effort in the upper limbs assessed using SYSNAV Syde, a wearable device widely used in clinical trials to track patient movement in real-world settings, was also observed. There was a mean improvement of approximately 34% from a CL-101 baseline of 16.1 joules/kg to 21.6 joules/kg at TRAILHEAD month six, suggesting enhanced upper limb activity.
The mean performance of the upper limb 2.0 (PUL2.0) score increased by one point in two patients and remained stable in two patients from TRAILHEAD; however, Satellos touts that natural history data for patients with DMD would ordinarily see upper limb function decline over time, making stability notable.
Across all measures of upper extremity strength (muscle force), including handgrip and handheld dynamometry of the elbow and shoulder, patients demonstrated stability through the end of six months of treatment.
The near-doubling of handgrip strength reported during the 28-day CL-101 study was maintained through to the end of month six of the TRAILHEAD follow-up period.
The drug remained well tolerated, with the safety profile being consistent with previously reported data, with no serious treatment-emergent adverse events (TEAEs) and no TEAEs leading to withdrawal or discontinuation.
The TRAILHEAD study is expected to enrol up to 30 male patients in Australia and the US aged 16 years and over with a definitive diagnosis of DMD and a confirmed mutation in the DMD gene.
In the ongoing trial, patients receive a 60mg dose of SAT-3247, which is administered orally using a five-days-on, two-days-off dosing regimen.
Meanwhile, the BASECAMP study is a global, Phase II, randomised, double-blind, placebo-controlled, proof-of-concept trial (NCT07287189) of SAT-3247 in ambulatory boys with DMD aged seven to nine years.
The study includes an initial 12-week randomised, double-blind, placebo-controlled treatment period, followed by a 36-week active-treatment period in which all patients will receive SAT-3247.
Following the TRAILHEAD update, Satellos’ stock was up 9.37% from a 7 July close of $8.21 to an 8 July close of $8.98. The company, which is listed on the Nasdaq exchange, has a market cap of $187m.
DMD landscape steering toward gene therapies
Satellos’ work in DMD marks a divergence from general pipeline trends. A significant number of recent approaches for DMD have been with gene therapy treatments, including Roche and Sarepta’s approved therapy Elevidys (delandistrogene moxeparvovec-rokl).
While the one-and-done approach is convenient for DMD patients, both the cost and some safety concerns are impacting the uptake of gene therapies.
When launched, Sarepta and Roche confirmed Elevidys would carry a US list price of approximately $3.2m per infusion. Costs vary globally; however, for instance, it is priced at JPY304,972,042, which is just shy of $2m, in Japan.
This creates a significant barrier, as while insurance plans will cover some of this cost, a significant out-of-pocket expense will still be required by patients.
There have also been some safety concerns with adeno-associated virus (AAV)-based gene therapies, with several specifically reported with Elevidys. The therapy was linked to two non-ambulatory patient deaths in mid-2025. This led to a label change for Elevidys’ use only in ambulatory DMD patients, along with a boxed warning.
Elevidys is not the only gene therapy to have been associated with safety concerns and patient fatalities. Pfizer also reported a fatality in the Phase II DAYLIGHT trial (NCT05429372) evaluating its DMD gene therapy fordadistrogene movaparvovec, with a three-year-old boy having suffered a cardiac arrest. Pfizer has now discontinued development of the gene therapy after it also failed to show benefit in a Phase III trial.
Research by GlobalData estimates that across the seven major markets (7MM: US, France, Germany, Italy, Spain, the UK, and Japan), the market for DMD treatments is expected to rise from sales of $2.3bn in 2023 to $5.2bn by 2033, driven heavily by sales of Elevidys and Santhera Pharmaceuticals’ Agamree (vamorolone).
Speaking in February 2025, at the time of the analysis, Asiyah Nawab, healthcare analyst at GlobalData, said: “The DMD treatment landscape is evolving with the emergence of novel therapies such as exon-skipping and gene therapies. However, gene therapies in particular, compared to exon-skipping, will have less of an impact due to the small patient share eligible for treatment, in addition to the high cost of these medicines limiting patients’ access. By 2033, GlobalData forecasts gene therapies to contribute $821m to the DMD market, a lower figure relative to exon-skipping therapies.”
GlobalData is the parent company of Clinical Trials Arena.
