Sarcomed develops treatments for Duchenne muscular dystrophy and related conditions, using active substances with established human clinical use. Our programs share one measurable idea: more working muscle, and less fat within it.
The unmet need
In Duchenne muscular dystrophy and related conditions, fragile muscle fibres are damaged during everyday use. Over time the body can no longer repair them, and working muscle gives way to fat and fibrous tissue.
Strength, walking, arm function and breathing decline as a result. Current therapies address parts of this process, but preserving the amount of working muscle remains a major unmet need.
Approach
Muscle fat fraction is the share of fat within a muscle, measured with quantitative MRI. In Duchenne muscular dystrophy it rises as the disease progresses, and in natural history studies a higher fat fraction has been associated with later loss of function.3
Our hypothesis is that treatments which increase contractile muscle lower muscle fat fraction, because fat fraction is a ratio, and that this slows functional decline. MRI muscle fat fraction is under evaluation in FDA’s Biomarker Qualification Program, based on work by the ImagingDMD consortium.5
Fat fraction = fat ÷ (fat + water)
Illustrative arithmetic: fat signal held constant at 34, muscle signal starting at 66. Not clinical data.
Anabolic and growth signalling raises muscle protein synthesis and fibre size.
As contractile tissue grows, the fat share of each muscle falls on quantitative MRI.
Assessed with established motor function scales alongside imaging.
Every active substance in our portfolio has been studied in people, which informs dose selection and safety monitoring from the start.
For established substances we use pathways such as 505(b)(2), which allow reference to existing data where scientifically justified.
An FDA Orphan Drug Designation can provide seven years of US market exclusivity for the designated indication upon approval.
Clinical evidence
Each study used an active substance in our portfolio. Results from published studies may not predict the outcome of future clinical trials.
Wood et al., 2021. Open-label study, n = 15.1
In natural history cohorts, muscle fat fraction in DMD typically increases over a comparable period.3
Rutter et al., 2020. Controlled study.2
Native rhIGF-1 needs twice-daily injections, and six-minute walk distance did not change significantly. SAR-101 is being developed to provide sustained exposure.
Kletzl et al., 2017. Phase 1 study.4
Schematic exposure profiles, not to scale.
Pipeline
Our portfolio covers 16 rare disease indications. One designation includes both Duchenne and Becker muscular dystrophy.
| Indication | Substance | FDA orphan designation | DesignationPlanningClinicalRegistration |
|---|---|---|---|
| IGF-1SAR-101, long-acting PEGylated IGF-1 | |||
| Duchenne muscular dystrophy (DMD)LeadMuscle mass and muscle fat fraction | SAR-101 | 10 Jan 2022 |
|
| Myotonic dystrophy type 1 (DM1)Muscle protein synthesis and insulin signalling | SAR-101 | 26 Jun 2025 |
|
| Spinal muscular atrophy (SMA)Muscle support independent of SMN | SAR-101 | 23 Jul 2025 |
|
| Amyotrophic lateral sclerosis (ALS)Motor neuron and muscle trophic support | SAR-101 | 22 Jul 2025 |
|
| Spinal and bulbar muscular atrophy (SBMA)Kennedy’s disease, without androgen receptor activation | SAR-101 | 21 Jun 2023 |
|
| Congenital muscular dystrophy (CMD)Muscle growth in early-onset disease | SAR-101 | 11 Apr 2022 |
|
| Phelan-McDermid syndrome (PMS)SHANK3-related neurodevelopment | SAR-101 | 18 Jul 2024 |
|
| AndrogensTestosterone and nandrolone | |||
| Duchenne muscular dystrophy (DMD)Contractile muscle area and puberty | Testosterone | 12 Jan 2022 |
|
| Duchenne and Becker muscular dystrophy (DMD/BMD)Skeletal muscle mass | Nandrolone | 13 Jun 2017 |
|
| Limb-girdle muscular dystrophy (LGMD)Hip and shoulder girdle muscle | Nandrolone | 4 Dec 2019 |
|
| Facioscapulohumeral muscular dystrophy (FSHD)Asymmetric muscle loss | Nandrolone | 6 Jan 2022 |
|
| PrednisoneOptimising an established corticosteroid | |||
| Duchenne muscular dystrophy (DMD)Anti-inflammatory standard of care | Prednisone | 13 Jul 2022 |
|
| Limb-girdle muscular dystrophy (LGMD)Immune-mediated muscle damage | Prednisone | 5 Mar 2024 |
|
| Myasthenia gravis (MG)Autoimmune neuromuscular junction disease | Prednisone | 12 Mar 2024 |
|
| Chronic inflammatory demyelinating polyneuropathy (CIDP)Autoimmune peripheral nerve disease | Prednisone | 20 Mar 2024 |
|
Designation dates are those of the FDA Office of Orphan Products Development. Stages reflect Sarcomed’s own development activities; hatched segments show where published clinical data on the active substance exist.
Our clinical plans pair functional outcomes with quantitative MRI. Functional measures are matched to each population, such as the North Star Ambulatory Assessment for boys who walk and Performance of the Upper Limb for those who no longer do.
MRI muscle fat fraction adds an objective measure of muscle composition. Final study designs will be agreed with regulatory authorities.
Science
Our programs act on the signalling pathways that control muscle protein synthesis, muscle breakdown and tissue remodelling.
IGF-1 binds its receptor on muscle cells and activates the PI3K–Akt pathway. Akt increases protein synthesis through mTOR and blocks FOXO transcription factors, which otherwise switch on the muscle-wasting genes MuRF1 and atrogin-1.
Preclinical studies suggest Akt can also dampen TGF-β–Smad3 signalling, a driver of fibrosis in dystrophic muscle. SAR-101 is a long-acting form of IGF-1 designed to sustain this signalling with once-weekly dosing.
Corticosteroids are standard care in Duchenne muscular dystrophy, but long-term use contributes to muscle breakdown, delayed growth, weight gain and bone loss.
Glucocorticoids activate FOXO-driven atrophy programs and suppress the growth hormone and IGF-1 axis. Restoring IGF-1 signalling is designed to counter these effects. In a controlled study in boys with DMD, rhIGF-1 nearly doubled height velocity compared with controls.2
Our prednisone programs focus on optimising the use of an established therapy in DMD, limb-girdle muscular dystrophy, myasthenia gravis and CIDP.
Testosterone and nandrolone act through the androgen receptor to increase muscle protein synthesis and fibre size.
Delayed puberty is common in boys with DMD on long-term corticosteroids. In an open-label study, testosterone treatment was accompanied by stable muscle fat fraction and larger contractile muscle area over two years.1
Androgens also support bone growth, which matters in a population at high risk of fractures.
Spinal and bulbar muscular atrophy, also called Kennedy’s disease, is caused by an expanded CAG repeat in the androgen receptor gene. The altered receptor becomes toxic when activated by androgens, so androgen therapy is not appropriate in SBMA.
In preclinical models, IGF-1 signalling through Akt reduced the toxicity of the mutant receptor and supported muscle without activating the androgen receptor. This is why our SBMA program uses IGF-1.
Patients & Families
Families living with rare neuromuscular disease deserve reliable, honest information. We will keep this section up to date as our programs progress.
When Sarcomed starts a clinical study, it will be listed here, on ClinicalTrials.gov and in the EU Clinical Trials Information System, with details on who can take part.
Search ClinicalTrials.govOur treatments are investigational and not approved. Our policy on requests for access outside clinical trials will be published here.
Ask a questionWe welcome contact with patient organisations and advocacy groups, and value their input as we plan our studies.
Get in touchWe cannot give individual medical advice. Please speak with your treating physician about treatment decisions.
About
Sarcomed was founded in Stockholm in 2014 to develop treatments for people living with rare neuromuscular diseases. We build on active substances with human clinical history and focus our resources on the clinical and regulatory work needed to reach patients.
Founder and Chief Executive Officer
Filmon has almost two decades of experience in biotech, spanning CMC and regulatory affairs. He built Sarcomed’s portfolio of 15 FDA Orphan Drug Designations across 16 rare disease indications, and also advises companies as a regulatory consultant with Cleracs Consulting in Boston.
Chair of the Board
Dr. Solomon Wan is a physician and Specialist in General Medicine within the Region Stockholm public primary healthcare system. She brings extensive frontline clinical diagnostic and patient-care experience, combined with hands-on background as a clinical investigator at Karolinska Trial Alliance conducting GCP-compliant clinical trials.
Partner with us
We partner with biopharmaceutical companies and life science investors.
Joint development of SAR-101 in Duchenne muscular dystrophy through a pivotal study.
Development and commercial rights by territory, including the US, Europe and Japan.
Equity investment in Sarcomed or in program-specific structures.