At the start of the trial, baseline measurements will be taken. These measurements will serve as a reference point to compare changes throughout the trial.

Baseline assessments include muscle force measurements using a device called a dynamometer, which measures how strong your muscles are.

Additional baseline tests include imaging of leg muscles using magnetic resonance imaging (a scan that creates detailed pictures of muscles), lung function tests using spirometry (a test that measures how well your lungs work), and functional assessments such as the NSAA (North Star Ambulatory Assessment, which evaluates your ability to perform daily movements).

A small sample of muscle tissue from the upper arm will be taken through a procedure called a muscle biopsy. This allows doctors to examine the muscle cells under a microscope.

Blood samples will be collected to measure certain substances in your blood, including creatine kinase (an enzyme that can indicate muscle damage) and inflammatory cytokines (proteins that show inflammation levels in the body).

You will be randomly assigned to receive either SAT-3247 or placebo. A placebo looks like the actual medication but contains no active ingredient.

Neither you nor the study doctors will know which treatment you are receiving. This is called a double-blind trial.

The medication comes in tablet form and is taken by mouth.

There are two possible doses of SAT-3247: 10 mg tablets or 50 mg tablets. The specific dose and number of tablets you will take depends on which treatment group you are assigned to.

You will take the tablets daily for the duration of the treatment period.

The treatment period lasts for 12 weeks.

During this time, you will continue taking your assigned tablets every day.

You must maintain stable doses of any other medications you are taking, including glucocorticoids (steroids such as prednisolone, deflazacort, or vamorolone), heart medications, and any supplements.

If you are participating in physical therapy or strength training, you must continue the same routine throughout the trial without changes.

Regular monitoring visits will occur during this period to check your safety and how you are responding to treatment.

Throughout the 12-week treatment period, you will be monitored for any side effects or changes in your health.

Safety assessments include physical examinations, blood tests to check how your organs are functioning, measurements of vital signs (such as blood pressure and heart rate), and electrocardiograms (tests that measure the electrical activity of your heart).

A questionnaire called the C-SSRS (Columbia-Suicide Severity Rating Scale) will be used to assess your mental well-being.

Any adverse events, meaning any unwanted or unexpected health problems, will be recorded and evaluated to determine if they are related to the study medication.

At the end of the 12-week treatment period, the same assessments performed at baseline will be repeated.

Muscle force will be measured again using the dynamometer to see if there have been any changes compared to the beginning of the trial.

Muscle imaging using magnetic resonance will be performed again to measure changes in intramuscular fat fraction (the amount of fat within the muscle) and T2 relaxation time (a measure that can indicate muscle damage or inflammation) in the thigh muscle.

Another muscle biopsy will be taken from the upper arm to examine changes in muscle cells, including muscle fiber size, the presence of new muscle cells, and levels of scarring or fat tissue in the muscle.

Functional assessments such as the NSAA and SV95C (a test measuring speed and velocity during climbing stairs) will be repeated.

Lung function will be tested again using spirometry.

Blood samples will be collected to measure changes in creatine kinase and inflammatory cytokines.