Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not yet recruitingRare disease

Phase 3 Randomized Double‑Blind Placebo‑Controlled Study of Intravenous sgt-003 in Ambulatory Male Patients with Duchenne Muscular Dystrophy

Verified siteInvestigational
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

The study focuses on Duchenne muscular dystrophy, a rare genetic condition that causes progressive weakening of the muscles, especially those used for walking and breathing. The investigational product is SGT-003, a form of gene therapy designed to deliver a functional copy of the missing protein to muscle cells. The medication is given as a single intravenous infusion, meaning it is delivered directly into a vein through a drip. A matching infusion of normal saline is used as a placebo for comparison. The purpose of the study is to determine whether this single dose can improve muscle function compared with placebo.

Participants who join the trial receive the assigned infusion and then return for regular check‑ups over the next 18 months. During these visits, simple tests are performed to measure how quickly a person can stand up, walk a short distance, climb stairs, and breathe fully. A small wearable device may be used to record walking speed in everyday life. Blood and muscle samples may be taken to look for the presence of a protein called microdystrophin, which the therapy is meant to produce. Safety is also monitored by recording any side effects, checking heart rhythm with an ECG, and listening to the lungs with an echo.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline assessments

    after you join the study, a series of baseline measurements are taken to record your current muscle function and lung capacity.

    these include a timed test of how quickly you can stand up, a walk/run speed test, a stair‑climb test, a questionnaire about daily activities, and breathing tests such as forced vital capacity (fvc) and forced expiratory volume in 1 second (fev1).

  2. Step 2

    Randomization

    based on the baseline data, you are randomly assigned to receive either the study drug sgt-003 or a placebo (normal saline).

    the assignment is double‑blind, meaning neither you nor the study staff know which treatment you receive.

  3. Step 3

    Single intravenous infusion

    on the day of infusion you receive a single dose through a vein.

    if you are assigned to the active group, the infusion contains sgt-003 at a dose of 100000000000000 units, prepared as a suspension for iv infusion.

    if you are assigned to the placebo group, the infusion contains normal saline (0.9% sodium chloride) with no active drug.

    the infusion is administered once, and the rate is controlled by the study staff.

  4. Step 4

    Immediate post‑infusion monitoring

    after the infusion you are observed for several hours.

    vital signs such as heart rate, blood pressure, and breathing are checked, and any side effects are recorded.

  5. Step 5

    Day 90 follow‑up visit

    about three months after the infusion you return for a follow‑up visit.

    the visit includes blood tests to measure the amount of microdystrophin protein produced by the gene therapy and to assess its distribution in muscle tissue.

    safety is also evaluated by recording any adverse events that have occurred since the infusion.

  6. Step 6

    Day 540 comprehensive assessment

    approximately fifteen months after the infusion you attend a comprehensive assessment visit.

    muscle function is re‑evaluated using the same tests performed at baseline: time to rise, stride velocity measured by a wearable device, 10‑meter walk/run speed, 4‑stair climb speed, and the north star ambulatory assessment (nsaa) score, which rates overall ambulatory ability.

    lung function is measured again with % predicted forced vital capacity (fvc) and % predicted peak expiratory flow (pef).

    the patient‑reported outcome questionnaire (podi) is completed to capture quality‑of‑life changes.

    all safety information, including any treatment‑emergent adverse events, serious adverse events, and events of special interest, is collected and reviewed.

Who can join the trial?

11 criteria

  • Be between 7 and less than 12 years old.
  • Be able to understand what the study asks and follow the instructions, with help from a parent or legal guardian who also understands and agrees to the study.
  • If you could have children in the future, you and your partner must agree to use two very reliable birth‑control methods for one year after receiving the study drug.
  • Be able to walk on your own without using a cane, walker, or other assistive device. (Ambulatory means walking without help.)
  • Have a confirmed diagnosis of Duchenne muscular dystrophy (DMD) and a known change in the dystrophin gene that causes this condition.
  • Test negative for antibodies against AAV (a type of virus that could affect the study medication).
  • Take a stable dose of the steroid medicines prednisone (at least 0.5 mg per kilogram of body weight each day) or deflazacort (at least 0.75 mg per kilogram each day) for at least the past six months, without major changes.
  • Pass the required test of how fast you can walk or run 10 meters (about 33 feet).
  • Pass the required test of how quickly you can get up from lying on your back.
  • Weigh 50 kilograms (about 110 pounds) or less.
  • Be genetically male (have male sex chromosomes).

Who cannot join the trial?

13 criteria

  • If you have any other health problem or physical finding that the doctor believes could make the study unsafe, stop you from finishing it, or affect the results, you cannot join.
  • If you have had a severe allergic reaction (including a life‑threatening reaction called anaphylaxis) to the study drug or any of its ingredients, you cannot join.
  • If you have already received or are currently receiving any gene therapy (a treatment that changes your DNA) or a gene‑editing therapy, you cannot join.
  • If you have taken certain other medicines for Duchenne muscular dystrophy (such as vamorolone, givinostat, eteplirsen, golodirsen, casimersen, viltolarsen, or ataluren) or any other experimental drug within the past 6 months (or longer if the drug stays in the body for a long time), you cannot join.
  • If you have an active infection (a current illness caused by bacteria, viruses, or other germs), you cannot join.
  • If you have had major surgery within the last 3 months, or plan to have surgery during the study that could affect your ability to do the muscle tests, you cannot join.
  • If your genetic test shows a specific type of Duchenne muscular dystrophy that lacks certain parts of the DMD gene (missing exons 1‑11, 42‑45, or 57‑69), you cannot join.
  • If you are an employee of the study sponsor or a family member of an employee, you cannot join.
  • If you have known liver disease, an active viral hepatitis infection, or abnormal liver test results, you cannot join.
  • If you have abnormal kidney function (the kidneys are not working properly), you cannot join.
  • If you have significant problems with blood clotting (coagulation), you cannot join.
  • If you have impaired heart function (cardiovascular problems), you cannot join.
  • If your lung function is so reduced that you need daytime breathing support (a ventilator) outside of a short‑term illness, you cannot join.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

SGT-003 is an experimental drug being tested in a single intravenous infusion. It is given as a liquid suspension that is slowly mixed into the bloodstream through an IV line. In this study, researchers are looking to see if one dose of SGT-003 can improve muscle strength and function in ambulant males who have Duchenne muscular dystrophy. The medication is compared with a saline solution, but only the active drug is described here.

What is already known about the treatment

  • SGT-003

    This medication is given as a sterile suspension that is infused into a vein (intravenous infusion). It is currently an investigational drug being studied in Phase 3 clinical trials and has not yet been approved for general medical use. The main aim is to help boys with Duchenne muscular dystrophy by supporting the missing muscle protein that keeps muscles strong. It works by delivering a specially designed molecule that replaces or repairs the defective protein inside muscle cells, and it is classified as an experimental biologic therapy.

  • Normal saline (0.9% sodium chloride) for infusion

    This product is a clear, sterile salt‑water solution that is administered through an IV line. It is a well‑established, approved medical fluid used worldwide for hydration and as a control (placebo) in studies. Its purpose is to provide the body with water and normal levels of sodium and chloride, without any active drug effect. It belongs to the class of isotonic crystalloid solutions.

Investigated diseases

Duchenne muscular dystrophy - Duchenne muscular dystrophy is a genetic disorder that primarily affects boys and leads to muscle weakness. It appears in early childhood, often before age five, with difficulty walking and climbing stairs. The weakness spreads from the legs to the arms and torso over time. Muscles become less able to contract, causing slower movements and reduced endurance. Heart and breathing muscles may also become weaker as the condition advances.
Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase IIITrial ID2025-522949-22-00Protocol codeSGT-003-301Estimated enrolment114 patientsSponsorSolid Biosciences Inc.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.