A Study of SGT-003 Gene Therapy in Duchenne Muscular Dystrophy

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Solid Biosciences Inc.

Participant type

Pediatric, Patients

Age range

0-17 years

Gender

Male

Therapeutic area

Diseases [C] - Musculoskeletal Diseases [C05]

Trial duration

20 Jun 2025 → ongoing

Decision date (initial)

2025-01-27

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

Yes

Funding sources

Solid Biosciences Inc.

External identifiers

EU CT number

2024-514501-57-00

ClinicalTrials.gov

NCT06138639

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Pharmacokinetic, Safety, Pharmacodynamic, Efficacy, Therapy

To investigate the safety and tolerability of a single intravenous dose of SGT-003 and to investigate the efficacy of a single intravenous dose of SGT-003 by assessing microdystrophin expression in muscle biopsies.

Secondary objectives 10

1. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing microdystrophin expression in muscle biopsies.
2. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in ambulatory function in participants who are ambulatory at baseline.
3. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in pulmonary function in participants enrolled at 4 years of age and older.
4. To investigate the safety and tolerability of a single intravenous dose of SGT-003 by assessing changes in upper limb function in participants enrolled in Cohort 4 and Cohort 5.
5. To investigate the safety of a single intravenous dose of SGT-003 by assessing pharmacokinetics, shedding, and immunogenicity.
6. To investigate the safety and tolerability of a single intravenous dose of SGT-003.
7. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in cardiac structure and function in participants with a cardiac magnetic resonance imaging (MRI) at Screening Part A or Rescreening.
8. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in development in participants enrolled up to 30 months of age.
9. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in patient-reported outcomes in participants enrolled at 2 years of age and older.
10. To investigate the efficacy of a single intravenous dose of SGT-003 by assessing changes in biomarkers of muscle structural integrity.

Conditions and MedDRA coding

Duchenne muscular dystrophy

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 12

1. Participant age at the time of signing the informed consent form (ICF): Cohort 1: 4 to <7 years Cohort 2: 7 to <12 years Cohort 3: 0 to < 4 years Cohort 4: 12 to < 18 years Cohort 5: 10 to < 18 years
2. Participant ambulatory status at the time of Screening Part A or Rescreening, as defined by the ability to complete a 10-meter walk/run test in < 30 seconds: Cohorts 1, 2, and 4: Ambulatory; Cohort 3: Either ambulatory or non-ambulatory, Cohort 5: Non-ambulatory, but having been previously ambulatory by history
3. Established clinical diagnosis of DMD and documented dystrophin gene mutation predictive of DMD phenotype, confirmed by Sponsor genetic testing. In cases where a genotype may be predictive of residual dystrophin production and/or a clear clinical diagnosis of DMD cannot be made (e.g., due to age), evaluation of dystrophin levels in baseline muscle biopsies may be required to determine eligibility under this criterion
4. Negative for AAV antibodies
5. Steroid regimen: a. Cohorts 1, 2, 4, and 5: A stable daily oral steroid regimen of at least 0.5 mg/kg/day of prednisone or 0.75 mg/kg/day of deflazacort for ≥12 weeks prior to Screening Part A or Rescreening, allowing for weight-based modifications consistent with clinical practice. b. Cohort 3: N/A
6. Meet 10-meter walk/run time criteria
7. Meet time to rise from supine criteria
8. Cohort 5: meet Performance of Upper Limb (PUL) 2.0 criteria
9. Participant has body weight ≤ 90 kg.
10. Participant is male.
11. Able to understand and comply with all study procedures as appropriate by age and have a parent(s) or legal guardian(s) (i.e., legally authorized representative [LAR]) who is (are) able to understand and comply with the study procedure requirements
12. If participant is of reproductive potential, participant and partner of childbearing potential are willing to use 2 highly effective forms of contraception for 12 months following study drug administration.

Exclusion criteria 14

1. Any prior or ongoing medical condition, medical history, physical finding that in the Investigator's opinion could adversely affect the safety of the participant, make it unlikely that the course of treatment or follow-up would be completed, or could impair the assessment of study results.
2. Abnormal liver function, evidence of active viral hepatitis
3. Abnormal renal function
4. Clinically significant abnormalities of coagulation
5. Impaired cardiovascular function
6. Pulmonary function predictive of (or requiring) the use of daytime ventilatory support
7. Have severe hypersensitivity reactions, including anaphylaxis, to SGT-003 or its components.
8. Treatment with dystrophin modifying drugs within 3 months prior to screening.
9. Current or prior treatment with an approved or investigational gene transfer drug.
10. Exposure to certain approved or investigational drugs within 3 months prior to screening or 5 half-lives since last administration, whichever is longer.
11. Major surgery within 3 months prior to recruitment or planned orthopedic surgery for any time during this study which would interfere with the ability to perform outcome measures.
12. Established clinical diagnosis of DMD that is associated with any deletion variant or variant predicted to not express exons 1 to 11, exons 42 to 45, or exons 57 to 69 inclusive, in the DMD gene as documented by a genetic report and confirmed by Sponsor genetic testing.
13. Sponsor employees and their family members are ineligible to participate in this study.
14. Any active infection

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 2

1. Incidence of treatment-emergent adverse events (AEs) through Day 360
2. Change from baseline of microdystrophin protein levels at Day 90

Secondary endpoints 13

1. Change from baseline of microdystrophin tissue distribution at Day 90
2. Change from baseline of microdystrophin tissue distribution at Day 360
3. Change from baseline of microdystrophin protein levels at Day 360
4. Change from baseline in time to rise velocity at Day 360 and Day 540
5. Change from baseline in stride velocity 95th centile (SV95C) at Day 360 and Day 540
6. Change from baseline in 10-meter walk/run velocity at Day 360 and Day 540
7. Change from baseline in 4-stair climb velocity at Day 360 and Day 540
8. Change from baseline in the North Star Ambulatory Assessment (NSAA) score at Day 360 and Day 540
9. Change from baseline in 6-minute walk test (6MWT) distance at Day 360 and Day 540
10. Incidence of clinically significant laboratory abnormalities through Day 360 and Day 540
11. Incidence of clinically significant abnormalities in vital signs through Day 360 and Day 540
12. Incidence of clinically significant abnormalities in physical examinations through Day 360 and Day 540
13. Incidence of cardiac abnormalities by electrocardiogram (ECG) or echocardiography (ECHO) through Day 360 and Day 540

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Solid Biosciences Inc.

Sponsor organisation

Solid Biosciences Inc.

Address

500 Rutherford Avenue

City

Charlestown

Postcode

02129-1647

Country

United States

Scientific contact point

Organisation

Solid Biosciences Inc.

Contact name

Amber Conklin

Public contact point

Organisation

Solid Biosciences Inc.

Contact name

Amber Conklin

Third parties 11

Locations

1 EU/EEA country · 1 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 16 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

7 submissions — initial application plus substantial / non-substantial modifications