Long-term, Extension Study of DS-5141b in Patients With Duchenne Muscular Dystrophy

A Phase II, Long-term, Extension Study of DS-5141b in Patients With Duchenne Muscular Dystrophy

This is a multicenter, open-label, long-term, extension, phase 2 study to evaluate the safety and efficacy of long-term treatment with DS-5141b in patients with DMD who have completed DS5141-A-J101.

Study Overview

• Status: Active, not recruiting
• Conditions: Duchenne Muscular Dystrophy
• Intervention / Treatment: Drug: DS-5141b

• Study Type: Interventional
• Enrollment (Estimated): 8
• Phase: Phase 2

Contacts and Locations

Study Locations

• Japan
  • Hyōgo, Japan, 650-0017
    • Kobe University Hospital
  • Kodaira-Shi
    • Tokyo, Kodaira-Shi, Japan, 187-8551
      • National Center of Neurology and Psychiatry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Has competed a study of DS5141-A-J101

Exclusion Criteria:

• Significant safety issues in a study of DS5141-A-J101
• Patient who does not consent to use appropriate contraception
• Patient not appropriate to participant in the study as determined by the Investigator

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: DS-5141b 2.0 mg/kg; Participants who will receive DS-5141b 2.0 mg/kg once weekly.	Drug: DS-5141b; Administered via subcutaneous injection once weekly; Other Names: Renadirsen
Experimental: DS-5141b 6.0 mg/kg; Participants who will receive DS-5141b 6.0 mg/kg once weekly.	Drug: DS-5141b; Administered via subcutaneous injection once weekly; Other Names: Renadirsen

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of Adverse Events (AEs)	From first injection to after the last injection of DS-5141b in this study (within approximately 2 years)
Change in distance walked during 6-minute walk test (6MWT)	Every 3 months (within approximately 2 years)
Change in time to stand (TTSTAND)	Every 3 months (within approximately 2 years)
Change in time in Timed up and go test	Every 3 months (within approximately 2 years)
Change in time in 10-meter Run/Walk test	Every 3 months (within approximately 2 years)
Change in score in the North Star Ambulatory Assessment (NSAA)	Every 3 months (within approximately 2 years)
Change in score in the Performance of Upper Limb (PUL)	Every 3 months (within approximately 2 years)
Change in Muscle Strength Measured by Quantitative Muscle Strength Assessment	Every 3 months (within approximately 2 years)
Change in Left Ventricular Ejection Fraction percentage (LVEF %)	Every 6 months (within approximately 2 years)
Change in in Forced Vital Capacity (FVC) (percent predicted)	Every 6 months (within approximately 2 years)

Secondary Outcome Measures

Outcome Measure	Time Frame
Concentration of DS-5141a in plasma	Every 3 months (within approximately 2 years)

Collaborators and Investigators

• Sponsor: Daiichi Sankyo Co., Ltd.
• Investigators: Study Director: Clinical Study Leader, Daiichi Sankyo Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2020
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): January 31, 2027

Study Registration Dates

• First Submitted: June 12, 2020
• First Submitted That Met QC Criteria: June 12, 2020
• First Posted (Actual): June 16, 2020

Study Record Updates

• Last Update Posted (Estimated): September 19, 2025
• Last Update Submitted That Met QC Criteria: September 18, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: DMD; Duchenne muscular dystrophy; Exon skipping; Oligonucleotides, antisense; DS-5141b
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Genetic Diseases, Inborn; Genetic Diseases, X-Linked; Muscular Disorders, Atrophic; Muscular Dystrophies; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Muscular Dystrophy, Duchenne
• Other Study ID Numbers: DS5141-A-J201; 205321 (Other Identifier: JapicCTI)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No