CompletedNCT04060199Updated Dec 11, 2024Results posted

Study to Assess the Efficacy and Safety of Viltolarsen in Ambulant Boys With DMD (RACER53)

A Phase 3 interventional study of Viltolarsen and Placebo in Duchenne Muscular Dystrophy, sponsored by NS Pharma, Inc.. Completed at 40 sites in 19 countries. Open to male participants aged 4 Years to 7 Years. Per ClinicalTrials.gov, last updated 2024-12-11.

Sponsored by NS Pharma, Inc. · Phase 3, Interventional, and Treatment

Phase: Phase 3
Study type: Interventional
Enrollment: 77
Allocation: Randomized
Ages: 4 Years to 7 Years
Sex: Male

Study summary

The main objective of this study is to evaluate the efficacy of Viltolarsen compared to placebo in Duchenne muscular dystrophy (DMD) patients amenable to exon 53 skipping.

Read the detailed description

This is a Phase 3 randomized, double-blind, placebo-controlled, multi-center study to assess the efficacy and safety of Viltolarsen in ambulant boys with Duchenne muscular dystrophy. Eligible patients with out-of-frame deletion mutations amenable to exon 53 skipping will be randomized to receive once weekly intravenous (IV) infusions of 80 mg/kg Viltolarsen or placebo for up to 48 weeks.

The study will enroll approximately 74 patients amenable to exon 53 skipping. Clinical efficacy will be assessed at regularly scheduled study visits, including functional tests such as Time to Stand Test (TTSTAND), Time to Run/Walk 10 Meters Test (TTRW), Six-minute Walk Test (6MWT), North Star Ambulatory Assessment (NSAA), Time to Climb 4 Steps Test (TTCLIMB) and Hand-held dynamometer (elbow extension, elbow flexion, knee extension and knee flexion on the dominant side only).

Safety will be assessed through the collection of adverse events (AEs), laboratory tests, electrocardiograms (ECGs), vital signs, and physical examinations throughout the study.

Blood samples will be taken periodically throughout the study to assess the pharmacokinetics of study drug.

Conditions studied

Duchenne Muscular Dystrophy

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In context

Muscular Dystrophies

548 studies on the registry are indexed under Muscular Dystrophies; 89 are open to participants now.

This study's enrollment of 77 is above the median of 24 across 344 interventional studies indexed under Muscular Dystrophies.

Browse Muscular Dystrophies studies →

Lead sponsor

NS Pharma, Inc. is the lead sponsor of 14 studies on the registry; 2 are open to participants now.

Of its 5 completed or terminated interventional studies of FDA-regulated products, 5 (100%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 4 Years to 7 Years
Sexes eligible: Male
Accepts healthy volunteers: No

Inclusion criteria

Male ≥ 4 years and \< 8 years of age
Confirmed DMD mutation(s) in the dystrophin gene that is amenable to skipping of exon 53 to restore the dystrophin mRNA reading frame
Able to walk independently without assistive devices
TTSTAND \< 10 seconds
Stable dose of glucocorticoid (GC) for at least 3 months prior to study entry and is expected to remain on stable dose of GC treatment for the duration of the study
Other inclusion criteria may apply

Exclusion criteria

Exclusion Criteria:

Current or history of chronic systemic fungal or viral infections
Acute illness within 4 weeks prior to the first dose of study drug
Evidence of symptomatic cardiomyopathy (Note: Asymptomatic cardiac abnormality on investigation would not be exclusionary)
Allergy or hypersensitivity to the study drug or to any of its constituents
Severe behavioral or cognitive problems that preclude participation in the study, in the opinion of the investigator
Previous or ongoing medical condition, medical history, physical findings or laboratory abnormalities that could affect safety, make it unlikely that treatment and follow-up will be correctly completed or impair the assessment of study results, in the opinion of the investigator;
Surgery within the 3 months prior to the first dose of study drug or surgery is planned for anytime during the duration of the study
Participant has positive test results for hepatitis B antigen, hepatitis C antibody or human immunodeficiency virus (HIV)
Currently taking any other investigational drug or has taken any other investigational drug within 3 months prior to the first dose of study drug or within 5 times the half-life of a medication, whichever is longer
Previously enrolled in an interventional study of viltolarsen
Currently taking any other exon skipping agent or has taken any other exon skipping agent within 3 months prior to the first dose of study drug
Having taken any gene therapy
Other exclusion criteria may apply

Study design

Phase: Phase 3
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment: 77 participants (actual)

Study arms

Experimental
Viltolarsen
Patients amenable to exon 53 skipping will receive viltolarsen intravenous (IV) infusions, weekly, at 80 mg/kg for up to 48 weeks.
Drug: Viltolarsen
Placebo comparator
Placebo
Patients amenable to exon 53 skipping will receive placebo intravenous (IV) infusions, weekly, for up to 48 weeks.
Drug: Placebo

Interventions

DrugViltolarsen
IV infusion
Also known as: NS-065/NCNP-01
DrugPlacebo
IV infusion

What researchers measure

Primary outcomes

Change From Baseline in Time to Stand (TTSTAND) Velocity
The change from baseline for velocity converted from TTSTAND was compared between the viltolarsen-treated patients and the placebo-treated patients. TTSTAND was assessed as the time it takes the participant to go from lying flat on the floor to standing. The time measured for TTSTAND was converted to a velocity expressed as rise per second.
Time frame: baseline, Week 13, 25, 37, 49

Results

Posted Dec 11, 2024

Participant flow

Participants were enrolled in the study from April 14, 2020 to October 19, 2023 at 30 sites in 17 countries, predominantly in Europe, Asia, North America, and South America

Participant flow — Overall Study
Milestone	Viltolarsen	Placebo
Started	38	39
Completed	36	38
Not completed	2	1

Outcome measures

PrimaryChange From Baseline in Time to Stand (TTSTAND) Velocity

The change from baseline for velocity converted from TTSTAND was compared between the viltolarsen-treated patients and the placebo-treated patients. TTSTAND was assessed as the time it takes the participant to go from lying flat on the floor to standing. The time measured for TTSTAND was converted to a velocity expressed as rise per second.

Time frame:: baseline, Week 13, 25, 37, 49
Reported as:: Least squares mean · rise/s

Change From Baseline in Time to Stand (TTSTAND) Velocity
rise/s	Viltolarsen	Placebo
Week 13	0.026 ± 0.0103	0.013 ± 0.0104
Week 25	0.027 ± 0.0100	0.014 ± 0.0100
Week 37	0.027 ± 0.0107	0.027 ± 0.0108
Week 49	0.009 ± 0.0096	0.013 ± 0.0096

Adverse events

Collected over Up to 48 weeks. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Viltolarsen	0/38 (0%)	2/38 (5.3%)	33/38 (86.8%)
Placebo	0/39 (0%)	3/39 (7.7%)	37/39 (94.9%)

Most frequent serious events

Most frequent serious events
Event	Viltolarsen	Placebo
PharyngitisInfections and infestations	1/38	0/39
Adverse drug reactionGeneral disorders	1/38	0/39
InfluenzaInfections and infestations	0/38	1/39
VomitingGastrointestinal disorders	0/38	1/39
Blood creatine phosphokinase increasedInvestigations	0/38	1/39
EpilepsyNervous system disorders	0/38	1/39

Most frequent other events

Showing 10 of 54

Most frequent other events
Event	Viltolarsen	Placebo
PyrexiaGeneral disorders	10/38	13/39
COVID-19Infections and infestations	12/38	12/39
CoughRespiratory, thoracic and mediastinal disorders	12/38	5/39
VomitingGastrointestinal disorders	4/38	11/39
Upper respiratory tract infectionInfections and infestations	10/38	9/39
NasopharyngitisInfections and infestations	9/38	7/39
DiarrheaGastrointestinal disorders	8/38	7/39
RhinitisInfections and infestations	6/38	3/39
RhinorrheaRespiratory, thoracic and mediastinal disorders	6/38	2/39
Abdominal painGastrointestinal disorders	4/38	6/39

Baseline characteristics

The ITT Population was defined as all randomized patients.

Age, Continuous
Age, Continuous(years)	Viltolarsen	Placebo	Total
Mean	5.5 ± 1.20	5.7 ± 1.16	5.6 ± 1.18

Sex: Female, Male
Sex: Female, Male(Participants)	Viltolarsen	Placebo	Total
Female	0	0	0
Male	38	39	77

Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)	Viltolarsen	Placebo	Total
Hispanic or Latino	2	4	6
Not Hispanic or Latino	36	33	69
Unknown or Not Reported	0	2	2

Race (NIH/OMB)
Race (NIH/OMB)(Participants)	Viltolarsen	Placebo	Total
American Indian or Alaska Native	0	0	0
Asian	10	11	21
Native Hawaiian or Other Pacific Islander	0	0	0
Black or African American	0	0	0
White	27	26	53
More than one race	0	0	0
Unknown or Not Reported	1	2	3

Weight
Weight(kg)	Viltolarsen	Placebo	Total
Mean	21.12 ± 4.354	20.70 ± 4.277	20.91 ± 4.292

Height
Height(cm)	Viltolarsen	Placebo	Total
Mean	110.9 ± 9.78	111.8 ± 7.78	111.4 ± 8.78

Body Mass Index (BMI)
Body Mass Index (BMI)(kg/m^2)	Viltolarsen	Placebo	Total
Mean	17.053 ± 1.9427	16.439 ± 2.1105	16.742 ± 2.0396

Study locations

40 sites

University of California Davis Medical Center
Sacramento, California 95817, United States
Ann and Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois 60611, United States
Queensland Children's Hospital
Brisbane, Australia
Perth Children's Hospital
Nedlands, Australia
The Childrens Hospital at Westmead
Westmead, Australia
The Hospital for Sick Children (SickKids)
Toronto, Ontario, Canada
Alberta Children's Hospital
Calgary, Canada
CHU de Quebec Research Centre
Quebec City, Canada
Hospital de Niños Roberto del Rio
Santiago, Chile
Pontificia Universidad Católica de Chile
Santiago, Chile
Chinese PLA General Hospital
Beijing, China
The Third Medical Center of PLA General Hospital
Beijing, China
Hunan Children's Hospital
Changsha, China
Children's Hospital of Fudan University
Shanghai, China
Shenzhen Children's Hospital
Shenzhen, China
Agia Sofia Children's Hospital
Athens, Greece
Hippokration General Hospital of Thessaloniki
Thessaloníki, Greece
Hong Kong Children's Hospital
Kowloon Bay, Hong Kong
Fondazione Policlinico Universitario A. Gemelli - Universita Cattolica del Sacro Cuore
Rome, Italy
Pusan National University Yangsan Hospital
Pusan, Korea, Republic of
Seoul National University Hospital
Seoul, Korea, Republic of
Hospital Angeles Chihuahua
Chihuahua, Mexico
Instituto Nacional de Pediatria
Ciudad de mexico, Mexico
Radboud Universitair Medisch Centrum
Nijmegen, Gelderland, Netherlands
Leids Universitair Medisch Centrum
Leiden, Netherlands
New Zealand Clinical Research Ltd
Auckland, New Zealand
Rikshospitalet
Oslo, Norway
Russian National Research Medical University n.a. N.I.Pirogov, structural branch - Research Clinical Institute of Pediatrics n.a. Academician Yu. E. Veltishchev
Moscow, Russian Federation
"Saint Petersburg State Paediatric Medical University" based at Consultative and Diagnostic Centre
Saint Petersburg, Russian Federation
Tomsk National Research Medical Center of Russian Academy of Sciences
Tomsk, Russian Federation
Hospital Sant Joan de Deu
Barcelona, Spain
Hospital Universitario La Paz
Madrid, Spain
Kaohsiung Medical University Chung-Ho Memorial Hospital
Kaohsiung, Taiwan
National Taiwan University Hospital
Taipei, Taiwan
Yeditepe University Kosuyolu Hospital
Istanbul, Turkey
State Institution "Ukrainian Medical rehabilitation Center for Children with organic disorders of the nervous system of the Ministry of Health of Ukraine"
Kyiv, Ukraine
Birmingham Heartlands Hospital
Birmingham, United Kingdom
Royal Hospital for Children - Glasgow
Glasgow, United Kingdom
University College London Institute of Child Health
London, United Kingdom
Royal Manchester Children's Hospital
Manchester, United Kingdom

References and documents

Study documents

Protocol and statistical analysis plan · Dec 8, 2022

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Dec 11, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT04060199
Lead sponsor: NS Pharma, Inc.
Collaborators: Nippon Shinyaku Co., Ltd.
Responsible party: Sponsor
First posted: Aug 19, 2019
Start date: Apr 14, 2020
Primary completion: Oct 19, 2023
Completion: Oct 19, 2023
Results posted: Dec 11, 2024
Last update: Dec 11, 2024

Oversight

FDA-regulated drug: Yes
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Oct 2024. You cannot join it, but the record below documents what was studied.

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