Brief Summary

The purpose of this study is to evaluate the efficacy and safety of TAS-205 in patients with Duchenne muscular dystrophy

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

104

participants targeted

Target at P25-P50 for phase_3

Timeline

12mo left

Started Nov 2020

Longer than P75 for phase_3

Geographic Reach

1 country

5 active sites

Status

active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

6.5 years study duration

Study Progress85%

Nov 2020May 2027

First Submitted

Initial submission to the registry

October 13, 2020

Completed

1 day until next milestone

First Posted

Study publicly available on registry

October 14, 2020

Completed

18 days until next milestone

Study Start

First participant enrolled

November 1, 2020

Completed

6.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2027

Expected

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 1, 2027

Last Updated

September 11, 2025

Status Verified

September 1, 2025

Enrollment Period

6.5 years

First QC Date

October 13, 2020

Last Update Submit

September 4, 2025

Conditions

Duchenne Muscular Dystrophy

Outcome Measures

Primary Outcomes (2)

Mean change from baseline to Week 52 in the time to rise from the floor
Ambulatory Cohort
Baseline to Week 52 of treatment
Incidence of Adverse Events and Adverse Reactions
Non-ambulatory Cohort
Week 52

Secondary Outcomes (9)

Time measured in the time to rise from the floor test, as well as the change from baseline in each measured value
Baseline to 52 weeks of treatment
Change from baseline in the Timed Up and Go Test (TUG)
Baseline to 52 weeks of treatment
Change from baseline in North Star Ambulatory Assessment (NSAA)
Baseline to 52 weeks of treatment
Change from baseline in Six-minutes Walk Test (6MWT)
Baseline to 52 weeks of treatment
Measured values of Muscle volume index (MVI), Percent Muscle volume index (%MVI) and skeletal muscle mass in skeletal muscle computed tomography (CT), as well as the change from baseline in each measured value
Baseline to 52 weeks of treatment
+4 more secondary outcomes

Study Arms (2)

TAS-205

EXPERIMENTAL

Drug: TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort]

Placebo

PLACEBO COMPARATOR

Drug: Placebo [Ambulatory Cohort] only

Interventions

TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort]DRUG

・Treatment period：oral administration for 52 weeks, BID after meal

TAS-205

Placebo [Ambulatory Cohort] onlyDRUG

* Observation period：oral administration for 2 weeks, BID after meal * Treatment period：oral administration for 52 weeks, BID after meal

Placebo

Eligibility Criteria

Age5 Years+

Sexmale

Healthy VolunteersNo

Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

Patients with a diagnosis of dystrophinopathy as determined by a dystrophin genetic test at the time of informed consent, symptoms or signs characteristic to DMD (e.g., proximal muscular weakness, waddling gait, Gower's sign)
Patients aged 5 years or more at the time of informed consent
Patients weighing more than 7.5 kg and less than 60 kg at the time of screening test
Patients who meet all of the following at the time of screening test
walk by themselves
time to rise from the floor on own is ≥ 3 seconds and \<10 seconds
Patients who can expect a 6-minute walking test of 350 meters or more
If taking oral glucocorticoids no significant change in the total daily or dosing 6 months before enrollment.
\[Non-ambulatory Cohort\]
Patients with a diagnosis of DMD as determined by a dystrophin genetic test at the time of informed consent.
Patients weighing more than 7.5 kg and less than 90 kg at the time of screening test
Patients who meet all of the following criteria as definition of non-ambulatory at the time of enrollment
Use of a wheelchair on a daily basis.
No orthopedic pathology (fracture, sprain, injury, etc.) or acute deterioration associated with surgical treatment.
Inability to walk 10 meters within 30 seconds on the 10-meter run/walk test at enrollment.
+4 more criteria

You may not qualify if:

Patients who have serious concomitant drug hypersensitivity or medical history
Patients who have used cyclooxygenase-1 (COX-1) or COX-2 inhibitors, or nonsteroidal anti-inflammatory drugs (NSAIDs) during 7 days before the measurement of time to rise from the floor in the screening period
Patients who have incurred an injury (trauma/damage) that may affect muscle strength or motor function within 3 months before enrollment or who have an uncured injury (trauma/damage) that may affect muscle strength or motor function at the enrollment
Patients who have received gene-/cell-based therapy or stop-codon readthrough therapy with antisense oligonucleotides
Patients who have participated in another clinical trial and received a study drug within 90 days before study drug administration in the present study
Patients with a left ventricular ejection fraction (EF) of \<40% or left ventricular fractional shortening (FS) of \<25% on the cardiac ultrasonography (echocardiography) at observation period
\[Non-ambulatory Cohort\]
Patients with severe cardiac disease (including a history of pacemaker surgery)
Patients with left ventricular EF \<40% on echocardiography within 14 days prior to enrollment
Patients with %FVC less than 40% within 14 days prior to enrollment
Patients with respiratory diseases such as asthma, bronchitis, COPD, bronchiectasis, emphysema, pneumonia, etc. (including chronic use of beta2 agonists, inhaled steroids, sympathomimetics, anticholinergic agents, etc.)
Patients on continuous ventilator use (excluding use while sleeping)
Patients who have undergone surgery within 180 days prior to enrollment that may affect muscle strength or exercise, pulmonary function, or cardiac function, or are planning such surgery during the study period
Injury (trauma/injury) within 90 days prior to enrollment that may affect muscle strength or motor, pulmonary, or cardiac function, or that has not healed at the time of enrollment
Patients who are judged by the principal investigator or subinvestigator to have brain dysfunction such as intellectual disability, autistic tendencies, and attention deficit hyperactivity disorder that would interfere with the performance of efficacy and safety evaluation
+2 more criteria

Contact the study team to confirm eligibility.