Duchenne Muscular DystrophyPhase 3NCT04587908
A Phase 3 Study of TAS-205 in Patients With Duchenne Muscular Dystrophy（REACH-DMD）
A Phase 3 study testing TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort] in people with Duchenne Muscular Dystrophy, run by Taiho Pharmaceutical Co., Ltd. at 5 sites in Japan.
Trial summary
The purpose of this study is to evaluate the efficacy and safety of TAS-205 in patients with Duchenne muscular dystrophy Read more about this study
- Who is it for?
- Ages 5 years and older, men only
- Conditions the study is for
- Duchenne Muscular Dystrophy
- What is being tested?
- TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort]
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 104 participants
- Where
- 5 sitesJapan
- Study dates
- 1 Nov 2020to 18 Jun 2026
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 5 years and older
- Men only
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- 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
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- 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.
- Patients with a Brooke Score of 5 or less in the arm and shoulder at enrollment.
- Patients who are able to take the drug orally throughout the treatment period (crushed or suspended doses are not acceptable)
- If taking oral glucocorticoids no significant change in the total daily or dosing 90 days prior to obtaining consent, or not taking oral glucocorticoids for more than 90 days prior to obtaining consent and whose symptoms are stable.
- Patients on angiotensin-converting enzyme inhibitors, beta-blockers, and angiotensin II receptor blockers for the treatment (including prophylaxis) of heart failure who are symptomatically stable with no change in dosage (prescription basis) within 90 days prior to enrollment.
Who cannot join
- 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
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- [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
- Patients with systemic allergic or chronic inflammatory diseases that may interfere with the interpretation of efficacy or safety data (except allergic rhinitis, localized or mild atopic dermatitis, eczema, etc.)
- Patients enrolled in Treatment Phase Part A of this study's Ambulatory Cohort
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
Japan5 sites
A site selected by Taiho Pharmaceutical Co., Ltd.
Aichi
A site selected by Taiho Pharmaceutical Co., Ltd.
Fukuoka
A site selected by Taiho Pharmaceutical Co., Ltd.
Hokkaido
A site selected by Taiho Pharmaceutical Co., Ltd.
Osaka
A site selected by Taiho Pharmaceutical Co., Ltd.
Tokyo
About this study
Official title: A Phase 3, Randomized, Placebo-controlled, Double-blind and Open-label, Extension Study of TAS-205 in Patients With Duchenne Muscular Dystrophy
The purpose of this study is to evaluate the efficacy and safety of TAS-205 in patients with Duchenne muscular dystrophy
Read the detailed description
[Ambulatory Cohort] The main purpose of this cohort is to assess the efficacy of TAS-205 in patients with Duchenne muscular dystrophy (DMD) compared with placebo as measured by the mean change from baseline to 52 weeks in the time to rise from the floor． Following completion of the treatment period, patients may elect to continue in open-label extension study.
[Non-ambulatory Cohort] The main purpose of this cohort is to assess the safety of TAS-205 in patients with DMD by collecting the incidence of adverse events for 52 weeks.
- Conditions
- Duchenne Muscular Dystrophy
- Being tested
- TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort], Placebo [Ambulatory Cohort] only
- Medical subject headings
- Muscular Dystrophy, Duchenne
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort]Drug
・Treatment period：oral administration for 52 weeks, BID after meal
Placebo [Ambulatory Cohort] onlyDrug
- Observation period：oral administration for 2 weeks, BID after meal
- Treatment period：oral administration for 52 weeks, BID after meal
| Study group | Role | What they receive |
|---|---|---|
| TAS-205 | Experimental | Not described Receives: Drug: TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort] |
| Placebo | Placebo comparator | Not described Receives: Drug: Placebo [Ambulatory Cohort] only |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean change from baseline to Week 52 in the time to rise from the floor
Ambulatory Cohort
Measured: Baseline to Week 52 of treatment
Incidence of Adverse Events and Adverse Reactions
Non-ambulatory Cohort
Measured: 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
Ambulatory Cohort
Measured: Baseline to 52 weeks of treatment
Change from baseline in the Timed Up and Go Test (TUG)
Ambulatory Cohort Timed Up and Go Test (TUG) The time required for the subject to stand up from a sitting position on a table (chair), walk to a cone placed 3 m ahead as quickly as possible, and then return to the table will be evaluated.
The time required for the subject to stand up from a sitting position on a table (chair), walk to a cone placed 3 m ahead as quickly as possible, and then return to the table will be evaluated.
Measured: Baseline to 52 weeks of treatment
Change from baseline in North Star Ambulatory Assessment (NSAA)
Ambulatory Cohort
Measured: Baseline to 52 weeks of treatment
Change from baseline in Six-minutes Walk Test (6MWT)
Ambulatory Cohort
Measured: 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
Ambulatory Cohort
Measured: Baseline to 52 weeks of treatment
Assessment of upper limb function: The Brooke upper extremity scale, measured values of performance of the upper limb (PUL) and change from baseline in measured values
Non-ambulatory Cohort
Measured: week 52
Change from baseline in grip strength
Non-ambulatory Cohort
Measured: week 52
Pulmonary function tests: measured effort lung capacity (FVC, %FVC), volume in 1 second (Forced Expiratory Volume :FEV1.0), fraction in 1 second (FEV1.0%), and change from baseline (at enrollment) of measured values.
Non-ambulatory Cohort
Measured: week 52
Echocardiography: Measured EF and FS and change from baseline in measured values
Non-ambulatory Cohort
Measured: week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Oct 2020
- Study start1 Nov 2020
- Primary completion18 Jun 2026
- Study completion18 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Duchenne Muscular DystrophyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 104 participants (actual)
Sponsor and investigators
- Lead sponsor
- Taiho Pharmaceutical Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Taiho Pharmaceutical Co., Ltd., Study director, Taiho Pharmaceutical Co., Ltd.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04587908
- Sponsor's protocol ID
- 10053050
- Status last verified
- Aug 2026
- First submitted
- 13 Oct 2020
- Last updated
- 17 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data will not be shared according to the Sponsor policy on data sharing. Taiho policy on data sharing may be found at https://www.taiho.co.jp/en/science/policy/clinical\_trial\_information\_disclosure\_policy/index.html.
Study at a glance
From the registry record, last updated by the sponsor on 17 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Randomized, Placebo-controlled, Double-blind and Open-label, Extension Study of TAS-205 in Patients With Duchenne Muscular Dystrophy
- ClinicalTrials.gov ID
- NCT04587908
- Acronym / sponsor ID
- 10053050
- Conditions
- Duchenne Muscular Dystrophy
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 104 participants (actual)
- Lead sponsor
- Taiho Pharmaceutical Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 1 Nov 2020 (actual)
- Primary completion
- 18 Jun 2026 (actual)
- Study completion
- 18 Jun 2026 (actual)
- First posted
- 14 Oct 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the efficacy and safety of TAS-205 in patients with Duchenne muscular dystrophy
Detailed description
[Ambulatory Cohort] The main purpose of this cohort is to assess the efficacy of TAS-205 in patients with Duchenne muscular dystrophy (DMD) compared with placebo as measured by the mean change from baseline to 52 weeks in the time to rise from the floor． Following completion of the treatment period, patients may elect to continue in open-label extension study.
[Non-ambulatory Cohort] The main purpose of this cohort is to assess the safety of TAS-205 in patients with DMD by collecting the incidence of adverse events for 52 weeks.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| TAS-205 | Experimental | Drug: TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort] |
| Placebo | Placebo comparator | Drug: Placebo [Ambulatory Cohort] only |
Who may qualify
- Ages
- 5 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (19 listed)
- 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
Key exclusion criteria (17 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort]・Treatment period：oral administration for 52 weeks, BID after meal | Drug | TAS-205 |
| Placebo [Ambulatory Cohort] only* Observation period：oral administration for 2 weeks, BID after meal * Treatment period：oral administration for 52 weeks, BID after meal | Drug | Placebo |
Primary outcome
Mean change from baseline to Week 52 in the time to rise from the floor
Time frame: Baseline to Week 52 of treatment
Ambulatory Cohort
Incidence of Adverse Events and Adverse Reactions
Time frame: Week 52
Non-ambulatory Cohort
9 secondary outcomes
Time measured in the time to rise from the floor test, as well as the change from baseline in each measured value
Time frame: Baseline to 52 weeks of treatment
Change from baseline in the Timed Up and Go Test (TUG)
Time frame: Baseline to 52 weeks of treatment
Change from baseline in North Star Ambulatory Assessment (NSAA)
Time frame: Baseline to 52 weeks of treatment
Change from baseline in Six-minutes Walk Test (6MWT)
Time frame: 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
Time frame: Baseline to 52 weeks of treatment
Assessment of upper limb function: The Brooke upper extremity scale, measured values of performance of the upper limb (PUL) and change from baseline in measured values
Time frame: week 52
Change from baseline in grip strength
Time frame: week 52
Pulmonary function tests: measured effort lung capacity (FVC, %FVC), volume in 1 second (Forced Expiratory Volume :FEV1.0), fraction in 1 second (FEV1.0%), and change from baseline (at enrollment) of measured values.
Time frame: week 52
Echocardiography: Measured EF and FS and change from baseline in measured values
Time frame: week 52
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Aug 2026.
- Individual participant dataSharing planned: No. Data will not be shared according to the Sponsor policy on data sharing. Taiho policy on data sharing may be found at https://www.taiho.co.jp/en/science/policy/clinical_trial_information_disclosure_policy/index.html.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Taiho Pharmaceutical Co., Ltd. study director
Taiho Pharmaceutical Co., Ltd.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing TAS-205 [Ambulatory Cohort] [Non-ambulatory Cohort] in people with Duchenne Muscular Dystrophy, run by Taiho Pharmaceutical Co., Ltd. at 5 sites in Japan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 19 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean change from baseline to Week 52 in the time to rise from the floor (time frame: Baseline to Week 52 of treatment). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Aug 2026.