Systemic SclerosisPhase 3NCT05198557
A Study of MT-0551 in Patients With Systemic Sclerosis
A Phase 3 study testing Inebilizumab in people with Systemic Sclerosis, run by Tanabe Pharma Corporation at 4 sites in Japan.
Trial summary
The study will verify the superiority of MT-0551 to placebo at 26 weeks after treatment initiation in systemic sclerosis (SSc) patients using the modified Rodnan Total Skin thickness Score (mRTSS) as a measure of skin thickening. The safety and pharmacokinetics will also be investigated. Read more about this study
- Who is it for?
- Ages 20 to 80 years
- Conditions the study is for
- Systemic Sclerosis
- What is being tested?
- Inebilizumab
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- 4 sitesJapan
- Study dates
- 20 Jul 2022to Aug 2026
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
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 20 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Additional screening criteria check may apply for qualification:
- ACR/European League Against Rheumatism (EULAR) criteria (2013) systemic sclerosis (SSc) diagnostic criteria satisfied.
- Skin thickening score based on the mRTSS between 10 and 22 inclusive.
Who cannot join
- Additional screening criteria check may apply for qualification:
- Pulmonary hypertension associated with SSc.
- Presence of a serious, SSc-related concurrent illness other than interstitial pneumonia.
- Finding of inadequate respiratory reserve capacity.
- Past history of rituximab, blinatumomab, obinutuzumab, or ofatumumab.
- Presence of a clinically significant active infection requiring antimicrobial therapy.
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- A past history of cancer.
- Past history of a recurrent, clinically significant infection.
- Past history of severe allergy or anaphylactic reaction to a biologic drug product.
- Treatment with live vaccine within a certain period (inactivated vaccine is acceptable).
Trial locations and contacts
4 sites in 1 country.
Japan4 sites
The University of Tokyo Hospital
Bunkyo-ku, Tokyo, 113-8655
Kanazawa University Hospital
Kanazawa, Ishikawa-ken, 920-8641
St. Marianna University Hospital
Kawasaki-shi, Kanagawa, 216-8511
University of Fukui Hospital
Yoshida-gun, Fukui, 910-1193
About this study
Official title: Phase 3 Study of MT-0551 in Patients With Systemic Sclerosis (Placebo-Controlled Double-Blind Study)
The study will verify the superiority of MT-0551 to placebo at 26 weeks after treatment initiation in systemic sclerosis (SSc) patients using the modified Rodnan Total Skin thickness Score (mRTSS) as a measure of skin thickening. The safety and pharmacokinetics will also be investigated.
- Conditions
- Systemic Sclerosis
- Being tested
- Inebilizumab, Placebo
- Medical subject headings
- Scleroderma, Systemic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
InebilizumabDrug
Also called MT-0551
Participants will receive IV inebilizumab.
PlaceboDrug
Participants will receive IV placebo matched to inebilizumab.
| Study group | Role | What they receive |
|---|---|---|
| MT-0551 group | Experimental | Participants will receive intravenous (IV) inebilizumab on Day 1 and Day 15 of randomized controlled period (RCP). The participants who entered open label period (OLP) will receive IV inebilizumab on Day 1 and IV placebo on Day 15 of OLP and will be followed by IV inebilizumab every 26 weeks. Receives: Drug: Inebilizumab; Drug: Placebo |
| Placebo group | Placebo comparator | Participants will receive IV placebo on Day 1 and Day 15 of the RCP. The participants who entered OLP will receive IV inebilizumab on both Day 1 and Day 15 in OLP and will be followed by IV inebilizumab every 26 weeks. Receives: Drug: Inebilizumab; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in the mRTSS up to the end of the long-term extension period
Measured: baseline, RCP 4, 12, 26, OLP 4,12, 26, the long-term extension period 26, 52, 78, 104 weeks
Secondary outcomes (4)
Pulmonary function tests: Change from baseline in the percent predicted forced vital capacity (%FVC) and percent predicted diffusing capacity of the lung carbon monoxide (%DLco)
Measured: Baseline to at least 52 weeks or early termination
Pulmonary function tests: Percentage change from baseline in the %FVC and %DLco
Measured: Baseline to at least 52 weeks or early termination
Change from baseline in the mRTSS
Measured: Baseline to at least 52 weeks or early termination
Composite response index in diffuse cutaneous systemic sclerosis
Measured: Week 26 to at least 52 weeks or early termination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jan 2022
- Study start20 Jul 2022
- Primary completion31 Jul 2025
- Study completionAug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Systemic SclerosisStudies 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
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tanabe Pharma Corporation
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- General Manager, Study director, Tanabe Pharma Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05198557
- Sponsor's protocol ID
- MT-0551-A-301
- Status last verified
- Dec 2025
- First submitted
- 6 Jan 2022
- Last updated
- 8 Dec 2025
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase 3 Study of MT-0551 in Patients With Systemic Sclerosis (Placebo-Controlled Double-Blind Study)
- ClinicalTrials.gov ID
- NCT05198557
- Acronym / sponsor ID
- MT-0551-A-301
- Conditions
- Systemic Sclerosis
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Tanabe Pharma CorporationIndustry (pharma, biotech, devices)
- Study start
- 20 Jul 2022 (actual)
- Primary completion
- 31 Jul 2025 (actual)
- Study completion
- Aug 2026 (estimated)
- First posted
- 20 Jan 2022 (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 study will verify the superiority of MT-0551 to placebo at 26 weeks after treatment initiation in systemic sclerosis (SSc) patients using the modified Rodnan Total Skin thickness Score (mRTSS) as a measure of skin thickening. The safety and pharmacokinetics will also be investigated.
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 |
|---|---|---|
| MT-0551 group | Experimental | Drug: Inebilizumab, Drug: PlaceboParticipants will receive intravenous (IV) inebilizumab on Day 1 and Day 15 of randomized controlled period (RCP). The participants who entered open label period (OLP) will receive IV inebilizumab on Day 1 and IV placebo on Day 15 of OLP and will be followed by IV inebilizumab every 26 weeks. |
| Placebo group | Placebo comparator | Drug: Inebilizumab, Drug: PlaceboParticipants will receive IV placebo on Day 1 and Day 15 of the RCP. The participants who entered OLP will receive IV inebilizumab on both Day 1 and Day 15 in OLP and will be followed by IV inebilizumab every 26 weeks. |
Who may qualify
- Ages
- 20 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- ACR/European League Against Rheumatism (EULAR) criteria (2013) systemic sclerosis (SSc) diagnostic criteria satisfied.
- Skin thickening score based on the mRTSS between 10 and 22 inclusive.
Key exclusion criteria (10 listed)
- Pulmonary hypertension associated with SSc.
- Presence of a serious, SSc-related concurrent illness other than interstitial pneumonia.
- Finding of inadequate respiratory reserve capacity.
- Past history of rituximab, blinatumomab, obinutuzumab, or ofatumumab.
- Presence of a clinically significant active infection requiring antimicrobial therapy.
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 |
|---|---|---|
| InebilizumabAlso: MT-0551Participants will receive IV inebilizumab. | Drug | MT-0551 group, Placebo group |
| PlaceboParticipants will receive IV placebo matched to inebilizumab. | Drug | MT-0551 group, Placebo group |
Primary outcome
Change from baseline in the mRTSS up to the end of the long-term extension period
Time frame: baseline, RCP 4, 12, 26, OLP 4,12, 26, the long-term extension period 26, 52, 78, 104 weeks
4 secondary outcomes
Pulmonary function tests: Change from baseline in the percent predicted forced vital capacity (%FVC) and percent predicted diffusing capacity of the lung carbon monoxide (%DLco)
Time frame: Baseline to at least 52 weeks or early termination
Pulmonary function tests: Percentage change from baseline in the %FVC and %DLco
Time frame: Baseline to at least 52 weeks or early termination
Change from baseline in the mRTSS
Time frame: Baseline to at least 52 weeks or early termination
Composite response index in diffuse cutaneous systemic sclerosis
Time frame: Week 26 to at least 52 weeks or early termination
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Dec 2025.
- Individual participant dataSharing planned: No
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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.
General Manager study director
Tanabe Pharma Corporation
4 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 Inebilizumab in people with Systemic Sclerosis, run by Tanabe Pharma Corporation at 4 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 3 inclusion and 10 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: under way, not looking for participants, as of the sponsor's last update on 8 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 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?
This study is still under way. Results are not available in the source record yet.
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?
Change from baseline in the mRTSS up to the end of the long-term extension period (time frame: baseline, RCP 4, 12, 26, OLP 4,12, 26, the long-term extension period 26, 52, 78, 104 weeks). 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 8 Dec 2025; AzTrials last refreshed its copy on 6 Nov 2026.