Study to Evaluate Efficacy, Safety, and Tolerability of MT-7117 in Subjects With Diffuse Cutaneous Systemic Sclerosis

Additional screening criteria check may apply for qualification.

Inclusion Criteria

• Subjects who meet all the following criteria will be considered eligible to participate in the study:
• Must provide signed and dated informed consent form (ICF) to participate in the study. Subjects must be able to (in the judgment of the Investigator) understand the nature of the study and all risks involved with participation in the study. Subjects must be willing to cooperate and comply with all protocol restrictions and procedures including study visits.
• Male or female age ≥ 18 years at screening with documented diagnosis of systemic sclerosis (SSc), as defined using the 2013 ACR/European League Against Rheumatism (EULAR) criteria.
• Has diffuse cutaneous form of SSc according to Leroy and Medsger's criteria.
• Disease duration ≤ 5 years from the first non-Raynaud's phenomenon manifestation.
• Has an mRSS of 15 to 45 units at screening and have clinical skin involvement proximal and distal to the elbows, knees, or both or any truncal involvement, with or without face involvement.
• If disease duration is > 24 months defined as time from the first non Raynaud phenomenon manifestation, subject must fulfill at least 1 of the criteria listed below that are indicatives of active disease at screening:
• A documentation of new skin involvement that occurred within the past 9 months, or
• Increase in mRSS ≥ 3 units within the past 9 months, or
• Presence of TFRs or,
• C- reactive protein (CRP) ≥ 6 mg/L, or
• Erythrocyte sedimentation rate ≥ 28 mm/hr, or
• Platelet count ≥ 330 x 10^9/L (330,000/microliter).

NOTE: Investigator should exclude all other acute intercurrent illness if subjects fulfilling laboratory criteria (d, e, f) only.

• Willing to follow restrictions regarding concomitant medications that are described.
• Female subjects who are non-lactating and have a negative urine pregnancy test at baseline visit prior to receiving the first dose of study drug.
• Female subjects of childbearing potential and male subjects with partner of child-bearing potential currently using/willing to use 2 effective methods of contraception including barrier method as described.

Exclusion Criteria

• Subjects will be excluded from the study if any of the following criteria apply:
• Has a history or presence of rheumatic autoimmune diseases other than dcSSc unless the dominant features of the disease are dcSSc, as determined by the Investigator.
• Has a pulmonary disease with FVC ≤ 50% of predicted at time of screening.
• Has a diagnosis of clinically significant resting pulmonary hypertension (if exceeding estimated right ventricular systolic pressure of > 40 mmHg estimated by transthoracic echocardiography [unless the right heart catheterization is normal within the last 6 months] or mean pulmonary artery pressure > 30 mmHg as measured by right heart catheterization) and requires treatment with more than one oral medication.
• Has a cardiac abnormality such as left ventricular failure with ejection fraction 1.5 × ULN at screening.
• Has a history or presence of clinically significant disease not related to SSc [neurologic, renal, endocrinal, gastrointestinal cardiovascular, hepatic, dermatologic, hematological, musculoskeletal, genitourinary, thromboembolic, advanced arteriosclerosis, hyperthyroidism, moderate to severe hypertension, immunologic disease, pulmonary (e.g., uncontrolled asthma, emphysema, chronic obstructive pulmonary disease) or any other disorder] as determined by the Investigator at screening. Conditions deemed not-clinically significant according to the Investigator's discretion are acceptable.
• Has a history or presence of psychiatric disease judged to be clinically significant by the Investigator and which may interfere with the study evaluation and/or safety of the subject.
• Has any clinically significant disease or laboratory abnormality judged to be clinically significant by the Investigator an