A Study of KHK4827 in Patients With Systemic Sclerosis

Inclusion Criteria: * Subject meets the criteria for diagnosis of the Diagnostic Criteria, Severity Classification, and Clinical Practice Guidelines for Systemic Sclerosis （Japanese Dermatological Association 2016） at the pre-examination * Subject presented the first symptoms of sclerosis other than Raynaud's phenomenon within 60 months before enrollment * Subject who has systemic sclerosis accompanied by moderate to severe skin thickening with an mRSS of 10 to \<30 at the pre-examination and who has progressing skin thickening Exclusion Criteria: 1. Any of the following significant concomitant diseases: * Type 1 diabetes * Poorly controlled type 2 diabetes (HbA1c \> 8.5%) * Congestive heart failure (Class II to IV of the New York Heart Association Functional Classification) * Myocardial infarction, unstable angina, or stroke occurring within 12 months before the first dose of investigational product * Poorly controlled hypertension (systolic pressure \> 150 mm Hg or diastolic pressure \> 90 mg Hg at screening) * Severe chronic lung disease (%Forced Vital Capacity (FVC) \< 60% and %Diffusing capacity of lung for carbon monoxide (DLco) \< 40%, calculated according to the Reference Values for Spirometry, Including Viral Capacity, in Japanese Adults Calculated with the LMS Method and Compared with Previous Values \[Japanese Respiratory Society\]) * Major chronic inflammatory diseases or connective tissue diseases other than scleroderma 2. Patient has a history or evidence of a psychiatric disorder, alcohol and/or substance abuse, or any other mental health disorder that, in the opinion of the investigators, would pose a risk to subject safety or interfere with the study evaluation, procedures or completion 3. Patient has a history or evidence of suicidal ideation (severity of 4 or 5) or any suicidal behavior based on an assessment with the Columbia-Suicide Severity Rating Scale (C-SSRS) at enrollment 4. Patient has severe depression based on a total score of ≥ 15 on the Patient Health Questionnaire-8 (PHQ-8) at enrollment