A Study to Assess the Efficacy and Safety of Efgartigimod PH20 SC in Adults With Systemic Sclerosis

Inclusion Criteria: * Is aged ≥18 years and the local legal age of consent for clinical studies * Has diffuse or limited SSc diagnosis and fulfills the 2013 ACR/EULAR classification criteria * Has a positive antinuclear antibodies (ANA) test result at the central laboratory with titer of at least 1:160 * Has a Health Assessment Questionnaire-Disability Index (HAQ-DI) score of at least 0.5 OR a Patient Global Assessment (PGA) score of at least 3 * Has a modified Rodnan Skin Score (mRSS) score between 15 and 35 * The participant is anti-RNA polymerase III autoantibody negative at central laboratory and had the first non-Raynaud's phenomenon manifestation less than 5 years before screening or the participant is anti-RNA polymerase III autoantibody positive at central laboratory and had the first non-Raynaud's phenomenon manifestation less than 2 years before screening * Has uninvolved or mildly thickened skin area in at least 1 injection site Exclusion Criteria: * Isolated anticentromere antibodies (ACA) seropositivity at the central laboratory * Significant Pulmonary Arterial Hypertension * Severe digital vasculopathy within the past 3 months * Skin thickening due to scleroderma mimics or localized scleroderma * Scleroderma renal crisis within the past 6 months of participating to the study * Another rheumatic autoimmune disease, except for secondary Sjögren's syndrome or fibromyalgia