Tibulizumab Systemic Sclerosis Understanding and Response Evaluation (TibuSURE)

The study is a Phase 2, multi-center, randomized, double-blind, placebo-controlled study to evaluate the effects of tibulizumab over 24 weeks (Period 1) in adult participants with systemic sclerosis, followed by an open-label extension period where all active participants will receive tibulizumab and will be evaluated for an additional 28 weeks (Period 2)

Inclusion Criteria: * Male or female, 18 to 75 years of age * Body mass index between 18.0 and 38.0 kg/m² * Fulfills classification criteria for SSc according to ACR/EULAR 2013 criteria * Has diffuse cutaneous SSc, defined as mRSS \>0 over at least one skin area proximal to the elbows and/or knees, in addition to acral fibrosis * Has had SSc (defined as the first non-Raynaud's phenomenon (RP) symptom or sign attributed to SSc) for ≤7 years * mRSS ≥15 and ≤45 at screening. Additional requirements for participants ≥2 years to ≤7 years from SSc onset and RNA Polymerase III antibody positive * FVC \>50% predicted * Diffusing capacity of the lungs for carbon monoxide (DLCO) ≥40% predicted (corrected for hemoglobin) Exclusion Criteria: * Has any of the following complications: * Left ventricular failure * Pulmonary arterial hypertension * Renal crisis within previous 6 months * Gastrointestinal dysmotility within previous 3 months * Digital ischemia with gangrene, amputation, or unscheduled hospitalization within previous 3 months * Current rheumatic disease other than SSc that could interfere with assessment of SSc * Lung disease requiring continuous oxygen therapy * Evidence or suspicion of active or latent tuberculosis * Active Crohn's Disease or ulcerative colitis