A Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of RO7303509 in Participants With Systemic Sclerosis

Inclusion Criteria:

Inclusion Criteria for the MAD Stage:

Weight of 45-150 kg at screening
Diagnosis of SSc, as defined by 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria and ≤ 10 years disease duration from first non-Raynaud's symptom
Agreement to remain abstinent or use an effective contraceptive method among males and females with childbearing potential for 4 months after last dose of study drug

Inclusion Criteria for the OSE Stage:

No clinically significant change in eligibility status
Completion of the MAD and ability to roll over into the OSE within 5 days

Exclusion Criteria:

Active rheumatic autoimmune disease other than SSc requiring treatment with disease-modifying therapy
Pulmonary disease with forced vital capacity (FVC) ≤ 50% of predicted
History or clinical manifestations of significant metabolic, hepatic, renal, pulmonary, cardiovascular, hematologic, gastrointestinal, urologic, neurologic, or psychiatric disorders
History of severe allergic or anaphylactic reactions to human, humanized, or murine monoclonal antibodies
Pregnant or breastfeeding, or intending to become pregnant during the study or within 4 months after the final dose of study drug
Major surgery within 8 weeks prior to screening, or major planned surgery during the study or within 3 months after the final dose
Positive hepatitis C virus (HCV) antibody, hepatitis B surface antigen (HBsAg), or human immunodeficiency virus (HIV) antibody test at screening
Any serious medical condition or abnormality in clinical laboratory tests