A Phase 1 Open-label Study to Evaluate Safety in Healthy Participants and Participants With Autoimmune Diseases

Inclusion Criteria: Healthy participants - Adult participants in good health Idiopathic inflammatory myopathy (IIM) participants - Adult participants that meet the 2017 European Alliance of Association Rheumatology (EULAR)/American College of Rheumatology (ACR) Classification Criterion for IIM Systemic sclerosis (SSc) participants - Adult participants that meet the 2013 ACR/EULAR Classification Criteria for SSc Sjogren's Disease participants that meet the 2016 ACR/EULAR Classification Criteria for Primary Sjogren's Syndrome All participants - Use of highly effective methods of contraception Exclusion Criteria: * Major surgery within 12 weeks prior to dosing or planned within the study * Recurrent infections or active clinically significant infection * Active or untreated latent tuberculosis * Cancer or history of cancer or lymphoproliferative disease within the previous 5 years * Uncontrolled cardiovascular, pulmonary, renal, hepatic, endocrine, or gastrointestinal disease Note: Additional, more specific inclusion/exclusion criteria are defined in the protocol.