A Phase 1b Study of Budoprutug in Systemic Lupus Erythematosus (SLE)

Inclusion Criteria:

1. Aged 18 to 65 years at the time of consent.

2. Diagnosis of SLE according to the 2019 European League Against. Rheumatism and theAmerican College of Rheumatology (ACR) classification criteria.

3. Active, seropositive disease, with SLEDAI 2K >=8.

4. Inadequate response to at least 2 therapeutic interventions, including at least oneoral immunosuppressive or biologic standard-of care therapy.

Exclusion Criteria:

1. Active neuropsychiatric SLE.

2. History of inflammatory or autoimmune diseases including, but not limited to,rheumatoid arthritis, scleroderma, myositis, vasculitis, inflammatory bowel disease,or other conditions that require immune suppressive therapy. Subjects with stableconcurrent Sjogren's, asthma, or autoimmune thyroid disease may be considered forparticipation.

3. Active systemic infection or history of chronic, recurrent, latent, or recentserious infections.