The study will evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of cevostamab in participants with systemic lupus erythematosus (SLE) with or without active lupus nephritis (LN).
Diagnosis of SLE according to the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) Classification Criteria at least 6 months prior to the first screening visit
Active biopsy-proven LN established within 9 months of screening, demonstrating LN per 2018 Revised International Society of Nephrology/Renal Pathology Society (ISN/RPS) criteria
Diagnosis of active SLE disease, as demonstrated by the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score
Inadequate response or intolerance to, in the investigator's judgement, standard of care regimens for active SLE with or without LN
Pregnant or breastfeeding, or intending to become pregnant during the study or within the timeframe in which contraception is required
Treatment with investigational or non-investigational biologic therapies that directly deplete B cells (e.g., anti-CD20 or anti-CD19 monoclonal antibodies) (or blinded comparators) is prohibited within 6 months or 5 drug elimination half-lives, whichever is longer, prior to screening and during the study
Treatment with investigational biologic therapies that do not directly deplete B cells (or blinded comparators) is prohibited within 90 days or 5 drug elimination half-lives, whichever is longer, prior to initiation of study drug and during the study
Treatment of SLE/LN with non-investigational biologic therapies that do not directly deplete B cells (e.g., belimumab, anifrolumab) is prohibited within 4 weeks prior to screening and during the study