Clinical trial parameters that influence outcomes in lupus trials that use the systemic lupus erythematosus responder index

Abstract Objective The SLE Responder Index (SRI) is a composite endpoint used in SLE trials. This investigation examined the clinical trial elements that drive response measured by the SRI. Methods Analyses are based on data from two phase 3 trials (n = 2262) that evaluated the impact of an anti-B-cell activating factor antibody on disease activity using SRI-5 as the primary endpoint (ClinicalTrials.gov NCT01196091 and NCT01205438). Results The SRI-5 response rate at week 52 for all patients was 32.8%. Non-response due to a lack of SLEDAI improvement, concomitant medication non-compliance or dropout was 31, 16.5 and 19.1%, respectively. Non-response due to deterioration in BILAG or Physician's Global Assessment after SLEDAI improvement, concomitant medication compliance and trial completion was 0.5%. Disease activity in three SLEDAI organ systems was highly prevalent at baseline: mucocutaneous, 90.6%; musculoskeletal, 82.9%; and immunologic, 71.6%. Disease activity in each of the other organ systems was