Systemic Lupus Erythematosus (SLE) Responder Index response is associated with global benefit for patients with SLE

A post-hoc analysis of pooled data from two Phase IIb trials (sifalimumab; NCT01283139, anifrolumab; NCT01438489) assessed the clinical significance of a Systemic Lupus Erythematosus (SLE) Responder Index (SRI(4)) response (Week 52) for 736 patients with moderate to severe SLE disease activity (study entry). SRI(4) responders achieved significantly greater improvements in clinical outcome measures (including percentages of patients with a ≥ 7-point reduction in SLE Disease Activity Index (SLEDAI)-2000 (2K), British Isles Lupus Assessment Group "A" or "2B" flare rate, and oral corticosteroid reduction to ≤7.5 mg/day; change from baseline in Physician's Global Assessment; and numbers of SLEDAI-2K organ domains with improvement), as well as in patient-reported outcomes (Patient's Global Assessment, Functional Assessment of Chronic Illness Therapy-Fatigue; Short-Form 36 Health Survey Physical Component Summary, Mental Component Summary, Vitality domain scores) vs. nonresponders. Of patients with abnormal serologies, SRI(4) responders had numerically greater improvements (baseline to Week 52) in anti-double-stranded DNA concentrations vs. nonresponders ( p = 0.051), but there were no differences in C3/C4 concentration changes between the two groups. These results confirm previous findings in a different cohort, indicating that an SRI(4) response is associated with global clinical benefit.