Systemic Lupus Erythematosus Disease Activity Score Remission and Low Disease Activity States Discriminate Drug From Placebo and Better Health‐Related Quality of Life

Objective Our objective was to evaluate the ability of Systemic Lupus Erythematosus Disease Activity Score (SLE‐DAS) remission and low disease activity (LDA) to discriminate active drug from placebo and to discriminate outcomes in the patients’ perspective (health‐related quality of life [HR‐QoL]) in SLE trials. Methods This was a post hoc analysis of the pooled Belimumab in Subjects With SLE (BLISS)‐52 (NCT00424476) and BLISS‐76 (NCT00410384) trials data. SLE‐DAS remission and LDA attainment and discrimination between belimumab and placebo at 52 weeks were compared using chi‐square tests. At week 52, 36‐item Short Form Health Survey (SF‐36) and Functional Assessment of Chronic Illness Therapy Fatigue (FACIT‐F) scores were compared between patients attaining SLE‐DAS remission versus nonremission and SLE‐DAS LDA versus non‐LDA using the t ‐test and Mann‐Whitney test. Mean changes from week 0 to 52 in SF‐36 and FACIT‐F scores were compared between groups using multivariate regression analysis adjusted for baseline scores. Results At week 52, significantly more patients attained SLE‐DAS LDA taking belimumab 1 mg/kg (17.9% vs 13.0%; P = 0.023; odds ratio [OR] 1.459; relative risk [RR] 1.377; number needed to treat [NNT] 20.4) and 10 mg/kg (21.7% vs 13.0%; P < 0.001; OR 1.853; RR 1.668; NNT 11.5) compared with placebo. Likewise, more patients attained SLE‐DAS remission taking belimumab 10 mg/kg compared to placebo (14.7% vs 10.1%; P = 0.019; OR 1.532; RR 1.454; NNT 21.7). At week 52, patients attaining SLE‐DAS remission and LDA presented higher SF‐36 domain and summary scores (all P < 0.001) and FACIT‐F scores (both P < 0.001). Mean improvements from baseline in SF‐36 and FACIT‐F scores were significantly higher in patients achieving SLE‐DAS remission and LDA. Conclusion SLE‐DAS remission and LDA showed discriminant ability for identifying patients receiving active drug in SLE clinical trials. Attainment of these SLE‐DAS targets are associated with better HR‐QoL.