SF-36v2 and FACIT-Fatigue quality of life improvements with organ-specific SELENA-SLEDAI response and belimumab treatment in patients with systemic lupus erythematosus.

Objective: Explore organ-specific SLE burden by assessing health-related quality of life (HRQoL) and fatigue changes associated with Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) organ system response (score improvement) and belimumab treatment.

Methods: Data from four phase III belimumab trials were pooled for post hoc analysis (GSK Study 217382): BLISS-52 (NCT00424476), BLISS-76 (NCT00410384), BLISS-SC (NCT01484496) and EMBRACE (NCT01632241). Patients with baseline organ system involvement were classed as organ system responders if SELENA-SLEDAI scores for that organ system decreased at any post-baseline visit. HRQoL (36-Item Short Form Health Survey version 2 (SF-36v2)) and fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue)) changes over 52 weeks were compared between organ system responders and non-responders, and separately between belimumab versus placebo treatment arms among organ system responders. Group-level differences were compared using analysis of variance; differences were interpreted using published group-level minimal important difference (MID).

Results: In these post hoc analyses, musculoskeletal and mucocutaneous organ system responders had greater SF-36v2 improvements than non-responders across most SF-36v2 domains, but differences were largely MID), with FACIT-Fatigue also improving >MID for renal responders receiving belimumab.

Conclusions: SLE disease burden differs with the organ system(s) involved. While these analyses are limited by mutual inclusivity of organ system groupings, differing patient numbers between groups and small numbers in some groups, they suggest that mucocutaneous and musculoskeletal organ system response improves SF-36v2 domain scores; cardiovascular and respiratory organ system response may meaningfully improve fatigue; and belimumab may offer additional HRQoL or fatigue benefits beyond standard therapy for musculoskeletal and renal responders.