THU0387 Effects of Blisibimod, An Inhibitor of B Cell Activating Factor, On Patient Reported Outcomes and Disease Activity in Patients with Systemic Lupus Erythematosus

BackgroundBlisibimod (A-623, AMG 623), a potent and selective inhibitor of B-cell activating factor (BAFF), was evaluated in the phase 2b clinical trial PEARL-SC (NCT01162681) in patients with systemic lupus erythematosus (SLE). Effects of blisibimod on disease activity and safety were reported previously [1].ObjectivesTo conduct secondary endpoint analyses of the effects of subcutaneously-administered blisibimod on patient-reported outcomes from the PEARL-SC trial.Methods547 SLE patients who met the ACR classification criteria, had anti-double-stranded DNA or anti-nuclear antibodies, and SELENA-SLEDAI score ≥6 at baseline, were randomized in the PEARL-SC study 1:1 to receive placebo or blisibimod administered at 1 of 3 dose levels, 100 mg weekly (QW), 200 mg QW, or 200 mg every 4 weeks for up to 52 weeks (with a median of 37 weeks) or until the last subject completed 6 months of study drug therapy. Patient self-reported outcomes were evaluated using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale, and disease activity was evaluated utilizing both SELENA-SLEDAI and BILAG.ResultsSignificant improvements in measures of disease activity in subjects with severe disease (defined as baseline SELENA-SLEDAI score≥10 and receiving steroids), especially at the highest blisibimod dose of 200mg QW, were reported previously [1]. Approximately 76% of subjects had SELENA-SLEDAI musculoskeletal involvement at enrollment, and 89% of subjects had mucocutaneous involvement. At Week 24, approximately 12% and 39% of subjects randomized to the 200mg QW blisibimod arm had musculoskeletal or mucocutaneous organ involvement, compared with approximately 15% and 42% respectively in the placebo arm (p