Repository Corticotropin Injection for Persistently Active Systemic Lupus Erythematosus: Results from a Phase 4, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

INTRODUCTION: We assessed the efficacy and safety of repository corticotropin injection (RCI; Acthar(®) Gel) for persistently active systemic lupus erythematosus (SLE) despite use of moderate-dose glucocorticoids. METHODS: This multicenter, double-blind, randomized, placebo-controlled study enrolled patients ≥ 18 years with active SLE and moderate to severe rash and/or arthritis despite stable glucocorticoid doses (7.5–30 mg/day prednisone equivalent) and antimalarials for ≥ 4 weeks and/or immunosuppressants for ≥ 8 weeks before screening. Stable glucocorticoid doses were required through week 16 with optional taper from weeks 16 to 24. Patients were randomized (1:1) to 80 U RCI subcutaneously or placebo every other day to week 4, then twice weekly to week 24. Endpoints included the proportion of SLE Responder Index (SRI)-4 responders at week 16; changes from baseline to week 16 in 28 Swollen Joint Count/Tender Joint Count (28 SJC/TJC) and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI)-Activity score; and changes from baseline to week 24 in inflammatory cytokines. Safety was assessed by adverse events. RESULTS: In the modified intention-to-treat population (RCI, n = 84; placebo, n = 85), the proportion of SRI-4 responders at week 16 was not significantly different between groups (RCI, 47.6%; placebo, 43.5%; OR [95% CI] 1.2 [0.6 to 2.2]; p = 0.5762). RCI treatment resulted in a reduction from baseline to week 16 in 28 SJC/TJC and CLASI-Activity score and from baseline to week 8 in B-cell activating factor cytokine. Post hoc analyses demonstrated a greater proportion of BILAG-based Combined Lupus Assessment responders for RCI than placebo at weeks 4, 12, and 20 and greater SRI-4 response in RCI-treated patients with baseline SLE Disease Activity Index-2000 ≥ 10 and CLASI-Activity ≥ 11. No new safety signals were identified. CONCLUSIONS: Despite failure to achieve the primary endpoint, these results support the utility of RCI for treating persistently active SLE. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02953821. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40744-020-00236-1) contains supplementary material, which is available to authorized users.