Repository Corticotropin Injection for Active Rheumatoid Arthritis Despite Aggressive Treatment: A Randomized Controlled Withdrawal Trial

INTRODUCTION: The objective of this study was to assess efficacy and safety of repository corticotropin injection (RCI) in subjects with active rheumatoid arthritis (RA) despite treatment with a corticosteroid and one or two disease-modifying antirheumatic drugs (DMARDs). METHODS: All subjects received open-label RCI (80 U) twice weekly for 12 weeks (part 1); only those with low disease activity [LDA; i.e., Disease Activity Score 28 joint count and erythrocyte sedimentation rate (DAS28-ESR) < 3.2] were randomly assigned to receive either RCI (80 U) or placebo twice weekly during the 12-week double-blind period (part 2). The primary efficacy endpoint was the proportion of subjects who achieved LDA at week 12. Secondary efficacy endpoints included proportions of subjects who maintained LDA during weeks 12 through 24 and achieved Clinical Disease Activity Index (CDAI) ≤ 10 at weeks 12 and 24. Safety was assessed via adverse event reports. RESULTS: Of the 259 enrolled subjects, 235 completed part 1; 154 subjects (n = 77 each for RCI and placebo) entered part 2, and 127 (RCI, n = 71; placebo, n = 56) completed. At week 12, 163 subjects (62.9%) achieved LDA and 169 (65.3%) achieved CDAI ≤ 10 (both p < 0.0001). At week 24, 47 (61.0%) RCI-treated and 32 (42.1%) placebo-treated subjects maintained LDA (p = 0.019); 66 (85.7%) RCI-treated and 50 (65.8%) placebo-treated subjects maintained CDAI ≤ 10 (p = 0.004). No unexpected safety signals were observed. CONCLUSIONS: RCI was effective and generally safe in patients with active RA despite corticosteroid/DMARD therapy. By week 12, > 60% of patients achieved LDA, which was maintained with 12 additional weeks of treatment. Most patients who achieved LDA maintained it for 3 months after RCI discontinuation. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02919761. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40744-020-00199-3) contains supplementary material, which is available to authorized users.