AB1166 DETERMINANTS OF REPOSITORY CORTICOTROPIN INJECTION TREATMENT INITIATION FOR PATIENTS WITH RHEUMATOID ARTHRITIS IN A LARGE CLAIMS DATABASE

Abstract

Background:The treatment goal in rheumatoid arthritis (RA) is sustained remission and prevention of RA flares [1]. While targeted biologics have improved disease outcomes, almost one-third of patients (pts) discontinue treatment by 1 year and 50% by 2 years, with lack of efficacy as the most common reason [2]. Repository corticotropin injection (RCI) is a naturally sourced complex mixture of adrenocorticotropic hormone analogues and other pituitary peptides and is an agonist for all 5 melanocortin receptors (MCRs). Activation of MCRs by RCI has been shown to have direct and indirect anti-inflammatory and immunomodulatory effects. RCI is indicated for adjunctive therapy for short-term administration in RA flares or uncontrolled disease [3].Objectives:To characterize RA pts that initiate RCI therapy and identify predictors of RCI initiation, compared to biologic disease-modifying antirheumatic drugs (DMARDs).Methods:This retrospective cohort study identified pts with ICD-9/10 diagnosis for RA over an 11-year period (2008-2018) in a large claims database (Truven MarketScan®). Adults with ≥1 claim for RCI (RCI cohort) or ≥1 RA-related biologic claim but no RCI (non-RCI cohort) were selected and characterized by demographics, disease severity (Claims-based Index for RA Severity, CIRAS), comorbidities (Charlson Comorbidity Index, CCI), treatment patterns, and healthcare resource utilization in the 12-month baseline (BL) period prior to their index date (i.e., the 1stRCI claim or last claim for biologic for non-RCI cohort). Predictors of RCI initiation were identified by multivariable logistic regression, controlling for demographics and BL characteristics.Results:A total of 393 pts initiated RCI therapy while 188,062 initiated biologic treatment with no RCI claims. At BL, cohorts were similar with respect to mean age (~56 years), gender (76-79% female), and insurance type (79-80% commercial). Cohorts differed by region, plan type, and index year. Compared to non-RCI patients, the RCI cohort had significantly higher CCI and CIRAS scores; higher use of traditional DMARDs (65.6% vs. 61.9%), corticosteroids (CS, 91.3% vs 68.8%), prescription nonsteroidal anti-inflammatory drugs (NSAIDs, 66.9% vs 58.5%), and opioids (67.7% vs 47.5%), but lower biologic use (45.8% vs. 87.7%) (all p<0.05). RCI pts had significantly higher mean number of inpatient, emergency room, office, and outpatient visits (all p<0.05).RCI therapy initiation was most significantly impacted by treatment patterns, including number of DMARDs, CS, and opioids tried in the previous year (Figure 1). Corticosteroid use was the strongest predictor of RCI initiation, especially extended use at any dose (OR≥2.6) and extended use of the highest doses (>15 mg/day, OR=8.5), present in 21% of the RCI cohort (Figure 1). Drug benefit generosity (proportion of out-of-pocket costs) was also associated with RCI initiation in any plan qualified as better than “below average” (OR=2.1-2.9). Anemia, renal disease, and Sjogren’s syndrome were also associated with higher odds of RCI initiation (OR=1.4-2.1).Conclusion:RA pts initiating RCI therapy were prescribed a greater number of traditional DMARDs, CS, and opioids in the previous 12 months compared to non-RCI pts, and have evidence of more severe disease and comorbidities. Extended and high dose CS use were the factors most associated with RCI initiation.