AB0345 Comparative Effectiveness of Biologic Agents for Patients with Rheumatoid Arthritis – Primary Analysis from The US Corrona Certain Study

BackgroundComparative effectiveness research (CER) can inform decisions regarding the choice of biologics for the treatment of RA.ObjectivesTo compare the efficacy of tumor necrosis factor inhibitors (TNFis) and non-TNFis (nTNFis) in real-world patients with RA previously treated with ≥1 TNFi.MethodsCERTAIN was a CER study nested within the US Corrona registry.1 Adult patients with RA with moderate to high disease activity (CDAI >10) starting a TNFi or nTNFi (physician-driven choice of agent) were enrolled. For the primary analysis, only patients previously treated with ≥1 TNFi were included. The primary outcome was achievement of low disease activity (LDA) at 12 months (CDAI ≤10). A propensity score (PS) for the probability of treatment with a TNFi vs nTNFi was generated; patients outside the common area of support in the PS were excluded. Response rate was modeled using a mixed-effect logistic regression model with start of a biologic as the unit of analysis, adjusting for a priori and imbalanced baseline factors and to account for the clustering of patients within practice sites. As a sensitivity analysis, patients were matched 1:1 on the PS within each site.ResultsOf the 2795 biologic starts captured, 1142 biologic naive and 562 nTNFi experienced were excluded, leaving 1091 biologic starts in 998 patients for analysis of response after a TNFi. After PS trimming, 1081 starts (566 [52.4%] nTNFi and 515 [47.6%] TNFi) remained. Patients who started nTNFis were significantly more likely to have longer disease duration, higher patient fatigue scores, Medicare insurance and more prior TNFi use. At 12 months, 29.4% of nTNFi and 24.3% of TNFi initiators were in LDA. In the adjusted analysis (Table), patients on nTNFis were significantly more likely to achieve LDA. However, when adjusting for site clustering, the results were no longer significant.Table 1.Adjusted ORs of achieving LDA after failure of ≥1 prior TNFinTNFi vs TNFi Initiation*OR (95% CI)P ValuePartially adjusted logistic regression model (n=963)1.55 (1.12–2.13)0.008Fully adjusted mixed model with adjustment for siteq clustering (n=963)1.17 (0.82–1.67)0.382Sensitivity analysis, 1:1 matching on PS within site (n=292)0.81 (0.48–1.36)0.428LDA, low disease activity; nTNFi, non-TNFi; OR, odds ratio; PS, propensity score; TNFi, tumor necrosis factor inhibitor. *Adjusted for number of prior TNFis, duration of RA, seropositivity, fatigue, baseline CDAI, insurance status, baseline methotrexate and steroid use