Risk of malignancy associated with use of tocilizumab versus other biologics in patients with rheumatoid arthritis: A multi-database cohort study

Objectives: To examine the rate of incident malignancies excluding non-melanoma skin cancer (NMSC) in patients with rheumatoid arthritis (RA) newly treated with tocilizumab versus other biologic drugs. Methods: We conducted a cohort study using data from 3 U.S. insurance claims databases - Medicare (2010-2015), 'IMS' PharMetrics Plus (2011-2015) and Truven 'MarketScan' (2011-2015). Adults with RA who newly started tocilizumab or a TNF inhibitor (TNFi) after failing a different TNFi, abatacept or tofacitinib were included. The primary outcome was development of any malignancies excluding NMSC. For confounding control, tocilizumab starters were propensity score (PS)-matched to TNFi starters with a variable ratio of 1:3 within each database. Hazard ratios (HR) from the 3 PS-matched cohorts were combined by an inverse variance-weighted, fixed-effects model. We conducted a secondary analysis where we compared tocilizumab initiators with abatacept initiators. Results: We included 13,102 tocilizumab initiators PS-matched to 26,727 TNFi initiators in all three databases. The incidence rate of malignancies per 1,000 person-years ranged from 8.27 (IMS) to 23.18 (Medicare) in the tocilizumab group and from 9.64 (MarketScan) to 21.46 (Medicare) in the TNFi group. The risk of incident malignancies was similar between tocilizumab and TNFi initiators across all three databases, with a combined HR of 0.98 (95%Cl 0.80-1.19) in tocilizumab versus TNFi. The secondary analysis comparing tocilizumab versus abatacept showed similar results (combined HR 0.97, 95%CI 0.74-1.27). Conclusions: This large multi-database cohort study found no difference in the risk of malignancies excluding NMSC in RA patients who newly started tocilizumab compared with TNFi or abatacept. (C) 2019 Elsevier Inc. All rights reserved.