Tocilizumab, a monoclonal antibody that targets the IL-6 receptor to inhibit IL-6 signaling, is approved for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to ≥1 disease-modifying antirheumatic drugs. Although tocilizumab has been known to elevate serum lipid levels in patients with RA, its cardiovascular (CV) effects are unknown. Using 3 US healthcare claims databases (Medicare, Truven MarketScan, and IMS PharMetrics Plus), this population-based cohort study compared the CV risk associated with tocilizumab versus abatacept in adult patients with RA who newly started tocilizumab (n = 6237) or abatacept (n = 14,685).
The study cohort included patients aged ≥18 years, ≥365 days of eligibility prior to index date, and either 1 inpatient or 2 outpatient codes for RA within 365 days from cohort entry for either tocilizumab or abatacept initiators. The primary study outcome was a composite CV end point of hospitalization of any length for myocardial infarction (MI) and stroke based on claims-based algorithms (positive predictive value >94%). Secondary outcomes included the individual end points of MI, stroke, acute coronary syndrome, coronary revascularization, heart failure, and all-cause mortality.
Across the 3 databases (Medicare, n = 1516; MarketScan, n = 9756; PharMetrics, n = 5575), tocilizumab starters experienced a total of 32 CV events, whereas abatacept starters experienced 112 events. In the tocilizumab cohort, the incidence rates of composite CV events per 100 person-years were 0.37 for PharMetrics, 0.42 for MarketScan, and 1.64 for Medicare, for a combined rate of 0.70; and 0.59, 0.68, and 1.69, respectively, in the abatacept cohort, for a combined rate of 0.96. The risk for the primary composite CV events was similar between the 2 treatment groups across all 3 databases, with a combined hazard ratio of 0.82 (95% confidence interval, 0.55-1.22) in tocilizumab initiators versus abatacept initiators. Secondary outcomes of hospitalization for MI, stroke, coronary revascularization, heart failure, and all-cause mortality were also similar between the 2 cohorts.
Based on these results, the authors concluded that patients with RA who newly started tocilizumab faced no increased risk for CV events versus those who started abatacept.
Kim SC, et al. ACR 2017. Abstract 527.