Background Several biological disease-modifying antirheumatic drugs (bDMARDs) are approved for the treatment of moderate-to-severe RA. Switching between bDMARD therapies is common in real-world settings, and may have an impact on healthcare costs.
Objectives To evaluate bDMARD switching and associated healthcare costs in patients with RA across two commercially insured populations in the US.
Methods Two retrospective cohort studies of adult patients with RA who initiated a bDMARD were conducted using US commercial insurance claims databases. Patients were categorized into first- and second-line bDMARD cohorts. The first-line bDMARD cohort included patients who newly initiated a bDMARD (adalimumab, etanercept, infliximab or abatacept). The second-line bDMARD cohort included patients who initiated a second bDMARD. Patients in both first- and second-line bDMARD cohorts were required to have continuous eligibility 6 months before (pre-index) and 12 months after (post-index) initiation of first- or second-line bDMARD treatment. Patients in both cohorts were categorized into switchers and non-switchers. Switchers had a claim for a different bDMARD within a 200% gap in days supply for the index bDMARD. Non-switchers stayed on their index bDMARD in the post-index period. Switch rates were compared for each bDMARD. Patients who discontinued their index bDMARD and did not switch in the post-index period were excluded from the analyses. Rates of bDMARD switching, and pre- and post-index healthcare costs for switchers and non-switchers were examined.
Results The first- and second-line bDMARD cohorts included 9757 and 2174 patients, respectively, in Study 1, and 6320 and 1297 patients, respectively, in Study 2. In both studies, rates of switching for the first- and second-line bDMARD cohorts were lower for abatacept compared with adalimumab, etanercept and infliximab (Table 1). Pre- and post-index healthcare costs in both studies were higher for first- and second-line bDMARD switchers compared with non-switchers (Table 2).
Conclusions Patients on first- or second-line abatacept switched less frequently than patients on other bDMARDs. Post-index monthly healthcare costs were higher for first- and second-line bDMARD switchers versus non-switchers, suggesting there may be an economic benefit to using abatacept as the first- or second-line bDMARD in patients with moderate-to-severe RA.
Disclosure of Interest A. Nadkarni Employee of: Bristol-Myers Squibb, F. Lobo Employee of: Bristol-Myers Squibb, T. Juday Employee of: Bristol-Myers Squibb