BIOLOGIC SWITCHING RATES AMONG PATIENTS WITH RHEUMATOID ARTHRITIS

Background: Treatment guidelines for the management of RA recommend sequential use of biologic therapies, and the majority of patients switch from one anti-TNF agent to another. Previous data from commercial claims databases have shown that patients on a second-line anti-TNF agent are more likely to switch biologic treatment than those on second-line abatacept, a biologic with a different mechanism of action. This finding has not been studied in a Medicare population. Objectives: To compare subsequent switch rates of patients in a Medicare population who had switched between anti-TNFs and patients who had switched from an anti-TNF to abatacept. Methods: A retrospective, observational analysis using research-identifiable Medicare claims data (January 2006–December 2010) was conducted in patients with RA prescribed an initial biologic DMARD (bDMARD; abatacept, adalimumab, etanercept, infliximab), with a minimum of 6-month, pre-index and 12-month, post-index eligibility. Patients were assigned to the first-line switch cohort if they had a claim for a new bDMARD within 200% days supply of the last claim for initial bDMARD during the12-month follow up. Further analysis in a subgroup of the switch cohort compared first-line anti-TNF patients who switched to another anti-TNF (adalimumab, etanercept, infliximab) with those who switched to abatacept. These two cohorts were followed to determine subsequent switch rates to a third bDMARD. Patients were considered second-line switchers if they had a claim for a new bDMARD within 200% days supply of the last claim for their second bDMARD during 12-month follow up. Logistic regression analysis was conducted to determine anti-TNF to anti-TNF and anti-TNF to abatacept regimens as predictors of subsequent switching, while controlling for covariates (age, gender, socioeconomic status, region, severity of RA, comorbidities and non-biologic RA therapies). Results: Of the 33,026 patients with RA identified who initiated bDMARD therapy (81% anti-TNF and 19% abatacept), first-line switch rates were comparable (anti-TNF: 6.5%; abatacept: 5.7%). Of the 1728 initial anti-TNF patients who switched a second time, 535 switched to another anti-TNF and 739 switched to abatacept. Subsequent switch to a third bDMARD occurred in 7.3% of those who had previously switched to abatacept and 18.9% of those who had previously switched to an anti-TNF. Logistic regression demonstrated that, after adjusting for covariates, patients who switched to abatacept had significantly lower odds of switching again than anti-TNF switchers (odds ratio=0.33, 95% CI: 0.22, 0.51). Conclusions: In a Medicare population, patients with RA who switch between anti-TNFs have significantly higher rates of subsequent bDMARD switch compared with those who switch from an anti-TNF to abatacept. It is hypothesised that treatment pathways that include switching to a different class of bDMARD may reduce subsequent overall bDMARD switch rates and therefore reduce costs in the management of patients with RA. References: 1.Meissner B, et al. Arthritis Rheum 2011;63(Suppl 10): 2198 Disclosure of Interest: L. Rosenblatt Shareholder of: Bristol-Myers squibb, Employee of: Bristol-Myers Squibb, F. Lobo Shareholder of: Bristol-Myers squibb, Grant/research support from: Bristol-Myers squibb, Employee of: Bristol-Myers squibb, P. Cockrum Employee of: Bristol-Myers squibb, L. Wang: None Declared, E. Alemao Shareholder of: Bristol-Myers squibb, Employee of: Bristol-Myers squibb, O. Baser Grant/research support from: Bristol-Myers squibb, H. Yuce: None DeclaredCitation: , volume 72, supplement s3, year 2013, page Session: Poster session Friday ( )