Second-line treatment persistence and costs among patients with immune-mediated rheumatic diseases treated with subcutaneous TNF-alpha inhibitors

The objective of this study was to describe treatment persistence with second-line subcutaneous tumor necrosis factor-alpha inhibitors (SC-TNFis) in patients with immune-mediated rheumatic diseases (IMRDs) in Sweden, and the impact of non-persistence on healthcare costs. This retrospective observational study was based on Swedish national health register data. Adults were identified through filled prescriptions for adalimumab (ADA), etanercept (ETA), certolizumab pegol (CZP) and golimumab (GLM). Persistence was estimated over 3 years for propensity score-matched (PSM) cohorts using non-parametric survival analysis. Unadjusted comparisons of costs comprised specialized outpatient care, inpatient care, and medication. In total, N = 845 patients were identified and three PSM cohorts were generated (GLM vs. ADA, ETA, and CZP, respectively). GLM exhibited higher persistence than ADA over the study period (p = 0.040), and numerically higher persistence than ETA and CZP for 36 and 30 months, respectively. Persistent and non-persistent patients had similar mean total cost at 12 month pre-treatment ($5185 vs. $5064, p = 0.750). During the 12 month post-treatment initiation, persistent patients had lower mean total costs ($4377 vs. $6605), corresponding to a cost difference of $2228 (p < 0.001). In second-line treatment with SC-TNFis for IMRDs in Sweden, GLM exhibited significantly higher persistence than ADA over the course of the study. Similarly, GLM showed numerically higher persistence than ETA and CZP, which is concurrent with results observed in first-line SC-TNFi treatment. Considering the lower healthcare costs for persistent patients, the choice of second-line SC-TNFi among eligible patients may merit careful consideration given its impact on patients and payers.