Abstract
OBJECTIVES: Adults with RA are being switched from etanercept originator to biosimilar in non-medical/cost-saving switching. This analysis aims to investigate outcomes in these patients, including (i) drug survival and (ii) disease activity at 6 months and 12 months, compared with those who remain on the originator. METHODS: Using BSRBR-RA, those who switched directly from etanercept originator to biosimilar were identified and matched to patients receiving the originator, based on gender, age, disease duration and originator start year. Drug survival was calculated; Cox-proportional hazard models assessed differences in drug persistence between those who switched vs remaining on originator. Change in DAS28 after 6 months and 12 months was compared between cohorts. Multiple imputation was used. RESULTS: A total of 1024 adults with RA switching from etanercept originator to biosimilar were included, with a matched cohort of patients remaining on the originator. Patients who switched onto a biosimilar product were no more likely to discontinue etanercept treatment vs those who remained on the originator; hazard ratio 1.06 (95%CI 0.89-1.26), with 65% of patients remaining on treatment at three years. Ninety-five (9%) patients switched back to the originator within the first year. After 6 months and 12 months, biosimilar patients were no more likely to have a worsening of DAS28 (>0.6 units) compared with those who remained on the originator. CONCLUSIONS: This is the largest matched comparative effectiveness analysis showing patients switching from etanercept originator to biosimilar appearing to do just as well with regard to disease activity and drug persistence compared with those who remained on the originator. These data will be reassuring to clinicians and patients regarding non-medical switching.