RESUMO
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 (a) drug survival and (b) disease activity at six and 12-month, compared with those who remain on originator. METHODS: Using BSRBR-RA, those who switched directly from etanercept originator to biosimilar were identified and matched to patients receiving originator, based on gender, age, disease duration, originator start year. Drug survival was calculated; Cox-proportional hazard models assessed differences in drug persistence between those who switched versus remaining on originator. Change in DAS28 after six and 12-months was compared between cohorts. Multiple imputation was used. RESULTS: 1024 adults with RA switching from etanercept originator to biosimilar were included, with a matched cohort of patients remaining on originator. Patients who switched onto a biosimilar product were no more likely to discontinue etanercept treatment versus those who remained on 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 originator within the first year. After six and 12-months, biosimilar patients were no more likely to have a worsening of DAS28 (>0.6units) compared with those who remained on originator. CONCLUSIONS: This is the largest matched comparative effectiveness analysis showing patients switched from etanercept originator to biosimilar appear to do just as well with regards to disease activity and drug persistence compared with those who remained on originator. These data will be reassuring to clinicians and patients regarding non-medical switching.
RESUMO
OBJECTIVES: Etanercept biosimilars show comparable efficacy to their originators among biologic-naïve patients with RA in randomized controlled trials. Nationwide guidelines have obligated prescribing of etanercept biosimilars from 2016, resulting in significant cost savings. This analysis aimed to compare the effectiveness of etanercept originator vs etanercept biosimilar amongst biologic-naïve RA patients treated in routine clinical practice in the UK. METHODS: Biologic-naïve RA patients starting etanercept in the British Society for Rheumatology Biologics Register in Rhematoid Arthritis (BSRBR-RA) cohort study from 2010 were included. Data collected at start of therapy includes patient demographics and disease activity. Follow-up data includes changes in disease activity and anti-rheumatic therapy. Six- and 12-month primary outcomes include DAS for 28-joints (DAS28) remission, EULAR response and minimal clinically important difference in function. Etanercept drug survival was assessed using Kaplan-Meier and Cox regression, including reasons for treatment withdrawal. Multiple imputation accounted for missing data. Propensity-decile adjustment was used to account for confounding by indication. RESULTS: A total of 1806 biologic-naïve RA patients started etanercept: 1009 originator, 797 biosimilar. At 6 and 12 months, the proportion of patients achieving DAS28 remission and EULAR response were similar between treatments. During follow-up, 19% of originator patients switched onto etanercept biosimilar. Patients were censored at time of switch. Patients on originator were no more likely to stop therapy vs biosimilar; 71% of originator and 76% of biosimilar patients remained on therapy at 1 year. CONCLUSIONS: In one of the largest analyses of patients with RA, biologic-naïve RA patients treated with etanercept originator showed similar outcomes vs biosimilar using real-world data. Drug survival, and disease activity after 6 and 12 months of therapy, was similar between cohorts.