e55 Analysis of rheumatoid arthritis patients who failed the switch from originator etanercept to biosimilar etanercept in Croydon

Abstract

Background: The introduction of biosimilar medicines has paved the way for the NHS to make substantial savings. Etanercept biosimilar was launched in February 2016 and provided an opportunity for huge savings to be made for the overall health economy. The drug cost was 30% cheaper than etanercept originator. Methods: Croydon Health Services had 193 rheumatoid arthritis patients eligible for the switch. To date, 25 patients (13%) have not switched for various reasons and 168 patients were switched to the biosimilar. The total saving was over £200,000 for Croydon CCG. A monitoring database was set up to follow these patients to ensure safety and efficacy of the new treatment. Results: Of the 168 patients switched, 18 (11%) have switched back to the originator product. The reasons for switchback were lack of efficacy in 11 patients (7%) and intolerance in 7 (4%). The most common intolerances were painful injections, injection site reactions, headache a generally feeling unwell. Since reverting to the originator for lack of efficacy, 11 patients (92%) have shown an improvement in DAS at three months, one patient did not improve so was changed to rituximab and six patients still require DAS assessments. Conclusion: Despite the substantial financial benefits from switching to biosimilar etanercept, these data shows that a significant proportion of patients needed to be switched back to the originator from the biosimilar etanercept; approximately 1 in 10 patients. These patients showed an improvement in over 90% cases demonstrating that the switch backs were effective and appropriate. Surveillance of these patients is required to ensure safety and efficacy. These results demonstrate the complexity of biologic therapies and the need for careful assessment and monitoring of those patients switched from an originator biologic to a biosimilar.