P590 Reasons for Discontinuation and Switch of Biologic Therapy in IBD: Findings from a Large International Observational Study (03)

Background: Data on reason for change of biologic therapy mostly comes from clinical trials and hospital case series. This interim analysis presents data on reasons for change of biologic therapy among participants in the vedolizumab Post Authorisation Safety Study (PASS). Methods: The vedolizumab PASS study is a multicentre prospective observational cohort study of adult IBD patients starting or switching to a new biologic agent in 23 countries in North America and Europe. This analysis focused on patients recruited up to 30 September 2016, who at recruitment were biologic experienced and initiating a new biologic therapy. Changing from one anti-TNFα agent to a biosimilar of the same agent was not considered as starting a new biologic in this study. As part of baseline data collection, treating physicians reported the reason for discontinuation of previous biologic therapy for the study participants. Results: 300 IBD patients in the cohort study had discontinued a previous anti-TNFα agent and started vedolizumab (n=231) or a new anti-TNFα agent (n=69). The majority had used only one previous biologic (68% of UC and 62% of CD patients). Among UC patients switching to vedolizumab, the leading reasons for discontinuation of previous anti-TNFα treatment were lack of response (45%), loss of response (29%) and (28%). For UC patients switching to a new anti-TNFα agent, the leading reasons for discontinuation were also lack of response (32%), loss of response (23%) and intolerance/adverse event (14%). Among CD patients switching to vedolizumab, the leading reasons for discontinuation of pervious anti-TNFα agent were loss of response (32%) and intolerance/adverse event (19%). Among CD patients switching anti-TNFα agents, the main reasons for discontinuation of the previous agent were loss of response (28%), lack of response (21%) and intolerance/ adverse event (13%). Concurrent thiopurine use was common in the study population, with 23–26% of patients on thiopurine medication when switching biologic agent. Conclusions: This interim analysis of biologic use in clinical practice found the most frequent reason for discontinuation of previous anti-TNFα in UC was lack of response (primary non-response). Conversely in CD, the most frequent reasons for discontinuation of previous anti-TNFα were loss of response (secondary failure). Among patients changing from an anti-TNFα to vedolizumab, intolerance/adverse event was an important reason for changing therapy.