THE IBD BIOSIMILAR TO BIOSIMILAR SWITCHING STUDY (IBISS)

IntroductionIn 2013, the first biosimilar of infliximab was approved for use by the European Medicines Agency for the same indications as originator infliximab. The regulatory pathways involved compare the biosimilar with the originator only in controlled settings and not with other biosimilars. With the development of multiple biosimilars, patients may be asked to transition from one to another. There is a clear gap in the evidence with little data on switching between biosimilars. The aim of this study was to evaluate the clinical outcome of switching a cohort of IBD patients from CT-P13 to SB2 in a real-world setting, as well as explore the patient experience of having their medication switched.MethodsThis was a prospective, phase IV interventional study at University Hospital Southampton. Patients treated with CT-P13 (6/8 weekly regime at 5mg/kg) were approached and were switched to SB2. Demographics, disease history, validated disease activity scores (partial Mayo Score for UC and modified Harvey-Bradshaw Index for Crohn’s), patient reported outcome measures (IBD Control PROM and PRO2) and laboratory measurements (full blood count, C-reactive protein, albumin and faecal calprotectin) were collected at each visit. Semi-structured qualitative interviews were also conducted to explore the patient experience of having their medication switched and were analysed using thematic analysis.Results133/158 patients approached participated in iBiSS with a mean disease duration of 9.2 years. The primary objective was clinical outcome at week 30/32. The mean mHBI and pMCS at week 0 vs week 30/32 were 3.14 vs 2.9 and 1.53 vs 1.18 (p=0.77) respectively. The IBD Control-8 score for the whole cohort was 11.75 vs 13.19 (p=0.005) and the IBD Control-VAS was 75.24 vs 79.59 (p=0.57). 35 patients discontinued during the study (6 lost to follow-up, 12 due to adverse events, 4 withdrew consent, 13 for other reasons). There were 16 serious adverse events and no fatal adverse events. Interviews were conducted on 26 participants. Six major themes were identified that reflected the patient experience. These included confidence through information, worry through information, trust in the clinical team, barriers to switching, motivators for switching and the fragility of their condition.ConclusionsThe data presented here suggests there is no detrimental effect on the clinical outcomes of patients switched from one biosimilar of infliximab to another which is vital information to guide clinical practice.