An Update on Anti-TNF Biosimilar Switching-Real-World Clinical Effectiveness and Safety.

Background: Biological medications for inflammatory bowel disease (IBD) account for a significant burden on provincial budgets. In an effort to curb these rising costs, nationwide switching to biosimilars is expected to be complete in Canada before the end of 2023. Biosimilar products do not require the same rigor for licensing as the originator and therefore there has been appropriate scepticism as to how biosimilars will perform in real-world practice. Methods: We have performed a systematic review including real-world observational studies of adult patients with IBD. The primary outcome was clinical effectiveness and/or safety in patients who had switched from originator to biosimilar anti-TNF. Secondary outcomes included loss of response (LOR), treatment persistence or cessation and immunogenicity. Results: We included 43 studies (7,462 patients [70 percent Crohn's disease: 30 percent ulcerative colitis]; 32 infliximab studies, and 11 adalimumab studies). For infliximab, 75 percent patients were in clinical remission at the time of switch and 75 percent maintained clinical remission beyond 12 months, compared to 78 percent of patients who continued originator. For adalimumab, 86 percent patients were in remission at the time of switch with 82 percent maintaining remission at 6 months follow-up. Injection site pain was higher in patients who switched to a citrate containing adalimumab biosimilar, compared with those who continued originator. All other outcomes (LOR, treatment cessation or persistence and serious adverse events) were similar to patients who continued originator (in comparator cohorts or the available literature). Conclusion: Whilst ongoing vigilance is required, these data are reassuring to both patients and clinicians and will significantly help to reduce health-care costs across Canada.