The Experience with Biosimilars of Infliximab in Inflammatory Bowel Disease

Background: biosimilars are similar versions of existing innovator biologic agents but with distinct manufacturing processes. They were approved in inflammatory bowel disease (IBD) by extrapolation of indication from rheumatic diseases. As regulatory requirements for biosimilar approval focus on pre-clinical evidence of similarity rather than clinical data on efficacy, safety and immunogenicity, it is critical to review clinical evidence supporting their use in IBD in order to overcome reluctance from patients and clinicians alike. Objective: to review clinical studies using infliximab (IFX) biosimilars in IBD. Method: we reviewed PubMed for original articles published up to July 1st 2017, reporting data on efficacy and/or safety of IFX biosimilars in IBD. Results: 23 observational studies were found, 12 of them assessing switch from IFX originator to biosimilar and 17 assessing induction therapy with IFX biosimilar. Efficacy, safety and immunogenicity were compared, generally yielding similar results for originator and biosimilar IFX. So far only one randomized controlled trial assessed switching from originator to biosimilar IFX and it was not powered to show similarity in IBD. Ongoing trials are comparing IFX biosimilar and originator head to head in patients in remission, as well as switch versus reverse-switch. Current IBD clinical guidelines are discussed as well as future perspectives for biosimilars in IBD. Conclusion: observational studies seem to confirm biosimilarity in a real-world clinical setting. Current trials are expected to elucidate the remaining doubts about clinical biosimilarity.