The monoclonal antibody CT-P13 is a biosimilar of infliximab. Owing to a lack of confidence amongst gastroenterologists in using this drug for patients with IBD, a prospective, multicentre study was conducted to examine the safety, efficacy and immunogenicity of CT-P13 for the treatment of Crohn's disease and ulcerative colitis (n = 210). The investigators found that CT-P13 induced and maintained high clinical remission and response rates in IBD. However, patients with previous infliximab exposure showed markedly decreased responses and were more prone to allergic reactions.