Biosimilar switching in IBD: safety, efficacy, and immunogenicity in 10,812 patients - A systematic review and...

Biosimilars of infliximab and adalimumab are increasingly adopted in inflammatory bowel disease (IBD) to reduce healthcare costs, but concerns persist regarding their long-term efficacy, immunogenicity, and safety post-switch. This meta-analysis synthesizes contemporary evidence on outcomes after transitioning from originators to biosimilars.

We systematically searched PubMed, Embase, MEDLINE, and conference abstracts (inception-June 2025) to identify randomized controlled trials (RCTs) and observational studies comparing biosimilars (CT-P13, SB2, SB5, etc.) with originators in IBD. Primary outcomes included clinical remission, discontinuation rate, adverse events (AEs), C-reactive protein (CRP), and fecal calprotectin (FCAL), and anti-drug antibody (ADA) incidence. Risk of bias was assessed using Cochrane and Newcastle-Ottawa tools. Pooled odds ratios (ORs) and event rates were calculated using random-effects models.

Among 37 studies (36 observational, 1 RCTs) encompassing 10812 IBD patients, biosimilars demonstrated comparable clinical remission rates pre- and post-switch in Crohn's disease (CD) (OR = 0.87, 95% CI: 0.74-0.96) and ulcerative colitis (UC) (OR = 1.25, 95% CI: 0.83-1.90). Biomarkers (CRP, fecal calprotectin) remained stable post-transition. Pooled discontinuation rates were 13% (range: 2-36%) after switching. Safety profiles were similar between biosimilars and originators, ADA incidence (OR = 0.96, 95% CI: 0.46-2.02) showed no significant differences. Heterogeneity stemmed from differences in follow-up duration, disease subtype (CD vs. UC), and variable outcome definitions.

Biosimilars maintain comparable efficacy, safety, and immunogenicity to originators in IBD, supporting their use in single or multiple switching scenarios. Standardized reporting of mucosal healing, drug monitoring, and economic metrics is critical to optimize biosimilar adoption in real-world practice.