Real-World Data Suggest Long-Term Safety of CT-P13 in IBD, RA

The MEGA-J study assessed the safety of the infliximab biosimilar CT-P13 (Inflectra) after switching from the reference product (Remicade) in Japanese patients with Crohn disease (CD), ulcerative colitis (UC), and rheumatoid arthritis (RA). Among patients with CD, 39% experienced at least one uncommon adverse drug reaction (ADR), as well as 50% of patients with UC and 13% with RA. However, most ADRs (94%) were considered not related to CT-P13.

The tumor necrosis factor (TNF)-α inhibitor infliximab is used to treat a variety of immune-mediated inflammatory diseases, including IBD (CD and UC) and RA, in which the cytokine TNF plays a central role. CT-P13 was the first infliximab biosimilar and first biosimilar monoclonal antibody approved in Japan in 2014. Clinical trials and real-world studies have established CT-P13 is similarly effective and safe as the originator, however, according to the authors, there are few studies on long-term CT-P13 treatment in Japan, where patient co-pays for biosimilars and originators are the same.

Data on 220 patients was collected in routine clinical practice at multiple centers in Japan, 123 of whom had CD, 74 with UC, and 23 with RA. Patients were stable on the reference product prior to switching to CT-P13. The study is ongoing with patients continuing to complete annual follow-up visits.

After 2 years of CT-P13 therapy, 48 (39%), 37 (50%), and 3 (13%) patients with CD, UC, and RA reported at least 1 ADR. However, the vast majority (94%) were not related to CT-P13. Most ADRs (74%) were grade 1 or 2. The most frequent classes of ADRs reported were gastrointestinal disorders in 11% of patients with CD, infections and infestations in 20% of patients with UC, and injury, poisoning, and procedural implications in 9% of patients with RA.

Adverse events (AEs) and serious AEs (SAEs) were secondary endpoints of the study. AEs were reported by 59% of patients with CD, 70% of patients with UC, and 30% of patients with RA. Serious AEs were reported by 10%, 13.5%, and 9% of patients. Most AEs were grade 1 or 2 and most SAEs were grade 2 or 3. The most frequent AEs were gastrointestinal disorders in patients with CD (40%) and UC (40.5%), and infections and infestations in patients with RA (17%). Herpes zoster infection and pneumonia in patients with CD and UC and nasopharyngitis in patients with RA were considered to have a “plausible relationship to CT-P13 treatment.” One patient with CD and 4 patients with UC reported infusion-related reactions.

Nineteen patients (9%) discontinued CT-P13 for reasons related to the drug, 4 (9%) with CD, 11 (31%) with UC, and 4 (31%) with RA. The primary reason was loss of efficacy in patients with UC and RA, and AEs in patients with CD. Two patients with CD and 1 with UC experienced SAEs leading to discontinuation of treatment.

The authors concluded that CT-P13 was “well tolerated” over 2 years in this study, as most ADRs were not related to CT-P13, and few patients stopped treatment due to reasons related to the biosimilar. They added that the effectiveness of infliximab therapy was “well maintained,” and said their findings demonstrate long-term safety of CT-P13 in real-world practice. They plan to report 5-year data at the completion of the study.

Reference

Ishida T, Yokoe I, Obata H, Park S, Kim S, Nishimata N. A real-world, observational, prospective cohort study evaluating the safety and effectiveness of CT-P13 in inflammatory bowel disease and rheumatoid arthritis: the MEGA-J study. Curr Med Res Opin. 2025;41(4):601-606. doi:10.1080/03007995.2025.2492638