Retention rate and long-term safety of biosimilar CT-P13 in patients with ankylosing spondylitis: data from the Korean College of Rheumatology Biologics registry

Objective To evaluate the long-term drug retention, efficacy, and safety of the infliximab biosimilar CT-P13 in Korean patients with ankylosing spondylitis (AS) in clinical practice. The primary outcome was drug retention (i.e. time to treatment discontinuation or changing to another biologic) in Korean patients with AS. Additional outcomes included efficacy and safety. Methods Data were collected through the Korean College of Rheumatology Biologics (KOBIO) registry (ClinicalTrials.gov identifier: NCT01965132). CT-P13 efficacy was assessed using standard disease activity parameters, and safety was evaluated by adverse events (AEs). Results Between December 2012 and December 2017, 244 patients with AS treated with CT-P13 were enrolled. Of those, 203 (83.2%) received CT-P13 as first-line therapy. The median duration of treatment was 2.05 years. After 4 years’ follow-up, the retention rate of CT-P13 in the overall patient population was 66%. Treatment changes or discontinuations occurred in 38 (15.6%) and 32 (13.1%) patients, respectively. Lack of efficacy was the most common reason for treatment changes, whereas AEs were the most common single cause of discontinuation. Disease activity decreased markedly from baseline following initiation of CT-P13 treatment, and thereafter remained stable. A total of 313 AEs occurred in 118 patients (48.4%); the majority (94.6%) were mild or moderate in severity. The most common treatment-related AEs were infusion or injection-site reactions (4.1% of patients), uveitis (3.7%), and skin rash (3.7%). Conclusion In this real-world study, CT-P13 demonstrated encouraging drug retention rates and times, together with reasonable long-term efficacy and safety, in Korean patients with AS.