Long-Term KOBIO Registry Data Show Comparable Drug Retention for Biosimilar CT-P13, Reference Infliximab

Biosimilar infliximab CT-P13 (Inflectra, Remsima) has been the subject of numerous studies since its authorization in multiple regulatory territories, and this month, data from the Korean College of Rheumatology Biologics (KOBIO) registry add to the growing body of knowledge about this biosimilar’s use in patients with rheumatoid arthritis (RA) in routine clinical practice.

The registry, established in 2012, enrolls patients with RA and other inflammatory diseases at the time at which they initiate treatment with a biologic. In the current study, 199 adult patients with RA who received brand-name infliximab (n = 52) or CT-P13 (n = 147) together with methotrexate between 2012 and 2017 were included, and the primary outcome measure was drug retention over 4 years of follow-up.

Efficacy was assessed using a disease activity score in a count of 28 joints (DAS28) with either erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) or using the American College of Rheumatology (ACR) score scale.

Overall, the median duration of treatment was 1.22 years (range, 0.54-2.31) for the CT-P13 group and 1.40 years (range, 0.43-3.16) in the reference group (P = 0.67). Overall, there was no difference in drug retention with CT-P13 or the reference, and retention was also similar between both treatment groups in patients who received first-line therapy and subsequent-line therapy with infliximab. At 4 years, the retention rate was 17.5% for CT-P13 versus 33.6% for the reference in the overall population.

The rate of treatment changes or discontinuations was similar between the biosimilar and reference groups (65.2% vs 69.6%, respectively). Reasons for changing to another therapy or discontinuing treatment included lack of efficacy (CT-P13, 31.9%; reference, 34.8%); adverse events (AEs), including infusion-related reactions (CT-P13, 20.0%; reference, 23.9%); or remission (CT-P13, 3.0%; reference, 4.3%). Drugs received following treatment with infliximab included tocilizumab and adalimumab.

In terms of efficacy, the biosimilar and the reference were linked with comparable improvements over time. Over the 4-year observation period, treatment with either infliximab option resulted in a substantial reduction in disease activity, and after 2 years, DAS28 scores, whether measured with ESR or CRP, corresponded to low disease activity or remission, and disease control was maintained for up to 4 years.

Overall, there were 19 grade 3 AEs in the biosimilar group and 8 in the reference group. Four of the AEs in the biosimilar group (an infusion reaction, an infection, a case of mononeuritis multiplex, and a rash), and none in the reference group, were considered to be related to the drug. One death was reported in the biosimilar group (due to pneumonia), and 1 death was reported in the reference group (due to cardiac arrest).

According to the authors, these data demonstrate that CT-P13 has comparable drug retention to the reference, as well as similar efficacy and acceptable safety, in routine clinical practice in patients with RA.

Reference

Kim HA, Lee E, Lee SK, et al. Retention rate and safety of biosimilar CT-P13 in rheumatoid arthritis: data from the Korean College of Rheumatology Biologics Registry [published online November 16, 2019]. BioDrugs. doi: 10.1007/s40259-019-00393-y.