Infliximab Biosimilar CT-P13 Observational Studies for Rheumatoid Arthritis, Inflammatory Bowel Diseases, and Ankylosing Spondylitis: Pooled Analysis of Long-Term Safety and Effectiveness.

INTRODUCTION

Long-term, real-world safety and effectiveness data are required to support biosimilar use. This analysis pooled 5-year findings from observational studies of infliximab biosimilar CT-P13 treatment in patients with rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and ankylosing spondylitis (AS).

METHODS

Patients enrolled in the CT-P13 4.2, 4.3, or 4.4 Korea/European Union registries were analysed if they had initiated infliximab treatment with CT-P13 (CT-P13 group) or had switched from reference infliximab to CT-P13 (switched to CT-P13 group). The primary objective was to investigate long-term safety by evaluating adverse events of special interest (AESIs) per the CT-P13 risk-management plan. Incidence rates per 100 patient-years (PYs) were calculated. Additional long-term safety endpoints, immunogenicity (assessments optional), and effectiveness were evaluated.

RESULTS

Overall, 736 patients (642 CT-P13; 94 switched to CT-P13) were analysed. Median (range) exposure to CT-P13 was 19.433 (0.03-63.11) months overall. The incidence of treatment-emergent adverse events was 69.0% (CT-P13 group) and 60.6% (switched to CT-P13 group). Infusion-related reaction/hypersensitivity/anaphylactic reaction was the most frequent AESI overall, with an incidence of 4.3828 per 100 PY (95% confidence interval: 3.3603-5.6185). For most AESIs, incidence rates per 100 PY were broadly comparable between treatment groups, considering overlapping 95% confidence intervals. At baseline, 42/445 (9.4%) and 21/59 (35.6%) evaluable patients in the CT-P13 and switched to CT-P13 groups, respectively, were antidrug antibody (ADA)-positive. After CT-P13 treatment during the study, 188/425 (44.2%) evaluable patients had ≥ 1 ADA-positive result, including 147/425 (34.6%) patients with negative or no ADA results reported at baseline. Effectiveness tended to increase over time for all indications.

CONCLUSION

The analysis did not identify any new safety findings for patients with RA, IBD, and AS treated with CT-P13 for up to 5 years in those who were infliximab-naïve at CT-P13 initiation, or those who had switched from reference infliximab to CT-P13.

TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT02557295 (CT-P13 4.2; retrospectively registered on 23 September 2015); NCT02326155 (CT-P13 4.3; retrospectively registered on 25 December 2014); NCT02557308 (CT-P13 4.4; retrospectively registered on 23 September 2015).