A Retrospective Analysis Of Long Term Safety Up To Five Years Of Infliximab Biosimilar Ct-P13 In Patients With Rheumatoid Arthritis And Ankylosing Spondylitis

Background: Long term safety and efficacy of anti-TNF inhibitors in rheumatic diseases is an important aspect of patient treatment. CT-P13 is the first infliximab biosimilar approved by EMA and FDA and has demonstrated comparable efficacy and safety with reference infliximab in rheumatoid arthritis (RA)1,2 and ankylosing spondylitis (AS)3,4. However, long term data of infliximab biosimilar to date has been limited to two years5,6. Objectives: To demonstrate drug survival and long term safety and efficacy of CT-P13 up to 5 years in patients with RA or AS, including patients who switched from reference infliximab to CT-P13. Methods: Long term data was retrospectively collected from medical records of patients with RA and AS treated with CT-P13 at least once between September 2012 and December 2017 in five referral hospitals in Korea. Patients included both those who were infliximab-treatment naive at the start of CT-P13 treatment (naive patient) and those who switched from reference infliximab to CT-P13 (switched patient). Primary endpoints were safety and drug survival up to 5 years analyzed by Kaplan-Meier curve. Results: Data from 491 patients (154 RA and 337 AS) were collected and analyzed, including 19 and 118 switched patients with RA and AS, respectively. Median disease duration was 64.7 months (range: 4.7 to 265.9 months) for patients with RA and 56.3 months (range: 3.0 to 216.7 months) for patients with AS. The median duration of CT-P13 treatment was 46.8 weeks (range: 0 to 250.6 weeks) and 94.1 weeks (range: 0 to 246.0 weeks) for patients with RA and AS, respectively. The probability of survival at year 5 for patients with RA was 0.42 and 0.53 respectively for naive and switched patients. The probability of survival at year 5 for patients with AS was 0.64 and 0.72 respectively for naive and switched patients. Median DAS28-ESR score decreased from 5.80 at baseline to 2.73 at year 5 and median DAS28-CRP score decreased from 5.14 at baseline to 1.29 at year 4 for patients with RA. Median BASDAI score decreased from 6.60 at baseline to 3.00 at year 5 for patients with AS. The most common reason for discontinuation for both patients with RA and AS was lack of efficacy. 31.8% of patients with RA and 29.4% of patients with AS experienced at least one adverse event and the most frequently observed type of adverse event was upper respiratory tract infection for 3.90% in patients with RA and 4.15% in patients with AS. Conclusion: This is the longest evidence to date of safety and efficacy of infliximab biosimilar CT-P13 treatment in patients with RA or AS. Five year analysis of medical records showed that long term treatment with CT-P13 was safe and efficacious based on drug survival, disease activity measurements, and adverse events. Drug survival was similar between patients who were naive at the start of CT-P13 treatment and switched from reference to CT-P13. References [1] Yoo DH, et al. Ann Rheum Dis. 2013;72(10):1613-20. [2] Yoo DH, et al. Arthritis Res Ther. 2016;18:82. [3] Park W, et al. Ann Rheum Dis. 2013;72(10):1605-12. [4] Park, et al. Arthritis Res Ther. 2016;18:25. [5] Yoo DH, et al. Ann Rheum Dis. 2017;76(2):355-363. [6] Park W, et al. Ann Rheum Dis. 2017;76(2):346-354. Disclosure of Interests: Tae-hwan Kim: None declared, Shin-Seok Lee: None declared, Won Park Consultant for: Celltrion, Inc, Yeong Wook Song: None declared, Chang-Hee Suh Consultant for: Celltrion, Inc, SooKyoung Kim Shareholder of: Celltrion Healthcare, Employee of: Celltrion Healthcare, YoungNam Lee Shareholder of: Celltrion Healthcare, Employee of: Celltrion Healthcare, DaeHyun Yoo Grant/research support from: Celltrion, Inc., Consultant for: Celltrion, Inc.