Efficacy and safety of switching from reference infliximab to CT-P13 compared with maintenance of CT-P13 in ankylosing spondylitis: 102-week data from the PLANETAS extension study

Abstract

Objectives: To investigate the efficacy and safety of switching from infliximab reference product (RP) to its biosimilar or maintaining biosimilar treatment in patients with ankylosing spondylitis (AS).

Methods: This open-label extension study recruited patients with AS who completed a 54-week, randomised controlled study comparing CT-P13 with RP (PLANETAS). CT-P13 (5 mg/kg) was administered intravenously every 8 weeks from week 62 to week 102. Efficacy end points included the proportion of patients achieving Assessment of SpondyloArthritis international Society (ASAS)20. Antidrug antibodies (ADAs) were measured using an electrochemiluminescent method. Data were analysed for patients treated with CT-P13 in the main PLANETAS study and the extension (maintenance group) and those who were switched to CT-P13 during the extension study (switch group).

Results: Overall, 174 (82.9%) of 210 patients who completed the first 54 weeks of PLANETAS and agreed to participate in the extension were enrolled. Among these, 88 were maintained on CT-P13 and 86 were switched to CT-P13 from RP. In these maintenance and switch groups, respectively, ASAS20 response rates at week 102 were 80.7% and 76.9%. ASAS40 and ASAS partial remission were also similar between groups. ADA positivity rates were comparable (week 102: 23.3% vs 27.4%). Adverse events led to treatment discontinuation during the extension study in 3 (3.3%) and 4 (4.8%) patients, respectively.

Conclusions: This is the first study to show that switching from RP to its biosimilar CT-P13 is possible without negative effects on safety or efficacy in patients with AS. In the maintenance group, CT-P13 was effective and well tolerated over 2 years of treatment.

Trial registration number: NCT01571206; Results.

Keywords: Ankylosing Spondylitis; Anti-TNF; DMARDs (biologic); Treatment.

Conflict of interest statement

DHY and WP: Consultation for Celltrion. MB has received research grants from Celltrion, personal fees from lectures for Roche, Abbvie, MSD, Pfizer, Egis, UCB outside the submitted work; JB has received honoraria for talks, advisory boards, paid consultancies or grants for studies from Abbvie (Abbott), Amgen, Boehringer Ingelheim, Bristol-Myers-Squibb, Celgene, Celltrion, Centocor, Chugai, EBEWE Pharma, Janssen, Medac, MSD (Schering-Plough), Mundipharma, Novartis, Pfizer (Wyeth), Roche, Sanofi-Aventis and UCB. HUK, SJL, YJB and SYK are full-time employees of Celltrion. Otherwise, none declared.

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Figures

Figure 1

Patient disposition during the PLANETAS extension study. All patients who enrolled in the extension study (n=88 and n=86 in the maintenance and switch groups, respectively) were included in the ITT population. *One patient randomly assigned to RP received at least one dose of CT-P13 unintentionally. ITT, intent-to-treat; RP, reference product.

Figure 2

Additional efficacy end points assessed in the PLANETAS extension study. Mean (SD) BASDAI (A), BASFI (B), BASMI (C) and ASDAS-CRP (D) scores in maintenance* (n=88) and switch** (n=86) groups during the main study and the extension study (efficacy population). *Patients treated with CT-P13 during the 54 weeks of the main study and the 48-week extension study. **Patients treated with RP during the 54 weeks of the main study and then switched to CT-P13 during the 48-week extension study. ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; CRP, C reactive protein; RP, reference product.

Figure 2

Additional efficacy end points assessed in the PLANETAS extension study. Mean (SD) BASDAI (A), BASFI (B), BASMI (C) and ASDAS-CRP (D) scores in maintenance* (n=88) and switch** (n=86) groups during the main study and the extension study (efficacy population). *Patients treated with CT-P13 during the 54 weeks of the main study and the 48-week extension study. **Patients treated with RP during the 54 weeks of the main study and then switched to CT-P13 during the 48-week extension study. ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; CRP, C reactive protein; RP, reference product.