Efficacy, Safety and Pharmacokinetics of Up to Two Courses of the Rituximab Biosimilar CT-P10 Versus Innovator Rituximab in Patients with Rheumatoid Arthritis: Results up to Week 72 of a Phase I Randomized Controlled Trial

BACKGROUND: CT-P10 is a biosimilar of innovator rituximab (RTX), a biological therapy used to treat patients with rheumatoid arthritis (RA) who have responded inadequately to anti-tumor necrosis factor agents. OBJECTIVE: Our objective was to compare the clinical profile of CT-P10 versus RTX in patients with RA who received up to two courses of treatment and were followed for up to 72 weeks. METHODS: In this multicenter double-blind phase I study, patients were randomized 2:1 to receive CT-P10 1000 mg or RTX 1000 mg at weeks 0 and 2. Based on disease activity, patients could receive a second course of treatment between weeks 24 and 48. Efficacy endpoints, including mean change from baseline in Disease Activity Score using 28 joints (DAS28), safety, immunogenicity, pharmacokinetics, and pharmacodynamics were evaluated. RESULTS: In total, 154 patients were randomized to CT-P10 or RTX (n = 103 and 51, respectively); 137 (n = 92 and 45) completed the first course of treatment, of whom 83 (n = 60 and 23) were re-treated. Improvements from baseline in all efficacy endpoints were highly similar between the CT-P10 and RTX groups over both treatment courses. At week 24 after the second course, mean change from week 0 of the first course in DAS28 erythrocyte sedimentation rate was −2.47 and −2.04 for CT-P10 and RTX, respectively, (p = 0.1866) and in DAS28 C-reactive protein was −2.32 and −2.00, respectively (p = 0.3268). The proportion of patients positive for antidrug antibodies at week 24 after the second treatment course was 20.0% and 21.7% in the CT-P10 and RTX groups, respectively. The safety profile of CT-P10 was comparable to that of RTX, and pharmacokinetic and pharmacodynamic properties were similar. CONCLUSIONS: In patients with RA, efficacy, safety, and other clinical data were comparable between CT-P10 and RTX after up to two courses of treatment over 72 weeks. (ClinicalTrials.gov identifier NCT01534884). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s40259-017-0232-7) contains supplementary material, which is available to authorized users.