Long-Term Efficacy and Safety of Biosimilar CT-P10 Versus Innovator Rituximab in Rheumatoid Arthritis: 48-Week Results from a Randomized Phase III Trial.

OBJECTIVE: The aim of this study was to investigate long-term clinical outcomes of extended treatment with CT-P10, a rituximab biosimilar, compared with rituximab reference products sourced from the USA and the EU (US-RTX and EU-RTX) in rheumatoid arthritis (RA) for up to 48 weeks. METHODS: In this multinational, randomized, double-blind trial, adults with active RA received up to two courses of CT-P10, US-RTX, or EU-RTX alongside methotrexate. Efficacy endpoints included Disease Activity Score 28-joint count (DAS28) and American College of Rheumatology (ACR) response rates. Pharmacokinetics, pharmacodynamics, immunogenicity, and safety were also assessed. RESULTS: Of 372 patients randomized to the study drug, 330 (88.7%) completed the second treatment course. Mean change from baseline to week 48 in DAS28-C-reactive protein was comparable in the CT-P10 and combined rituximab (US-RTX and EU-RTX) groups (- 2.7 and - 2.6, respectively). ACR20, ACR50, and ACR70 response rates at week 48 indicated no differences between groups (80.6%, 55.4%, and 31.7% vs. 79.8%, 53.9%, and 33.7% in the CT-P10 and combined rituximab groups, respectively). Similar improvements in the Health Assessment Questionnaire Disability Index and all medical outcomes in the Short Form 36-Item Health Survey, including physical and mental health, were seen in all groups. At week 48, antidrug antibodies were detected in 4.9%, 9.4%, and 8.6% of patients in the CT-P10, US-RTX, and EU-RTX groups, respectively. CT-P10 and rituximab displayed similar pharmacokinetic, pharmacodynamic, and safety profiles. CONCLUSION: CT-P10 was similar to EU-RTX and US-RTX in terms of efficacy, pharmacokinetics, pharmacodynamics, immunogenicity, and safety up to week 48. CLINICALTRIALS. GOV IDENTIFIER: NCT02149121.

Comparison of biosimilar CT-P10 and innovator rituximab in patients with rheumatoid arthritis: a randomized controlled Phase 3 trial.

This multinational, randomized, double-blind trial, (ClinicalTrials.gov identifier NCT02149121) was designed to demonstrate equivalence in pharmacokinetics and efficacy between CT-P10 and innovator rituximab (RTX) in patients with rheumatoid arthritis (RA). Adults with active RA were treated with CT-P10, United States-sourced RTX (US-RTX; Rituxan®), or European Union-sourced RTX (EU-RTX; MabThera®) at weeks 0 and 2. The co-primary pharmacokinetic endpoints were area under the serum concentration-time curve (AUC) from time zero to last measurable concentration (AUC0-last), AUC from time zero to infinity (AUC0-∞), and maximum concentration (Cmax) after two infusions. The primary efficacy endpoint was change from baseline to week 24 in Disease Activity Score using 28 joints-C-reactive protein (DAS28-CRP). Pharmacodynamics, immunogenicity, and safety were also assessed. 372 patients were randomly assigned to CT-P10 (n = 161) or RTX (n = 211 [US-RTX, n = 151; EU-RTX, n = 60]). For the co-primary pharmacokinetic endpoints, 90% confidence intervals (CI) for ratios of geometric means (CT-P10/US-RTX, CT-P10/EU-RTX or EU-RTX/US-RTX) all fell within the equivalence margin of 80-125%. Adjusted least squares (LS) mean (standard error) change from baseline in DAS28-CRP at week 24 was -2.13 (0.175) for CT-P10 and -2.09 (0.176) for RTX. The 95% CI (-0.29, 0.21) of the estimated treatment difference between CT-P10 and RTX (-0.04) was entirely within the efficacy equivalence margin of ±0.5. Pharmacodynamics, immunogenicity, and safety profiles were similar for CT-P10 and RTX. The pharmacokinetics of CT-P10, US-RTX, and EU-RTX were equivalent. CT-P10 and RTX were also equivalent in terms of efficacy and displayed similar pharmacodynamic, immunogenicity, and safety profiles up to week 24.