Adalimumab, CT-P17 biosimilar exhibit comparable safety, equivalent efficacy in RA
The adalimumab biosimilar CT-P17 demonstrates equivalent efficacy, and comparable safety and immunogenicity, to its reference product in patients with rheumatoid arthritis, according to data published in Arthritis Research & Therapy.
“European League Against Rheumatism (EULAR) recommendations for the treatment of RA position biosimilar DMARDs (bsDMARDs) equivalently to their reference products in treatment algorithms, and suggest that lower-priced biosimilars are preferred for their potential to reduce healthcare expenditures,” Jonathan Kay, MD, of the University of Massachusetts Medical School and UMass Memorial Medical, in Worcester, and colleagues wrote. “CT-P17 is in development as a proposed adalimumab biosimilar.”
“CT-P17 is administered at 100mg/ml, reflecting the high-concentration formulation of reference adalimumab, and is also citrate-free, which could reduce discomfort during injection,” they added. “To date, CT-P17 has been evaluated in two randomized phase 1 studies evaluating the pharmacokinetics (PK) and safety of CT-P17 in healthy adults: A double-blind study comparing CT-P17 to European Union-approved adalimumab (EU-adalimumab) and U.S.-licensed adalimumab and an open-label study comparing CT-P17 administration via autoinjector or prefilled syringe.”
To analyze whether CT-P17 (Celltrion) was equivalent in efficacy to EU-approved adalimumab (Humira, AbbVie) in patients with rheumatoid arthritis, Kay and colleagues conducted a randomized, active-controlled, double-blind, multicenter, phase 3 study. A total of 648 participants, from 52 centers in Bulgaria, Hungary, Lithuania, Peru, Poland and Ukraine, were assigned 1:1 to receive 100 mg/ml of CT-P17 or 40 mg of subcutaneous EU-adalimumab every 2 weeks until week 52. The researchers reported results to week 24.
The primary endpoint was 20% improvement based on the ACR20 response rate at week 24. Equivalence was determined if the corresponding confidence intervals for the estimate of treatment difference were within predefined margins: 95% CI, –15% to 15% 95% for the European Medicines Agency (EMA) assumption, or 90% CI, –12% to 15% for the FDA assumption. Additional efficacy, pharmacokinetic, usability, safety and immunogenicity endpoints were also assessed.
According to the researchers, 82.7% of participants in both groups achieved ACR20 response at week 24. In addition, the 95% CI (–5.94 to 5.94) and 90% CI (–4.98 to 4.98) were within the predefined equivalence margins for both the EMA and FDA assumptions, confirming equivalent efficacy. The other endpoints and overall safety were comparable between groups, the researchers added. Mean trough serum concentrations for CT-P17 were slightly higher than those for EU-adalimumab. Additionally, immunogenicity was slightly lower numerically for the biosimilar group compared with the EU-adalimumab group.
“This study demonstrated equivalent efficacy of CT-P17 to EU-adalimumab in the proportion of subjects achieving an ACR20 response at week 24,” Kay and colleagues wrote. “Demonstration of equivalent efficacy and comparable safety and immunogenicity of CT-P17 to EU-adalimumab in this study support the ongoing clinical evaluation of CT-P17 as an adalimumab biosimilar.”