A Single-Arm, Open-Label Study to Assess the Immunogenicity, Safety, and Efficacy of Etanercept Manufactured Using the Serum-Free, High-Capacity Manufacturing Process Administered to Patients with Rheumatoid Arthritis

Objective: To evaluate the immunogenicity, safety, and efficacy of etanercept (ETN) manufactured using the serum-free, high-capacity manufacturing (SFHCM) process in patients with rheumatoid arthritis (RA). Methods: In this global, multicenter, open-label, single-arm study (NCT02378506), 187 adult patients with moderate to severe RA received ETN 50 mg once weekly for 24 weeks manufactured using the SFHCM process. Immunogenicity (presence of antidrug antibodies (ADAs) and neutralizing antibodies (NAbs)) was assessed at 12 and 24 weeks. Safety and efficacy were evaluated at 4, 12, and 24 weeks. Results: Eight (4.5%) patients tested positive for ADA, and there were no NAbs detected at any time throughout the study. Ninety (48.1%) patients reported treatment-emergent adverse events (AEs), of which 27 (14.4%) reported injection-site reactions, and 43 (23.0%) reported infections. The majority of AEs were mild or moderate in severity, and the drug was well tolerated. Throughout the duration of the study (week 4 to week 24), there was a progressive increase in the American College of Rheumatology (ACR)-defined responses (ACR20: 55.9%-82.0%, ACR50: 16.1%-57.8%, and ACR70: 3.2%-26.7%) from baseline and the proportion of patients achieving low disease activity and remission, with a corresponding decrease in measures of disease activity. Conclusion: The immunogenicity, safety, and efficacy of ETN manufactured using the SFHCM process were similar to the current approved ETN formulation.