Usability of Prefilled Syringe and Autoinjector for SB4 (An Etanercept Biosimilar) in Patients with Rheumatoid Arthritis

Introduction This study aimed to compare the usability of subcutaneous administration of SB4 (an etanercept biosimilar) via prefilled syringe (PFS) and autoinjector (AI) based on injection site pain, patient preference, and safety in patients with rheumatoid arthritis (RA). Methods This was an open-label, single-arm, multicenter study to evaluate the usability and safety of the AI and PFS of SB4. Adult patients with RA received two injections of SB4 via the PFS, followed by six injections by the AI every week, up to 8 weeks. The primary endpoint was the change in injection site pain score immediately post-injection from week 1 (PFS) to week 3 (AI). Injection site pain after 15-30 min post-injection, overall impression, and preference for PFS and AI were also assessed. Safety was assessed up to 11 weeks after the first injection. Results A total of 54 patients were enrolled and 52 patients (96.3%) completed the 8-week treatment period. The mean difference in pain scores between PFS and AI was - 0.057 and the 95% CI of the difference was [- 0.63, 0.51], which was within the equivalence margin of +/- 5. Overall impression of the device slightly favored the AI. Overall preference for the AI was more favorable when compared to the PFS in all categories. Adverse events were mild to moderate and found to be generally consistent with those expected for reference etanercept. There were no deaths or serious adverse events reported. Conclusions This study demonstrated comparable usability and safety between the PFS and AI when self-administrated by patients with RA. Funding Samsung Bioepis.