Usability and safety of SB5 (an adalimumab biosimilar) prefilled syringe and autoinjector in patients with rheumatoid arthritis

Objective: To demonstrate comparability between administration of the adalimumab biosimilar, SB5, via prefilled syringe (PFS) and autoinjector (AI) pen based on injection site pain, patient preference, and safety in rheumatoid arthritis (RA) patients. Methods: In this phase 2, open-label study (NCT02565810; EudraCT Number 2014-004887-39), adult RA patients self-administered 40 mg SB5 subcutaneously via PFS at weeks 0 and 2, followed by AI at weeks 4, 6, 8, and 10. Patients rated injection site pain from 0 (no pain) to 10 (severe pain) using a visual numeric scale immediately and 15-30 min post-injection at weeks 0, 2, 4, and 6. Equivalence between PFS and AI was concluded if the 97.5% confidence interval (CI) of the difference in the injection site pain scores at weeks 2 and 6 was contained within the equivalence margin of +/- 5. Overall impression and preference for PFS and AI were also evaluated. Safety was assessed up to 20 weeks after the first injection. Results: Of 49 patients enrolled, 48 completed the study. Mean injection site pain scores were equivalent between PFS and AI immediately (2.3 vs 2.0; 97.5% CI = -0.99-0.30) and 15-30 min post-injection (0.8 vs 0.7; 97.5% CI = -0.47-0.25). The overall impression of both devices was comparable. The overall preference of AI was higher than PFS. Treatment-emergent adverse events (TEAE) were mild-to-moderate. There were no severe or serious TEAEs reported during the study. Conclusions: In RA patients, SB5 showed equivalent injection site pain and comparable safety when administered via PFS and AI.