Usability, efficacy, and safety of candidate tocilizumab biosimilar CT-P47 self-administration via auto-injector and pre-filled syringe in patients with rheumatoid arthritis: a single-arm, open-label, phase 3 study

CT-P47 is a candidate tocilizumab biosimilar that is currently in clinical development. We assessed the usability of CT-P47 self-administration via auto-injector (AI) in patients with rheumatoid arthritis (RA). This was a 12-week, single-arm, open-label, multiple-dose, Phase 3 study. Patients self-injected CT-P47 (162 mg/0.9 mL) via AI at Weeks 0 and 2, and then every other week via pre-filled syringe (PFS) from Week 4 through Week 10. The primary endpoint was POST-Self-Injection Assessment Questionnaire (SIAQ) at Week 2. Efficacy, safety, and immunogenicity were also assessed. Thirty-three patients were enrolled. Mean scores for all POST-SIAQ domains at Week 2 exceeded 8, except for ‘self-confidence’ (7.11) and ‘satisfaction with self-injection’ (7.98), indicating positive patient experiences with CT-P47 AI. Furthermore, an observer-completed checklist found that all patients successfully followed the required steps for self-injection. Efficacy, assessed by Disease Activity Score in 28 joints and its components, showed improvements from baseline to Week 12. No new safety signals were observed; the most common adverse events were leukopenia, neutropenia, and injection-site reaction, each occurring in 3 (9.1%) patients. CT-P47 self-administered using an AI showed successful usability in patients with moderate-to-severe RA. ClinicalTrials.gov identifier: NCT05725434.