Efficacy and safety of certolizumab pegol in combination with methotrexate in methotrexate-inadequate responder Chinese patients with active rheumatoid arthritis: 24-week results from a randomised, double-blind, placebo-controlled phase 3 study.

Objective To evaluate the efficacy and safety of certolizumab pegol (CZP) in combination with methotrexate (MTX) in Chinese patients with active rheumatoid arthritis (RA) and an inadequate response to MTX. Methods This 24-week, phase 3, double-blind, placebo-controlled study was conducted in 30 centres across China. A total of 430 patients were randomised 3: 1 to receive CZP 200 mg every 2 weeks (loading dose: 400 mg CZP at Weeks 0, 2 and 4) plus MTX or placebo (PBO) plus MTX. The primary endpoint was ACR20 response at Week 24, for which the superiority of CZP+MTX over PBO+MTX was evaluated. Additional parameters for clinical efficacy, health outcomes, immunogenicity and safety were assessed. Results At Week 24, 54.8% of CZP+MTX patients and 23.9% of PBO+MTX patients achieved ACR20 (odds ratio: 3.9, p<0.001). CZP+MTX patients also achieved greater improvements in HAQ-DI, higher ACR50/70 responses and higher DAS28(ESR) remission rate at Week 24. Rapid onset of response to CZP+MTX was observed as early as Week 1 for most of the clinical, functional and patient-reported outcomes. Incidences of treatment-emergent adverse events (TEAEs) were similar between treatment arms. Serious TEAEs were reported by 6.3% of CZP+MTX patients and 2.7% of PBO+MTX patients. No new safety signals were observed. Conclusion CZP in combination with MTX showed an acceptable safety profile, a rapid onset of response and sustained effects in reducing the signs and symptoms of RA and improving physical function in Chinese patients with RA and an inadequate response to MTX.