A randomized double-blind parallel-group phase III study to compare the efficacy and safety of NI-071 and infliximab reference product in Japanese patients with active rheumatoid arthritis refractory to methotrexate.

Objectives: This study aimed to demonstrate the equivalence of NI-071, an infliximab biosimilar (BS), and the infliximab reference product (RP) for treating Japanese patients with active rheumatoid arthritis (RA) refractory to methotrexate.Methods: In this multicenter two-period phase III study, patients were treated with BS or RP for 30 weeks (Period I) in a randomized double-blind manner and then with BS for the following 24 weeks (Period II). The efficacy and safety of BS and RP were compared.Results: The disease activity score in 28-joint count based on erythrocyte sedimentation rate or C-reactive protein and the American College of Rheumatology 20/50/70-based efficacy profiles of BS were similar to those of RP during Period I (30 weeks) including evaluations at week 14, a critical time point. BS efficacy was maintained throughout the 54-week study period. BS efficacy profile matched the RP profile until week 54 after the drug switch from RP to BS at week 30. The safety profiles of BS and RP were comparable and the long-term safety of BS was confirmed.Conclusion: BS demonstrated equivalent efficacy and safety to RP at treatment weeks 14 and 30, and long-term safety until week 54 in Japanese RA patients.