Poniatowa Wies

Researchers are evaluating the proposed biosimilar MB04 compared to Enbrel, a known treatment, in patients with moderate to severe rheumatoid arthritis RA who continue to have active disease despite methotrexate therapy. The study aims to assess the effectiveness, safety, how the body processes the drugs, and immune responses to MB04 versus Enbrel. This phase 3 trial will include approximately 458 patients aged 18 to 75 years. Participants will receive a stable dose of methotrexate and folic acid before starting the study. They will be randomly assigned to receive a 50 mg weekly subcutaneous injection of either MB04 or EU-sourced Enbrel during the 36-week main treatment period. After 24 weeks, some patients initially on Enbrel will be re-randomized to either continue Enbrel or switch to MB04, while those on MB04 will continue the same treatment. Following treatment, patients will be monitored for safety for an additional 4 weeks. Throughout the study, patients will undergo regular assessments including measures of joint swelling and tenderness, and blood tests to evaluate inflammation and immune response. The primary outcome is the American College of Rheumatology 20% Response Criteria ACR20 at Week 24, with additional assessments at Week 36. Safety will be monitored continuously, and participant involvement will last approximately 40 weeks including follow-up.