Poniatowa Wies

Researchers are evaluating the efficacy, pharmacokinetics, safety, and immunogenicity of MB04, a proposed etanercept biosimilar, compared to Enbrel4 (EU-sourced) in adults aged 18 to 75 years with active moderate to severe rheumatoid arthritis despite methotrexate therapy. This Phase 3 study includes approximately 458 patients who have been on a stable methotrexate dose for at least 8 weeks before randomization. The goal is to compare these treatments over time to understand their effects in this patient population. Participants will be randomly assigned in a 1:1 ratio to receive either MB04 or EU-sourced Enbrel4 as a 50 mg subcutaneous injection once weekly during the main treatment period. After completing 24 weeks of treatment, those initially receiving Enbrel4 will be re-randomized to either continue Enbrel4 or switch to MB04 until week 36. Patients who started on MB04 will continue the same treatment through week 36. All participants will continue their stable methotrexate and folic acid regimen throughout the study. Participants will undergo screening within 28 days before randomization and will be monitored through week 40, including a 4-week safety follow-up after treatment ends. Researchers will assess treatment response using the American College of Rheumatology 20% Response Criteria (ACR20) at week 24, along with safety, pharmacokinetics, and immunogenicity evaluations. Regular assessments and monitoring will help determine how patients respond to the treatments and ensure their safety throughout the study.