Safety and Efficacy of Filgotinib: Up to 4-Year Results From an Open-Label Extension Study of Phase 2 Rheumatoid Arthritis Programs

A long-term extension study of filgotinib showed consistent safety profile and sustained efficacy with the drug for up to four years. The DARWIN 3 study, for patients who previously completed either the 24-week DARWIN 1 study (filgotinib + MTX) or the DARWIN 2 study (filgotinib monotherapy), enrolled 739 patients with RA. At the time of analysis, 440 patients had received four years or more of filgotinib. Exposure-adjusted incidence rate per 100 patient-years-of-exposure for TEAEs was 24.6 in the filgotinib plus MTX group and 25.8 in the filgotinib monotherapy group, demonstrating tolerability comparable to that seen in the two phase 2b parent studies. Furthermore, observational assessment of efficacy, showed that ACR responses among patients remaining in the study could be maintained through this same period. Overall, Kavanaugh A, et al. have been able to demonstrate a consistent safety profile and sustained efficacy for filgotinib, when administered as 200 mg daily either alone or in combination with MTX, for up to four years.