Geographic Analysis of the Safety and Efficacy of Filgotinib in Rheumatoid Arthritis.

Abstract

Global clinical trials in rheumatoid arthritis (RA) often do not recruit enough patients from diverse racial and ethnic backgrounds to identify any potential differences in treatment outcome across such groups. To overcome this limitation, using data from five previous clinical trials and two ongoing trial extensions, this study aimed to assess the efficacy and safety of filgotinib in patients with RA across geographic regions. This was a post hoc, exploratory analysis of data from male and female patients with RA meeting the 2010 RA criteria as defined by the American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology. Data were analyzed from phase 2 (DARWIN 1-2) and phase 3 (FINCH 1-3) clinical trials, as well as two long-term extension studies (DARWIN 3, FINCH 4), of filgotinib. Efficacy endpoints included ACR 20%/50%/70% improvement (ACR20/50/70) responses, disease activity score in 28 joints using C-reactive protein [DAS28(CRP)], Clinical Disease Activity Index scores, Boolean remission, and change from baseline in Health Assessment Questionnaire-Disability Index (HAQ-DI).Safety data were presented as exposure-adjusted incidence rates per 100 patient-years of exposure of treatment-emergent adverse events. Compared with placebo, at week 12 a greater proportion of patients receiving filgotinib 200mg (FIL200) or 100mg (FIL100) achieved ACR20 (p < 0.01), with similar outcomes in most regions. Overall, the reduction in HAQ-DIwith FIL200 or FIL100was greater thanwith placebo (p < 0.05) at week 12. Compared with placebo, at week 24 the proportions of patients achieving DAS28(CRP) ≤ 3.2 were greater for both doses of FIL, as seen in most regions (p < 0.01). Safety outcomes did not indicate regional or ethnic differences in the safety profile of filgotinib. Filgotinib efficacy and safety in patients with RA were generally consistent across geographic regions. NCT02889796; NCT02873936; NCT02886728; NCT03025308; NCT01888874; NCT01894516; NCT02065700.