Integrated safety analysis of filgotinib treatment for rheumatoid arthritis in patients from Japan over a median of 1.5 years.

Objective: Characterize safety of the Janus kinase-1 preferential inhibitor filgotinib (FIL) in Japanese patients with moderately to severely active rheumatoid arthritis (RA).

Methods: Data from three Phase 3 trials (NCT02889796, NCT02873936, and NCT02886728) and a long-term extension (NCT03025308) through September 2019 were integrated; patients received ≥1 dose of FIL 200 (FIL200) or 100 mg (FIL100) daily, or placebo (PBO). We calculated exposure-adjusted incidence rates (EAIRs) per 100 patient-years FIL exposure (100PYE) for treatment-emergent adverse events (TEAEs) and adverse events of special interest.

Results: Among 3691 total patients and 6080.7 PYE, 229 Japanese patients received FIL for 311.4 PYE (median 1.5, maximum 2.5 years). During the 12-week PBO-controlled period, serious TEAEs and TEAEs leading to study drug disruption were comparable between FIL and PBO. Serious infection rates were 1.9%, 0%, and 2% for FIL200, FIL100, and PBO during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.8 and 2.1/100PYE. No herpes zoster (HZ) or major adverse cardiovascular events (MACEs) occurred during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.0 and 2.1/100PYE (HZ) and 0.6 and 0/100PYE (MACE).

Conclusion: Long-term FIL treatment (median 1.5, maximum 2.5 years exposure) was well tolerated at 100- and 200-mg doses in Japanese patients with RA.