A pooled safety analysis of peficitinib (ASP015K) in Asian patients with rheumatoid arthritis treated over a median of 2 years

Objective To evaluate the safety of peficitinib for the treatment of rheumatoid arthritis (RA) in Asian patients. Methods Safety data from one Phase 2b, two Phase 3, and one open-label long-term extension study [data cut-off 31 May 2018] were pooled into Phase 3 studies (peficitinib 100 and 150 mg/day, and placebo) and Phase 2/3 studies (all peficitinib-treated patients). Incidence rates per 100 patient-years (PY) of adverse events (AEs) of special interest were calculated. Results Overall, 1052 patients received peficitinib for 2336.3 PY of exposure (median 2.1 years); four deaths occurred, including one death after the studies. AE incidence was similar across peficitinib 100 and 150 mg/day groups (Phase 3 studies). Respective peficitinib and placebo incidence rates (95% confidence interval) per 100 PY were 2.9 (1.9, 4.6) and 0.0 for serious infections, 5.7 (4.2, 7.9) and 2.3 (0.6, 9.4) for herpes zoster-related disease, and 0.6 (0.2, 1.6) and 1.2 (0.2, 8.3) for malignancies (excluding non-melanoma skin cancer) (Phase 3 studies), and 0.1 (0.0, 0.3) for venous thromboembolism in all peficitinib-treated patients (Phase 2/3 studies). Conclusion Peficitinib was well tolerated in Asian patients with RA over a median of 2 years, with no observed dose or temporal dependency for AEs with prolonged administration.