Six-month safety and effectiveness of tofacitinib in patients with rheumatoid arthritis in Japan: Interim analysis of post-marketing surveillance

Objectives We evaluated the real-world safety/effectiveness of tofacitinib, an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA), in patients with RA in Japan registered in a post-marketing surveillance study. Methods This interim analysis included data from July 2013 to December 2018. Adverse events (AEs), serious AEs (SAEs), Simplified Disease Activity Index (SDAI)/Clinical Disease Activity Index (CDAI)/Disease Activity Score in 28 joints, erythrocyte sedimentation rate [DAS28-4(ESR)] scores, and rates of SDAI/CDAI/DAS28-4(ESR)-defined remission and low disease activity were analysed using 6 months of data. Risk factors for serious infections were assessed by multivariable analyses. Results Safety and disease activity were evaluated in 6866 and 6649 patients, respectively. Overall, 32.73%/7.37% of patients reported AEs/SAEs. Clinically important AEs with tofacitinib included serious infections/infestations [3.13% of patients; incidence rate (IR; patients with events) 6.91/100 patient-years (PY)], herpes zoster (3.63%; IR 8.02/100 PY), and malignancies (0.68%; IR 1.45/100 PY). SDAI/CDAI/DAS28-4(ESR) scores and remission/low disease activity rates improved over 6 months. Male sex, older age, Steinbrocker's stage IV, history of infection, and diabetes mellitus at baseline were independent risk factors for serious infection. Conclusions In patients with RA receiving tofacitinib in Japan, safety was consistent with the reported profile, and disease activity improved over 6 months. Study identifier NCT01932372.