Safety and Efficacy of Tofacitinib, an Oral Janus Kinse Inhibitor, for the Treatment of Rheumatoid Arthritis, in Open-Label Longterm Extension Studies
This study pooled data from two LTE studies involving patients who had previously participated in qualifying phase I, II and III studies. Data up to 60 months was included for safety aspects and efficacy data up to 48 months. However data for 10 mg BID and tofacitinib monotherapy was limited after 24 and 36 months respectively. Over the two studies, 4102 patients were treated for a total of 5963 patient years.
Herpes zoster, both serious and non-serious, had a higher incidence rate in tofacitinib groups than literature reported rates for RA patients treated with both biologic and non-biologic DMARDs. It is also worth noting that in the phase III studies, patients receiving placebo or adalimumab as comparator therapies also had higher zoster rates than those observed with other DMARDs among RA patients in the literature. Asian patients were reported as having a higher risk of zoster infection compared with white patients.
In relation to efficacy, ACR20, ACR50 and ACR70 response rates were sustained from month 1 through to month 48. At month 1 response rates were 72.5%, 48.0% and 27.4% respectively. At month 48 equivalent response rates were 74.4%, 49.6% and 34.1%. Both mean DAS28-4-ESR and mean HAQ-DI decreased to month 48.
Tofacitinib has been observed to have good tolerability and efficacy in open-label studies of up to 48 months. Overall, tofacitinib monotherapy and combination therapy with a nonbiologic DMARD showed a similar safety profile.