An Integrated Analysis of the Safety of Tofacitinib in Psoriatic Arthritis across Phase III and Long-Term Extension Studies with Comparison to Real-World Observational Data

Introduction: Tofacitinib is an oral Janus kinase inhibitor for the treatment of psoriatic arthritis (PsA). Objective: Our objective was to compare the incidence rates (IRs) of adverse events in tofacitinib clinical trials and real-world observational data for alternative treatments. Methods: The tofacitinib “dose-comparison cohort” included months 0–12 of two phase III studies (tofacitinib 5 [n = 238] and 10 [n = 236] mg twice daily [BID]); the “all-tofacitinib comparison cohort” (n = 783) included two phase III and one ongoing long-term extension study (data cutoff May 2016). An “observational comparison cohort” (n = 5799) comprised patients initiating a conventional synthetic disease-modifying antirheumatic drug (DMARD), biologic DMARD, or apremilast in the US Truven MarketScan database from 2010 to 2015. IRs for serious infections (SIEs; requiring hospitalization), herpes zoster (HZ), malignancies (excluding non-melanoma skin cancer [NMSC]), NMSC, and major adverse cardiovascular events (MACE) across cohorts were qualitatively compared. Results: IRs (patients with events/100 patient-years) for SIEs were similar between the tofacitinib dose-comparison cohort (5 mg BID: 1.3; 10 mg BID: 2.0) and the observational comparison cohort (1.1–7.9; treatment dependent). The tofacitinib dose-comparison cohort had a higher rate of HZ (5 mg BID: 2.0; 10 mg BID: 2.7) than did the observational comparison cohort (0.8–2.0). IRs for NMSC were generally lower in the all-tofacitinib comparison cohort (0.5) than in the observational comparison cohort (0.4–6.0). IRs for MACE, malignancies excluding NMSC, and NMSC were similar between cohorts. Conclusion: In patients with PsA, tofacitinib had a safety profile similar to that of other systemic therapies in real-world settings, except for the risk of HZ, a known risk of tofacitinib. Trial Registration: ClinicalTrials.gov: NCT01877668; NCT01882439; NCT01976364.