Efficacy and safety of tofacitinib by background methotrexate dose in psoriatic arthritis: post hoc exploratory analysis from two phase III trials

Objective Analyze tofacitinib efficacy and safety by background methotrexate (MTX) dose in patients with psoriatic arthritis (PsA). Methods This post hoc analysis pooled data from two phase III, double-blind trials (OPAL Broaden, NCT01877668; OPAL Beyond, NCT01882439) including patients receiving tofacitinib 5 or 10 mg twice daily (BID), or placebo, with stable MTX. Efficacy outcomes at month 3 stratified by MTX dose (≤ 15 month 3 stratified by MTX dose vs > 15 mg/week) were American College of Rheumatology (ACR)20/50/70, Health Assessment Questionnaire-Disability Index (HAQ-DI); Psoriasis Area and Severity Index (PASI)50/75; change from baseline in HAQ-DI; physician’s global assessment of PsA (PGA-PsA-visual analog scale [VAS]); patient’s global joint and skin assessment (PGJS-VAS), Leeds Enthesitis Index (LEI); and Dactylitis Severity Score (DSS). Safety assessments included adverse events and laboratory parameters. Results Five hundred fifty-six patients received tofacitinib 5 mg BID ( n = 186), 10 mg BID ( n = 178), or placebo ( n = 192), plus MTX (≤ 15 mg/week, n = 371; > 15 mg/week, n = 185). At month 3, tofacitinib efficacy was generally greater than placebo. Patients receiving tofacitinib 5 mg BID demonstrated greater numerical improvements in efficacy outcomes at month 3 with MTX > 15 mg/week vs MTX ≤ 15 mg/week; patients receiving tofacitinib 10 mg BID displayed the opposite. The safety profile was generally consistent between groups; headache was associated with MTX > 15 mg/week; decreased hemoglobin levels were observed in patients receiving tofacitinib 10 mg BID and MTX ≤ 15 mg/week. Conclusion Efficacy of tofacitinib was generally numerically greater than placebo, regardless of MTX dose. Tofacitinib 5 mg BID was generally more efficacious with MTX > 15 mg/week vs ≤ 15 mg/week; the opposite was observed for tofacitinib 10 mg BID. Headache was more frequent with MTX > 15 mg/week. Trial registration ClinicalTrials.gov . Identifier: NCT01877668 (registration: June 14, 2013) and NCT01882439 (registration: June 20, 2013). Key Points • Methotrexate is widely used in the treatment of psoriatic arthritis; however, there are limited data on the impact of varying background methotrexate doses on the efficacy and safety of Janus kinase inhibitors in patients with psoriatic arthritis. • This post hoc analysis assessed the impact of background methotrexate dose (≤ 15 or > 15 mg/week) on tofacitinib efficacy and safety in patients with psoriatic arthri