Placebo-Controlled Trial of Tofacitinib Monotherapy in Rheumatoid Arthritis

Tofacitinib (CP-690,550) is a novel oral Janus kinase inhibitor that is being investigated as a targeted immunomodulator and disease-modifying therapy for rheumatoid arthritis.

In this phase 3, double-blind, placebo-controlled, parallel-group, 6-month study, 611 patients were randomly assigned, in a 4:4:1:1 ratio, to 5 mg of tofacitinib twice daily, 10 mg of tofacitinib twice daily, placebo for 3 months followed by 5 mg of tofacitinib twice daily, or placebo for 3 months followed by 10 mg of tofacitinib twice daily. The primary end points, assessed at month 3, were the percentage of patients with at least a 20% improvement in the American College of Rheumatology scale (ACR 20), the change from baseline in Health Assessment Questionnaire-Disability Index (HAQ-DI) scores (which range from 0 to 3, with higher scores indicating greater disability), and the percentage of patients with a Disease Activity Score for 28-joint counts based on the erythrocyte sedimentation rate (DAS28-4[ESR]) of less than 2.6 (with scores ranging from 0 to 9.4 and higher scores indicating more disease activity).