OBJECTIVE: To compare the efficacy, safety, and tolerability of 5 doses of oral 
tofacitinib (CP-690,550) or adalimumab monotherapy with placebo for the 
treatment of active rheumatoid arthritis (RA) in patients with an inadequate 
response to disease-modifying antirheumatic drugs.
METHODS: In this 24-week, double-blind, phase IIb study, patients with RA (n = 
384) were randomized to receive placebo, tofacitinib at 1, 3, 5, 10, or 15 mg 
administered orally twice a day, or adalimumab at 40 mg injected subcutaneously 
every 2 weeks (total of 6 injections) followed by oral tofacitinib at 5 mg twice 
a day for 12 weeks. The primary end point was the responder rate according to 
the American College of Rheumatology 20% improvement criteria (ACR20) at week 
12.
RESULTS: Treatment with tofacitinib at a dose of ≥3 mg twice a day resulted in a 
rapid response with significant efficacy when compared to placebo, as indicated 
by the primary end point (ACR20 response at week 12), achieved in 39.2% (3 mg; P 
≤ 0.05), 59.2% (5 mg; P < 0.0001), 70.5% (10 mg; P < 0.0001), and 71.9% (15 mg; 
P < 0.0001) in the tofacitinib group and 35.9% of patients in the adalimumab 
group (P = 0.105), compared with 22.0% of patients receiving placebo. 
Improvements were sustained at week 24, according to the ACR20, ACR50, and ACR70 
response rates as well as classifications of remission according to the 
3-variable Disease Activity Score in 28 joints (DAS28) using C-reactive protein 
and the 4-variable DAS28 using the erythrocyte sedimentation rate. The most 
common treatment-emergent adverse events (AEs) in patients across all 
tofacitinib treatment arms (n = 272) were urinary tract infection (7.7%), 
diarrhea (4.8%), headache (4.8%), and bronchitis (4.8%).
CONCLUSION: Tofacitinib monotherapy at ≥3 mg twice a day was efficacious in the 
treatment of patients with active RA over 24 weeks and demonstrated a manageable 
safety profile.