PT  - JOURNAL ARTICLE
AU  - Yoshiya Tanaka
AU  - Kahaku Emoto
AU  - Zhihong Cai
AU  - Takehiro Aoki
AU  - Douglas Schlichting
AU  - Terence Rooney
AU  - William Macias
TI  - Efficacy and Safety of Baricitinib in Japanese Patients with Active Rheumatoid Arthritis Receiving Background Methotrexate Therapy: A 12-week, Double-blind, Randomized Placebo-controlled Study
AID  - 10.3899/jrheum.150613
DP  - 2016 Feb 01
TA  - The Journal of Rheumatology
PG  - jrheum.150613
4099  - http://www.jrheum.org/content/early/2016/01/26/jrheum.150613.short
4100  - http://www.jrheum.org/content/early/2016/01/26/jrheum.150613.full
AB  - Objective To evaluate efficacy and safety, baricitinib [Janus kinase (JAK) 1/JAK2 inhibitor] was compared with placebo in Japanese patients with active rheumatoid arthritis (RA) despite background treatment with methotrexate (MTX). Methods This was a phase IIB, double-blind, randomized, placebo-controlled study (clinicaltrials.gov: NCT01469013). Patients had moderate to severe active adult-onset RA despite stable treatment with MTX. Patients (n = 145) were randomized in a 2:1:1:1:1 ratio to placebo or 1 mg, 2 mg, 4 mg, or 8 mg oral baricitinib daily for 12 weeks. The primary analysis compared the combined 4/8-mg dose groups with placebo for the American College of Rheumatology (ACR) 20 response rate at 12 weeks. Other outcomes included additional measures of disease activity, physical function, laboratory abnormalities, and adverse events. Results A significantly higher proportion of patients in the combined 4/8-mg baricitinib group (37/48, 77%) compared with the placebo group (15/49, 31%) had at least an ACR20 response after 12 weeks of treatment (p < 0.001). Significant improvements in disease activity, remission, and physical function were observed as early as Week 2 of treatment with baricitinib, particularly with daily doses of ≥ 4 mg. Only 1 patient receiving baricitinib discontinued because of an adverse event. Adverse event rates with baricitinib doses ≤ 4 mg daily were similar to placebo, but there was a higher incidence of adverse events and laboratory abnormalities in the 8-mg group. Conclusion In this phase II study, baricitinib was well tolerated and rapidly improved the signs, symptoms, and physical function of Japanese patients with active RA, supporting continued development of baricitinib (clinicaltrials.gov NCT01469013).