Rapid Onset of Efficacy of Baricitinib in Chinese Patients with Moderate to Severe Rheumatoid Arthritis: Results from Study RA-BALANCE.

INTRODUCTION: Baricitinib is an oral, selective inhibitor of Janus kinase which demonstrates clinical efficacy in patients with rheumatoid arthritis (RA). This report aims to analyze the onset time of baricitinib in Chinese patients with moderately to severely active RA who had an inadequate response to methotrexate. METHODS: This post hoc analysis evaluated clinical improvements of Chinese patients treated with baricitinib 4 mg once daily compared with placebo, based on data from a phase 3 study RA-BALANCE. Efficacy measures including American College of Rheumatology 20% (ACR20) response, ACR core set values, Disease Activity Score modified to include the 28 diarthrodial joint count (DAS28) using high-sensitivity C-reactive protein (hsCRP), DAS28-erythrocyte sedimentation rate, Simplified Disease Activity Index, Clinical Disease Activity Index, DAS28-hsCRP ≤ 3.2 response (low disease activity), and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) were evaluated at weeks 1, 2, 4, 8, 12, 14, 16, 20, and 24 (except for FACIT-F evaluated every 4 weeks). A logistic regression model and an analysis of covariance model were used to analyze treatment comparisons of categorical and continuous measures, respectively. RESULTS: Statistically significant (p ≤ 0.05) improvements were observed as early as week 1 or 2 for the baricitinib group compared to placebo in almost all main efficacy measures. For other outcomes including 66 swollen joint count, 68 tender joint count, FACIT-F, and DAS28-hsCRP ≤ 3.2 response rate, differences were evident (p ≤ 0.05) by week 4 in the baricitinib group compared with placebo. Significant improvements in all efficacy measures were sustained through 24 weeks. CONCLUSIONS: Baricitinib demonstrated a rapid onset of efficacy on ACR20 response, ACR core set values, disease activity, and patient-reported outcome improvements in Chinese patients from RA-BALANCE. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02265705.

Efficacy and Safety of Baricitinib in Chinese Rheumatoid Arthritis Patients and the Subgroup Analyses: Results from Study RA-BALANCE.

INTRODUCTION: Baricitinib is an oral selective inhibitor of Janus kinase (JAK) 1 and JAK 2, which has demonstrated significant efficacy in patients with moderately to severely active rheumatoid arthritis (RA). This analysis aims to describe the efficacy and safety of baricitinib in Chinese RA patients with an inadequate response to methotrexate (MTX-IR), and to analyze the effects of baseline characteristics on the efficacy of baricitinib treatment. METHODS: In this 52-week, randomized, double-blind, placebo-controlled study, 231 Chinese patients with moderately to severely active RA who had MTX-IR were randomly assigned to placebo (n = 115) or baricitinib 4 mg once daily (n = 116). The primary endpoint was American College of Rheumatology 20% (ACR20) response at week 12. Other efficacy measures included ACR50, ACR70, Physician's Global Assessment of Disease Activity, Patient's Global Assessment of Disease Activity, patient's assessment of pain, Disease Activity Score in 28 joints using high-sensitivity C-reactive protein, remission and low disease activity rates according to Simplified Disease Activity Index or Clinical Disease Activity Index, Health Assessment Questionnaire-Disability Index, and mean duration and severity of morning joint stiffness, worst tiredness and worst joint pain were analyzed. Additionally, subgroup analyses were performed across baseline characteristics. RESULTS: Statistically significant improvement in ACR20 response was achieved with baricitinib at week 12 (53.4 vs. 22.6%, p = 0.001) in Chinese patients, compared to placebo. Most of the secondary objectives were met with statistically significant improvements. Efficacy of baricitinib was irrespective of patient demographics and baseline characteristics. Safety events were similar between the baricitinib and placebo groups. CONCLUSIONS: The efficacy of baricitinib 4 mg in Chinese patients with moderately to severely active RA and prior MTX-IR was clinically significant compared to placebo regardless of baseline characteristics. Baricitinib was well tolerated with an acceptable safety profile during the full study period. TRIAL REGISTRATION: NCT02265705.