Laboratory markers predicting tofacitinib efficacy in Japanese patients with rheumatoid arthritis: A pooled analysis of Phase 2/3 randomised controlled clinical trials.

Abstract

Objectives: We characterised early changes in laboratory parameters in Japanese patients with rheumatoid arthritis and assessed whether these changes at Month (M)1 were predictive of tofacitinib efficacy at M3.

Methods: This post hoc analysis included pooled data from Japanese patients receiving tofacitinib or placebo in three Phase 2/Phase 3 studies (NCT00603512; NCT00687193; NCT00847613). Outcomes included changes from baseline in laboratory parameters (Week 2 and M1/3); efficacy end points were Disease Activity Score in 28 joints, based on C-reactive protein; Disease Activity Score in 28 joints, based on erythrocyte sedimentation rate; and American College of Rheumatology-N index at M3. Univariate/multivariable analyses assessed whether changes at M1 were predictive of efficacy at M3.

Results: Overall, 467 patients receiving tofacitinib and 104 receiving placebo were included. Tofacitinib treatment was associated with decreases from baseline in C-reactive protein, erythrocyte sedimentation rate, neutrophils, and platelets and increases in lymphocytes, haemoglobin, and lipids up to M3. Decreased platelet count and increased low-density lipoprotein cholesterol and haemoglobin at M1 were predictive of changes in efficacy outcomes at M3.

Conclusions: Changes in laboratory parameters at M1 could potentially be used to assess whether tofacitinib therapy will be effective at M3; however, further investigation is needed.