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

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.

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.

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.

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.