A double-blind, placebo-controlled, randomized multiple dose phase 1b trial of a CDK4/6 inhibitor, TCK-276, in patients with active rheumatoid arthritis.

Objective: The purpose of this study was to evaluate the safety, tolerability, pharmacokinetics, and efficacy (as an exploratory endpoint) of TCK-276, a novel CDK4/6 inhibitor, after multiple oral doses for 7 days in patients with active RA.

Methods: This multicentre, randomized, placebo-controlled, dose-ascending, double-blind, phase 1b, multiple-dose study included 32 patients with active RA in 4 cohorts of 8 patients (6 active and 2 matching placebo), each receiving an oral dose of TCK-276 or matching placebo for 7 days (once daily). The doses of TCK-276 were 10, 25, 75, and 175 mg/day.