The JAK1 Inhibitor Upadacitinib Has No Effect on the Pharmacokinetics of Levonorgestrel and Ethinylestradiol: A Study in Healthy Female Subjects

Upadacitinib is a novel selective oral Janus kinase 1 (JAK) inhibitor being developed for treatment of several inflammatory diseases. Oral contraceptives are anticipated to be a common concomitant medication in the target patient populations. This study was designed to evaluate the effect of multiple doses of upadacitinib on the pharmacokinetics of ethinylestradiol and levonorgestrel in healthy female subjects. This phase I, single‐center, open‐label, 2‐period crossover study evaluated the effect of multiple doses of 30 mg once daily extended‐release upadacitinib on the pharmacokinetics of a single oral dose of ethinylestradiol/levonorgestrel (0.03/0.15 mg; administered alone in period 1 and on day 12 of a 14‐day regimen of upadacitinib in period 2) in 22 healthy female subjects. The ratios (90% confidence intervals) for maximum plasma concentration and area under the plasma drug concentration–time curve from time zero to infinity following administration of ethinylestradiol/levonorgestrel with upadacitinib compared with administration of ethinylestradiol/ levonorgestrel alone were 0.96 (0.89–1.02) and 1.1 (1.04–1.19), respectively, for ethinylestradiol, and 0.96 (0.87–1.06) and 0.96 (0.85–1.07), respectively, for levonorgestrel. The harmonic mean terminal half‐life for ethinylestradiol (7.7 vs 7.0 hours) and levonorgestrel (37.1 vs 33.1 hours) was similar in the presence and absence of upadacitinib. Ethinylestradiol and levonorgestrel were bioequivalent in the presence and absence of upadacitinib. Therefore, upadacitinib can be administered concomitantly with oral contraceptives containing ethinylestradiol or levonorgestrel.