Upadacitinib (UPA) extended release (ER) formulation dosing achieved the target profile that enables single dosing in patients with RA. In early clinical studies, UPA was given as an immediate release (IR) formulation, however patients were noted to experience fluctuations in blood plasma concentrations. To enhance patient compliance in UPA Phase 3 trials, ER tablets have been developed. Here, authors aimed at characterising the pharmacokinetics of UPA single and multiple doses of ER compared wi...