Upadacitinib is an orally administered, selective, Janus kinase inhibitor that is approved for several auto-immune conditions, such as axial spondyloarthritis, an inflammatory rheumatic disease that includes ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The approvals of upadacitinib for the treatment of AS and nr-axSpA were based on the safety and efficacy data for upadacitinib 15 mg once-daily compared to placebo from the SELECT-AXIS 1 and SELECT-AXIS 2 studies. Population pharmacokinetic analyses based on data from 244 patients with axSpA showed that the pharmacokinetics of upadacitinib were comparable in subjects with AS and nr-axSpA. Exposure-response relationships were characterized for key efficacy and safety end points using data from 482 patients with axSpA. The exposure-response analyses for efficacy based on Assessment of SpondyloArthritis International Society (ASAS)20 and ASAS40 responses at week 14, showed a clear differentiation from placebo with no evidence of increased responses with increasing upadacitinib plasma exposures. There were no clear exposure-response trends observed for safety end points that included serious infections, herpes zoster, pneumonia, lymphopenia (grade ≥3), neutropenia (grade ≥3), or a greater than 2 g/dL decrease in hemoglobin from baseline through week 14. The exposure-response analyses for efficacy and safety presented here supported the favorable benefit-risk profile with the use of upadacitinib 15 mg once-daily for the treatment of axSpA.

The fixed-dose combination of the direct acting antivirals glecaprevir (GLE) and pibrentasvir (PIB) is an oral, once-daily treatment for all six major genotypes of chronic hepatitis C virus infection. A single and multiple-dose rifampin study (N = 12) and a carbamazepine study (N = 12) were conducted in healthy subjects to evaluate the effects of CYP3A/P-gp induction and OATP inhibition on the pharmacokinetics of GLE and PIB. In study 1, GLE 300 mg + PIB 120 mg was administered as a single dose either alone, after single and multiple daily doses of rifampin 600 mg, or 24 h after the last rifampin dose. In study 2, GLE 300 mg + PIB 120 mg was administered as a single dose either alone or after multiple doses of carbamazepine 200 mg. Relative to GLE + PIB alone, exposure of GLE was significantly increased by the first co-administered rifampin dose due to OATP inhibition, significantly decreased 24 h after the last rifampin dose due to CYP3A/P-gp induction, and slightly increased when co-administered with steady-state rifampin due to a combination of inhibition and induction forces. Exposure of PIB was not affected when co-administered with the first rifampin dose but was significantly decreased with steady-state rifampin co-administration, or 24 h after the last rifampin dose due to P-gp induction. Carbamazepine significantly decreased GLE and PIB exposure, mainly attributed to P-gp induction. The regimens tested were generally well-tolerated by the subjects and no new safety issues were identified.