POS0672 FIRST-IN-HUMAN STUDY OF GS-5718, AN ORAL IRAK-4 INHIBITOR, IN HEALTHY SUBJECTS: PHARMACOKINETICS, SAFETY, TOLERABILITY, AND ASSESSMENT OF EFFECT OF FOOD AND ACID REDUCING AGENTS ON EXPOSURE

Background: GS-5718 is a potent and selective interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor in clinical development for treatment of inflammatory diseases. Objectives: The aim of this first-in-human study was to evaluate the pharmacokinetics, safety, and tolerability of GS-5718; and the effect of food and acid-reducing agents (ARA) on GS-5718 pharmacokinetics in healthy subjects. Methods: This was a blinded, randomized, placebo-controlled, single and multiple (once daily for 10 days) oral dose study. Healthy male and female subjects were enrolled in ascending dose cohorts and randomized to receive GS-5718 (15, 50 or 150 mg) or placebo. GS-5718 was administered fasted in the single ascending dose cohorts, and under fed conditions (standard meal) in the multiple dose cohorts. The effects of a high-fat meal and omeprazole (a representative ARA) on GS-5718 50 mg dose pharmacokinetics were also evaluated. Serial blood samples were collected and GS-5718 pharmacokinetic parameters were characterized. Safety was assessed by review of adverse events (AEs), clinical laboratory tests, and vital signs. Results: A total of 74 subjects (n = 62 GS-5718; n = 12 placebo) enrolled and completed study drug treatments in this study. GS-5718 was generally well tolerated at all evaluated dose levels; AEs were mild in severity and no dose-limiting toxicities, serious AEs, nor clinically relevant electrocardiogram or vital sign abnormalities were observed in subjects administered GS-5718. GS-5718 exposure was approximately dose proportional across the evaluated multiple ascending dose range. GS-5718 showed low-to-moderate pharmacokinetic variability with median half-life of 25 to 33 hours and 1.6 to 2.4- fold accumulation at steady-state, which was achieved by Day 5-7 of dosing. Food had no clinically meaningful impact on GS-5718 exposure (AUC and Cmax) at the 50 mg dose. Co-administration of omeprazole with GS-5718 reduced GS-5718 exposure (AUC and Cmax) by 23% and 43%, respectively, at the 50 mg dose. Conclusion: GS-5718, administered once daily, was well tolerated following single or multiple dosing up to 150 mg. The pharmacokinetic and safety profile of GS-5718 support the further development in inflammatory diseases with once-daily administrations. Disclosure of Interests: Kacey Anderson Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Chia-Hsiang Hsueh Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Oksana Gurtovaya Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Anubhav Mathur Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, James Taylor Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Adrian Serone Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Ahmed A. Othman Shareholder of: Gilead Sciences, Employee of: Gilead Sciences