P540 GB004, a novel prolyl hydroxylase inhibitor for inflammatory bowel disease, leads to gut-targeted HIF-1α pathway engagement in a multiple-dose study in healthy subjects
B. Levesque1, K. Taylor Meadows2, A. Buch3, M. Flynn4, K. Peters5, A. Olson1, J. Shen1, D. Slee6, C. Van Biene7, R. Aranda1, N. Vande Casteele8, G. Opiteck1
1Clinical Development, Gossamer Bio Inc., San Diego, USA, 2Department of Biology, Gossamer Bio Inc., San Diego, USA, 3Department of Clinical Pharmacology and Pharmacokinetics, Aerpio Pharmaceuticals Inc., Cinncinati, USA, 4Department of Project Management, Aerpio Pharmaceuticals Inc., Cincinnati, USA, 5Department of Research and Development, Aerpio Pharmaceuticals Inc., Cincinnati, USA, 6Department of Research and Development, Gossamer Bio Inc., San Diego, USA, 7Department of Biometrics, Gossamer Bio Inc., San Diego, USA, 8Department of Precision Medicine, Robarts Clinical Trials, San Diego, USA
Background
GB004 is a small-molecule prolyl hydroxylase inhibitor that stabilises hypoxia-inducible factors (HIF-1α), key transcription factors involved in the protective cellular responses at the intersection of hypoxia and inflammation. GB004 was selected based on its gut-targeted profile to limit systemic on-target effects associated with HIF-1α stabilisation. GB004 is in clinical development for the treatment of inflammatory bowel disease and was shown to be safe in a single ascending dose study. The study described here evaluates the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of multiple daily doses of GB004 in plasma and colon biopsies.
Methods
This was a randomised, double-blind, placebo-controlled, multiple-dose, Phase 1a study conducted in healthy subjects at a single site in Canada. Three dose levels of GB004 or placebo formulated as a solution were administered orally once a day for 8 days; safety and PK were evaluated. Colon biopsies were obtained one day prior to the first dose and on Day 8. Colonic tissue concentrations of GB004 and HIF pathway target genes were determined.
Results
Forty-two subjects (20 male and 22 female) were dosed. No serious adverse events or deaths were recorded. The most commonly observed adverse event in GB004-treated subjects was dizziness (31%,10/32); all events were mild and did not result in study drug discontinuation. There were no identified risks of GB004. Following oral dosing, GB004 was rapidly absorbed and eliminated from the systemic circulation, with a median time to maximum concentration of 0.5 h for all dose levels. Concentrations of GB004 measured in colon biopsies were greater than in plasma at the time of the biopsy. Dose-related HIF pathway target gene engagement and PD were confirmed.
Conclusion
This study demonstrated that multiple daily doses of GB004 solution were safe and tolerable. The PK profile was consistent with its intended preferential exposure in the gut. A clinical study of GB004 is ongoing in patients with ulcerative colitis to explore safety, tolerability, PK and PD both systemically and within colonic tissue (NCT03860896). A tablet formulation is also being developed.