Oncostellae has received permission from the regulator to start a Phase 2a study with OST-122 in patients suffering from ulcerative colitis. Previously, the oral, GI-restricted JAK3/TYK2/ARK5 inhibitor has been shown to be safe and well tolerated in healthy volunteers up to 1200 mg and multiple dosing. Minimal plasma levels and high compound concentrations in feces demonstrated that the pharmacokinetic profile of OST-122 is: 1) specifically suitable for the local treatment of gastrointestinal diseases, and 2) lowers the risk of acquiring systemic side effects associated with current JAK inhibitors in clinical use.
The upcoming proof of concept study has been designed as a randomized, double blind, placebo controlled, multicenter clinical trial with the objective to evaluate the safety, pharmacokinetics and efficacy of oral treatment with OST-122 for 28 days in 32 patients with moderate to severe ulcerative colitis. Recruitment is about to start in March 2020 and will be carried out in collaboration with several hospital centers in Spain. Interim data from the first dose group (400 mg) are planned to be available by the end of 2020, and treatment of the second cohort (800 mg) is expected to be completed in 2021.