OST-122, a novel, gut-restricted Jak3/Tyk2 inhibitor for the local treatment of gastrointestinal diseases, has completed the first part of a randomized, double-blind, placebo-controlled clinical Phase I trial in healthy volunteers which was carried out at the Sant Pau Hospital of Barcelona.
During the single dose escalation study, the compound has been well tolerated in all dose groups (up to 1200 mg) and caused no significant adverse effects. Minimal plasma levels at the lower limit of detection (< 1 ng/mL) and millimolar compound concentrations in feces have been detected which demonstrates that oral administration of OST-122 is specifically suitable for targeting the gastrointestinal tract.
These data highlight the excellent safety profile of OST-122 probably due to its minimal systemic exposure which lowers the risk of acquiring systemic side effects like infections, thromboembolism and heart problems that have been observed with first generation JAK inhibitors in clinical use and limit their therapeutic window.
OST-122 has now moved into Phase Ib dose escalation studies with multiple administrations that are due to be completed in April 2019.