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In the Regulus program, Aqilion is developing the drug candidate AQ280 as a potential treatment for eosinophilic esophagitis (EoE), an inflammatory disease of the esophagus that is also known as “allergic esophagitis” and which makes it difficult to swallow.

To date, no drugs with the same mechanism of action have been developed for EoE and there is a high unmet medical need.

AQ280 is an oral, small-molecule selective JAK1 inhibitor. JAK1 is an enzyme, a kinase, that accelerates inflammatory processes, which control conditions such as allergic diseases and fibrosis. Inhibiting its mechanism may facilitate symptom mitigation and disease progression in chronic inflammatory diseases. A selective compound has the potential to optimize efficacy and minimize side effects. Drugs with a similar mechanism of action have shown good clinical efficacy in autoimmune and inflammatory diseases.

In August 2022, Aqilion initiated the first-in-human clinical trial with AQI28 in the UK. This study, known as ARIA-1, was successfully concluded in August 2023. In October 2023 Aqilion reported positive results from the Phase 1 clinical trial in healthy volunteers. AQ280 was well tolerated, and the exposure achieved, in single and multiple doses, is in line with estimates of a therapeutically effective range based on preclinical models in terms of dose, safety, pharmacokinetics, pharmacodynamics and selectivity.

Now, Aqilion has started preparations for a clinical phase 2 study in patients, expected to start in 2024.