Ziretaxestat, an oral autotaxin (ATX) inhibitor originated by Galapagos, once garnered excitement as the first molecule to complete a Ph. III clinical program in idiopathic pulmonary fibrosis since the approvals of nintedanib and pirfenidone. Following the disappointing clinical data and discontinuation of the molecule, this annotation revisits ziritaxestat in the context of other inhibitors, recaps the therapeutic hypothesis and how it was discovered, summarizes notable molecular properties for drug discovery scientists, and discusses what happened and what’s next.

Reviewer Christian Kuttruff comments, “I think what is important to the Ziritaxestat story is [...]