Chymase is a serine protease that has been studied as a drug target in inflammatory diseases, so far with limited success. Fulacimstat is a novel drug candidate inhibiting chymase that has been investigated in clinical trials for the role of chymase in inflammation. Despite a good safety profile, further clinical development of fulacimstat was not pursued due to a lack of efficacy. Recently, a new role of chymase in blood clot biology has been identified, this resparks interest in chymase inhibitors, and positions fulacimstat as a potential innovative option to treat thrombotic conditions.