A substance that is being studied as a treatment for advanced prostate cancer and for pain caused by prostate cancer that has spread to the bone. It belongs to the family of drugs called endothelin ETA receptor antagonists.

An orally active synthetic substituted phenylethenesulfonamide. As a selective endothelin A receptor antagonist, YM598 inhibits endothelin-mediated mechanisms involved in tumor cell growth and progression, angiogenesis, and metastasis.