SB-245570 is a serotonin 5-HT<sub>1B</sub> receptor antagonist which was under development for the treatment of major depressive disorder but was never marketed. It was being developed by GlaxoSmithKline in the 1990s. A chemical synthesis for SB-245570 has been published. The drug reached the preclinical research stage of development prior to the discontinuation of its development.