Clazosentan: First Approval

Clazosentan (PIVLAZ™) is a small molecule, endothelin (ET) A receptor-selective antagonist being developed by Idorsia Pharmaceuticals. ETA receptor inhibition by clazosentan decreases ET-related cerebral vasospasm, which may occur after an aneurysmal subarachnoid haemorrhage. Clazosentan has been approved in Japan for use in the prevention of cerebral vasospasm, vasospasm-related cerebral infarction and cerebral ischaemic symptoms after aneurysmal subarachnoid haemorrhage, following the results from the JapicCTI163369 and JapicCTI163368 phase III trials. This article summarises the milestones in the development of clazosentan leading to this first approval in this indication.