[Pharmacological Profile and Clinical Study Results of endothelin receptor antagonist, Clazosentan Sodium (PIVLAZ® I.V. Infusion liquid 150 mg)].

Cerebral vasospasm occurs within 4 to 14 days from the onset of aneurysmal subarachnoid hemorrhage (aSAH) in 40 to 70% of patients. Of patients with cerebral vasospasm, 17 to 40% experience delayed ischemic neurological deficits and about half of them develop cerebral infarction. Although the mechanism of the onset of cerebral vasospasm has not been fully elucidated, one of mechanisms is considered that after the onset of aSAH, the level of endothelin, a potent and sustained vasoconstriction substance, increases by production induced by oxyhemoglobin and release from erythrocytes and thus cerebral vasospasm develops via endothelin (ET)A receptor. PIVLAZ I.V. Infusion liquid 150 mg (clazosentan sodium) is an endothelin receptor antagonist with a binding affinity for ETA receptor approximately 1,000 times higher than that for ETB receptor. In the clinical study, the incidence of cerebral vasospasm-related morbidity and all-cause mortality was significantly decreased by clazosentan compared with the placebo. The marketing approval was obtained for the indication of "Prevention of cerebral vasospasm, and vasospasm-related cerebral infarction and cerebral ischemic symptoms after aSAH securing" in January 2022. It is expected to contribute to reducing the risk of sequela and improving quality of life in patients with aSAH.