Evaluation of the Efficacy and Safety of Clazosentan in Reversing Cerebral Vasospasm in Adult Subjects With Aneurysmal Subarachnoid Hemorrhage

Inclusion Criteria: * Signed informed consent from the subject or proxy/legal representative * Aneurysmal subarachnoid hemorrhage (aSAH)confirmed by digital subtraction angiogram (DSA) or computed tomography angiogram (CTA), successfully secured by surgical clipping or endovascular coiling within 72 hours of rupture * World Federation of Neurological Surgeons (WFNS) grade 1-4 at admission, and which must not increase to grade 5 at the time of enrollment * Moderate or severe global cerebral vasospasm at the time of enrollment, documented by digital subtraction angiography (DSA) performed not earlier than 48 hours post aneurysm-securing procedure * Women of childbearing potential must have a negative serum pregnancy test at screening and must use a reliable method of contraception from hospital discharge up to 30 days after discontinuation of study drug infusion, and fertile males must use a condom as a contraceptive method during this same period Exclusion Criteria: * SAH due to causes other than a saccular aneurysm * Any moderate or severe cerebral vasospasm on angiography prior to the aneurysm-securing procedure * Presence of a new or worsened cerebral infarct or evidence of significant bleeding post aneurysm-securing procedure, or re-bleeding, on a CT scan performed within 24 hours prior to enrollment * Total bilirubin \> 2 times the upper limit of normal, and / or a known diagnosis or clinical suspicion of liver cirrhosis or moderate to severe hepatic impairment * Any s…