CONSCIOUS 3: Randomized Trial of Clazosentan in Patients with Aneurysmal Subarachnoid Hemorrhage Undergoing Endovascular Coiling

Sponsor: Actelion

Investigators: Thanh Nguyen MD (principal), Alexander Norbash MD, Carlos Kase MD, Viken Babikian MD, Jose Romero MD

Stroke. 2012 Jun;43(6):1463- 9

Clazosentan, an endothelin receptor antagonist, has been shown to reduce vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). CONSCIOUS-3 assessed whether clazosentan reduced vasospasm-related morbidity and all-cause mortality postaSAH secured by endovascular coiling. This double-blind, placebo- controlled, phase III trial randomized patients with aSAH secured by endovascular coiling to ≤ 14 days intravenous clazosentan (5 or 15 mg/h) or placebo. The primary composite end point (all-cause mortality; vasospasm-related new cerebral infarcts or delayed ischemic neurological deficits; rescue therapy for vasospasm) was evaluated 6 weeks postaSAH. The main secondary end point was dichotomized extended Glasgow Outcome Scale (week 12). In conclusion, Clazosentan significantly reduced postaSAH vasospasm-related morbidity/all-cause mortality; however, neither dose improved outcome (extended Glasgow Outcome Scale).