Clinical Research Study With Clazosentan to Evaluate Its Effects on Preventing Complications Due to the Narrowing of the Blood Vessels (Vasospasm) in the Brain, Caused by Bleeding Onto the Surface of the Brain

Study Overview
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Brief Summary
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This study will evaluate if clazosentan (on top of normal routine medical care) can reduce the risk of developing complications related to cerebral vasospasm and permanent brain damage as compared to normal routine medical care alone.

Detailed Description
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When a blood vessel just outside the brain bursts and causes bleeding onto its surface, the space surrounding the brain (the subarachnoid space) fills with blood. This condition is called subarachnoid hemorrhage. The bleeding due to the rupture of a pouch-like structure or a bulge (called an aneurysm) that formed on one of the blood vessels is condition called aneurysmal subarachnoid hemorrhage (aSAH). In this study, clazosentan is being tested against normal routine medical care to determine if clazosentan can reduce the risk of developing complications related to vasospasm and permanent brain damage. Participation will last for approximately 6 months from the episode of bleeding. For subjects randomized in the high-risk prevention group, treatment will start within 96 hours following the time of the aneurysm rupture, and be administered where possible, for 14 days. For subjects randomized in the early treatment group, treatment must begin within 24 hours of the time of the angiogram documenting the cerebral vasospasm necessary for entry into the study. Treatment will be administered for a minimum of 6 days and a maximum of 14 days. Recruitment in the early treatment group has been discontinued. The end-of-study will be conducted as a telephone interview 6 months after the episode of bleeding.

Official Title
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A Prospective, Multi-center, Double-blind, Randomized, Placebo-controlled, Parallel-group, Phase 3 Study to Assess the Efficacy and Safety of Clazosentan in Preventing Clinical Deterioration Due to Delayed Cerebral Ischemia (DCI), in Adult Subjects With Aneurysmal Subarachnoid Hemorrhage (aSAH)

Conditions
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Aneurysmal Subarachnoid Hemorrhage

Intervention / Treatment
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* Drug: Clazosentan
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent to participate in the study must be obtained from the subject or proxy/legal representative at any time from hospital admission to prior to initiation of any study-mandated procedure, Males and females aged 18 to 70 years (inclusive, at hospital admission), Subjects with a ruptured saccular aneurysm, angiographically confirmed by DSA or CTA, which has been successfully secured within 72 hours of rupture, by surgical clipping or endovascular coiling, WFNS (World Federation of Neurosurgical Societies) grades 1-4 (based on Glasgow Coma Scale [GCS]) assessed after recovery from the aneurysm-securing procedure and after external ventricular drainage for hydrocephalus, if required. Subjects must meet the criteria for the high-risk prevention group: Subjects with a thick and diffuse clot (thick and diffuse is defined as a thick confluent clot, more than 4 mm in thickness, involving 3 or more basal cisterns) on the hospital admission CT scan, absence of cerebral vasospasm at the time of randomization, and possibility to start study drug in the ICU (or equivalent environment where all protocol assessments can be performed and the Patient Management Guidelines followed), within 96 hours after the time of the aneurysm rupture. The recruitment into the early treatment group, i.e. subjects without a thick and diffuse clot on the hospital admission CT scan who develop asymptomatic or minimally symptomatic moderate to severe angiographic vasospasm, within the 14-day period post-aneurysm rupture, and for whom it is possible to start study drug in the ICU (or equivalent environment where all protocol assessments can be performed and the Patient Management Guidelines followed), within 24 hours of this angiographic diagnosis, has been discontinued. Presence of a cerebral CT scan performed at least 8 hours post aneurysm securing procedure and within 24 hours prior to randomization. Absence of a significant (e.g., symptomatic or large) new or worsened cerebral infarct or re-bleeding of the repaired aneurysm on the post-procedure CT scan. A woman of childbearing potential is eligible only if the pregnancy test performed during the screening period is negative. Agreement must be obtained to take the necessary precautions to avoid pregnancy from hospital discharge until 30 days post-study drug discontinuation. If breastfeeding, agreement must be obtained to refrain for the duration of the treatment with study drug and until 30 days post-study drug discontinuation. Males are eligible for study participation only if they agree to take the necessary precautions to avoid pregnancy in a female partner from hospital discharge until 30 days post-study drug discontinuation. Exclusion Criteria: Aneurysmal subarachnoid hemorrhage (aSAH), aneurysm-securing procedure, vasospasm: Subjects with SAH due to causes other than a saccular aneurysm (e.g., trauma or rupture of fusiform or mycotic aneurysms, SAH associated with arterio-venous malformation, vertebral dissections), Significant bleeding post aneurysm-securing procedure (e.g., due to intra-ventricular drain, intra-cerebral hemorrhage, epidural hematoma, vessel dissection or rupture, re-bleeding of the repaired aneurysm), based on investigator judgment, Intra-or peri-aneurysm securing procedure complication requiring non-routine medical or interventional treatment such as administration of an antithrombotic or anti-platelet agent (e.g., abciximab), which is not completely resolved prior to randomization, Intraventricular hemorrhage on the hospital admission CT scan, filling more than 50% of both lateral ventricles and with involvement of the 3rd and 4th ventricles. Intracerebral hemorrhage on the hospital admission CT scan, with an approximate volume of > 50 mL, Presence of cerebral vasospasm at hospital admission (initial admission or transfer from another hospital) believed to be associated with a prior bleed (i.e., occurring before the bleed for which the subject is currently hospitalized). Vasospasm occurring during the aneurysm securing procedure is not an exclusion criterion, Neurological and functional status: Subjects with a new major neurological deficit occurring post aneurysm-securing procedure which is attributable to the procedure and does not improve to pre-procedure status before randomization, Subjects with a GCS score of ≤ 9 at the time of randomization and without intracranial pressure (ICP) monitoring, Modified Rankin Score of 3 or higher, prior to the aSAH (i.e., due to a chronic condition), Other clinical considerations: Subjects with 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, Hypotension (systolic blood pressure [SBP] ≤ 90 mmHg) at time of randomization that is refractory to treatment, Unresolved pulmonary edema or significant pneumonia still present at the time of randomization, or severe hypoxia at the time of randomization in intubated subjects, defined as PaO2/FiO2 ≤ 200, High sustained ICP (> 25 mmHg lasting > 20 minutes) at time of randomization, despite optimal treatment, in subjects with ICP monitoring, Severe cardiac failure requiring inotropic support at the time of random

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Clazosentan<br>Participants will receive clazosentan for up to 14 days, followed by a safety follow-up period of 24 hours, and an extended follow-up period to the end-of-study visit at Week 24 post aneurysmal subarachnoid hemorrhage (aSAH). | Drug: Clazosentan<br>* Clazosentan will be administered as a continuous intravenous infusion at the dose of 15 mg/hour for up to 14 days.<br>* Other names: ACT-108475;|
| Placebo Comparator: Placebo<br>Participants will receive clazosentan matching-placebo for up to 14 days, followed by a safety follow-up period of 24 hours, and an extended follow-up period to the end-of-study visit at Week 24 post aneurysmal subarachnoid hemorrhage (aSAH). | Drug: Placebo<br>* Placebo will be administered at the same infusion rate as clazosentan for up to 14 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrence of clinical deterioration due to delayed cerebral ischemia (DCI) from study drug initiation up to 14 days post-study drug initiation | Clinical deterioration due to DCI is defined as a worsening of at least 2 points compared to the reference score, on the mGCS or the aNIHSS, lasting for at least 2 hours, which cannot be entirely attributed to causes other than cerebral vasospasm. It is centrally adjudicated by the CEC based on a written charter and review of clinical data, case narratives, angiograms and CT scans. | Up to 14 days post-study drug initiation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrence of clinically relevant cerebral infarction at Day 16 post-study drug initiation | A clinical relevant cerebral infarction is defined as: all-cause cerebral infraction ≥ 5 cm3 or cerebral infarction < 5 cm3 in subjects with clinical deterioration due to delayed cerebral ischemia (DCI). Cerebral infarction refers to new or worsened infarcts and is determined by central radiology review comparing the total volume of infarcts on the computed tomography (CT) scan performed 16 days after study drug initiation with the CT performed just prior to randomization. | At Day 16 post study drug initiation | 
| Long-term clinical outcome assessed by the modified Rankin Scale (mRS) at Week 12 post-aSAH, dichotomized into poor outcome (score ≥ 3) and good outcome (score < 3) |  | At Week 12 post-aSAH | 
| Long-term clinical outcome assessed by the Glasgow Outcome Scale Extended (GOSE) at Week 12 post-aSAH, dichotomized as follows: poor outcome (score ≤ 4) and good outcome (score > 4) |  | At Week 12 post-aSAH |