Recombinant Human C1 Esterase Inhibitor (Conestat Alfa) in the Prevention of Acute Ischemic Cerebral and Renal Events After Transcatheter Aortic Valve Implantation

Phase 2

Recruiting

• Conditions: Acute Ischemic Stroke; Acute Renal Injury
• Interventions: Drug: Conestat alfa (Ruconest®); Drug: NaCl 0.9%)

• Registration Number: NCT05145283
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

The aim of this trial is to assess the safety and efficacy of conestat alfa (Ruconest®, Pharming Technologies B.V.) on renal and cerebral ischemic events in patients undergoing TAVI for severe symptomatic aortic stenosis (AS) compared to placebo.

Detailed Description

Severe aortic stenosis (AS) is a frequent valvular heart disease in the elderly with a prevalence of 4 to 10% and a mean survival of only 0.5 to 5 years if left untreated. Transcatheter aortic valve implantation (TAVI) has evolved as standard of care for high-, intermediate and potentially even low surgical risk candidates due to a lower perioperative risk compared to surgical aortic valve replacement (SAVR). Despite its relative safety compared to SAVR, embolic events originating from the calcified valve and leading to ischemic stroke and acute renal injury are major complications following TAVI in the acute and subacute period, and are associated with increased morbidity including cognitive decline and mortality. While cerebral embolic protection devices (CEPD) such as the Sentinel® CEPD (Boston Scientific) were designed to reduce the burden of cerebral embolic events, their impact on clinical events has yet to be determined, and other prophylactic options are currently not available. Ischemia/reperfusion injury (IRI) is a key pathophysiological mechanism involved in cerebral and renal embolic events after TAVI resulting in activation of endothelial cells, the contact activation and the complement system and attraction of neutrophils to the site of injury. In this regard, recombinant human C1 esterase inhibitor (rhC1INH, conestat alfa), a potent inhibitor of the complement and the contact system has been shown to reduce the size of cerebral ischemic damage and of renal injury in experimental IRI models, and has successfully been investigated in a pilot study of acute kidney injury following the administration of contrast media. The aim of the current trial is to assess the safety and efficacy of conestat alfa (Ruconest®, Pharming Technologies B.V.) on renal and cerebral ischemic events in patients undergoing TAVI for severe symptomatic AS compared to placebo.

Study Timeline

• Study First Submitted: 2021-11-17
• Study First Submitted QC: 2021-11-22
• Study First Posted: 2021-12-06
• Study Start: 2022-03-16
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-10
• Last Update Posted: 2025-03-12
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 250

Inclusion Criteria

• Informed consent as documented by signature
• Severe AS and scheduled for transfemoral TAVI

Exclusion Criteria

• Contraindications to the class of drugs under study (C1INH), e.g., known hypersensitivity or allergy to class of drugs or the investigational product
• History of allergy to rabbits (as rhC1INH is derived from the breast milk of transgenic rabbits)
• Women who are pregnant or breast feeding
• Hemodynamic instability requiring emergency TAVI
• Valve-in-valve procedure
• Other access route than transfemoral
• Non-cardiac co-morbidity with expected survival <6 months
• Ischemic or hemorrhagic stroke within 30 days before TAVI
• Dialysis or estimated glomerular filtration rate (eGFR) <20 ml/min/1.73m2
• Contraindication for MRI such as a permanent non-MRI compatible pacemaker or severe claustrophobia
• Liver cirrhosis (any Child-Pugh score)
• Incapacity or inability to provide informed consent
• Participation in another study with investigational drug or medical device within the 30 days preceding and during the present study
• Previous enrolment into the current study
• Any uncontrolled or significant concurrent illness that would put the patient at a greater risk or limit compliance with the study requirements at the discretion of the investigator

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Conestat alfa (Ruconest®) intervention group	Conestat alfa (Ruconest®)	The intervention group will receive conestat alfa (Ruconest®) as a 10-minute slow intravenous injection (up to 56 ml) once during the TAVI procedure followed by a second administration (up to 28 ml) again three hours later. The first administration will include a dosage of 100 U/kg (maximum 8400 U) conestat alfa. The dosing of the second administration will be 50 U/kg (maximum 4200 U).
saline injection placebo group	NaCl 0.9%)	Subjects randomized into the placebo group will receive an intravenous normal saline injection with corresponding volume over 10 minutes during the TAVI procedure and three hours later after the first administration.

Primary Outcome Measures

Name	Time	Method
Total volume of new cerebral ischemic lesions as evaluated by magnetic resonance imaging (MRI)	on day 4 (+/-1 day) after transfemoral TAVI	Total volume of new cerebral ischemic lesions as evaluated by magnetic resonance imaging (MRI)

Secondary Outcome Measures

Name	Time	Method
Maximum new lesion volume as measured by MRI (i.e. volume of the largest new lesion)	on day 4 (+/-1 day) after transfemoral TAVI	Maximum new lesion volume as measured by MRI (i.e. volume of the largest new lesion)
Number of new cerebral ischemic lesions as measured by MRI	on day 4 (+/-1 day) after transfemoral TAVI	Number of new cerebral ischemic lesions as measured by MRI
Number (incidence) of clinically manifest ischemic stroke	within 48 hours after TAVI	Number (incidence) of clinically manifest ischemic stroke
Change in secondary brain atrophy at 3-months follow-up	at baseline and at 3-months follow-up	Secondary brain atrophy at 3-months follow-up related to the gradual cellular loss as measured by high resolution 3D T1-weighted MR images (defined as the difference between the brain volumes)
Change in secondary infarct growth at 3-months follow-up (defined as the difference between the infarct volumes)	at day 4 and at 3-months	Change in secondary infarct growth at 3-months follow-up (defined as the difference between the infarct volumes)
Total brain damage (defined as the sum of secondary brain atrophy and final infarct volume)	at 3 months	Total brain damage (defined as the sum of secondary brain atrophy and final infarct volume)
Change in National Institutes of Health Stroke Scale Score (NIHSS)	at baseline and at 3-months follow-up	The NIHSS is composed of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment. The individual scores from each item are summed in order to calculate a patient's total NIHSS score. The maximum possible score is 42, with the minimum score being a 0.
Change in modified Rankin scale	at baseline and at 3-months follow-up	Change in modified Rankin scale; scale runs from 0-6, running from perfect health (0) without symptoms to death (6)
Change in trail making test	at baseline and at 3-months follow-up	Change in trail making test; scoring is based on time taken to complete the test (e.g. 35 seconds yielding a score of 35) with lower scores being better.
Change in Montreal Cognitive Assessment test (MOCA)	at baseline and at 3-months follow-up	Montreal Cognitive Assessment test scores range between 0 and 30. A score of 26 or over is considered to be normal
Incidence of acute kidney injury (AKI) defined according to the Kidney Disease: Improving Global Outcomes criteria (any stage)	within 3 days after TAVI	Incidence of AKI defined according to the Kidney Disease: Improving Global Outcomes criteria (any stage)
Peak increase of urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL)	within 48 hours after TAVI	Peak increase of urinary NGAL (surrogate marker of acute renal injury)
Incidence of significant increase in serum cystatin C (>10%)	within 48 hours after TAVI	Incidence of significant increase in serum cystatin C (\>10%)

Trial Locations

Locations (2)

University Hospital Basel, Division of Internal Medicine; 🇨🇭 Basel, Switzerland

Stadtspital Triemli Zürich, Division of Cardiology; 🇨🇭 Zürich, Switzerland