NCT05482945: CPAr

CardioPulmonary Resuscitation With Argon (CPAr) Trial

Recruiting now Phase 2 Last updated 17 September 2025

What this trial tests

Phase 2 trial testing Noble gas Argon in Cardiac Arrest, Out-Of-Hospital in 120 participants. Currently enrolling.

Timeline

30 May 2022

Primary endpoint
31 March 2026

30 June 2026

Quick facts

Lead sponsor	Mario Negri Institute for Pharmacological Research
Phase	Phase 2
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	120
Start date	30 May 2022
Primary completion	31 March 2026
Estimated completion	30 June 2026
Sites	9 locations across Italy

Drugs / interventions tested

• Noble gas Argon — full drug profile →

Conditions studied

• Cardiac Arrest, Out-Of-Hospital — all drugs for Cardiac Arrest, Out-Of-Hospital →
• Cardiac Arrest With Successful Resuscitation — all drugs for Cardiac Arrest With Successful Resuscitation →

Sponsor

Mario Negri Institute for Pharmacological Research

Who can join

18 and older, any sex, with Cardiac Arrest, Out-Of-Hospital or Cardiac Arrest With Successful Resuscitation. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Preclinical studies suggest that argon (Ar) might diminish the neurological and myocardial damage after any hypoxic-ischemic insult. Indeed, Ar has been tested in different models of ischemic insult, at concentrations ranging from 20% up to 80%. Overall, Ar emerged as a protective agent on cells, tissues and organs, showing less cell death, reduced infarct size and faster functional recovery. More specifically, encouraging data has been reported in animal studies on cardiac arrest (CA) in which a better and faster neurological recovery was achieved when Ar was used in the post-resuscitation ventilation. More importantly, these benefits have been replicated in different studies, enrolling both small and large animals. Finally, ventilation with Ar in O2 has been demonstrated to be safe both in animals and humans. Based on this evidence, a clinical translation is advocated. Thus, the CardioPulmonary resuscitation with Argon - CPAr trial has been conceived. The trial initially started as phase I-II trial to specifically address the question about the safety of the post resuscitation Ar-treatment. The available data on the first 30 randomized patients, evaluated by the Data Safety Monitoring Board (DSMB), were considered absolutely reassuring with regard to the safety of the experimental treatment. In this perspective, the DSMB supported the continuation of the study as a phase II trial, maintaining the study protocol in all its aspects. Thus, the aim of the CPAr trial is now to evaluate efficacy in reducing post-CA neurological injury of Ar/O2 ventilation in patients resuscitated from CA.

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. Treatment with inhaled Argon: a systematic review of pre-clinical and clinical studies with meta-analysis on neuroprotective effect.
   Merigo G, Florio G, Madotto F, Magliocca A, et al · · 2024 · cited 8× · PMID 38691938 · DOI 10.1016/j.ebiom.2024.105143
2. Postresuscitation Ventilation With a Mixture of Argon and Hydrogen Reduces Brain Injury After Cardiac Arrest in a Pig Model.
   Motta F, De Giorgio D, Cerrato M, Salmaso A, et al · · 2024 · cited 5× · PMID 38639335 · DOI 10.1161/jaha.123.033367
3. CardioPulmonary resuscitation with <i>Ar</i>gon (CP<i>Ar)</i>: A protocol for a randomised controlled multicentre clinical trial.
   Ristagno G, Staszewsky L, Merigo G, Magliocca A, et al · · 2025 · cited 1× · PMID 41079544 · DOI 10.1016/j.resplu.2025.101096