RecruitingPhase IIInterventional

NOVEL: A Clinical Trial of the Oxygen-carrying Substance NanO2 to Protect the Brain after Stroke

When a blood clot blocks a major artery in the brain, it cuts off oxygen and quickly damages brain tissue. Doctors use emergency treatments like clot-busting medicines or surgery to clear the blockage, but preparing these treatments takes valuable time. The NOVEL clinical trial is investigating whether a new medicine called NanO2 can protect the brain during this critical window. NanO2 carries extra oxygen directly to the starving brain tissue, helping it survive longer until normal blood flow is restored. Adults admitted to participating UK hospitals within 24 hours of a stroke may take part. Along with standard emergency care, participants will receive either NanO2 or an inactive salt-water drip. Doctors will monitor brain recovery using scans and check-ups over 90 days. Taking part is voluntary and will not delay any standard NHS emergency treatment.

At a glance

Status

Recruiting

Phase

Phase II

Enrolment target

172

Start

01 Jun 2025

Estimated completion

31 Jan 2027

Large vessel occlusion stroke

What is this study about?

A stroke happens when blood cannot reach part of the brain. In most cases, this is caused by a blood clot blocking an artery. Without a steady supply of blood, brain cells quickly run out of oxygen and nutrients. If this lasts for too long, the affected brain cells become permanently damaged, which can lead to life-altering disability.

Doctors currently have effective emergency treatments to clear these blockages, such as clot-busting drugs or a procedure to remove the clot physically. However, these procedures take time to set up and perform. Every minute that passes without oxygen puts more brain tissue at risk. Researchers are therefore searching for ways to keep brain cells alive while doctors get ready to open the blocked artery.

The NOVEL trial is testing a new drug called NanO2. It acts like an extra oxygen carrier in the bloodstream, delivering oxygen directly to the threatened areas of the brain. By providing this vital lifeline, doctors hope to minimise permanent brain damage and give patients a better chance at a full recovery.

This research is funded by the National Institute for Health and Care Research (NIHR) and coordinated by the University of Glasgow across several NHS hospitals. It aims to gather the evidence needed to show whether NanO2 is safe and effective for stroke patients in the UK.

Key takeaways

Tests a new oxygen-carrying medicine (NanO2) designed to protect the brain during a stroke.
Aims to buy precious time while doctors prepare treatments to clear the blocked blood vessel.
For adults treated within 24 hours of experiencing a major clot-related stroke.
Most trial assessments occur in the hospital during the first five days, followed by two check-in calls.
Participation is entirely voluntary and will not interfere with normal NHS emergency care.

Who may be eligible?

This trial is for adults aged 18 and older who have had a sudden stroke caused by a blood clot blocking a major brain artery. Treatment must begin within 24 hours of the patient last being known to be well. Participants must also have been able to carry out their daily activities independently before the stroke occurred.

Doctors will perform standard emergency brain scans to confirm that a major artery is blocked and to see if there is still brain tissue that can be saved. If the scans show that the patient fits the study criteria, they may be offered the chance to take part.

People cannot take part if they are pregnant or have severe pre-existing health problems. These include severe kidney failure, serious liver disease, unstable heart failure, or lung conditions that require long-term oxygen therapy at home.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Aged 18 or older
Diagnosed with a stroke caused by a blocked large artery in the brain
Symptoms started (or person was last known well) within the past 24 hours
Lived independently without major disability before the stroke
Not currently pregnant
No severe kidney disease, severe heart failure, or need for regular home oxygen

Answer every question to see your result.

What does participation involve?

Taking part in this study lasts about 90 days in total. It begins in the emergency hospital setting as soon as a stroke is diagnosed. You will receive either the study medicine (NanO2) or an inactive dummy treatment (a simple salt-water drip) through a vein, given alongside your standard emergency stroke care. Neither you nor your doctor can choose which treatment you receive.

Most of the study tests take place during your first five days in the hospital. You will have brain scans (such as CT or MRI scans) to check how well your brain tissue is doing. After you are discharged from the hospital, the study team will keep in touch through two follow-up telephone calls—one at 30 days and another at 90 days—to check on your health and recovery.

Potential risks and benefits

There is no guarantee that taking part will directly help your recovery, but the findings may help improve stroke care for future patients. NanO2 has been tested in over 2,000 people in earlier studies. Reported side effects were generally mild and went away quickly, including headaches, feeling sick, mild dizziness, or changes in blood pressure. You will also have standard scans; MRI scans can feel noisy or tight, and CT scans involve a small dose of routine medical radiation. Taking part is completely voluntary. You or your family can choose to leave the study at any time without affecting your standard NHS medical care.

Locations (9)

NHS Greater Glasgow and Clyde
City only
Glasgow, Scotland
Aberdeen Royal Infirmary
Approximate
Aberdeen, Scotland
St George's University Hospital
City only
London, England
University College London Hospital
City only
London, England
Charing Cross Hospital
Approximate
London, England
John Radcliffe Hopsital
Unverified
Oxford, England
Queens Medical Centre, Nottingham University Hospital
Unverified
Nottingham, England
Royal Victoria Infirmary
Unverified
Newcastle upon Tyne, England
The Royal London Hospital
Unverified
London, England

Common questions

Will joining the study delay my normal emergency stroke treatment?

No. Standard emergency treatments, such as clot-busting medicines or surgery to remove the clot, will be given as quickly as possible and will not be delayed.

What is a placebo?

A placebo is a harmless, inactive substance—in this case, a plain salt-water drip. It allows researchers to compare the active medicine fairly against standard care.

Can I choose whether to receive NanO2 or the placebo?

No. A computer randomly decides which treatment you receive so that the study results remain fair, accurate, and unbiased.

What happens if I feel uncomfortable during an MRI scan?

You will hold a call button during the scan. If you feel uncomfortable or claustrophobic, you can press it, and staff will stop the scan right away.

Does taking part cost anything?

No. All study medicines, scans, and doctor check-ups related to the trial are completely free as part of NHS care.

How to find out more

Keith Muir

Keith.Muir@glasgow.ac.uk +44 141 451 5892 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.