Global trial of twice-yearly injection could help millions manage high blood pressure
Barts Health NHS Trust is the first site in Europe to recruit into a major new global trial testing whether a twice-yearly injection can help control high blood pressure and lower the risk of heart attacks and strokes.
Speaking to the Daily Express, Dr Manish Saxena, hypertension specialist at Barts Health and national coordinating investigator for the trial in the UK, said the treatment could be "a real game-changer" if proven to work.
What is the trial testing?
High blood pressure affects around one in three adults in the UK. Often causing no symptoms, this "silent killer" is the leading cause of heart attacks and strokes. Many patients end up taking several tablets a day to manage it, which can also bring side effects like dizziness, headaches and fatigue.
The Zenith Phase 3 trial is testing zilebesiran, an experimental treatment that works in a completely new way. The drug is a small interfering RNA (siRNA) therapy that blocks a biological process in the liver. This affects levels of a hormone that narrows blood vessels and raises blood pressure. By reducing it, zilebesiran helps blood vessels stay relaxed for months at a time, rather than needing daily medication.
Rather than a daily tablet, zilebesiran is given as an injection under the skin just twice a year. Researchers want to find out whether the injection reduces the risk of heart attacks, strokes, urgent hospital visits and death from cardiovascular causes.
Dr Manish Saxena, Deputy Director for Research for Barts Health NHS Trust & Queen Mary University of London, and Clinical Co-Director at the William Harvey Clinical Research Centre, is national coordinating investigator for the trial in the UK.
Dr Manish Saxena, who also serves as clinical co-director of the William Harvey Clinical Research Centre at Queen Mary University of London, explained that the long-lasting nature of the injection is what sets it apart. One dose every six months could help patients who struggle to remember daily medication. Adherence, he said, is one of the biggest challenges in managing high blood pressure.
Dr Saxena explained that the trial isn't about dismissing existing treatments. For many patients, he said, zilebesiran is likely to work alongside their current prescriptions rather than replace them. But for some with mild to moderate hypertension, he hoped it could eventually mean fewer daily tablets.
A patient perspective
Barts Health enrolled the first patient in Europe into the trial earlier this year, building on years of research into this treatment. Working with Queen Mary University of London, the team also previously led the Phase 2 study, KARDIA-2 , investigating zilebesiran.
Guy Liebenberg, 72, a retired veterinary surgeon from Brighton, took part in one of these earlier studies after struggling for years with high blood pressure on three daily tablets.
Speaking to the Daily Express , Guy described a "burning feeling" when the injection was administered, but said it was worth it. His blood pressure readings improved significantly during the study, and he added that not having to remember daily medication, especially while travelling, was a real benefit.
Who can take part?
The Zenith Phase 3 trial, sponsored by Roche and Alnylam, aims to recruit more than 11,000 people worldwide, including participants at over 50 UK sites, and will run for up to five years.
The trial is looking for adults with established cardiovascular disease, or those aged 55 and over at high risk of developing it, who are already taking at least two blood pressure medications including a diuretic. Participants are offered either the zilebesiran injection or a placebo every six months, alongside their usual treatment.
If you're interested in taking part in the Zenith trial, you can find out more and check your nearest research centre on the NIHR's Be Part of Research website.