A new drug has been found to significantly lower blood pressure in people whose blood pressure remains dangerously high even after taking multiple existing drugs. The findings come from a phase III clinical trial led by UCL professors.
Approximately 1.3 billion people worldwide suffer from high blood pressure. In almost half of these cases, symptoms are not controlled or do not respond well to treatment. This significantly increases your risk of heart attack, stroke, kidney disease, and premature death. Around 14 million people in the UK alone live with high blood pressure.
Large-scale international trial of baxdrostat
The international BaxHTN trial, led by Professor Brian Williams (UCL Institute of Cardiovascular Science) and funded by AstraZeneca, tested a new drug called baxdrostat, which is taken as a pill. The study involved approximately 800 patients from 214 clinics around the world.
This research was supported by the NIHR Biomedical Research Center at UCLH.
The results were presented at the 2025 European Society of Cardiology (ESC) Congress in Madrid. New England Medical Journal.
Significant drop in blood pressure
After 12 weeks, patients taking baxdrostat (1 mg or 2 mg once daily in tablet form) experienced an average decrease in blood pressure of about 9 to 10 mmHg more than those taking a placebo. This level of reduction is thought to be large enough to reduce the risk of cardiovascular events.
About 40 percent of patients who took vaxdrostat achieved healthy blood pressure levels, compared with less than 20 percent in the placebo group.
Lead researcher Professor Williams, presenting the results at the ESC, said: “It is interesting that Baxdrostat achieved nearly 10 mmHg reductions in systolic blood pressure with Baxdrostat in the phase III trial, as this level of reduction is associated with a substantial reduction in the risk of heart attack, stroke, heart failure and kidney disease.”
How Baxdrostat targets key hormones
Blood pressure is greatly influenced by a hormone called aldosterone, which helps regulate salt and water levels in the body.
In some people, the body produces too much aldosterone. This causes excess salt and water retention, which increases blood pressure and makes it difficult to control blood pressure.
Scientists have long tried to address this imbalance, but it has proven difficult.
Vaxdrostat works by blocking the production of aldosterone, directly targeting the main cause of high blood pressure (hypertension).
A new approach to difficult cases
Professor Williams, Director of Medicine at UCL, said: “These findings are an important advance in treatment and an important advance in our understanding of why blood pressure is difficult to control.”
“About half of people treated for high blood pressure have uncontrolled high blood pressure, but this is a conservative estimate and this number could be much higher, especially since the blood pressure targets we are trying to reach are much lower than they used to be. (1)
“In hypertensive patients with uncontrolled or resistant hypertension, adding baxdrostat 1 mg or 2 mg once daily to background antihypertensive therapy resulted in clinically meaningful reductions in systolic blood pressure that were sustained for up to 32 weeks, with no unexpected safety findings.
“This suggests that aldosterone plays an important role in compromising blood pressure control for millions of patients, and holds promise for more effective treatments in the future.”
Growing global burden and future possibilities
Previously, high rates of high blood pressure were primarily found in wealthy Western countries. However, changes in dietary habits, such as salt reduction in some regions, have changed the global burden. Far more cases are now being found in eastern and low-income countries. More than half of hypertensive patients live in Asia, including 226 million people in China and 199 million people in India (2).
Professor Williams added: “These results suggest that this drug has the potential to help up to 500 million people around the world, and as many as 10 million people in the UK alone, particularly with new target levels of optimal blood pressure control.”
Precautions
- The ESC 2024 Hypertension Guidelines recommend a target blood pressure of less than 130/80 mmHg. Before 2024, the goal was 140/90 mmHg.
- Figures from UK Blood Pressure
