A powerful new pill has been shown to bring down stubbornly high blood pressure that resists standard treatments, according to results from a landmark global trial.
The drug, baxdrostat, lowered blood pressure by nearly 10 mmHg on average — enough to slash the risk of heart attack, stroke, and kidney failure.
Breakthrough Trial Shows New Hope
Around the world, an estimated 1.3 billion people live with high blood pressure (hypertension). In roughly half of these cases, the condition remains uncontrolled or does not respond to standard treatments. This group faces a sharply increased risk of heart attack, stroke, kidney problems, and early death. In the UK alone, about 14 million people are affected.
To address this challenge, researchers launched the international BaxHTN trial, directed by Professor Bryan Williams of the UCL Institute of Cardiovascular Science and sponsored by AstraZeneca. The study tested a new oral drug, baxdrostat, with close to 800 patients taking part across 214 medical centers worldwide.
Findings from the study were shared on August 30 at the European Society of Cardiology (ESC) Congress 2025 in Madrid and published at the same time in the New England Journal of Medicine.
Powerful Results in Resistant Patients
After 12 weeks of treatment, participants who received baxdrostat (1 mg or 2 mg once daily in pill form) experienced an average reduction in blood pressure of about 9 to 10 mmHg more than those given a placebo. This decrease is significant enough to meaningfully lower cardiovascular risk. Roughly 40 percent of patients taking baxdrostat achieved healthy blood pressure levels, compared with fewer than 20 percent of those on placebo.
Professor Williams, the trial’s Principal Investigator and lead presenter at ESC, said: “Achieving a nearly 10 mmHg reduction in systolic blood pressure with baxdrostat in the BaxHTN Phase III trial is exciting, as this level of reduction is linked to substantially lower risk of heart attack, stroke, heart failure and kidney disease.”
How the Pill Works Inside the Body
Blood pressure is strongly influenced by a hormone called aldosterone, which helps the kidneys regulate salt and water balance.
Some people produce too much aldosterone, causing the body to hold onto salt and water. This aldosterone dysregulation pushes blood pressure up and makes it very difficult to control.
Addressing aldosterone dysregulation has been a key effort in research over many decades, but it has been so far difficult to achieve.
Baxdrostat works by blocking aldosterone production, directly addressing this driver of high blood pressure (hypertension).
An Important Step Forward in Treatment
Professor Williams, Chair of Medicine at UCL, said: “These findings are an important advance in treatment and in our understanding of the cause of difficult-to-control blood pressure.
“Around half of people treated for hypertension do not have it controlled. However, this is a conservative estimate and the number is likely higher, especially as the target blood pressure we try to reach is now much lower than it was previously.[1]
“In patients with uncontrolled or resistant hypertension, the addition of baxdrostat 1mg or 2mg once daily to background antihypertensive therapy led to clinically meaningful reductions in systolic blood pressure, which persisted up to 32 weeks with no unanticipated safety findings.
“This suggests that aldosterone is playing an important role in causing difficult-to-control blood pressure in millions of patients and offers hope for more effective treatment in the future.”
A Global Health Challenge
Historically, higher-income Western countries were reported to have far higher levels of hypertension; however, largely due to changing diets (adding less salt to food), the number of people living with the condition is now far higher in Eastern and lower-income countries. More than half of those affected live in Asia, including 226 million people in China and 199 million in India.[2]
Professor Williams added: “The results suggest that this drug could potentially help up to half a billion people globally – and as many as 10 million people in the UK alone, especially at the new target level for optimal blood pressure control.”
Notes
- The ESC 2024 hypertension guidelines recommended a target blood pressure of less than 130/80 mmHg. Prior to 2024 the target had been 140/90 mmHg.
- Figures from Blood Pressure UK
Reference: “Efficacy and Safety of Baxdrostat in Uncontrolled and Resistant Hypertension” by John M. Flack, Michel Azizi, Jenifer M. Brown, Jamie P. Dwyer, Jakub Fronczek, Erika S.W. Jones, Daniel S. Olsson, Shira Perl, Hirotaka Shibata, Ji-Guang Wang, Ulrica Wilderäng, Janet Wittes and Bryan Williams, 29 August 2025, New England Journal of Medicine.
DOI: 10.1056/NEJMoa2507109
The study was supported by the NIHR Biomedical Research Centre at UCLH.
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