A new drug that significantly lowers "stubborn" blood pressure is on the horizon, following the results of its Phase III clinical trial. The treatment, called baxdrostat, has been hailed as the most promising advance in hypertension management in decades, demonstrating the ability to help patients whose blood pressure remains dangerously high despite standard therapy.
In the study, led by researchers from University College London (UCL), baxdrostat was administered to nearly 800 adults across 214 sites worldwide. All participants were already taking multiple blood pressure medications but were still struggling to shift the needle on their hypertension – a group often described as having resistant or hard-to-control hypertension. Over 12 weeks, patients given the drug in oral pill form once a day saw their systolic blood pressure fall by an additional 9 to 10 mmHg compared with placebo. And by the end of that period, 40% of participants had reached healthy blood pressure levels – which is meaningful, given trial length.
If granted Food and Drug Administration (FDA) approval – drug company AstraZeneca plans to file by the end of 2025, with likely approval in 2026 – baxdrostat would be the first drug of its kind on the market. It would also be a whole new way of treating hypertension, something that hasn’t happened in decades. This makes it quite a big deal for the estimated eight million US adults with this stubborn condition.
What makes baxdrostat different is that it shuts off production of the hormone aldosterone at its source. Excess aldosterone drives salt retention and raises blood pressure, but existing drugs that block its receptor, such as spironolactone (Aldactone), can cause hormonal side effects and dangerous rises in potassium. Baxdrostat directly inhibits aldosterone synthase, the enzyme responsible for making the hormone, lowering aldosterone without affecting cortisol.
The drug was well tolerated in the trial participants, with only around 1% reporting serious adverse events (rise in potassium levels) – on par with the placebo treatment – and was safe to be taken with other blood pressure medication.
“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," said lead researcher Bryan Williams, a professor at UCL. “In patients with uncontrolled or resistant hypertension, the addition of baxdrostat 1 mg or 2 mg 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."
The results of the trial, which were presented at the European Society of Cardiology (ESC) Congress 2025 in Madrid this week, meant baxdrostat achieved all its benchmarks, giving AstraZeneca the green light to now seek FDA approval.
“These findings are an important advance in treatment and in our understanding of the cause of difficult to control blood pressure," said Williams. “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.
“The results suggest that this drug could potentially help up to half a billion people globally," he added.
Incidentally, aldosterone was first identified in 1952 by scientists at Middlesex Hospital Medical School – now known as the UCL Medical School, which led this latest research.
The study was published in the New England Journal of Medicine.
Source: University College London
