Bax24: Baxdrostat Successful Again, This Time in Resistant Hypertension

Baxdrostat, a novel aldosterone synthase inhibitor, provides a “highly clinically meaningful reduction” in 24-hour ambulatory systolic blood pressure in patients with treatment-resistant hypertension, according to top-line results of the phase III Bax24 trial released Tuesday by drugmaker AstraZeneca.

The findings reinforce the impact of baxdrostat observed in BaxHTN, another phase III trial that showed substantial reductions in BP compared with placebo in patients with either uncontrolled or resistant hypertension.

Bax24 included 218 patients with treatment-resistant hypertension, defined as having high BP despite use of at least three antihypertensive medications. Investigators randomized patients to baxdrostat 2 mg or placebo once daily for 12 weeks, both on top of standard of care.

The primary endpoint was the change in ambulatory 24-hour systolic BP from baseline to 12 weeks. According to the company press release, baxdrostat provided a greater reduction in that endpoint compared with placebo, with efficacy seen throughout the day.

AstraZeneca said the drug was well tolerated, with a safety profile similar to what was seen in BaxHTN. In that trial, most adverse events were mild and there were no cases of adrenal insufficiency. The most common adverse events, all more frequent with baxdrostat versus placebo, were hyperkalemia, hyponatremia, hypotension, muscle spasms, and dizziness.

Full results from Bax24 are slated for presentation during a late-breaking session next month at the American Heart Association 2025 Scientific Sessions in New Orleans, LA.

In a press release, AstraZeneca said baxdrostat is being developed as a monotherapy not just for hypertension, but also for primary aldosteronism. It’s also being studied in combination with dapagliflozin (Farxiga; AstraZeneca) for the treatment of patients with chronic kidney disease and hypertension and for the prevention of heart failure in patients with hypertension.