Bax24: Baxdrostat Achieves Primary Endpoint in Treatment-Resistant Hypertension

Baxdrostat has achieved its primary endpoint of a statistically significant reduction in ambulatory 24-hour average systolic blood pressure (SBP) in patients with treatment-resistant hypertension (rHTN), according to data from the Bax24 phase 3 trial.1

Baxdrostat is a potential first-in-class, highly potent and selective oral small molecule from AstraZeneca, designed to inhibit aldosterone synthase. Previous clinical trials have shown baxdrostat’s capacity to significantly lower aldosterone levels without affecting cortisol levels across a wide dose range. The drug is currently under investigation as a monotherapy for hypertension and primary aldosteronism, in combination with dapagliflozin for chronic kidney disease and hypertension, and for the prevention of heart failure (HF) in patients with hypertension.1

“The Bax24 results show that a once-daily baxdrostat regimen can deliver highly clinically meaningful reductions in 24-hour systolic blood pressure, including in the morning when people are at greater risk of heart attack and stroke,” Bryan Williams, MD, chair of medicine at University College London and primary investigator for Bax24, said in a statement. “These results are groundbreaking and together with the BaxHTN results mean we have the potential to change our treatment approach for the many patients whose hypertension remains uncontrolled despite current therapies.”1

Bax24 is a randomized, double-blind, placebo-controlled, parallel group study, evaluating the effect of baxdrostat versus placebo, administered once a day orally, on the reduction of ambulatory SBP in participants with rHTN. For inclusion, patients had to be ≥18 years old with a mean seated SBP of ≥140 mmHg and <170 mmHg at screening. Additionally, patients needed a stable regimen of ≥3 antihypertensive medications from different therapeutic classes including ≥1 diuretic; beta blockers were not included among antihypertensive medication during this study.2

A total of 218 patients were randomly assigned in a 1:1 ratio to either baxdrostat 2mg or placebo over the course of a 12-week double-blind period. The primary efficacy endpoint was change from baseline in ambulatory 24-hour average SBP at week 12. Secondary endpoints included the effect of baxdrostat on change from baseline in ambulatory night-time average SBP at week 12, change from baseline in ambulatory daytime average SBP at week 12, and the number of participants achieving ambulatory 24-hour average SBP of <130 mmHg at week 12 and a nocturnal SBP dipping of >10% at week 12, among others.1

Ultimately, investigators found a statistically significant reduction in ambulatory 24-hour SBP versus placebo. Efficacy was also observed throughout the 24-hour period, including early morning, at which point patients with hypertension are at increased cardiovascular risk.1

“This second phase 3 trial of baxdrostat shows substantial improvement in blood pressure, which reflects its durable half-life of up to 30 hours and highly selective inhibition of aldosterone synthase,” Sharon Barr, executive vice president of BioPharmaceuticals R&D, said in a statement. “Too many patients today have hypertension that remains hard-to-control throughout the day and night, making them especially vulnerable to cardiac events.”1

According to the press release from AstraZeneca, full data from Bax24 will be shared with regulatory authorities and presented in a late-breaking session at the American Heart Association Scientific Sessions in November 2025.1

References

1. AstraZeneca. Baxdrostat met the primary endpoint in Bax24 Phase III trial in patients with resistant hypertension. BusinessWire. October 7, 2025. Accessed October 7, 2025. https://www.businesswire.com/news/home/20251007514703/en/Baxdrostat-met-the-primary-endpoint-in-Bax24-Phase-III-trial-in-patients-with-resistant-hypertension

2. AstraZeneca. A Study to Investigate the Effect of Baxdrostat on Ambulatory Blood Pressure in Participants with Resistant Hypertension (Bax24). ClinicalTrials.gov identifier: NCT06168409. Updated October 3, 2025. Accessed October 7, 2025. https://clinicaltrials.gov/study/NCT06168409