AstraZeneca today announced positive topline results from the Phase III Bax24 trial, demonstrating that baxdrostat, a potential first-in-class aldosterone synthase inhibitor, achieved a statistically significant and clinically meaningful reduction in 24-hour average systolic blood pressure (SBP) compared with placebo at 12 weeks.
Key Findings
- Efficacy Across 24 Hours: Baxdrostat lowered blood pressure consistently throughout the day, including the morning surge, when patients are at higher risk of cardiovascular events.
- Population: Patients with treatment-resistant hypertension (rHTN) received 2 mg baxdrostat or placebo on top of standard-of-care therapy.
- Safety: Baxdrostat was generally well tolerated, with a safety profile consistent with previous BaxHTN trials.
"The Bax24 results show that a once-daily baxdrostat regimen can deliver meaningful reductions in 24-hour SBP, including during the morning risk window for heart attack and stroke. These results are groundbreaking and may transform treatment approaches for patients whose hypertension remains uncontrolled despite current therapies.”
- Dr. Bryan Williams, Chair of Medicine at University College London.
Clinical Context
- Global burden: Hypertension affects 1.4 billion people worldwide. In the U.S., ~50% of patients on multiple therapies still do not achieve blood pressure control.
- Importance of 24-hour control: Ambulatory 24-hour SBP is a stronger predictor of cardiovascular events than clinic-based readings. A 9.5 mmHg increase in 24-hour SBP raises all-cause mortality risk by 30%.
- Mechanism: Baxdrostat selectively inhibits aldosterone synthase, lowering aldosterone without affecting cortisol, a key driver of hard-to-control hypertension.
Study Design (Bax24)
- Type: Randomized, double-blind, placebo-controlled, parallel-group Phase III trial
- Participants: 218 patients with rHTN
- Treatment: Baxdrostat 2 mg once daily vs placebo for 12 weeks
- Primary endpoint: Change from baseline in ambulatory 24-hour average SBP
- Secondary endpoints: Daytime and nighttime SBP, seated SBP, achievement of <130 mmHg 24-hour SBP, and nocturnal SBP dipping >10%
Implications
- Baxdrostat’s durable half-life (26–30 hours) supports once-daily dosing and continuous blood pressure control.
- The therapy is being evaluated both as a monotherapy and in combination with dapagliflozin for conditions where aldosterone plays a key role, including primary aldosteronism, chronic kidney disease, and heart failure prevention.
- Data will be submitted to regulatory authorities worldwide and presented at the American Heart Association (AHA) Scientific Sessions, November 2025.
About Baxdrostat
Baxdrostat is an oral small molecule aldosterone synthase inhibitor, discovered by CinCor Pharma and acquired by AstraZeneca in 2023. By targeting aldosterone, it addresses a key mechanism in uncontrolled hypertension, reducing the risk of heart, kidney, and vascular complications.
About AstraZeneca CVRM
Cardiovascular, Renal, and Metabolism (CVRM) is one of AstraZeneca’s main therapeutic areas. The team focuses on organ protection, disease slowing, and ultimately regenerative therapies, aiming to improve millions of lives by addressing the interconnections between heart, kidney, liver, and metabolic diseases.
