AstraZeneca announced positive full results from the BaxHTN Phase III trial, showing that baxdrostat, a first-in-class aldosterone synthase inhibitor, achieved statistically significant and clinically meaningful reductions in systolic blood pressure (SBP) in patients with hard-to-control hypertension. These findings were presented in a Hot Line session at the European Society of Cardiology (ESC) Congress 2025 and published simultaneously in the New England Journal of Medicine.

Key Findings from BaxHTN

• At 12 weeks, baxdrostat 2mg lowered SBP by 15.7 mmHg from baseline, equating to a 9.8 mmHg placebo-adjusted reduction (p<0.001).

• The 1mg dose lowered SBP by 14.5 mmHg from baseline, corresponding to an 8.7 mmHg placebo-adjusted reduction (p<0.001).

• Results were consistent across both uncontrolled and resistant hypertension subgroups.

• Baxdrostat was generally well tolerated, with no unanticipated safety findings and a low incidence of hyperkalemia (1.1% in both dose groups vs. 0.0% in placebo). Most adverse events were mild.

• The therapy also met all confirmatory secondary endpoints, including durable long-term BP reduction with the 2mg dose, significant improvements in diastolic blood pressure, and tripled odds of achieving target SBP <130 mmHg compared with placebo.

In a prespecified exploratory analysis, baxdrostat also reduced 24-hour and nighttime ambulatory SBP, both key indicators of sustained blood pressure control and reduced cardiovascular risk.

Expert Commentary

Dr. Bryan Williams, Chair of Medicine at University College London and primary investigator, said:

“Achieving nearly a 10 mmHg placebo-adjusted reduction with baxdrostat is exciting, as this magnitude of blood pressure lowering is strongly linked to reduced risks of heart attack, stroke, heart failure and kidney disease. These results highlight the importance of aldosterone as a driver of hypertension and the potential of baxdrostat to change treatment paradigms.”

Sharon Barr, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca, added:

“The BaxHTN Phase III results demonstrate baxdrostat’s potential in tackling one of the toughest challenges in cardiovascular care. We are preparing regulatory submissions and expanding our development program into chronic kidney disease and heart failure prevention, where aldosterone is a key driver.”

Hypertension: An Unmet Global Health Need

Hypertension affects 1.3 billion people worldwide, and nearly half of patients in the US fail to achieve adequate blood pressure control despite multiple therapies. Dysregulated aldosterone is increasingly recognized as a major contributor to uncontrolled and resistant hypertension, amplifying cardiovascular and renal risk.

Evidence shows that every 10 mmHg reduction in systolic blood pressure reduces major cardiovascular events by about 20%, underscoring the urgent need for novel treatments like baxdrostat that target the disease at its source.