Baxdrostat lifts hopes in stubborn hypertension

Patients with dangerously hard-to-control blood pressure may be moving closer to a new treatment option after late-stage evidence showed baxdrostat can cut systolic pressure in people who do not respond adequately to standard medicines. The once-daily pill, developed by AstraZeneca, works by blocking aldosterone synthase, an enzyme involved in producing the hormone aldosterone, which drives salt and water retention and can keep blood pressure elevated despite multiple drugs.

The strongest data come from the phase III BaxHTN trial, which enrolled patients with uncontrolled or treatment-resistant hypertension already taking background therapy. Full results reported in 2025 showed that the 2 mg dose lowered seated systolic blood pressure by 15.7 mmHg from baseline at 12 weeks, or 9.8 mmHg more than placebo. The 1 mg dose also produced a significant placebo-adjusted reduction of 8.7 mmHg. Those findings matter because even single-digit reductions in systolic pressure can translate into meaningful cuts in the long-term risk of stroke, heart attack and kidney damage.

Baxdrostat’s appeal lies in its mechanism. Most established blood pressure treatments act through broader pathways such as fluid removal, blood-vessel relaxation or suppression of the renin-angiotensin system. Baxdrostat instead targets aldosterone more directly, aiming at a hormonal driver that specialists increasingly see as central in difficult cases of hypertension. AstraZeneca and independent scientific reviews say the drug has lowered aldosterone without materially affecting cortisol, an issue that had complicated earlier attempts to inhibit the same pathway.

The latest evidence has also gone beyond clinic readings. In the separate phase III Bax24 trial in resistant hypertension, baxdrostat achieved a placebo-adjusted 14.0 mmHg reduction in 24-hour ambulatory systolic blood pressure at 12 weeks, according to results released in late 2025 and later published in The Lancet in 2026. Ambulatory monitoring is closely watched by cardiologists because it measures blood pressure over an entire day and night rather than at a single office visit, giving a better picture of sustained control.

That does not mean the medicine’s path has been without setbacks. Earlier development included mixed signals, most notably the HALO trial, which did not show the same clear advantage over placebo. Researchers and later reviews suggested that unusually large placebo effects and issues linked to adherence to background therapy may have clouded the result. Even so, the broader programme, including phase II BrigHTN and the two phase III studies, has helped rebuild confidence that baxdrostat’s effect is real when studied in better-controlled settings.

Safety will remain central as regulators review the file. AstraZeneca has said baxdrostat was generally well tolerated in phase III testing, with no unanticipated safety findings. That will reassure clinicians, though practice-changing adoption will depend on how doctors weigh risks such as electrolyte disturbances, including hyperkalaemia, against benefits in patients already taking complex multi-drug regimens. Resistant hypertension patients are often older and more medically complicated, which means tolerability in everyday use will matter as much as efficacy in trials.

The commercial and regulatory race is also intensifying. AstraZeneca said in December 2025 that the US Food and Drug Administration had accepted baxdrostat’s new drug application under Priority Review, with a decision expected in the second quarter of 2026. That timeline places the drug among the more closely watched cardiovascular regulatory events this year. Competition is emerging from Mineralys Therapeutics, whose aldosterone synthase inhibitor lorundrostat has also posted positive late-stage data, underlining a broader industry shift towards hormone-targeted treatment for hypertension that persists despite standard care.