AstraZeneca has unveiled positive outcomes from its Phase III BaxHTN trial for hard-to-control hypertension, indicating that the aldosterone synthase inhibitor (ASI), baxdrostat, achieved a decrease in mean seated systolic blood pressure (SBP) at two dosage levels, 2mg and 1mg, over placebo at the 12-week mark.
The study targeted those with challenging cases of hypertension, including those unresponsive to conventional treatment, who were administered the therapy or a placebo in addition to their standard care regimen.
The trial comprised three segments, with the primary goal of evaluating over a 12-week placebo-controlled, double-blind period.
A cohort of 796 subjects was randomised and given daily doses of either baxdrostat 2mg, 1mg, or a placebo.
The primary efficacy endpoint was the mean change in variation from baseline in seated SBP between those treated with baxdrostat compared to subjects in the placebo group at week 12.
The trial also evaluated the persistence of baxdrostat's efficacy from week 24 to week 32 during a randomised withdrawal phase.
About 300 subjects on the 2mg dose were reassigned at random to continue with baxdrostat or a placebo for the following eight weeks.
The SBP results at the end of this period were then compared. Additionally, the trial tested the long-term safety of the therapy over 52 weeks against a standard care control group.
Baxdrostat achieved both the primary and all secondary goals. At week 12, the 2mg dose resulted in an absolute SBP decrease of 15.7mmHg from baseline, with a placebo-adjusted reduction of 9.8mmHg.
The 1mg dose saw a baseline decrease of 14.5mmHg, with a placebo-adjusted decrease of 8.7mmHg. The placebo group experienced a 5.8mmHg decrease, with consistent results across various subject subgroups.
The therapy was found to be tolerated well, with a low incidence of confirmed hyperkalaemia and no unexpected safety concerns.
Baxdrostat also achieved all confirmatory secondary endpoints.
AstraZeneca BioPharmaceuticals R&D executive vice-president Sharon Barr said: “We look forward to advancing our regulatory filings for baxdrostat with health authorities in the months ahead, in addition to rapidly progressing a robust clinical development programme across indications where aldosterone plays a key role, including chronic kidney disease and heart failure prevention.”
The company added baxdrostat to its portfolio following the acquisition of CinCor Pharma in February 2023.
In July 2025, AstraZeneca reported that its Tagrisso (osimertinib), when combined with pemetrexed and platinum-based chemotherapy, improved overall survival rates in patients with first-line locally advanced or metastatic EGFR-mutated non-small cell lung cancer (NSCLC).
