Baxdrostat Significantly Lowers Blood Pressure in Resistant Hypertension in Phase 3 trial
AstraZeneca announced that baxdrostat, a selective aldosterone synthase inhibitor, met its primary and all secondary endpoints in the BaxHTN Phase III trial, effectively lowering blood pressure in patients with uncontrolled or treatment-resistant hypertension.
Positive high-level results from the BaxHTN Phase III trial showed baxdrostat at two doses (2mg and 1mg) demonstrated a statistically significant and clinically meaningful reduction in mean seated systolic blood pressure (SBP) compared with placebo at 12 weeks. The trial also successfully met all secondary endpoints. Patients with uncontrolled or treatment resistant hypertension received baxdrostat or placebo on top of standard of care. Baxdrostat was generally well tolerated with a favourable safety profile.
There are 1.3 billion people worldwide living with hypertension. When uncontrolled, hypertension can lead to a higher risk of heart attack, stroke, heart failure and kidney disease. In the US, approximately 50% of hypertensive patients who are on multiple treatments do not have their blood pressure under control.4 Growing evidence points to aldosterone dysregulation as one of the key biological drivers of hypertension.
Dr. Bryan Williams, Chair of Medicine at University College London, primary investigator, said: “Many people continue to struggle with high blood pressure that is hard to control, even when taking multiple medications. The highly promising BaxHTN Phase III results show that once-daily baxdrostat on top of standard of care can meaningfully lower systolic blood pressure and offer a potential new treatment approach for controlling hypertension, the leading risk factor for cardiovascular disease.”
Sharon Barr, Executive Vice President, BioPharmaceuticals R&D, said: “We are very excited with the BaxHTN Phase III results, which show statistically significant and clinically meaningful reductions in systolic blood pressure. These findings provide compelling evidence of baxdrostat’s potential to address a critical unmet need by targeting aldosterone dysregulation, bringing a novel mechanism to a field that has seen little innovation in over two decades.”
BaxHTN is a Phase III, multicentre, randomised, double-blinded, placebo-controlled, parallel group study to evaluate the safety, tolerability and effect of baxdrostat in patients with uncontrolled hypertension being treated with two different antihypertensive medications and patients with resistant hypertension being treated with three or more different antihypertensive medications, one of which is a diuretic.
The data will be shared with regulatory authorities around the world and presented in a late‑breaking Hot Line session at the European Society of Cardiology (ESC) Congress in August 2025.
Baxdrostat is a potential first-in-class, highly selective aldosterone synthase inhibitor (ASI) that targets the hormone driving elevated blood pressure and increased cardiovascular and renal risk. It is currently being investigated in clinical trials as a monotherapy for hypertension and primary aldosteronism, and in combination with dapagliflozin for chronic kidney disease and the prevention of heart failure in high-risk hypertensive patients.
BaxHTN trial
The BaxHTN Phase III trial7 had three components to it that support the following endpoints: The primary endpoint was assessed during a 12-week double-blind, placebo-controlled period. A total of 796 patients were randomised in a 1:1:1 ratio to receive baxdrostat 2mg, 1mg or placebo once daily. The primary efficacy endpoint was the difference in mean change from baseline in seated SBP at Week 12 between participants treated with baxdrostat (2mg or 1mg separately) and participants treated with placebo. Persistence of efficacy was assessed during a randomised withdrawal period from week 24 to week 32. Approximately 300 patients treated with baxdrostat 2mg were re-randomised in a 2:1 ratio to either continue receiving baxdrostat 2mg or placebo for the 8 weeks. SBP at the end of the 8 weeks was compared with placebo and the baxdrostat 2mg dose. Long-term safety is assessed at the end of the 52 weeks compared to a standard of care arm.
Additional secondary endpoints include the effect of baxdrostat versus placebo on seated SBP at Week 12 in the resistant hypertension subpopulation, the effect of baxdrostat versus placebo on seated diastolic blood pressure at Week 12, participants achieving seated SBP less than 130 mmHg at Week 12 and occurrence of adverse events.
Baxdrostat
Baxdrostat is a potential first-in-class, highly selective and potent, oral, small molecule that inhibits aldosterone synthase, an enzyme encoded by the CYP11B2 gene, which is responsible for the synthesis of aldosterone in the adrenal gland. In clinical trials, baxdrostat was observed to significantly lower aldosterone levels without affecting cortisol levels across a wide range of doses. Baxdrostat is currently being investigated in clinical trials as a monotherapy for hypertension7-9 and primary aldosteronism,10 and in combination with dapagliflozin for chronic kidney disease and the prevention of heart failure in hypertensive patients.
AstraZeneca acquired baxdrostat through its purchase of CinCor Pharma, Inc. in February 2023.18 A contingent value right of $10 per share in cash ($0.5 billion) is payable to former CinCor shareholders upon the submission of a new drug application either in the US or Europe.
