Physicians' Academy for Cardiovascular Education

No change in placebo-corrected SBP after 8 weeks with aldosterone synthase inhibitor

News - Mar. 5, 2023

HALO: Results From a Phase 2, Double-blind, Placebo-controlled Trial Evaluating the Efficacy and Safety of Baxdrostat in Patients With Uncontrolled Hypertension

Presented at the ACC.23/WCC by: Prof. Deepak Bhatt, MD - New York, NY, USA

Introduction and methods

Early phase 1 studies have shown that the highly selective aldosterone synthase inhibitor baxdrostat resulted in a sustained, dose-dependent reduction of plasma aldosterone by >70%. The phase 2 trial BrigHTN demonstrated that baxdrostat reduced SBP by 11 mHg more than placebo in patients with treatment-resistant hypertension.

In the HALO trial -a double-blinded phase 2 study- the efficacy and safety of baxdrostat was examined in patients with uncontrolled hypertension.

Patients on a stable regimen of an ACEi or ARB, an ACEi/ARB plus a thiazide diuretic, or an ACEi/ARB plus a calcium channel blocker with a mean seated SBP ≥140 mmHg were included. Those with seated SBP ≥180 mmHg, BMI >50 kg/m2, or eGFR <30 mL/min/1.73 m2 were excluded. After screening and a run-in phase, 249 patients were randomized in a 1:1:1:1 ratio to baxdrostat 0.5 mg, baxdrostat 1 mg, baxdrostat 2 mg, or placebo on a background of antihypertensive medication.

The primary endpoint was change in mean seated SBP from baseline to 8 weeks of treatment.

Main results

Primary and secondary endpoints


Post-hoc analysis


The primary endpoint of placebo-corrected change in mean seated SBP with baxdrostat in patients with uncontrolled hypertension in the HALO trial was not achieved. In general, baxdrostat appeared to have a favorable safety profile and was well tolerated. There was a large effect on SBP lowering by placebo in this study.

When only adherent patients were included, a significant lowering of mean seated SBP was observed with 2 mg baxdrostat, which needs to be further investigated in future trials.

Watch a video on the HALO trial

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