An interventional study of baxdrostat in Primary Aldosteronism, sponsored by Queen Mary University of London. Not yet recruiting at 2 sites in United Kingdom. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Queen Mary University of London · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to find out whether treatment with baxdrostat changes aldosterone-producing activity in the adrenal glands of people with primary aldosteronism. The study will use specialised imaging to measure changes in the adrenal glands before and after treatment.
Participants will receive baxdrostat for 24 weeks and will be followed for changes in their adrenal imaging, blood pressure and hormone levels. The study will also investigate whether changes caused by treatment continue after baxdrostat is stopped.
This is a single-group study, meaning that all participants receive baxdrostat and there is no placebo or comparison group.
Primary aldosteronism (PA) is a common cause of hypertension in which the adrenal glands produce excess aldosterone. In some participants, the source of excess aldosterone can be associated with a small adrenal nodule. Aldosterone synthase, encoded by the CYP11B2 gene, is the enzyme responsible for the final steps of aldosterone production.
Molecular imaging using [18F]-CETO PET-CT can be used to visualise aldosterone-producing tissue in the adrenal glands. This study will investigate whether treatment with the aldosterone synthase inhibitor baxdrostat produces a measurable reduction in aldosterone-producing activity on molecular imaging.
This is an open-label, single-arm experimental medicine study. All participants will receive baxdrostat and there is no placebo or control group. Participants will receive baxdrostat 2 mg once daily for 24 weeks. Molecular imaging will be performed before treatment and following the treatment period, allowing the adrenal imaging signal to be compared within the same participant before and after treatment.
The study is designed to investigate whether pharmacological inhibition of aldosterone synthase is associated with a quantitative reduction in the molecular imaging signal from aldosterone-producing adrenal tissue. It will also investigate whether changes in imaging are associated with changes in biochemical measures of aldosterone production and clinical measures such as blood pressure, and how long suppression of aldosterone production persists after treatment has ended.
[18F]-CETO PET-CT is performed following dexamethasone pretreatment to suppress background uptake and improve visualisation of aldosterone-producing adrenal tissue. The radioligand is administered intravenously and PET imaging is performed together with a low-dose anatomical CT scan. Imaging will be undertaken at St Bartholomew's Hospital or Cambridge University Hospitals.
Participants will undergo regular follow-up during and after treatment. Assessments include blood pressure measurements, blood tests for electrolytes and adrenal hormones, 24-hour urine collections for measurement of aldosterone-related biomarkers, and quality-of-life assessment. Follow-up after treatment will allow the investigators to assess whether biochemical and clinical effects of baxdrostat persist after treatment has stopped.
The study also provides an opportunity to investigate the relationship between molecular imaging findings and subsequent clinical management. Where participants subsequently undergo adrenalectomy or ablation as part of their usual clinical care, adrenal tissue may be used for exploratory laboratory analyses of aldosterone synthase expression and markers of apoptosis. Adrenalectomy or ablation is not a research intervention and is not required by the study.
The study uses a within-participant comparison of adrenal molecular imaging before and after baxdrostat treatment. Participants are stratified according to the characteristics of the largest [18F]-CETO-positive adrenal nodule, but there is no randomisation or allocation to different treatment groups.
The study is intended to improve understanding of the effects of aldosterone synthase inhibition on aldosterone-producing adrenal tissue. The findings may help clarify the relationship between biochemical suppression of aldosterone production and changes in adrenal molecular imaging, and may inform the development of future approaches to the treatment and investigation of primary aldosteronism.
201 studies on the registry are indexed under Hyperaldosteronism; 93 are open to participants now.
This study's planned enrollment of 30 is below the median of 63 across 94 interventional studies indexed under Hyperaldosteronism.
Browse Hyperaldosteronism studies →Queen Mary University of London is the lead sponsor of 253 studies on the registry; 58 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive baxdrostat 2 mg once daily for 24 weeks. All participants will receive the same intervention; there is no placebo or control group. Participants will undergo study assessments before, during and after treatment, including molecular imaging and biochemical assessments.
Drug: baxdrostat
Baxdrostat 2 mg administered orally once daily for 24 weeks as an aldosterone synthase inhibitor. Treatment begins after the baseline \[18F\]-CETO PET-CT has confirmed eligibility for study treatment.
Change in total lesion uptake of [18F]-CETO in adrenal lesions
Change, between pre- and post-baxdrostat PET-CT images, in total \[18F\]-CETO-positive lesion uptake, calculated by multiplying the volume (ml) of each lesion by its mean standardised uptake value (SUVmean) (unitless) and summing these values across all lesions. SUVmean is a dimensionless ratio of measured to injected radioactivity. This calculation generates a single reported value, expressed in SUV·ml, the conventional unit for this measurement. \[Each lesion will be defined according to the 2025 European Association of Nuclear Medicine guideline.\]
Time frame: Baseline to approximately 8 months
Change in SUVmax between pre- and post-baxdrostat PET-CT images
Change, between pre- and post-baxdrostat PET-CT images, in maximum standardised uptake value (SUVmax) (unitless) of individual \[18F\]-CETO-positive lesions. SUVmax is a dimensionless ratio of measured to administered radioactivity. Where more than one lesion is present, SUVmax will be measured separately for each lesion and the values averaged to provide a single participant-level result.
Time frame: Baseline to approximately 8 months
Voxel level change between pre- and post-baxdrostat PET-CT images
Voxel-level change in standardised uptake value (SUV) (unitless) between corresponding voxels across \[18F\]-CETO-positive lesions in pre- and post-baxdrostat PET-CT images. Pre- and post-treatment images will be registered to permit comparison of corresponding voxels, and the mean difference in SUV between paired voxels will be reported. SUV is a dimensionless ratio of measured to injected radioactivity.
Time frame: Baseline to approximately 8 months
Change in the individual components of the primary endpoint: 1. Volume
Change, between pre- and post-baxdrostat PET-CT images, in total volume (ml) of all \[18F\]-CETO-positive lesions. Where more than one lesion is present, individual lesion volumes will be summed to generate a single reported value.
Time frame: Baseline to approximately 8 months
Change in the individual components of the primary endpoint - 2. mean SUV
Change, between pre- and post-baxdrostat PET-CT images, in mean standardised uptake value (SUVmean) (unitless) across all \[18F\]-CETO-positive lesions. Where more than one lesion is present, a single overall SUVmean will be calculated across all lesions. SUVmean is a dimensionless ratio of measured to injected radioactivity.
Time frame: Baseline to approximately 8 months
Change in whole-adrenal [18F]-CETO uptake
Change, between pre- and post-baxdrostat PET-CT images, in whole adrenal gland uptake of \[18F\]-CETO, calculated as the total volume (ml) of adrenal tissue with SUV ≥4 multiplied by the mean standardised uptake value (SUVmean) (unitless) within that volume. This calculation generates a single reported value, expressed in SUV·ml, the conventional unit for this measurement. SUVmean is a dimensionless ratio of measured to injected radioactivity.
Time frame: Baseline to approximately 8 months
Change in serum aldosterone 12 months after completion of baxdrostat treatment
Change, between the end of baxdrostat treatment and 12 months after the end of treatment, in serum aldosterone (pmol/L).
Time frame: End of baxdrostat treatment (24 weeks) to 12 months after treatment.
Change in plasma renin activity 12 months after completion of baxdrostat treatment
Change, between the end of baxdrostat treatment and 12 months after the end of treatment, in plasma renin activity (nmol/L/hr).
Time frame: End of baxdrostat treatment (24 weeks) to 12 months after treatment
Change in 24-hour urinary tetrahydroaldosterone 12 months after completion of baxdrostat treatment
Change, between the end of baxdrostat treatment and 12 months after the end of treatment, in 24h urine tetrahydroaldosterone (micromoles per 24h).
Time frame: End of baxdrostat treatment (24 weeks) to 12 months after treatment
Change in systolic blood pressure 12 months after completion of baxdrostat treatment
Change, between the end of baxdrostat treatment (24 weeks) and 12 months after the end of treatment, in systolic blood pressure (mmHg).
Time frame: End of baxdrostat treatment (24 weeks) to 12 months after treatment
Change in aldosterone-to-renin ratio 12 months after completion of baxdrostat treatment
Change, between the end of baxdrostat treatment (24 weeks) and 12 months after the end of treatment, in the ratio of serum aldosterone (pmol/L) to plasma renin activity (nmol/L/hr). The single measure resulting from division of aldosterone by plasma renin activity, termed the aldosterone-to-renin ratio (ARR), is expressed in (pmol/L)/(nmol/L/hr).
Time frame: End of baxdrostat treatment (24 weeks) to 12 months after treatment
Change in serum 11-deoxycorticosterone after 12 weeks of baxdrostat treatment
Change, between baseline and 12 weeks of baxdrostat treatment, in serum 11-deoxycorticosterone (11-DOC) (pmol/L).
Time frame: Baseline to 12 weeks
Change in serum 11-deoxycorticosterone after 24 weeks of baxdrostat treatment
Change, between baseline and 24 weeks of baxdrostat treatment, in serum 11-deoxycorticosterone (11-DOC) (pmol/L).
Time frame: Baseline to 24 weeks
Change in serum 11-deoxycorticosterone 2 months after completion of baxdrostat treatment
Change, between baseline and 2 months after completion of baxdrostat treatment, in serum 11-deoxycorticosterone (11-DOC) (pmol/L).
Time frame: Baseline to 2 months after completion of baxdrostat treatment
Change in serum 11-deoxycorticosterone 6 months after completion of baxdrostat treatment
Change, between baseline and 6 months after completion of baxdrostat treatment, in serum 11-deoxycorticosterone (11-DOC) (pmol/L).
Time frame: Baseline to 6 months after completion of baxdrostat treatment
Change in serum 11-deoxycorticosterone 12 months after completion of baxdrostat treatment
Change, between baseline and 12 months after completion of baxdrostat treatment, in serum 11-deoxycorticosterone (11-DOC) (pmol/L).
Time frame: Baseline to 12 months after completion of baxdrostat treatment
Plan to share: No
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Start is estimated for Sep 2026; primary completion for May 2028, 20 months later.
Of 35 interventional studies with no phase under Hyperaldosteronism, half reached primary completion within 36 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 20 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Baxdrostat
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