Primary Aldosteronism Due to Aldosterone Producing AdenomaPhase 2/3NCT06100367
11C-Metomidate PET/CT for Endocrine Hypertension and Characterisation of Adrenal Tumours
A Phase 2/3 study testing 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre in people with Primary Aldosteronism Due to Aldosterone Producing Adenoma and Primary Aldosteronism, run by Changi General Hospital at 7 sites in Singapore.
Trial summary
10% of patients with hypertension potentially have the treatable condition - primary aldosteronism (PA). This is caused by either bilateral adrenal disease (~40%), managed with lifelong medications; or unilateral disease (~60%), cured with laparoscopic surgery (adrenalectomy). Read more about this study
- Who is it for?
- Ages 21 to 80 years
- Conditions the study is for
- Primary Aldosteronism Due to Aldosterone Producing Adenoma, Primary Aldosteronism, Adrenal Tumors
- What is being tested?
- 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 97 participants
- Where
- 7 sitesSingapore
- Study dates
- 30 Dec 2019to 31 Dec 2025
- Phase
- Phase 2/3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- For patients with primary aldosteronism (PA_CURE 2 / PA_MTO EH):
- Confirmed diagnosis of primary aldosteronism, as defined in Endocrine Society Guidelines 2016, with positive confirmatory test (post-salt loading aldosterone >140pmol/L); or hypokalemia with undetectable renin levels and aldosterone >550pmol/L; or likely primary aldosteronism / low-renin hypertension (inappropriate aldosterone levels and suppressed renin levels)
- Keen for surgical treatment if shown to have unilateral adrenal disease.
- For patients with suspected adrenal tumors (PA_MTO AT)
- All patients with suspected adrenal tumors based on imaging and clinical suspicion.
Who cannot join
- Inability to provide written informed consent.
- Chronic renal failure of Stage 3b or greater severity, estimated glomerular filtration rate (eGFR) < 45ml/min/1.73m2 using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. (only applicable for PA_CURE 2 / PA_MTO EH)
- Severe or terminal medical condition(s) that in the view of the investigator prohibits participation in the study or interferes with possible treatment or health-related quality of life, e.g. cancer, end-stage liver disease, end stage renal failure (only applicable for PA_CURE 2 / PA_MTO EH)
- Contraindications to isotope scanning (e.g. Female patients who are pregnant (self-declared or via positive pregnancy test), intending to become pregnant (within 3 months of scan) or breastfeeding) or CT Scan, which includes but not limited to waist circumference >140cm, morbid obesity or claustrophobia (limiting entry in CT scanner)
- Contraindication to ingestion of corticosteroids (e.g. poorly controlled diabetes, HbA1C >13%)
Trial locations and contacts
7 sites in 1 country.
7 sites in 1 country
Singapore7 sites
Changi General Hospital
Singapore
Khoo Teck Puat Hospital
Singapore
National University Hospital
Singapore
Ng Teng Fong General Hospital
Singapore
Sengkang General Hospital
Singapore
Singapore General Hospital
Singapore
Tan Tock Seng Hospital
Singapore
About this study
- 10% of patients with hypertension potentially have the treatable condition - primary aldosteronism (PA). This is caused by either bilateral adrenal disease (~40%), managed with lifelong medications; or unilateral disease (~60%), cured with laparoscopic surgery (adrenalectomy). Current diagnosis of PA includes a screening test with aldosterone-renin ratio, followed by a confirmatory salt loading test (in most patients) to demonstrate unsuppressed aldosterone levels. Of note, some patients with suppressed aldosterone after confirmatory tests (also termed low-renin hypertension) may also have unilateral adrenal tumors.
- The difficulty with identifying curable unilateral disease is due to adrenal vein sampling (AVS): an invasive, and technically-difficult procedure. An alternative novel imaging, 11C-Metomidate Positron emission tomography-computed tomography (PET-CT), can detect adrenal tumors which are over-producing aldosterone. It is non-invasive, non-operator-dependent, and potentially may identify more patients with curable unilateral disease. The results from our pilot study in 25 patients with confirmed PA (ClinicalTrials.gov NCT03990701, PA_CURE) showed that 11C-Metomidate PET-CT exhibited comparable performance to AVS in subtyping PA, and this should be validated in a larger study.
- In addition, 11C-Metomidate is also able to differentiate adrenocortical lesions in the adrenal gland from other lesions found in adrenal tissue, such as adrenomedullary lesions (e.g. pheochromocytoma).
- Hence, the investigators hypothesize that 11C-metomidate PET-CT can accurately (1) identify patients with surgically curable unilateral adrenal disease among hypertensive Asians with primary aldosteronism (PA_CURE 2 / PA_MTO EH study) and (2) differentiate adrenocortical lesions from other lesions in patients with adrenal tumors (PA_MTO AT study)
Read the detailed description
- The investigators aim to recruit 100 patients with confirmed, or likely, primary aldosteronism to undergo conventional tests, CT, AVS, and 11C-metomidate PET-CT.
- Results will be reviewed and discussed at a multidisciplinary meeting, and patients with unilateral PA or adrenal tumor will be offered surgery. Patients will be reviewed 6 months post-surgery.
- In a separate study, the investigators will recruit 10 patients with adrenal tumors to differentiate adrenocortical lesions from other lesions in patients with adrenal tumors
- Conditions
- Primary Aldosteronism Due to Aldosterone Producing Adenoma, Primary Aldosteronism, Adrenal Tumors
- Being tested
- 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre
- Keywords
- 11-C Metomidate PET/CT, Functional imaging, Secondary / Endocrine hypertension, Adrenal Vein Sampling, Subtyping; localization testing, Adrenalectomy
- Medical subject headings
- Hyperaldosteronism, Adrenal Gland Neoplasms, Neoplasm Metastasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
11C-Metomidate PET/CT imaging at Clinical Imaging Research CentreCombination product
11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre
| Study group | Role | What they receive |
|---|---|---|
| 11C-metomidate PET-CT | Experimental | All patients will undergo standard-of-care investigations (CT imaging of adrenals and AVS) and the research test (11C-metomidate PET-CT) with a dose of 100 - 300 Megabecquerel (MBq) (11C-metomidate) to identify functional unilateral adrenal disease Receives: Combination Product: 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre |
What is being measured
The primary outcome is the main question the study is designed to answer.
Biochemical outcome of unilateral primary aldosteronism based on the Primary Aldosteronism Surgical Outcome (PASO) criteria (PA_CURE 2 / PA_MTO EH study).
The number of patients with complete, partial, and absent biochemical success according to the PASO criteria.
Measured: 6 months
Diagnostic performance of 11C-Metomidate PET-CT in identifying unilateral adrenocortical tumor (PA_MTO AT study).
Percentage of patients accurately identified with adrenocortical tumor using 11C-Metomidate PET-CT, when compared to the histopathology of the excised tumor. In patients who have not undergone surgery, this will be determined by clinical diagnosis.
Measured: 6 months
Secondary outcomes (5)
Clinical outcome of unilateral primary aldosteronism based on the Primary Aldosteronism Surgical Outcome (PASO) criteria (PA_CURE 2 / PA_MTO EH STUDY).
The number of patients with complete, partial, and absent clinical success according to the PASO criteria.
Measured: 6 months
Diagnostic performance of 11C-Metomidate PET-CT in identifying unilateral aldosterone-producing adenoma (PA_CURE 2 / PA_MTO EH study).
Percentage of patients accurately identified with unilateral PA using 11C-Metomidate PET-CT and AVS, as compared to histopathology of the excised tumor (defined as 'Classical' single, functioning aldosterone-producing adenoma using HISTopathological classification by the Histopathology of primary ALDOsteronism (HISTALDO) consensus).
Measured: 6 months
Cost-effectiveness of 11C-Metomidate PET-CT versus AVS in diagnosing patients with unilateral primary aldosteronism (PA_CURE 2 / PA_MTO EH STUDY).
Cost-effectiveness of the diagnostic course will be calculated by using calculated costs per quality-adjusted life years (QALYs).
Measured: 6 months
Diagnostic criteria using 11C-metomidate PET/CT (PA_CURE 2 / PA_MTO EH study).
The cut-off level of maximum standard update value (SUVmax) values which offer the best sensitivity and specificity for lateralization of aldosterone-producing adenoma in 11C-metomidate PET/CT.
Measured: 6 months
Number of patients with low-renin hypertension with unilateral adrenal tumors (PA_CURE 2 / PA_MTO EH study).
Quantify the number of patients with low-renin hypertension or only obtain borderline diagnostic criteria for PA but have unilateral adrenal lesions detected on 11C-metomidate PET/CT.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Oct 2023
- Study start30 Dec 2019
- Primary completion25 May 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary Aldosteronism Due to Aldosterone Producing AdenomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- 11C-metomidate synthesis will be done at Clinical Imaging Research Centre in compliance with good manufacturing practice using a General Electric Medical Systems PET trace 860 cyclotron. Non-contrast CT images will be acquired over the adrenal. After an intravenous injection of 11C-metomidate, PET images will be acquired. Attenuation and decay-corrected images will be converted to standardized uptake value (SUV) maps through division by (injected activity per patient weight). The maximum SUV values over regions of interest will be determined for 10-min static images starting 35 min after the injection.
- Masking
- None (open label)
- Enrolment
- 97 participants (actual)
Sponsor and investigators
- Lead sponsor
- Changi General Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- National University Health System, Singapore, Clinical Imaging Research Centre, Singapore General Hospital, Tan Tock Seng Hospital, Khoo Teck Puat Hospital, Ng Teng Fong General Hospital, Sengkang General Hospital
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06100367
- Sponsor's protocol ID
- PA_MTO
- Other IDs
- PA_MTO
- Status last verified
- Oct 2026
- First submitted
- 13 Oct 2023
- Last updated
- 26 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 11C-Metomidate PET/CT for Endocrine Hypertension and Characterisation of Adrenal Tumours
- ClinicalTrials.gov ID
- NCT06100367
- Acronym / sponsor ID
- PA_MTO
- Conditions
- Primary Aldosteronism Due to Aldosterone Producing Adenoma, Primary Aldosteronism, Adrenal Tumors
- Keywords
- 11-C Metomidate PET/CT, Functional imaging, Secondary / Endocrine hypertension, Adrenal Vein Sampling, Subtyping; localization testing, Adrenalectomy
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 97 participants (actual)
- Lead sponsor
- Changi General HospitalUniversity, hospital or other
- Collaborators
- National University Health System, Singapore, Clinical Imaging Research Centre, Singapore General Hospital, Tan Tock Seng Hospital, Khoo Teck Puat Hospital, Ng Teng Fong General Hospital, Sengkang General Hospital
- Study start
- 30 Dec 2019 (actual)
- Primary completion
- 25 May 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 25 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
- 10% of patients with hypertension potentially have the treatable condition - primary aldosteronism (PA). This is caused by either bilateral adrenal disease (~40%), managed with lifelong medications; or unilateral disease (~60%), cured with laparoscopic surgery (adrenalectomy). Current diagnosis of PA includes a screening test with aldosterone-renin ratio, followed by a confirmatory salt loading test (in most patients) to demonstrate unsuppressed aldosterone levels. Of note, some patients with suppressed aldosterone after confirmatory tests (also termed low-renin hypertension) may also have unilateral adrenal tumors.
- The difficulty with identifying curable unilateral disease is due to adrenal vein sampling (AVS): an invasive, and technically-difficult procedure. An alternative novel imaging, 11C-Metomidate Positron emission tomography-computed tomography (PET-CT), can detect adrenal tumors which are over-producing aldosterone. It is non-invasive, non-operator-dependent, and potentially may identify more patients with curable unilateral disease. The results from our pilot study in 25 patients with confirmed PA (ClinicalTrials.gov NCT03990701, PA_CURE) showed that 11C-Metomidate PET-CT exhibited comparable performance to AVS in subtyping PA, and this should be validated in a larger study.
- In addition, 11C-Metomidate is also able to differentiate adrenocortical lesions in the adrenal gland from other lesions found in adrenal tissue, such as adrenomedullary lesions (e.g. pheochromocytoma).
- Hence, the investigators hypothesize that 11C-metomidate PET-CT can accurately (1) identify patients with surgically curable unilateral adrenal disease among hypertensive Asians with primary aldosteronism (PA_CURE 2 / PA_MTO EH study) and (2) differentiate adrenocortical lesions from other lesions in patients with adrenal tumors (PA_MTO AT study)
Detailed description
- The investigators aim to recruit 100 patients with confirmed, or likely, primary aldosteronism to undergo conventional tests, CT, AVS, and 11C-metomidate PET-CT.
- Results will be reviewed and discussed at a multidisciplinary meeting, and patients with unilateral PA or adrenal tumor will be offered surgery. Patients will be reviewed 6 months post-surgery.
- In a separate study, the investigators will recruit 10 patients with adrenal tumors to differentiate adrenocortical lesions from other lesions in patients with adrenal tumors
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- 11C-metomidate synthesis will be done at Clinical Imaging Research Centre in compliance with good manufacturing practice using a General Electric Medical Systems PET trace 860 cyclotron. Non-contrast CT images will be acquired over the adrenal. After an intravenous injection of 11C-metomidate, PET images will be acquired. Attenuation and decay-corrected images will be converted to standardized uptake value (SUV) maps through division by (injected activity per patient weight). The maximum SUV values over regions of interest will be determined for 10-min static images starting 35 min after the injection.
| Arm | Type | Receives |
|---|---|---|
| 11C-metomidate PET-CT | Experimental | Combination Product: 11C-Metomidate PET/CT imaging at Clinical Imaging Research CentreAll patients will undergo standard-of-care investigations (CT imaging of adrenals and AVS) and the research test (11C-metomidate PET-CT) with a dose of 100 - 300 Megabecquerel (MBq) (11C-metomidate) to identify functional unilateral adrenal disease |
Who may qualify
- Ages
- 21 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- For patients with primary aldosteronism (PA_CURE 2 / PA_MTO EH):
- For patients with suspected adrenal tumors (PA_MTO AT)
Key exclusion criteria (5 listed)
- Inability to provide written informed consent.
- Chronic renal failure of Stage 3b or greater severity, estimated glomerular filtration rate (eGFR) < 45ml/min/1.73m2 using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. (only applicable for PA_CURE 2 / PA_MTO EH)
- Severe or terminal medical condition(s) that in the view of the investigator prohibits participation in the study or interferes with possible treatment or health-related quality of life, e.g. cancer, end-stage liver disease, end stage renal failure (only applicable for PA_CURE 2 / PA_MTO EH)
- Contraindications to isotope scanning (e.g. Female patients who are pregnant (self-declared or via positive pregnancy test), intending to become pregnant (within 3 months of scan) or breastfeeding) or CT Scan, which includes but not limited to waist circumference >140cm, morbid obesity or claustrophobia (limiting entry in CT scanner)
- Contraindication to ingestion of corticosteroids (e.g. poorly controlled diabetes, HbA1C >13%)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre | Combination product | 11C-metomidate PET-CT |
Primary outcome
Biochemical outcome of unilateral primary aldosteronism based on the Primary Aldosteronism Surgical Outcome (PASO) criteria (PA_CURE 2 / PA_MTO EH study).
Time frame: 6 months
The number of patients with complete, partial, and absent biochemical success according to the PASO criteria.
Diagnostic performance of 11C-Metomidate PET-CT in identifying unilateral adrenocortical tumor (PA_MTO AT study).
Time frame: 6 months
Percentage of patients accurately identified with adrenocortical tumor using 11C-Metomidate PET-CT, when compared to the histopathology of the excised tumor. In patients who have not undergone surgery, this will be determined by clinical diagnosis.
5 secondary outcomes
Clinical outcome of unilateral primary aldosteronism based on the Primary Aldosteronism Surgical Outcome (PASO) criteria (PA_CURE 2 / PA_MTO EH STUDY).
Time frame: 6 months
Diagnostic performance of 11C-Metomidate PET-CT in identifying unilateral aldosterone-producing adenoma (PA_CURE 2 / PA_MTO EH study).
Time frame: 6 months
Cost-effectiveness of 11C-Metomidate PET-CT versus AVS in diagnosing patients with unilateral primary aldosteronism (PA_CURE 2 / PA_MTO EH STUDY).
Time frame: 6 months
Diagnostic criteria using 11C-metomidate PET/CT (PA_CURE 2 / PA_MTO EH study).
Time frame: 6 months
Number of patients with low-renin hypertension with unilateral adrenal tumors (PA_CURE 2 / PA_MTO EH study).
Time frame: 6 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing 11C-Metomidate PET/CT imaging at Clinical Imaging Research Centre in people with Primary Aldosteronism Due to Aldosterone Producing Adenoma and Primary Aldosteronism, run by Changi General Hospital at 7 sites in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Biochemical outcome of unilateral primary aldosteronism based on the Primary Aldosteronism Surgical Outcome (PASO) criteria (PA_CURE 2 / PA_MTO EH study). (time frame: 6 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Oct 2026.