An Early Phase 1 interventional study of [18F]ZDG2- Single Dose in Pulmonary Artery Hypertension, sponsored by The Methodist Hospital Research Institute. Not yet recruiting. Open to participants aged 21 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-12.
Sponsored by The Methodist Hospital Research Institute · Early Phase 1, Interventional, and Diagnostic
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The goal of this study is to find out whether [18F]ZDG2 can detect early blood vessel changes in people with pulmonary arterial hypertension (PAH). The study will help answer this question:
Can a positron emission tomography (PET) scan using [18F]ZDG2 help identify PAH?
Participants will:
Pulmonary arterial hypertension (PAH) affects approximately 220,000 people in the United States and more than 2 million people worldwide. There is currently no cure, and despite available treatments, the five-year mortality rate remains approximately 50%. Diagnosis is often delayed by more than two years because commonly used screening tests lack accuracy, while the gold-standard diagnostic test requires invasive right heart catheterization. By the time PAH is diagnosed, patients may have already lost up to 70% of their pulmonary vascular reserve, resulting in irreversible disease progression.
Current diagnosis is based on elevated pulmonary artery pressure, a relatively late manifestation of the disease, rather than the underlying biological changes that occur during its early stages. One of these early changes is pulmonary vascular remodeling, which leads to loss of pulmonary vascular reserve and is driven in part by vascular endothelial growth factor (VEGF) signaling.
To address this unmet need, we have developed an imaging tracer designed to detect these early molecular changes by targeting dysregulation of vascular endothelial growth factor receptor 2 (VEGFR2). Houston Methodist Research Institute has developed [18F]ZDG2, a novel PET imaging tracer that selectively binds to VEGFR2 and can be visualized using positron emission tomography. This approach may enable noninvasive measurement of VEGFR2 expression and provide a means to detect PAH at earlier stages of disease, before significant and irreversible vascular damage has occurred.
The Methodist Hospital Research Institute is the lead sponsor of 161 studies on the registry; 60 are open to participants now.
Of its 28 completed or terminated interventional studies of FDA-regulated products, 18 (64%) have results posted.
Counted across the registry records on this site, refreshed daily.
Healthy Volunteer Criteria
Inclusion Criteria- Healthy Volunteers
No history of cardiovascular disease including:
Normal baseline echocardiogram within 6 months demonstrating:
For women of :
-Agrees to use highly effective from screening through 30 days after imaging
For men with Women of Childbearing Potential partners:
Exclusion Criteria- Healthy Volunteers
History of pulmonary disease including:
PAH Patients Criteria
Inclusion Criteria- PAH Patients
Confirmed diagnosis of pulmonary arterial hypertension (World Health Organization (WHO) Group 1) by right heart catheterization meeting ALL of the following hemodynamic criteria within the last 3 months:
PAH etiology limited to WHO Group 1 subtypes:
Associated PAH including:
WHO Functional Class I, II or III:
6-minute walk distance: 150-450 meters (performed with 8 weeks of screening)
-≥150 meters: Ensures patient can complete study procedures
-≤450 meters: Ensures meaningful disease severity for signal detection
Adequate organ function:
Clinically stable for ≥8 weeks prior to enrollment:
Stable PAH-specific medication regimen for ≥8 weeks:
Comprehensive echocardiogram within 8 weeks demonstrating:
Pulmonary function tests (as measured per standard of care) within 12 months demonstrating:
High-resolution chest CT (as measured per standard of care) within 12 months demonstrating:
Ventilation-perfusion scan (as measured per standard of care) within 12 months demonstrating:
For Women Of Childbearing Potential:
-Agrees to use highly effective contraception through 30 days after imaging
For men with Women Of Childbearing Potential partners:
-Agrees to use barrier contraception through 30 days after imaging
Exclusion Criteria- PAH Patients
Classification of other PH groups confirmed by:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
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.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
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.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients diagnosed with PAH will receive the tracer. A subset (10/12) will participate in reproducibility testing.
Drug: [18F]ZDG2- Single Dose
Healthy volunteers will receive the tracer.
Drug: [18F]ZDG2- Single Dose
\[18F\]ZDG2 will be administered as an intravenous injection on the day of imaging. Participants in the reproducibility cohort will receive an additional dose and imaging session one to weeks after the first. Heathy volunteers and PAH patients not in the reproducibility cohort will receive only one dose and imaging session.
Incidence and severity of adverse events
Incidence recorded and severity graded per CTCAE v6.0
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Changes in blood pressure from baseline
Systolic and diastolic (mmHg)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Changes in heart rate from baseline
(bpm)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Changes in oxygen saturation from baseline
As measured via pulse oximetry (%)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Changes in temperature from baseline
(°C or °F)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Standardized uptake values in major organs
(SUVmax, SUVmean)
Time frame: From tracer administration to the final scan at 180 minutes post administration
Number of participants with abnormal results in hematology assessments
The following will be assessed as part of the hematology panel: WBC, Platelet count, RBC, Neutrophils, HGB, Lymphocytes, HCT, Monocytes, MCV, Eosinophils, MCH, Basophils, MCHC Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance.
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Number of participants with abnormal results in chemistry laboratory assessments
The following will be assessed as part of the chemistry panel: Sodium, Calcium, Potassium, Protein, Chloride, Albumin, CO2, Alkaline phosphatase, BUN, AST, Creatinine, ALT, Glucose, Total bilirubin, eGFR Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance.
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Number of participants with abnormal results in coagulation laboratory assessments
The following will be assessed as part of the coagulation panel: INR, Prothrombin time (PT) Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance.
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Number of participants with abnormal results in urinalysis laboratory assessments
The following will be assessed as part of the urinalysis panel: Color, Bilirubin, Appearance, Blood, Specific gravity, Nitrite, pH, Urobilinogen, Protein, WBC, Glucose, RBC, Ketones Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance.
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Number of participants with abnormal results in NTproBNP laboratory assessments
Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance. (pg/mL)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Number of participants with abnormal results in HgbA1c laboratory assessments
Changes from baseline and results outside of the normal range will be evaluated by the PI and safety committee for clinical significance. (%)
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Time-activity curves for major organs including lungs and heart
Organ radioactivity concentration measured over time following tracer administration.
Time frame: From tracer administration to the final scan at 180 minutes post administration
Identification of excretory pathways
Determined from serial PET imaging and biologic sample analysis following tracer administration.
Time frame: From tracer administration to the final scan at 180 minutes post administration
Radiation Dosimetry
We will calculate organ-specific absorbed radiation doses and the total effective dose.
Time frame: From tracer administration to the final scan at 180 minutes post administration.
Plasma concentration-time profile
Plasma tracer concentration measured at multiple timepoints following administration.
Time frame: From tracer administration to the final scan at 180 minutes post administration
Parent fraction analysis
metabolite profiling
Time frame: From tracer administration to the final scan at 180 minutes post administration
Plasma free fraction determination
Fraction of tracer unbound to plasma proteins, reported as a percentage.
Time frame: From tracer administration to the final scan at 180 minutes post administration
VEGFR Quantification
We will quantify pulmonary artery and right ventricular VEGFR expression in PAH patients compared to healthy volunteers.
Time frame: From 90 minutes post tracer administration to 180 minutes post administration.
Mean pulmonary artery pressure
As measured via standard of care heart catheterization
Time frame: From tracer administration to the final scan at 180 minutes post administration
Pulmonary vascular resistance
As measured via standard of care heart catheterization
Time frame: From tracer administration to the final scan at 180 minutes post administration
Cardiac output
As measured via standard of care heart catheterization
Time frame: From tracer administration to the final scan at 180 minutes post administration
Cardiac index
As measured via standard of care heart catheterization
Time frame: From tracer administration to the final scan at 180 minutes post administration
WHO functional class
WHO functional class assessed at baseline per standard of care and reported as Class I, II, III, or IV.
Time frame: From enrolment to the final follow up visit, 3-7 days after the last dose.
Highest pulmonary artery-to-background ratio
As assessed via PET imaging
Time frame: From tracer administration to the final scan at 180 minutes post administration.
No study locations are listed for this record.
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Apr 2028, 17 months later.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Familial Primary Pulmonary Hypertension
The Methodist Hospital Research Institute →