The first-in-human study of \[18F\]GP1 positron emission tomography/computed tomography (PET/CT) showed that \[18F\]GP1 is safe and promising novel PET tracer for imaging acute venous thromboembolism with favorable biodistribution and pharmacokinetics in patients. The goal of this phase 2 study is to evaluate whether \[18F\]GP1 PET/CT is sensitive and specific for the diagnosis of acute deep vein thrombosis in the appropriate patient population and clinical setting. This study will provide preliminary evidence of efficacy and expand the safety database in a larger group of patients who were suspected of having acute deep vein thrombosis. This study will further optimize image acquisition techniques, and develop methods and criteria by which \[18F\]GP1 PET/CT will be evaluated. Other critical questions about \[18F\]GP1 biodistribution including \[18F\]GP1 uptake in pulmonary and systemic arteries will be evaluated.
This study is an open label, non-randomized, single center, intervention study. An estimated 63 symptomatic subjects with a pretest score of deep vein thrombosis likely (Wells score ≥ 2) or a positive D-dimer test will receive \[18F\]GP1 PET/CT to evaluate the diagnostic validity of \[18F\]GP1 PET/CT for detecting deep vein thrombosis foci in lower extremities. The study comprises 3 periods: screening, treatment, and follow-up. The screening period starts with the patient's signature on the informed consent form and ends with assignment to treatment that is inclusion of the subject for treatment. The treatment period starts with baseline measurements, and ends with the last measurement/procedure on the day of intravenous injection of 250 MBq of \[18F\]GP1. The follow-up period contains the end-of-study interview. Key measurement is the PET/CT image acquisition about 120 minutes after the single injection of \[18F\]GP1 This study includes venous ultrasonography of deep vein thrombosis as a valid reference standard. \[18F\]GP1 PET/CT will be assessed qualitatively and quantitatively by three experienced readers. This study will be monitored regularly by a clinical research associate from the sponsor or a designated contract research organization. Data quality and study integrity will be assessed. The investigator will document the items that are required to evaluate the study in the subject files. Data required according to this protocol are to be recorded on the case report forms provided by the sponsor as soon as possible.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
52
A radioactive dose of 250 MBq of the study drug with a total quantity of ≤ 10 µg will be administered as slow intravenous bolus injection over up to 60 seconds. PET/CT examinations will be performed at 120 ± 15 min after the administration of \[18F\]GP1.
Asan Medical Center
Seoul, South Korea
Sensitivity and specificity of qualitative [18F]GP1 PET/CT interpretation for the diagnosis of patients with acute proximal deep vein thrombosis
Sensitivity = (the number of \[18F\]GP1 PET/CT-positive patients divided by the number of ultrasonography-positive patients) x 100; specificity = (the number of \[18F\]GP1 PET/CT-negative patients divided by the number of ultrasonography-negative patients) x 100.
Time frame: within 7 days of [18F]GP1 PET/CT
Area under the receiver operating characteristic curve, sensitivity and specificity of quantitative [18F]GP1 PET/CT interpretation for the diagnosis of patients with acute proximal deep vein thrombosis
Area under the receiver operating characteristic curve. Sensitivity = (the number of \[18F\]GP1 PET/CT-positive patients divided by the number of ultrasonography-positive patients) x 100; specificity = (the number of \[18F\]GP1 PET/CT-negative patients divided by the number of ultrasonography-negative patients) x 100.
Time frame: Within 7 days of [18F]GP1 PET/CT
Positive and negative percent agreement between qualitative [18F]GP1 PET/CT and ultrasonography interpretation for the diagnosis of patients with acute distal deep vein thrombosis
Positive percent agreement = (the number of \[18F\]GP1 PET/CT-positive patients divided by the number of ultrasonography-positive patients) x 100; negative percent agreement = (the number of \[18F\]GP1 PET/CT-negative patients divided by the number of ultrasonography-negative patients) x 100
Time frame: Within 7 days of [18F]GP1 PET/CT
Positive and negative percent agreement between quantitative [18F]GP1 PET/CT and ultrasonography interpretation for the diagnosis of patients with acute distal deep vein thrombosis
Positive percent agreement = (the number of \[18F\]GP1 PET/CT-positive patients divided by the number of ultrasonography-positive patients) x 100; negative percent agreement = (the number of \[18F\]GP1 PET/CT-negative patients divided by the number of ultrasonography-negative patients) x 100
Time frame: Within 7 days of [18F]GP1 PET/CT
Intra- and inter-reader variability of qualitative [18F]GP1 PET/CT interpretation for the assessment of acute proximal and distal deep vein thrombosis
kappa statistic
Time frame: Within 1 day of [18F]GP1 PET/CT
Detection rate of pulmonary embolism with [18F]GP1 PET/CT
The number of \[18F\]GP1 PET/CT-positive patients divided by the number of ultrasonography-positive patients) x 100; negative percent agreement = (the number of all patients who underwent \[18F\]GP1 PET/CT
Time frame: Within 1 day of [18F]GP1 PET/CT
Percent fraction of unmetabolized [18F]GP1 in plasma
Percentage
Time frame: Within 1 day of [18F]GP1 PET/CT
Incidence of treatment emergent adverse events
Number of participants with treatment emergent adverse events graded by the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0)
Time frame: From the administration of [18F]GP1 to one day after [18F]GP1 PET/CT
Blood pressure
mmHg
Time frame: Pre-treatment and three hours after the administration of [18F]GP1
Heart rate
beats/minute
Time frame: Pre-treatment and three hours after the administration of [18F]GP1
Body temperature
Celsius
Time frame: Pre-treatment and three hours after the administration of [18F]GP1
Physical examination
The limited physical examination will comprise: general appearance, skin, neck, lungs, heart, abdomen, and a limited neurological examination (mental status, motor strength and sensor perception).
Time frame: Pre-treatment and three hours after the administration of [18F]GP1
Blood tests for safety
The clinical laboratory safety parameters to be assessed are as follows: glutamate pyruvate transaminase, glutamate-oxaloacetate transaminase, alkaline phosphatase, total bilirubin, creatinine, potassium, sodium, total protein, blood urea nitrogen, albumin.
Time frame: Pre-treatment and three hours after the administration of [18F]GP1
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