ANN ARBOR — A first-in-human study validated the PET radiotracer 11C-Nevanimibe for imaging overactive adrenal glands in patients with primary aldosteronism, a condition that causes secondary hypertension. The study demonstrated that the radiotracer can distinguish between healthy and overactive adrenal tissue based on cholesterol metabolism, offering a potential non-invasive alternative to current diagnostic methods.
Primary aldosteronism, also known as Conn’s syndrome, is the most common cause of curable secondary hypertension. In this disorder, the adrenal glands overproduce aldosterone—a hormone derived from cholesterol—which leads to elevated blood pressure. Accurate diagnosis is critical because treatment differs depending on whether one or both adrenal glands are affected. If only one gland is overactive, surgical removal can cure the condition; if both are involved, patients require lifelong medication.
Currently, adrenal vein sampling is used to determine which adrenal gland or glands are overproducing aldosterone. However, this procedure is highly invasive and available only at specialized medical centers, limiting access for many patients. The new PET radiotracer targets cholesterol metabolism in the adrenal glands, providing a functional imaging approach that could simplify diagnosis.
The first-in-human trial included nine participants: six healthy controls and three patients previously diagnosed with overactive adrenal glands. In those with primary aldosteronism, the adrenal-to-liver uptake ratio of 11C-Nevanimibe averaged 1.2, compared to 0.7 in healthy subjects, indicating higher tracer accumulation in diseased tissue. The human biodistribution of the radiotracer closely mirrored results from earlier preclinical studies.
"This work further expands molecular imaging to benefit a population of patients currently lacking in non-invasive accessible diagnostic techniques," said Gina Kaup, graduate student in medicinal chemistry at the University of Michigan. "Additional clinical studies are underway to study dosimetry and efficacy of this tracer," she added.
The study was led by Benjamin Viglianti, MD PhD, director of the Nuclear Medicine Division at the University of Michigan. Peter Scott, PhD, and Paul L. Carson, PhD, Legacy Professor of Radiology at the University of Michigan in Ann Arbor, were also associated with the research. The findings were presented at the Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting.