Recruiting is underway for a single-center prospective clinical trial evaluating iodine-124 evuzumitide (124I-evuzumitide) in patients with systemic amyloidosis, of which hereditary transthyretin amyloidosis (hATTR) is a form.

The trial aims to “identify and characterize the distribution and uptake of 124I-evuzumitide in patients with transthyretin amyloid cardiomyopathy (ATTR-CM)” and correlate 124I-evuzumitide uptake with the structure and function of different organs, such as the heart.

Participants will undergo primarily hybrid 124I-evuzumitide positron emission tomography and magnetic resonance imaging (PET/MRI). A subgroup of participants will undergo repeat imaging at an interval of 6 to 12 months. Participants unable to undergo PET/MRI will be evaluated by MRI.

The primary outcome measure of the study will be the correlation between extracellular volume and 124I-evuzumitide cardiac uptake and distribution.

Read more about hATTR diagnosis

Secondary outcome measures will include correlations between myocardial 124I-evuzumitide uptake and clinical cardiac biomarkers (ie, stage of amyloidosis), Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score, New York Heart Association (NYHA) class, liver and spleen extracellular volume, and the proportion of patients with ATTR-CM and monoclonal gammopathy of undetermined significance or smoldering myeloma who are correctly classified as ATTR-CM based on 124I-evuzumitide distribution and uptake.

The trial will enroll 30 participants with at least 1 of the following conditions: systemic amyloidosis with known organ involvement, carrier of a known pathogenic mutation in the transthyretin gene, multiple myeloma, and/or monoclonal gammopathy of undetermined significance.

Patients on dialysis or those with low estimated glomerular filtration rate (eGFR <30 cc/min/1.73 m2) will be excluded from undergoing gadolinium-enhanced cardiac MRI. Moreover, the study will exclude patients who have received heparin or its analogs within 7 days prior to drug administration, those with severe claustrophobia or any medical condition that would prevent completion of the imaging protocol, and those with a known allergy to potassium iodide treatment or gadolinium.

The trial is sponsored by Oregon Health and Science University and Attralus, Inc.


Characterizing iodine-124 evuzumitide (AT-01) in systemic amyloidosis. March 7, 2023. Accessed March 14, 2023.