PET/CT imaging with iodine-124 (I-124) evuzamitide could assist monitor how sufferers with cardiac amyloidosis reply to remedy over time, in response to a examine introduced on the American Society of Nuclear Cardiology annual assembly in Austin, TX.
Emily Martin, PhD, of the College of Tennessee Medical Middle in Knoxville, mentioned her group’s newest analysis on the investigational method, with repeat scans greater than two years after baseline displaying adjustments in cardiac and extracardiac amyloid load related to the illness.
“Cardiac uptake of I-124 evuzamitide in sufferers correlated with echocardiographic parameters of construction and performance and serum NT-proBNP,” Martin famous in a September 5 session.
Amyloidosis develops when, for causes that stay unclear, amyloid proteins misfold and construct up within the physique’s organs. There are two primary sorts, transthyretin amyloidosis (ATTR) and light-chain amyloidosis (AL). When the illness happens within the myocardium, the amyloid build-up restricts cardiac operate and might result in coronary heart failure and loss of life, the authors defined.
Presently, there are not any particular imaging brokers for semiquantitatively monitoring this so-called “cardiac amyloid load,” in response to the researchers.
Not too long ago, nevertheless, I-124 evuzamitide acquired breakthrough remedy designation from the U.S. Meals and Drug Administration, with research displaying that the tracer permits clinicians to discriminate between sufferers with the illness and wholesome topics. As well as, a variant of the imaging agent can be underneath improvement to be used in SPECT/CT imaging.
On this examine, the investigators additional evaluated the utility of the tracer. Between July 2022 and December 2023, they enrolled 19 sufferers, 9 with AL and 10 with ATTR amyloidosis who all confirmed optimistic cardiac uptake of I-124 evuzamitide in a earlier baseline examine.
Martin and colleagues quantified radiotracer uptake within the coronary heart, liver, spleen, and kidney based mostly on customary uptake worth ratios (SUVR) utilizing blood pool because the reference. Serum biomarkers have been measured, and transthoracic echocardiograms have been carried out previous to imaging. Moreover, they in contrast radiotracer uptake with serum NT-proBNP and echocardiographic parameters, two established scientific strategies for monitoring the illness.
I-124 evuzamitide PET/CT photos of a affected person with light-chain amyloidosis displaying a lower in amyloid load and organ quantity on follow-up.Picture courtesy of the American Society of Nuclear Cardiology
Based on the evaluation, the imply time between imaging was 2.9 years. A rise in cardiac uptake was noticed in three sufferers with ATTR amyloidosis and in just one with AL amyloidosis. For the complete inhabitants, there was a big correlation between the change in cardiac tracer uptake and alter in serum NTproBNP (Spearman rank correlation coefficient [rs] = 0.62, p = 0.005).
As well as, important correlations have been noticed between cardiac I-124 evuzamitide uptake and left ventricle wall thickness (Pearson correlation coefficient [rP] = 0.71, p = 0.0007), and world longitudinal pressure (rP = 0.47, p = 0.043). The researchers noticed decreases in hepatosplenic amyloid load and organ quantity in two of the AL sufferers.
In the end, therapies for ATTR and AL have been developed which might be particular to the amyloid sort and thus, along with early prognosis, identification of the amyloid sort is important for efficient affected person administration, the staff famous. Based mostly on this and earlier research, in these regards, I-124 evuzamitide exhibits promise, Martin prompt.
“PET/CT imaging of I-124 evuzamitide is a promising method for monitoring response to remedy in sufferers,” she concluded.
