A novel approach that combines the imaging agent, 99mTc-maraciclatide, with single photon emission computed tomography (SPECT), could guide therapeutic decision-making and expand developmental treatments. That’s according to the poster, “Imaging Lung Inflammation in Interstitial Lung Disease (ILD) with 99mTc-maraciclatide: A Therapy Selection Tool?” presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting in Los Angeles.
SPECT helps healthcare professionals better distinguish severity of pulmonary inflammation or fibrotic scarring without the need for more invasive procedures. The approach may improve diagnostic accuracy of interstitial lung disease (ILD) as well as predict which patients would likely benefit from an anti-inflammatory treatment strategy and which ones could experience harmful side effects.
“We saw during the COVID-19 pandemic — when all patients with the infection had inflammation — that anti-inflammatory treatments were highly effective,” said co-presenter Druin Burch, FRCP, in a press release. “While current imaging techniques can provide a structural view of fibrosis in the lungs, there is no reliable, noninvasive way to identify inflammation. A tool that could detect inflammation in ILD patients could help pinpoint those most likely to respond to anti-inflammatory therapy.”
In a phase 2 study, researchers investigated the molecular imaging agent 99mTc-maraciclatide, which captures new blood vessel formation (angiogenesis) — a key marker of inflammatory disease. Dr. Burch said the agent has already proven diagnostic success in other inflammatory conditions, such as endometriosis.
Researchers injected the agent then performed SPECT on a total of 15 patients: five healthy controls (HC) and ten with a form of ILD (five with idiopathic pulmonary fibrosis [IPF] and five with fibrotic hypersensitivity pneumonitis [fHP]). Thoracic radiologists and nuclear medicine physicians categorized the images based on radiological patterns, standardized uptake values and target-to-background ratios.
Images of the HC participants showed normal tracer uptake in the lungs. Conversely, images of the ILD patients showed substantial uptake, particularly those with fHP who had double the uptake of HCs. Those with ILD also had a distinctly higher target-to-background ratio compared to the healthy controls.
Sample images from each participant group. A: CT only; B: fused SPECT-CT 99mTc-maraciclatideSNMMI
The U.S. Food and Drug Administration (FDA) has already granted Fast Track Designation to 99mTc-maraciclatide for “visualization of inflammation in the lungs of patients with known and suspected interstitial lung disease.” Dr. Burch said this could make the approach broadly available in the next few years after testing it in a larger phase 3 study.
