Could the PET Imaging Agent ITM-94 be a Game Changer for Detecting Clear Cell Renal Cell Carcinoma?

For patients with clear cell renal cell carcinoma (ccRCC), Michael Hofman, MBBS, FRACP, suggests that the emerging gallium-68 radiolabeled positron emission tomography (PET) agent ITM-94 may offer significantly enhanced detection of ccRCC.

In a recent interview with Diagnostic Imaging, Dr. Hofman discussed preliminary research findings for ITM-94 (ITM Isotope Technologies), which is currently in the midst of a phase 1/2 trial assessing the combination of ITM-94 with the radiotherapeutic agent ITM-91 ((¹⁷⁷Lu)Lu-DPI-4452) for targeting the cell surface protein carbonic anhydrase IX (CAIX), which is over expressed in ccRCC.

“The tumor to background contrast is higher (with ITM-94) than we've seen with just about any new radiotracer that we've looked at in the last couple of decades,” maintained Dr. Hofman, the director of Prostate Cancer Therapeutics and the Imaging Centre of Excellence (ProsTIC), and head of PET/CT at the Peter MacCallum Cancer Centre in Melbourne, Australia.

“We can see SUVmax, over 100 typically in these cancers, but even up to 500 in some patients. This is just extraordinary uptake. When we have such intense uptake, it allows us to resolve very small lesions, definitely below one centimeter, but even below five millimeters, maybe even getting below two to three millimeters in some patients.”

Dr. Hofman pointed out that another key benefit of ITM-94, which received an FDA fast track designation in November for ccRCC, is minimal uptake in the renal parenchyma.

“Those familiar with, let's say, FDG PET or PSMA pet, you'll know that the kidney has very high uptake, which limits the assessment of that organ. But (ITM-94) is very rapidly excreted, and the renal parenchyma has very little uptake, so it allows us to assess for very small renal lesions with a degree of clarity that really we've never been able to do before,” added Dr. Hofman, a professor in the Sir Peter MacCallum Department of Oncology at the University of Melbourne.

(Editor’s note: For related content, see “Emerging PET Agent Garners FDA Fast Track Designation for Clear Cell Renal Cell Carcinoma,” “A Closer Look at New Guidelines for Molecular Imaging of Renal Masses: An Interview with Steven Rowe, MD, Part 1” and “Ultrasound Renal Denervation System for Hypertension Garners CMS National Coverage Determination.”)

For more insights from Dr. Hofman, watch the video below.