TLX250-CDx (Zircaix®) Included in Leading International Guidelines for Renal Imaging
Melbourne (Australia) and Indianapolis, IN (U.S.) | 23 October 2025
Telix today welcomes updated guidelines from the Society of Nuclear Medicine and Molecular Imaging (SNMMI), the European Association of Nuclear Medicine (EANM) and The American College of Nuclear Medicine (ACNM) that, for the first time, include the use of Telix’s investigational PET[1] agent, TLX250-CDx (Zircaix®[2], 89Zr-DFO-girentuximab), for molecular imaging of renal masses.
Published on the SNMMI website[3] and in The Journal of Nuclear Medicine[4], the guideline panel[5], comprising internationally renowned and multidisciplinary expert key opinion leaders, concludes that “the emerging use of molecular imaging for risk stratification of indeterminate renal masses offers the opportunity to more effectively characterize such lesions and optimize patient management decisions”.
The panel asserts that antibody-based radiotracers exhibit lower renal clearance, thereby improving visualization of renal masses. It emphasizes that TLX250-CDx PET “appears to be a well-tolerated and accurate method for non-invasive identification of ccRCC[6]” and notes by contrast, the high renal excretion with 18F-FDG PET, which obscures accurate lesion detection.
The panel references data from Telix’s pivotal Phase 3 ZIRCON trial[7], which met all primary and secondary endpoints, demonstrating a sensitivity of 86%, specificity of 87% and a positive predictive value (PPV) of 93% for ccRCC, including in very small, difficult-to-detect lesions[8]. TLX250-CDx works by specifically binding to carbonic anhydrase IX (CAIX), a validated target protein expressed on >95% of ccRCC cells[9], to produce images with high tumor-to-background ratio and high intra- and inter-reader consistency.
Professor Brian Shuch, MD, Director of the Kidney Cancer Program and the Alvin & Carrie Meinhardt Endowed Chair in Kidney Cancer Research at UCLA Institute of Urologic Oncology and guideline author, commented, “The recognition of ⁸⁹Zr-girentuximab PET in the SNMMI/EANM/ACNM clinical guidelines reflects a shift toward precision medicine in renal cancer, providing clinicians with a more accurate tool for diagnosis to guide optimal, individualized treatment planning for patients.”
Kevin Richardson, Chief Executive Officer, Precision Medicine, Telix, added, “The inclusion of TLX250-CDx PET imaging for the first time in SNMMI/EANM/ACNM guidelines is an important development for Telix and will help raise awareness of this breakthrough precision diagnostic. Subject to regulatory approval, endorsement by this expert global multidisciplinary panel will help to drive adoption and implementation into clinical workflows, supporting clinical utility and enhancing decision-making to improve patient outcomes.”
SNMMI, EANM and ACNM periodically define new procedure standards/guidelines to help advance the science of nuclear medicine and to improve the quality of service to patients. Each standard/guideline, representing a policy statement by these groups undergoes a thorough consensus process in which it has been subjected to extensive review.
TLX250-CDx has not received a marketing authorization in any jurisdiction.
[1] Positron emission tomography.
[2] Brand name subject to final regulatory approval.
[3] https://snmmi.org/common/Uploaded%20files/Web/Clinical%20Practice/Procedure%20Standards/2025/SNMMI_EANM _ACNM_Renal_Masses-Final%20JNM%20sumbission.pdf
[4] SNMMI/EANM/ACNM Procedure Standard/Procedure Guideline on the Use of Molecular Imaging for Renal Mass Characterization (October 2025), available at: https://jnm.snmjournals.org/content/early/2025/10/09/jnumed.125.271332.abstract
[5] Steven P. Rowe, Brian M. Shuch, Mark W. Ball, Axel Bex, Mehrbod S. Javadi, Alan Klitzke, Karolien Goffin,
Peter Mulders, Neeta Pandit-Taskar, Ashwin Singh Parihar, Benjamin L. Viglianti, Michael A. Gorin, and
Ken Herrmann.
[6] Clear cell renal cell carcinoma, the most common and one of the most aggressive subtypes of kidney cancer.
[7] ClinicalTrials.gov ID: NCT03849118.
[8] Telix ASX disclosures 7 November 2022. Shuch et al. Lancet Oncology. 2024.
[9] Stillebroer et al. Eur Urol. 2010.