Diagnosing renal masses, a growing medical dilemma

Telix’s kidney cancer portfolio targets CAIX (carbonic anhydrase IX), an antigen expressed on the surface of clear cell renal cell carcinoma (ccRCC), the most common and aggressive form of kidney cancer.

The detection of renal masses is increasing due to widespread use of cross-sectional imaging. Many of these are small and represent a diagnostic challenge as current imaging cannot reliably distinguish benign or malignant lesions from renal cell carcinoma, leading to invasive biopsy or partial nephrectomy (kidney removal) to confirm the diagnosis. These procedures are not always necessary and can lead to complications.

The highly positive result from the ZIRCON Phase III pivotal study of TLX250-CDx confirms that TLX250-CDx has the potential to become a standard of care in the diagnosis of renal masses.

The study delivered co-primary endpoints of 86% sensitivity and 87% specificity and 93% positive predictive value (secondary endpoint) exceeding clinical requirements for sensitivity and specificity targets.

The study also met the key secondary endpoint for the sensitivity and specificity required to diagnose ccRCC in tumours <4cm which currently presents a major unmet clinical need in the diagnosis of ccRCC.

Based on these results Telix intends to file a BLA for regulatory approval with the FDA and global regulatory agencies as a positron emission tomography/computed tomography (PET/CT) imaging agent for use in the characterisation of indeterminate renal masses previously identified on CT or MRI as ccRCC or non-ccRCC.

Kidney cancer rates have doubled in the last 50 years


people were diagnosed with kidney cancer globally in 2020


people died from kidney cancer globally in 2020


kidney / urinary biopsies or surgeries performed annually in the US


of small renal masses are thought to be malignant


5-year survival rate for metastatic renal cell carcinoma

Exploring CAIX as a multi-disease target

CAIX is also expressed on a number of other solid tumours including in bladder or urothelial, breast, brain, cervix, colon, oesophagus, head and neck, lung, ovarian, pancreatic and vulval cancers. It is often expressed in hypoxic (oxygenated) tumour cells. Hypoxic tumours are typically more aggressive and less responsive to current treatments, particularly immunotherapies.1

Based on this potential to target different tumour types, investigator-led studies are also in progress using these investigational assets in urothelial carcinoma or bladder cancer, triple negative breast cancer, and non-muscle invasive bladder cancer in imaging and as a stand-alone and combination therapy.

[1] Huizing, F.J., Garousi, J., Lok, J. et al. CAIX-targeting radiotracers for hypoxia imaging in head and neck cancer models. Sci Rep 9, 18898 (2019). https://doi.org/10.1038/s41598-019-54824-5