A new analysis from Telix Pharmaceuticals (ASX:TLX) has found that its investigational kidney cancer imaging agent TLX250-CDx could meaningfully alter clinical management for almost half of patients presenting with indeterminate renal masses (IRMs).
The findings from the ZIRCON-X study will be presented at the 26th Annual Meeting of the Society of Urologic Oncology in the US.
ZIRCON-X was a non-interventional, prospective, post-hoc study using imaging data from Telix’s pivotal Phase 3 ZIRCON trial. The analysis compared how multidisciplinary teams would manage patients based solely on standard-of-care contrast-enhanced imaging versus how plans changed when TLX250-CDx PET/CT imaging was added. The review covered 294 evaluable patients with IRMs.
The analysis found that 143 patients (48.6 per cent) would have experienced a change in their clinical management if TLX250-CDx imaging had been used. Notably, more than 20 per cent of these patients might have avoided an invasive biopsy. In total, over a third of patients (37.4 per cent) would have faced a significant change in their management plan, including shifts between biopsy, surgery, and further diagnostic testing. Approximately 30 per cent would have had their treatment escalated or de-escalated.
Among patients initially assigned to active surveillance, 18 would have been escalated to immediate treatment, highlighting the importance of accurate tumour characterisation in avoiding undertreatment. Conversely, TLX250-CDx provided clearer spatial localisation of clear cell renal cell carcinoma (ccRCC) in several cases, helping clinicians refine surgical planning, including whether to pursue partial or total nephrectomy.
Professor Karolien Goffin, a Principal Investigator for ZIRCON and ZIRCON-X, said the results demonstrate the clinical value of more precise diagnostic tools.
Dr David Cade, Telix’s Group Chief Medical Officer, noted that TLX250-CDx has recently been incorporated into international renal imaging guidelines, reinforcing its emerging role in the diagnostic pathway.
TLX250-CDx is a PET imaging agent labelled with zirconium-89 and built on girentuximab. This antibody specifically targets carbonic anhydrase IX (CAIX), a biomarker expressed in more than 95 per cent of clear cell renal cell carcinoma cells.