ZIRDOSE-CP Study of TLX250-CDx published in EJNMMI Research: Confirms Favorable Safety and Tolerability Profile in Chinese patients

Melbourne (Australia) | 9 January 2026

Telix today announces that final results from the ZIRDOSE-CP[1] Phase 1 study of TLX250-CDx (Zircaix®[2], 89Zr-girentuximab) PET[3] imaging in Chinese patients with suspected clear cell renal cell carcinoma (ccRCC) have been published in the European Journal of Nuclear Medicine and Molecular Imaging (EJNMMI) Research[4].

ZIRDOSE-CP was a prospective, single-centre Phase 1 study to evaluate the safety, tolerability, radiation dosimetry, and pharmacokinetics of TLX250-CDx PET imaging in ten Chinese patients with suspected ccRCC. While TLX250-CDx has been studied extensively, existing data is primarily derived from Western populations, with limited evidence specific to Chinese patients.

Authors assert that, “this study extends prior findings from the Phase 3 ZIRCON study by providing preliminary evidence in a Chinese patient population.” Authors conclude that TLX250-CDx “has a favorable safety and tolerability profile in Chinese patients, with a similar organ radiation and tumor dosimetry as previously reported in other populations”.

Results support existing data that suggests that TLX250-CDx is a promising non-invasive immuno-PET agent for the detection and characterization of ccRCC in patients with indeterminate renal masses (IRMs). TLX250-CDx is being further assessed in Chinese patients in the registrational Phase 3 ZIRCON-CP study[5], which is being conducted in collaboration with Telix’s strategic partner for the Greater China region, Grand Pharmaceutical Group Limited (00512.HK, Grand Pharma).

ZIRCON-CP, which is currently recruiting up to 82 patients, is designed to bridge to Telix’s pivotal global Phase 3 ZIRCON trial[6], which demonstrated high diagnostic accuracy for TLX250-CDx[7]. The goal is to confirm that the diagnostic utility of TLX250-CDx is equivalent in Chinese and Western patients, supporting future marketing authorization applications for this breakthrough[8] precision diagnostic in China.

Greater China represents a major market opportunity for radiopharmaceuticals, including TLX250-CDx, driven by increasing cancer incidence rates and an investment in installation of PET/CT[9] cameras. In China alone, 73,000 people are newly diagnosed with kidney cancer each year[10].

Dr. David N. Cade, Group Chief Medical Officer at Telix, commented: “This ZIRDOSE-CP study has been a critical step in our strategy to bring TLX250-CDx to patients in China as efficiently as possible. Having confirmed preliminary equivalence in Chinese and Western populations for safety and dosimetry, the ongoing ZIRCON-CP study aims to confirm equivalent diagnostic performance and support regulatory filings in Greater China, where there is currently critical unmet medical need for the non-invasive detection and characterization of kidney cancer.”

The full paper is available at: https://link.springer.com/article/10.1186/s13550-025-01332-5

TLX250-CDx has not received a marketing authorization in any jurisdiction.

[1] ClinicalTrials.gov ID: NCT05861778.

[2] Brand name subject to final regulatory approval.

[3] Positron emission tomography.

[4] Liu et al. EJNMMI Res. 2026.

[5] ClinicalTrials.gov ID: NCT06750419.

[6] ClinicalTrials.gov ID: NCT03849118.

[7] Telix ASX disclosures 7 November 2022. Shuch et al. Lancet Oncology. 2024.

[8] Telix ASX disclosure 1 July 2020. TLX250-CDx granted Breakthrough Therapy designation by U.S. FDA.

[9] Positron emission tomography/computed tomography.

[10] Global Cancer Statistics 2022: GLOBOCAN survey. Published August 2024.