ZIRCON-X Analysis: TLX250-CDx Impacts Clinical Decision Making for Almost Half of Patients with Indeterminate Renal Masses
MELBOURNE, Australia and INDIANAPOLIS, Nov. 20, 2025 (GLOBE NEWSWIRE) -- Telix Pharmaceuticals Limited (ASX: TLX, NASDAQ:TLX, "Telix") today announces results from the ZIRCON-X study which finds that almost half of all patients imaged with TLX250-CDx (Zircaix®1, 89Zr-DFO-girentuximab) PET/CT2 would have undergone a change in clinical management, when compared with baseline standard of care (SOC) imaging. The data will be presented at the 26th Annual Meeting of the Society of Urologic Oncology (SUO) being held in Phoenix, AZ, December 2 – 5, 2025.
ZIRCON-X was a non-interventional, prospective, post-hoc study sponsored by Telix – using imaging data from Telix's parent pivotal Phase 3 ZIRCON study3 – that assessed the impact of TLX250-CDx imaging on clinical decision-making versus SOC contrast-enhanced diagnostic imaging in 294 patients with indeterminate renal masses (IRMs)4. The study found that 143 patients (48.6%) would have undergone a change in clinical management if imaged with TLX250-CDx, and over 20% of these patients (31 out of 143) could have potentially avoided invasive biopsy5.
Of all evaluable patients, more than one third (110 out of 294, or 37.4%) would have had a major change in clinical management based on defined categories (see table below), with approximately 30% having their treatment escalated or de-escalated. A subset of 18 patients initially selected for active surveillance would have been escalated to immediate treatment5.
| Most common major changes in clinical management5 | n |
| Biopsy to surgery (partial or total nephrectomy) | 24 |
| Surgery (partial or total nephrectomy) to biopsy | 19 |
| Additional diagnostic to surgery (partial or total nephrectomy) | 18 |
| Partial nephrectomy to total nephrectomy | 8 |
| Surgery (partial or radical nephrectomy) to additional diagnostic test | 7 |
| Total nephrectomy to partial nephrectomy | 6 |
In patients whose planned surgery was changed, TLX250-CDx provided greater clarity on spatial localization of ccRCC within the kidney; thus allowing the physician to determine the most appropriate surgical procedure.
Professor Karolien Goffin, staff member of nuclear medicine at the University Hospital Leuven, Chair of the EANM Oncology & Theranostics Committee and a Principal Investigator on the ZIRCON and ZIRCON-X studies commented, "These are compelling results which demonstrate that TLX250-CDx PET/CT has significant potential to impact clinical decision making in the diagnostic work-up of patients presenting with small IRMs and give physicians greater confidence in clinical planning."
Dr. David N. Cade, Group Chief Medical Officer at Telix, added, "This analysis is another demonstration of the potential clinical usefulness of TLX250-CDx, Telix's breakthrough6 precision diagnostic candidate, which has recently been added to international guidelines for renal imaging7. These results indicate that TLX250-CDx may deliver on an unmet need for better non-invasive diagnostic work-up for ccRCC that can improve risk stratification and minimize overtreatment and undertreatment."
About ZIRCON-X
ZIRCON-X was a non-interventional, prospective, post-hoc study assessing imaging data collected during Telix's parent pivotal Phase 3 ZIRCON study. The primary objective was to assess whether TLX250-CDx PET/CT has an impact on clinical decision-making versus SOC conventional contrast-enhanced diagnostic imaging in patients presenting with an IRM.
Four multi-disciplinary teams8 (MDTs) at four separate institutions9 evaluated ZIRCON data from 294 evaluable patients in two steps:
| Step 1: | MDTs issued a patient management decision based on SOC conventional imaging and clinical/laboratory data (excluding histology) | |
| Step 2: | After a minimum 4-week interval, MDTs reassessed the same cases, this time informed by the TLX250-CDx PET/CT imaging results and the same clinical/laboratory data10 |
Clinical management for each individual patient was determined by MDT consensus. Data will support Telix's planned marketing authorization application for TLX250-CDx in Europe.
About TLX250-CDx
TLX250-CDx is an investigational PET agent that is under development for the diagnosis and characterization of ccRCC. It works by specifically binding to carbonic anhydrase IX (CAIX), a validated target protein expressed on >95% of ccRCC cells11, to produce images with high tumor-to-background ratio and high intra- and inter-reader consistency. Telix's pivotal Phase 3 ZIRCON trial evaluating TLX250-CDx in 300 patients, of whom 284 were evaluable, met all primary and secondary endpoints, including showing 86% sensitivity and 87% specificity and a 93% positive predictive value (PPV) for ccRCC across three independent radiology readers12. Telix believes this demonstrated the ability of TLX250-CDx to reliably detect the clear cell phenotype and provide an accurate, non-invasive method for diagnosing and characterizing ccRCC.
For more on TLX250-CDx and Telix's theranostic kidney cancer program, click here.
TLX250-CDx has not received a marketing authorization in any jurisdiction.
About Telix Pharmaceuticals Limited
Telix is a biopharmaceutical company focused on the development and commercialization of therapeutic and diagnostic radiopharmaceuticals and associated medical technologies. Telix is headquartered in Melbourne, Australia, with international operations in the United States, United Kingdom, Brazil, Canada, Europe (Belgium and Switzerland), and Japan. Telix is developing a portfolio of clinical and commercial stage products that aims to address significant unmet medical needs in oncology and rare diseases. Telix is listed on the Australian Securities Exchange (ASX: TLX) and the Nasdaq Global Select Market (NASDAQ:TLX).
Visit www.telixpharma.com for further information about Telix, including details of the latest share price, ASX and U.S. Securities and Exchange Commission (SEC) filings, investor and analyst presentations, news releases, event details and other publications that may be of interest. You can also follow Telix on LinkedIn, X and Facebook
Telix Investor Relations (Global)
Ms. Kyahn Williamson
Telix Pharmaceuticals Limited
SVP Investor Relations and Corporate Communications
Email: [email protected]
Telix Investor Relations (U.S.)
Annie Kasparian
Telix Pharmaceuticals Limited
Director Investor Relations and Corporate Communications
Email: [email protected]
Media Contact
Eliza Schleifstein
917.763.8106 (Mobile)
[email protected]
| Legal Notices |
| Cautionary Statement Regarding Forward-Looking Statements. |
| You should read this announcement together with our risk factors, as disclosed in our most recently filed reports with the Australian Securities Exchange (ASX), U.S. Securities and Exchange Commission (SEC), including our Annual Report on Form 20-F filed with the SEC, or on our website. |
| The information contained in this announcement is not intended to be an offer for subscription, invitation or recommendation with respect to securities of Telix Pharmaceuticals Limited (Telix) in any jurisdiction, including the United States. The information and opinions contained in this announcement are subject to change without notification. To the maximum extent permitted by law, Telix disclaims any obligation or undertaking to update or revise any information or opinions contained in this announcement, including any forward-looking statements (as referred to below), whether as a result of new information, future developments, a change in expectations or assumptions, or otherwise. No representation or warranty, express or implied, is made in relation to the accuracy or completeness of the information contained or opinions expressed in the course of this announcement. |
| This announcement may contain forward-looking statements, including within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, that relate to anticipated future events, financial performance, plans, strategies or business developments. Forward-looking statements can generally be identified by the use of words such as "may", "expect", "intend", "plan", "estimate", "anticipate", "believe", "outlook", "forecast" and "guidance", or the negative of these words or other similar terms or expressions. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements are based on Telix's good-faith assumptions as to the financial, market, regulatory and other risks and considerations that exist and affect Telix's business and operations in the future and there can be no assurance that any of the assumptions will prove to be correct. In the context of Telix's business, forward-looking statements may include, but are not limited to, statements about: the initiation, timing, progress, completion and results of Telix's preclinical and clinical trials, and Telix's research and development programs; Telix's ability to advance product candidates into, enroll and successfully complete, clinical studies, including multi-national clinical trials; the timing or likelihood of regulatory filings and approvals for Telix's product candidates, manufacturing activities and product marketing activities; Telix's sales, marketing and distribution and manufacturing capabilities and strategies; the commercialization of Telix's product candidates, if or when they have been approved; Telix's ability to obtain an adequate supply of raw materials at reasonable costs for its products and product candidates; estimates of Telix's expenses, future revenues and capital requirements; Telix's financial performance; developments relating to Telix's competitors and industry; the anticipated impact of U.S. and foreign tariffs and other macroeconomic conditions on Telix's business; and the pricing and reimbursement of Telix's product candidates, if and after they have been approved. Telix's actual results, performance or achievements may be materially different from those which may be expressed or implied by such statements, and the differences may be adverse. Accordingly, you should not place undue reliance on these forward-looking statements. |
| Trademarks and Trade Names. All trademarks and trade names referenced in this press release are the property of Telix Pharmaceuticals Limited (Telix) or, where applicable, the property of their respective owners. For convenience, trademarks and trade names may appear without the ® or ™ symbols. Such omissions are not intended to indicate any waiver of rights by Telix or the respective owners. Trademark registration status may vary from country to country. Telix does not intend the use or display of any third-party trademarks or trade names to imply any affiliation with, endorsement by, or sponsorship from those third parties. |
| ©2025 Telix Pharmaceuticals Limited. All rights reserved. |
_____________________________
1 Brand name subject to final regulatory approval.
2 Positron emission tomography/computed tomography.
3 Zirconium in Renal Cancer Oncology, ClinicalTrials.gov ID: NCT03849118.
4 Evaluable patient population of 294 differs from main ZIRCON patient population of 284 since histology was not required in ZIRCON-X.
5 Telix ZIRCON-X SUO 2025 abstract, available at: https://suo-abstracts.secure-platform.com/a/gallery/rounds/24/details/4869
6 Telix ASX disclosure 1 July 2020. TLX250-CDx granted Breakthrough Therapy designation by U.S. FDA.
7 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
8 Each MDT comprised at least three board-certified physicians, one nuclear medicine physician and two urologists.
9 University of California, Los Angeles (U.S.); University Hospitals Leuven (Belgium); Royal Free London (United Kingdom); European Institute of Oncology (Italy).
10 MDTs did not have access to the Step 1 outcomes during the Step 2 reading.
11 Stillebroer et al. Eur Urol. 2010.
12 Telix ASX disclosures 7 November 2022. Shuch et al. Lancet Oncology. 2024.
