Phase 3 trial launches of CAIX-targeted radiopharmaceutical for ccRCC

The first patient has been dosed in the pivotal phase 3 LUTEON trial (NCT07197580), evaluating the investigational CAIX-targeting radionuclide therapy lutetium-177 (¹⁷⁷Lu) girentuximab tetraxetan (TLX250-Tx) in patients with relapsed or recurrent clear cell renal cell carcinoma (ccRCC), Telix announced.¹

According to the company, this marks the first radiopharmaceutical to enter phase 3 development in ccRCC. The first participant in the study was treated at GenesisCare Murdoch in Western Australia under the supervision of principal investigator Aviral Singh, MD, PGDipCard, MSc, FAfNM, FRACP.

“Dosing the first patient in the LUTEON study marks an important milestone in the development of potential new treatment options for patients with relapsed or recurrent clear cell renal cell carcinoma,” said Singh, who serves as the clinical head of theranostics and nuclear medicine at GenesisCare Murdoch, in the news release.¹ “Despite advances in care, outcomes remain poor for many patients, underscoring the need for innovative therapeutic approaches. This study will play a critical role in evaluating the safety, tolerability, and efficacy of this investigational CAIX-targeted radiopharmaceutical for patients globally, and we look forward to helping advance the clinical evidence for this promising therapeutic candidate.”

How is the LUTEON trial designed?

LUTEON is a randomized, open-label, multicenter study evaluating ¹⁷⁷Lu-girentuximab tetraxetan in adult patients with advanced, relapsed, or recurrent CAIX-expressing ccRCC.² The study incorporates patient selection using the investigational PET imaging agent zirconium-89 girentuximab senvedoxam (TLX250-Px; Zircaix), which is intended to identify patients with CAIX-positive tumors before treatment.

To be eligible for enrollment, patients must have an ECOG performance status of 0 or 1, have received at least 2 and no more than 3 lines of prior systemic therapy for locally advanced or metastatic ccRCC, and have experienced radiographic disease progression during or after the most recent line of therapy.

The study includes an initial dose-optimization component followed by a randomized comparison of the recommended phase 3 dose vs investigator's choice of monotherapy consistent with standard-of-care in Australia. Part 1 of the study is expected to enroll up to 40 patients.³

The primary efficacy end point for the comparative portion of the study is median progression-free survival, with safety and tolerability as key objectives throughout the trial. Investigators will also assess overall survival, objective response rate, and duration of response, among other measures, as secondary end points.

Primary completion of the study is expected in 2027.

The ongoing global development program for TLX250-Tx also includes the phase 2a LUTEON ATLAS study in the US and Europe, which is evaluating the agent in parallel with the Australian-led phase 3 program.

REFERENCES

1. Telix doses first patient in phase 3 LUTEON trial of TLX250-Tx for renal cancer. News release. Telix Pharmaceuticals. July 20, 2026. Accessed July 21, 2026. https://telixpharma.com/news-views/telix-doses-first-patient-in-phase-3-luteon-trial-of-tlx250-txfor-renal-cancer/

2. Phase 3 study to assess safety and efficacy of 177Lu-TLX250 in advanced relapsed or recurrent ccRCC (LUTEON). ClinicalTrials.gov. Last updated April 1, 2026. Accessed July 21, 2026. https://clinicaltrials.gov/study/NCT07197580

3. Telix Q2 2026 revenue US$247M, strong momentum and pipeline progress. News release. Telix Pharmaceuticals. July 21, 2026. Accessed July 21, 2026. https://telixpharma.com/news-views/telix-q2-2026-revenue-us247m-strong-momentum-and-pipeline-progress/