MELBOURNE, Australia, and INDIANAPOLIS, Ind., July 21, 2026
Telix Pharmaceuticals announced that the first patient has been dosed in the Phase 3 LUTEON clinical trial evaluating TLX250-Tx (lutetium-177 girentuximab tetraxetan) for the treatment of relapsed or recurrent clear cell renal cell carcinoma (ccRCC). The milestone marks the launch of the first Phase 3 clinical study of a CAIX-targeted radiopharmaceutical therapy in ccRCC, representing a major advancement in precision oncology for kidney cancer. The randomized, prospective, open-label, multicenter trial will evaluate the safety, tolerability, and efficacy of TLX250-Tx in patients with recurrent disease. The first participant was treated at GenesisCare Murdoch in Western Australia, initiating Telix’s global late-stage clinical development program for its investigational targeted radiopharmaceutical therapy.
LUTEON Evaluates First Phase 3 CAIX-Targeted Radiopharmaceutical Therapy
The LUTEON Phase 3 trial is designed to investigate TLX250-Tx, a first-in-class CAIX-targeted radiopharmaceutical antibody-drug conjugate (rADC) that combines a highly specific monoclonal antibody with the therapeutic radionuclide lutetium-177. The therapy is designed to recognize carbonic anhydrase IX (CAIX), a protein expressed in more than 95% of clear cell renal cell carcinoma tumors while showing minimal expression in normal tissues, including healthy kidney tissue. By selectively binding to CAIX-positive cancer cells, TLX250-Tx delivers targeted radiation directly to tumor sites, aiming to maximize anti-tumor activity while limiting radiation exposure to surrounding healthy tissue. Patient selection for the study is guided by TLX250-Px (Zircaix®), Telix’s investigational zirconium-89 PET imaging agent, which identifies patients with CAIX-positive tumors suitable for targeted therapy.
Global Development Program Expands Precision Radiopharmaceuticals
The LUTEON trial forms a key component of Telix’s broader global clinical development strategy for TLX250-Tx. While the Australian study operates under a Phase 3 protocol, it complements the Phase 2a LUTEON ATLAS study currently underway in the United States and Europe, collectively supporting the clinical evaluation of the therapy across multiple regions. Investigators will assess whether targeted delivery of lutetium-177 can improve treatment outcomes for patients with relapsed or recurrent ccRCC, a disease that continues to present significant therapeutic challenges despite advances in surgery, immunotherapy, and targeted therapies. Successful results could establish TLX250-Tx as one of the first targeted radiopharmaceutical treatment options specifically developed for advanced kidney cancer.
Advertisement
TLX250-Tx Addresses Significant Unmet Need in Kidney Cancer
Clear cell renal cell carcinoma is the most common subtype of kidney cancer, accounting for approximately 85% of renal cell carcinoma cases, while renal cell carcinoma itself represents nearly 90% of all kidney cancer diagnoses. A substantial proportion of patients present with metastatic disease or experience disease recurrence following initial treatment, resulting in poor long-term outcomes and limited therapeutic options. Through its CAIX-targeted precision radiopharmaceutical approach, TLX250-Tx aims to improve treatment specificity by delivering radiation directly to cancer cells while reducing off-target toxicity. The initiation of the Phase 3 LUTEON trial represents an important milestone for Telix Pharmaceuticals as it advances its pipeline of precision radiopharmaceutical therapies designed to address difficult-to-treat cancers and expand the role of targeted nuclear medicine in oncology.
Source: Telix Pharmaceuticals press release
