TLX591-Tx ProstACT SELECT Study Published in Cancers Journal
Melbourne (Australia) and Indianapolis, IN (United States) | July 22, 2026
- Consistent with previously reported results[3], the publication highlights TLX591-Tx’s clinical differentiation and safety profile.
- TLX591-Tx, Telix’s lead PSMA-targeting rADC therapy candidate, is currently being evaluated in ProstACT Global Phase 3 study[4] for advanced metastatic prostate cancer.
Telix today announced publication of results from the ProstACT SELECT study in Cancers, a peer-reviewed journal. The Phase 1 study evaluated TLX591-Tx (lutetium-177 (177Lu) rosopatamab tetraxetan), Telix’s first-in-class prostate-specific membrane antigen (PSMA) targeting radio antibody-drug conjugate (rADC) therapy candidate. The study’s scientific purpose was to evaluate lesion concordance between 68Ga-PSMA-PET[5] and multi-time point SPECT[6] imaging for patient selection using a “theranostic” approach.
The publication highlights TLX591-Tx’s differentiated clinical profile, including an intensified dosing schedule, prolonged tumor retention and low exocrine (salivary) gland irradiation. The authors also concluded that in a heterogeneous population representative of a real-world setting, TLX591-Tx therapy in combination with standard of care (SOC) demonstrated a manageable and predictable safety profile, and indicative efficacy with a median radiographic progression-free survival (rPFS) of 8.8 months reported in evaluable patients.
Nat Lenzo, MD, Nuclear Medicine Oncologist and Principal Investigator on the ProstACT SELECT study commented, “A key objective of ProstACT SELECT was to determine whether PSMA-PET imaging could reliably identify patients suitable for TLX591-Tx therapy, and the results clearly support this approach. The results provide compelling evidence that the PSMA-PET imaging agent and TLX591-Tx are targeting the same disease sites, supporting the ongoing ProstACT Global trial for mCRPC[7], where there remains significant unmet need for additional treatment options.”
David N. Cade, MD, Group Chief Medical Officer, Telix, said, “The publication of ProstACT SELECT data further strengthens the scientific foundation for Telix’s lead therapeutic candidate, TLX591-Tx. The peer-reviewed results support our patient-selection strategy and demonstrate a differentiated pharmacologic profile characterized by durable tumor targeting, hepatobiliary clearance, and a manageable safety profile. Telix is further evaluating TLX591-Tx in the international multi-center Phase 3 ProstACT Global study, where we aim to meaningfully improve outcomes for patients living with advanced prostate cancer.”
The full paper is available at: https://www.mdpi.com/3989748
About ProstACT SELECT
The purpose of the ProstACT SELECT trial was to evaluate the utility of 68Ga-PSMA-PET imaging (Illuccix) to select patients for TLX591-Tx rADC therapy. The primary objectives were to determine whole body biodistribution and organ radiation dosimetry and assess the safety and tolerability of TLX591-Tx in patients with advanced mCRPC. rPFS was a secondary study objective.
TLX591-Tx has not received a marketing authorization in any jurisdiction
[1] ClinicalTrials.gov ID: NCT04786847.
[2] Lenzo et al. Cancers. 2026.
[3] Telix ASX disclosures October 19, 2023 and May 31, 2024.
[4] ClinicalTrials.gov ID: NCT06520345.
[5] Imaging of prostate-specific membrane antigen with positron emission tomography.
[6] Single-photon emission computed tomography.
[7] Metastatic castration-resistant prostate cancer.