TLX591-Tx (lutetium-177 (177Lu) rosopatamab tetraxetan) - (ProstACT SELECT)

July 22, 2026: Telix Pharmaceuticals Limited (ASX: TLX, NASDAQ: TLX) announced publication in the peer-reviewed journal Cancers of results from the Phase 1 ProstACT SELECT study (NCT04786847) evaluating TLX591-Tx (lutetium-177 rosopatamab tetraxetan), a PSMA-targeting radio antibody-drug conjugate candidate, in advanced metastatic castration-resistant prostate cancer (mCRPC). The study assessed whether gallium-68 PSMA-PET imaging (Illuccix) could reliably select patients for TLX591-Tx using a theranostic approach by evaluating lesion concordance between 68Ga-PSMA-PET and multi-time point SPECT imaging.

The publication reports TLX591-Tx’s differentiated profile (including intensified dosing schedule, prolonged tumor retention, and low salivary gland irradiation). In a heterogeneous, real-world-representative population, TLX591-Tx plus standard of care showed a manageable, predictable safety profile and “indicative efficacy,” with median radiographic progression-free survival of 8.8 months in evaluable patients. Telix stated TLX591-Tx is being evaluated in the ProstACT Global international Phase 3 study (NCT06520345) for advanced metastatic prostate cancer and has not received marketing authorization in any jurisdiction.