• Acceptable safety and tolerability profile with no new safety signals
• Lesion dosimetry indicates no difference in absorbed dose profile across cohorts
• Hematologic events are transient and manageable, with similar rates of recovery

Telix Pharmaceuticals Limited (ASX: TLX, NASDAQ: TLX) today announces that Part 1 of the ProstACT Global Phase 3 study, the safety and dosimetry lead-in for its therapeutic candidate - TLX591-Tx (lutetium-177 (177Lu) rosopatamab tetraxetan) - has achieved its primary objectives, demonstrating an acceptable safety and tolerability profile with no new safety signals observed. Key findings include: Tolerability profile supported by dosimetry and low-grade non-hematologic events, lesion dosimetry indicates no difference in absorbed dose profile across cohorts, no adverse drug-drug interactions observed in TLX591-Tx combinations, and hematologic events are in line with expectations and transient and manageable, with similar rates of recovery across all patient cohorts. The results from Part 1 are consistent with prior clinical studies of this first-in-class lutetium radio antibody-drug conjugate (rADC) therapy. Part 1 of the study confirmed the safety profile, biodistribution and dosimetry of TLX591-Tx administered in two doses, 14 days apart, in combination with one of three standard of care (SOC) therapies: abiraterone, enzalutamide or docetaxel. The patient population comprised prostate-specific membrane antigen (PSMA) positive metastatic castration resistant prostate cancer (mCRPC) patients previously treated with one androgen receptor pathway inhibitor (ARPI). Telix has already advanced the study into Part 2 - a 2:1 randomized treatment expansion - in jurisdictions where the clinical trial has obtained approval from health authorities.

The results from Part 1 of the ProstACT Global Phase 3 study demonstrate an acceptable safety and tolerability profile for TLX591-Tx, a first-in-class lutetium radio antibody-drug conjugate (rADC) therapy, in combination with standard of care therapies for metastatic castration resistant prostate cancer (mCRPC) patients.

Telix plans to present the Part 1 data to the United States (U.S.) Food and Drug Administration (FDA) to seek an Investigational New Drug (IND) amendment to progress Part 2 of the ProstACT Global Phase 3 study in the U.S. Telix is also continuing to advance enrollment in Part 2 in regions where clinical trial initiation has already been approved.