Telix Completes Proof-of-Concept Study of TLX592 Targeted Alpha Therapy in Prostate Cancer

• CUPID is a Phase I safety and dosimetry study of TLX592, Telix’s investigational antibody-based targeted alpha therapy for prostate cancer.
• Establishes proof-of-concept for Telix’s proprietary RADmAb engineered antibody platform, currently under pre-clinical evaluation for multiple cancer targets.
• Initial results demonstrate rapid elimination from blood circulation compared to standard antibodies and hepatic (liver) clearance – both highly desirable characteristics for use with alpha emitting agents.
• Successful completion of mass dose escalation study establishes a baseline dosing schedule for future studies of TLX592 using actinium-225.
• Data is supportive of advancement to a therapeutic Phase I/II study in H2 2024.
  

MELBOURNE, Australia, May 21, 2024 (GLOBE NEWSWIRE) -- Telix Pharmaceuticals Limited (ASX: TLX, Telix, the Company) today announces the successful completion of CUPID¹, a first-in-human Phase I dose escalation study of TLX592 in patients with advanced prostate cancer.

TLX592 (²²⁵Ac-PSMA-RADmAb) is Telix’s investigational “next generation” targeted alpha therapy (TAT) for the treatment of prostate cancer and is the first clinical program to utilise Telix’s proprietary RADmAb engineered antibody technology. The RADmAb approach accelerates blood clearance and reduces bone marrow residence time compared with standard monoclonal antibodies (mAbs), while retaining target selectivity, internalisation and retention. The RADmAb platform is currently under pre-clinical and clinical evaluation for multiple cancer targets.

The CUPID (⁶⁴Cu PSMA Imaging and (Bio) Distribution) study is a 3+3 mass dose escalation study with four patient cohorts intended to evaluate the safety, tolerability, pharmacokinetics, biodistribution and radiation dosimetry of TLX592. The study utilises copper-64 (⁶⁴Cu) which is detectable by Positron Emission Tomography (PET) as a surrogate for actinium-225 (²²⁵Ac), enabling a successful proof-of-targeting study as well as predictive dosimetry calculations for future studies with ²²⁵Ac. Preliminary results in 11 evaluable patients enrolled in the study demonstrated accelerated blood kinetics compared to the standard antibody TLX591, while demonstrating similar (favourable) on-target and off-target biodistribution and hepatic clearance. There were no serious adverse events observed in the study.