Telix Completes TLX592 Prostate Cancer Therapy Study

Telix Pharmaceuticals Limited recently announced the successful completion of the CUPID Phase I safety and dosimetry study for TLX592, an investigational antibody-based targeted alpha therapy designed to treat advanced prostate cancer. This study marks a significant milestone for Telix's proprietary RADmAb® engineered antibody platform, which is under pre-clinical evaluation for various cancer targets.

The initial findings from the CUPID study indicate that TLX592 exhibits rapid clearance from blood circulation and liver clearance, which are considered advantageous characteristics for therapies involving alpha-emitting agents. This successful dose escalation study has established a baseline dosing schedule for future research involving TLX592 with actinium-225. The data from this study supports advancing to a therapeutic Phase I/II study in the second half of 2024, pending regulatory approval.

The CUPID study utilized a 3+3 mass dose escalation design with four patient cohorts to evaluate the safety, tolerability, pharmacokinetics, biodistribution, and radiation dosimetry of TLX592. Copper-64 (64Cu) was used in the study as a proxy for actinium-225 (225Ac), detectable by Positron Emission Tomography (PET), enabling proof-of-targeting and predictive dosimetry for future studies. The preliminary results in 11 evaluable patients revealed that TLX592 demonstrated faster blood clearance compared to the standard antibody TLX591, with similar favorable on-target and off-target biodistribution and hepatic clearance. Notably, no serious adverse events were recorded during the study.

Dr. David N. Cade, Group Chief Medical Officer at Telix, highlighted the significance of the CUPID study in showcasing how theranostic approaches can streamline the development of novel radiopharmaceutical drugs. In this case, PET imaging was utilized to identify a targeting agent for future use with an alpha emitter while establishing basic safety and utility parameters that will inform the ongoing development of this product candidate.

Telix plans to advance TLX592 into therapeutic studies aimed at addressing early metastatic prostate cancer and late-stage patients unresponsive to lutetium therapy. This progress is expected to further enhance Telix's PSMA-targeting prostate cancer therapy portfolio, complementing its lead investigational radio antibody-drug conjugate TLX591, which is currently under investigation in the ProstACT GLOBAL Phase III study.

Telix Pharmaceuticals Limited, headquartered in Melbourne, Australia, is focused on developing diagnostic and therapeutic radiopharmaceuticals and associated medical devices. The company operates internationally, including in the United States, Europe, and Japan, and is listed on the Australian Securities Exchange.

Telix's lead imaging product, gallium-68 (68Ga) gozetotide injection, has received approval from the U.S. Food and Drug Administration (FDA), the Australian Therapeutic Goods Administration (TGA), and Health Canada. However, no other Telix product has received marketing authorization in any jurisdiction to date.

The company is committed to advancing its clinical and commercial stage products to address significant unmet medical needs in oncology and rare diseases. Telix intends to present non-clinical and clinical data supporting the CUPID study results at upcoming symposia.

Telix Pharmaceuticals emphasizes the importance of novel targeting platforms for alpha-emitting isotopes that avoid renal toxicity and other off-target effects, such as the exocrine gland uptake typical of PSMA small molecule agents. The company expresses gratitude to all participants involved in the CUPID study for their commitment.