Telix Pharmaceuticals (ASX: TLX) has successfully completed CUPID, a first-in-human Phase I dose escalation study of TLX592 in patients with advanced prostate cancer.
TLX592 is Telix’s investigational “next generation” targeted alpha therapy for the treatment of prostate cancer and is the first clinical programme to utilise the company’s proprietary RADmAb engineered antibody technology.
The RADmAb approach accelerates blood clearance and reduces bone marrow residence time compared with standard monoclonal antibodies , while retaining target selectivity, internalisation and retention. The RADmAb platform is currently under pre-clinical and clinical evaluation for multiple cancer targets.
The CUPID study is a 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 which is detectable by Positron Emission Tomography as a surrogate for actinium-225 (225Ac), enabling a successful proof-of-targeting study as well as predictive dosimetry calculations for future studies.
Preliminary results in 11 evaluable patients enrolled in the study demonstrated accelerated blood kinetics compared to the standard antibody TLX591, while demonstrating similar on-target and off-target biodistribution and hepatic clearance. There were no serious adverse events observed in the study.
Based on these encouraging results, Telix expects to advance TLX592 into a therapeutic Phase I/II study with 225Ac in the second half of 2024, subject to regulatory approval.
“The CUPID study demonstrated clearly how theranostic approaches can be used to streamline novel radiopharmaceutical drug development. In this case, PET imaging was used to dose-find a targeting agent for future use with an alpha emitter, while establishing basic safety and utility parameters that will greatly inform ongoing development of this product candidate,” Group Chief Medical Officer, Dr David Cade, said.
“There is a significant unmet need for novel targeting platforms that may be used with alpha emitting isotopes and avoid renal toxicity and other off-target effects, such as the exocrine gland uptake typical of PSMA small molecule agents. We are excited to progress TLX592 into therapeutic studies where our aim is to develop this agent for both early metastatic prostate cancer and late-stage patients who are no longer responding to lutetium therapy their commitment to the CUPID study.”
