TLX591 is an investigational anti-PSMA[1] radio-antibody-drug conjugate (rADC) therapy being developed for the treatment of mCRPC, differentiated by a short two-week dosing regimen.
Reported median radiographic progression-free survival (rPFS) is 8.8 months.
Builds on prior data from the ProstACT SELECT[2] trial, demonstrating favourable safety profile and biodistribution[3].
The study has reported a median rPFS of 8.8 months, representing an encouraging signal of the potential efficacy of TLX591 in this patient population. The evaluable sample size for rPFS comprised 23 patients with previously treated, progressive mCRPC and who received two 76 mCi intravenous (IV) infusions of TLX591, 14 days apart[5]. The SELECT trial included a heterogeneous population of low, medium and high disease burden patients to facilitate imaging cross-comparison, with the majority having undergone two prior lines of therapy.
TLX591 is being further evaluated in the Phase III ProstACT GLOBAL trial in first and second line mCRPC, which is now preparing to enrol patients at its first U.S. sites. This innovative trial design allows physicians a choice of androgen receptor inhibition or docetaxel chemotherapy, thus integrating with real-world standard of care, reflective of Telix’s continued innovation in prostate cancer care and commitment to patient outcomes.
TLX591 (INN: lutetium Lu 177 rosopatamab tetraxetan) is Telix’s lead investigational radio antibody-drug conjugate (rADC) for the treatment of mCRPC, composed of a high-specificity PSMA-targeting antibody, chelator linker, and cytotoxic lutetium (177Lu) payload. TLX591 is administered intravenously under a two-dose fractionated regimen, potentially enabling the delivery of a highly targeted and potent dose with improved off-target organ radiation exposure. The mAb-based approach may offer distinct advantages in selectivity, internalisation, and retention time over small molecule RLTs for the treatment of mCRPC.
A total of 242 patients have been treated with TLX591 across eight Phase I and Phase II trials9 including a previously published Phase II (open-label, single-arm) trial, which reported a 42.3 month OS in 17 patients with advanced mCRPC when TLX591 was delivered under a fractionated dosing regimen[10].
https://clinicaltrials.gov/study/NCT04786847
