Study launches exploring novel PSMA-targeted agent TLX592 in prostate cancer

The first patient has been dosed in the phase 1 CUPID study exploring TLX592 in patients with advanced prostate cancer, according to Telix, the manufacturer of the novel PSMA-targeted agent.1

“TLX592 is being developed as a PSMA-targeting antibody to be radiolabeled with a therapeutic radioisotope for the treatment of PSMA-expressing tumors,” according to the clinicaltrials.gov description of the trial.2 In the CUPID study (NCT04726033), the radioisotope being used is 64Cu and in future studies it will be 225Ac, according to Telix.

The trial is enrolling patients with biochemically recurrent prostate cancer, metastatic or locally advanced adenocarcinoma of the prostate. Patient tumors must express PSMA as identified by 68Ga-PSMA-11 or 18F-DCFPyl PSMA PET/CT scanning.

The targeted enrollment is 15 patients. The primary outcome measures are safety, tolerability, pharmacokinetics, biodistribution, and radiation dosimetry of TLX592. The estimated primary completion date is November 30, 2021.

“The initiation of the phase 1 CUPID PET imaging study represents a significant milestone in the development of next generation alpha particle treatments, a promising new frontier in nuclear medicine, with the potential to significantly improve outcomes for patients. The very high energy, short range properties of targeted alpha therapy have the potential to offer a potent and highly selective anti-cancer therapy to patients with advanced prostate cancer,” Nat Lenzo, BSc, BMedSci(Hons), MBBS MSc(Oncol), MMed, principal investigator for the CUPID study, stated in a press release.

TLX591-CDx

Telix’s lead product is TLX591-CDx (Illumet), a radiopharmaceutical cold kit for the preparation of 68Ga-PSMA-11 injection, which is used for PET imaging in prostate cancer. The FDA is currently reviewing a new drug application (NDA) for TLX591-CDx.

The NDA is supported by clinical results with TLX591-CDx accrued from more than 600 patients enrolled across several prospective and retrospective trials. Peer-reviewed research with TLX591-CDx has also been successfully conducted at several major academic centers, including the Peter MacCallum Cancer Centre in Australia, the University of California, and Heidelberg University Hospital in Germany.

PET imaging with 68Ga-PSMA-11 PET has been shown to trigger major changes in the management of biochemically recurrent prostate cancer. Findings from a prospective, single-arm trial presented during the 2020 European Association of Urology Virtual Congress showed that in a cohort of 136 patients, referring physicians implemented 68Ga-PSMA-11 PET­–based recommended management changes in 72% (n = 98) of patients.3 68Ga-PSMA-11 PET also led to the prevention of unnecessary diagnostic tests and a decline in the proportion of patients with unknown sites of disease.

References

1. First Patient Dosed in CUPID Study of Telix’s Targeted Alpha Therapy Candidate for Prostate Cancer. Published online August 5, 2021. Accessed August 5, 2021. https://bit.ly/3Ci8KZH.

2. NIH ClinicalTrials.gov. 64Cu-TLX592 Phase I Safety, PK, Biodistribution and Dosimetry Study (CUPID Study) (CUPID). https://clinicaltrials.gov/ct2/show/NCT04726033.

3. Ferdinandus J, Fendler WP, Calais J, et al. Impact of 68Ga-PSMA-11 PET on the management of biochemically recurrent prostate cancer in a prospective single-arm clinical trial. 2020 European Association of Urology Virtual Congress. July 17-26, 2020. Abstract 800.