225Ac-PSMA-617 is the next generation of prostate cancer treatment following the therapeutic success of 177Lu-Vipivotide tetraxetan.

By end of 2021, several hundredths of patients had been treated with 225Ac-PSMA-617. A study published in July 2016 reported the first results with two specific patients. 68Ga-PSMA-11 PET/CT validated the presence of the PSMA-positive tumor phenotype.  At time of publication, follow up was 23 months post treatment. Post treatment follow up for some patients reaches now 4+ years.

A prospective early Phase I clinical trial was initiated in China in January 2020 with a drug called 225Ac-PSMA (it is not clear which form of PSMA Vector was used, but there is a high probability that this drug is the same PSMA-617 derivative). This study was completed by end of 2021. South African data were published in February 2022. In this series of 53 patients, treatment with 225Ac-PSMA-617 resulted in a > 50% decrease in PSA level in 91% of the patients. Median OS of those patients with a PSA decline > 50% was not yet reached at the date of latest follow-up (55 months).

More recent clinical data have shown very interesting results in the tandem therapy combining lower doses of 177Lu-PSMA-617 and 225Ac-PSMA-617.

Target/Mechanism: PSMA

Carrier/Ligand: Vipivotide

Radiation Type: alpha particle (α)