actinium-225 PSMA I&T

Actinium-225 PSMA I&T is an investigational radiopharmaceutical designed for Targeted Alpha Therapy (TAT) in patients with metastatic castration-resistant prostate cancer (mCRPC). It consists of the alpha-emitting radioisotope actinium-225 conjugated to the PSMA I&T (Imaging and Therapy) ligand, a peptidomimetic that binds with high affinity to the extracellular domain of Prostate-Specific Membrane Antigen (PSMA). PSMA is significantly overexpressed on the surface of prostate cancer cells, particularly in advanced and metastatic stages. Upon binding and subsequent internalization into the tumor cell, the actinium-225 isotope undergoes alpha decay, releasing high-energy alpha particles. These particles have a very short path length (50-100 μm), allowing for the delivery of a highly localized and lethal radiation dose that induces complex double-strand DNA breaks, leading to cell death while minimizing damage to adjacent healthy tissues. This modality is being explored as a potent alternative or follow-up to beta-emitting radiopharmaceuticals like Lutetium-177 PSMA-617, especially in cases of resistance or high tumor burden.

Other names

Actinium-225 PSMA Imaging and TherapyActinium225 PSMA Imaging and TherapyActinium 225 PSMA Imaging and Therapy[225Ac]-DOTAGA-PSMA-I&T