A small-molecule pretargeting approach for PSMA-targeted conjugates

Abstract

We developed pretargeting approach for the targeted delivery of molecular payloads to prostate cancer cells expressing the hallmark enzyme-biomarker, prostate-specific membrane antigen (PSMA). We employed a phosphoramidate-based PSMA ligand (CTT1298) with a click-ready DBCO group for strain-promoted azide-alkyne cycloaddition (SPAAC) and used 6-FAM-Azide as a model payload. PSMA+ cells were treated with a fluorescent PSMA-targeted probe (FAM-C6–1298), confirming delivery and accumulation. Further, live-cell experiments with DBCO-C6–1298 and 5-FAM-azide demonstrated selective pretargeted delivery. These results validate the feasibility of this pretargeting strategy in PSMA+ cells, suggesting its potential for preclinical applications with therapeutic and diagnostic payloads, enhancing the specificity and safety of prostate cancer treatments.