CTT1401

CTT1401 is an experimental 177Lu-labeled small-molecule radiotherapeutic that targets prostate-specific membrane antigen (PSMA) using an irreversible phosphoramidate-based PSMA inhibitor scaffold derived from CTT1298 and linked to a DOTA chelator via click chemistry to deliver beta-emitting lutetium-177 to PSMA-expressing cells.[1][7] In preclinical PC3-PIP prostate cancer xenograft models, CTT1401 showed high, PSMA-mediated uptake and rapid internalization into PSMA-positive cells, favorable tumor-to-blood and tumor-to-muscle ratios, but relatively rapid blood clearance due to lack of an albumin-binding moiety compared with its analog CTT1403, translating into only minimal tumor growth inhibition and a modest, non-significant survival benefit over saline controls at the tested single-dose regimen.[1][7] The agent has been developed preclinically by Cancer Targeted Technology as part of a PSMA-targeted radiotherapeutic platform for prostate cancer, but subsequent clinical development has focused on the improved albumin-binding analog CTT1403 rather than CTT1401.[1][7][12]