CytomX’s fast track in metastatic colorectal cancer is one of multiple recent signals that ADC developers are pushing advanced programs toward earlier regulatory engagement. Varsetatug masetecan’s dose-expansion outcomes—particularly the higher-dose response rates—support a development path aimed at registrational evaluation. The program’s Probody-style masking and local activation strategy is designed to limit off-tumor exposure and improve therapeutic index, while the EpCAM target focuses on a solid-tumor marker frequently elevated in colorectal cancer. Clinically, the fast track decision may shorten time-to-trial initiation for a confirmatory effort planned for 2027, contingent on continued safety management and the prophylaxis plan used to address treatment-related gastrointestinal events.