CytomX won FDA Fast Track designation for varsetatug masetecan (CX-2051), an EpCAM-directed masked ADC for relapsed or refractory metastatic colorectal cancer. The agency’s action follows phase 1 dose-expansion data from CTMX-2051-101, with dose-dependent objective response rates reaching 32% at 10 mg/kg. The company is preparing a potential monotherapy registrational study for mid-2027. Fast Track status may accelerate review timelines, with the next gate focusing on durability, safety profile, and confirmation of clinical benefit across a broader R/R mCRC population.