CytomX released dose‑expansion data showing varsetatug masetecan (varseta‑M), an EpCAM‑targeting masked ADC, produced a 32% overall response rate and median progression‑free survival of 7.1 months at the highest dose in metastatic colorectal cancer. The Probody‑based ADC results triggered a dramatic market reaction: shares spiked roughly 75% intraday before retreating over subsequent sessions as investors reassessed longer‑term prospects and commercial assumptions. Management and analysts pointed to the asset’s potential beyond third‑line colorectal cancer, with Jefferies projecting multi‑billion dollar upside if the ADC moves earlier in treatment and expands to other EpCAM‑expressing tumors. The company is pursuing aggressive development plans despite the earlier termination of a collaboration with Astellas. Investors will watch follow‑up cohorts, safety at higher doses, and confirmatory expansion data to judge whether the early efficacy signal can translate into durable clinical benefit and commercial value.