Zymeworks Soars 10.28% on FDA Clearance for Liver Cancer Drug

On July 28, 2025, Zymeworks' stock surged by 10.28% in pre-market trading, marking a significant rise that has caught the attention of investors and analysts alike.

Zymeworks has recently received FDA clearance for its investigational new drug application for ZW251, a novel glypican 3-targeted topoisomerase 1 inhibitor antibody-drug conjugate. This clearance is a significant milestone for the company, as it allows ZW251 to progress into clinical development. ZW251 is designed to selectively target GPC3, a protein expressed in over 75% of hepatocellular carcinoma (HCC) cases, which is the most common type of primary liver cancer. The drug's novel camptothecin payload and optimized antibody structure make it a promising candidate for treating liver cancer, with preclinical results showing potential efficacy in a high percentage of cases.

This development is particularly noteworthy as it represents Zymeworks' second antibody-drug conjugate to advance into clinical trials, utilizing the company's proprietary payload and optimized antibody technology. The Phase 1 trials for ZW251 are set to begin in 2025, and the company is optimistic about the drug's potential to address a significant unmet medical need in liver cancer treatment. The FDA's clearance of ZW251 underscores the company's commitment to innovation and its ability to develop cutting-edge therapies that target specific cancer biomarkers.