Anti-HER2 x HER2 ADC Overview

ZW49 is a bispecific anti-HER2 ADC that is based on the same antibody framework as ZW25 but armed with a cytotoxic payload. ZW49 retains the mechanisms of action of ZW25 but takes advantage of high levels of antibody-target internalization to deliver our proprietary ZymeLink™ cytotoxic payload. We are developing ZW49 for several indications characterized by HER2 expression including breast and gastric cancers that have progressed or are refractory to existing HER2-targeted therapies, and other HER2 expressing solid tumors.

For more information regarding the ongoing Phase 1 trial, please visit

ZW49 can potentially mediate its therapeutic effect on HER2-expressing tumors through a combination of mechanisms, including:

  • cross-linked trans HER2 binding and HER2 receptor clustering;

  • increased HER2-mediated antibody internalization leading to:

    • enhanced toxin-mediated cytotoxicity and tumor growth inhibition;

    • enhanced HER2 downregulation;

  • increased maximum binding density and potent effector-function mediated cytotoxicity; and

  • enhanced blockade of ligand-dependent and ligand-independent tumor growth.