HER3 is expressed in more than 80% of EGFR-mutant NSCLC, and overexpression is associated with poor outcomes, but no HER3-targeted drugs have been approved to date.

A mid-stage trial of Daiichi Sankyo's HER3-targeting antibody-drug conjugate patritumab deruxtecan has hit the mark and will form the basis of regulatory filings for the drug later this year.