A Study of HER3-DXd in Subjects With Locally Advanced or Metastatic Solid Tumors

This study is designed to assess the safety and efficacy of HER3-DXd monotherapy in subjects with refractory locally advanced unresectable or metastatic solid tumors who have been previously treated with ≥1 prior line of systemic anticancer therapy. The primary objective of the study is to assess the efficacy of HER3-DXd monotherapy for each type of indicated locally advanced unresectable or metastatic tumor. Secondary objectives include the assessment of safety and tolerability, efficacy, and pharmacokinetics of HER3-DXd monotherapy for each type of indicated locally advanced unresectable or metastatic tumor. HER3 protein expression in tumor tissue and its relationship with HER3-DXd efficacy will also be evaluated.