Clinical Trial of YH32367 in Patients With HER2 Positive Locally Advanced or Metastatic Solid Tumor

This first-in-human study will be counducted to evaluate the safety, tolerability, pharmacokinetics (PK) and anti-tumor activity of YH32367 in Patients with HER2-Positive Locally Advanced or Metastatic Solid Tumors.

YH32367, a novel HER2/4-1BB bispecific antibody (BsAb), simultaneously targets HER2 and h4-1BB and binds to both targets. YH32367 exhibits a strong 4-1BB signal activation as well as blocking of HER2 signaling in HER2-expressing tumor cells. YH32367 stimulates IFN-γ secretion from T cells and thereby induces tumor cells lysis. This is a Phase 1/2, open-label, multicenter, first-in-human study of YH32367. This 2-part study will include both a Dose Escalation part, to identify the Maximum Tolerated Dose (MTD) and/or two dose levels for RP2D selection, and a Dose Expansion part, to determine RP2D and to confirm the safety, tolerability and efficacy of YH32367 at the RP2D.

Inclusion Criteria: \[Dose Escalation Part\] * Pathologically confirmed HER2-positive * Mandatory provision of tumor tissue sample \[Dose Expansion Part\] * Patients who have at least one measurable lesion * Mandatory provision of tumor tissue sample 1. Cohort 1: Pathologically confirmed HER2-positive biliary tract cancer 2. Cohort 2: Pathologically confirmed HER2-positive metastatic solid tumor malignancy other than breast and gastric or gastroesophageal junction adenocarcinoma and biliary tract cancer Exclusion Criteria: * Uncontrolled central nervous system (CNS) metastases * Spinal cord compression * Carcinomatous meningitis * Acute coronary syndromes * Heart failure * Interstitial lung disease (ILD) * Pneumonitis * History of a second primary cancer * Human immunodeficiency virus (HIV) * Active chronic hepatitis B * Hepatitis C * Systemic steroid therapy * Autoimmune disease