Study of T-DXd Monotherapy in Patients With HER2-expressing Locally Advanced or Metastatic Gastric or GEJ Adenocarcinoma Who Have Received 2 or More Prior Regimens

A Single-arm Study of Trastuzumab Deruxtecan (T-DXd) Monotherapy for Patients With HER2-expressing Locally Advanced or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma Who Have Received 2 or More Prior Regimens (DESTINY-Gastric06)

This is a Phase II, open-label, single-arm, multicentre, study in China assessing the efficacy and safety of T-DXd in participants with HER2-expressing advanced gastric or GEJ adenocarcinoma who have received at least 2 prior regimens including a fluoropyrimidine agent and a platinum agent

Inclusion Criteria:

1. Male or female ≥ 18 years of age
2. Pathologically documented gastric or GEJ adenocarcinoma
3. Disease progression on or after ≥ 2 prior platinum and fluoropyrimidine agents for advanced/metastatic disease
4. ECOG PS 0-1
5. Willing and able to provide an adequate newly-acquired tumour sample for confirmation of HER2 status
6. LVEF ≥ 50%

Exclusion Criteria:

1. Pleural effusion, ascites or pericardial effusion that requires drainage, peritoneal shunt, or Cell-free and CART. Drainage and CART.
2. Spinal cord compression or brain metastases unless asymptomatic, stable, and not requiring steroids
3. Active primary immunodeficiency, known HIV, active HBV, HCV infection.
4. Uncontrolled infection requiring IV antibiotics, antivirals, or antifungals.
5. History of non-infectious pneumonitis/ILD, current ILD, or where suspected ILD that cannot be ruled out by imaging at screening.
6. Lung-specific intercurrent clinically significant severe illnesses.