DESTINY-PANTUMOUR04

Inclusion Criteria:

1. Adults aged ≥18 years
2. Patients with locally advanced, unresectable, or metastatic HER2-positive (IHC 3+) solid tumors who have received prior systemic treatment for metastatic or advanced disease and have no satisfactory alternative treatment options as determined by the Investigator (see Exclusion Criterion 1 for excluded solid tumors);
3. A clinician decision has been made for treatment with T-DXd in accordance with the FDA label;
4. HER2-positive (IHC 3+) by local testing prior to study enrolment at the time of signed and dated informed consent;
5. Patients who are willing and able to provide a signed and dated informed consent.

Exclusion Criteria:

1. Primary diagnosis of adenocarcinoma of the breast, adenocarcinoma of the colon or rectum, NSCLC, adenocarcinoma of the gastric body or gastroesophageal junction or hematological malignancies;
2. Prior T-DXd therapy;
3. Patients without a baseline assessment of tumor burden undertaken prior to initiating T-DXd.
4. Patient is participating in a clinical trial at time of enrolment