Inclusion Criteria:

* Age: ≥18 years of age
* Histologically or cytologically confirmed diagnosis of HER-2 positive solid tumor as defined in the protocol
* Part 1: presence of advanced or metastatic disease that has progressed during or following previous treatment
* Part 2: Early stage HER-2 positive cancers with high risk for relapse following completion of SOC or after neoadjuvant systemic treatment
* AAV specified capsid total antibody ≤1:400
* ECOG performance status of 0 or 1
* Life expectancy ≥3 months
* Protocol-specified ranges for renal, liver, cardiac and pulmonary function
* Protocol-specified ranges for hematology parameters

Exclusion Criteria:

* Hepatoxicity (AST or ALT > 2x upper limit of normal)
* Known active CNS or leptomeningeal disease
* History of thrombotic microangiopathy or cardiomyopathy, or evidence of sensory neuropathy
* Pregnant or nursing (lactating) women
* History of other malignancy within 5 years prior to screening as defined in protocol
* History of hypersensitivity to corticosteroids or history of corticosteroid-related toxicity Concurrent anti-cancer treatment in another investigational trial

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 11/17/2025. Questions regarding updates should be directed to the study team contact.