A Clinical Trial of the Safety and Anti-Tumor Activity of AB-201 in Subjects With Advanced HER2+ Solid Tumors

Inclusion Criteria:

* ECOG performance status 0 to 1.
* Histologically confirmed HER2 expressed breast or gastric/GEJ cancer IHC ≥ 2+ within 6 months prior to study entry.
* Confirmed diagnosis of an advanced/unresectable or metastatic HER2+ breast or gastric/GEJ cancer that is refractory to, or intolerable of standard treatment, or for which no standard treatment is available.
* Must have received prior cancer therapy: Subjects with breast cancer must have received ≥ 2 prior systemic therapies; subjects with gastric/GEJ cancer must have received ≥ 1 prior systemic therapy(ies); subjects with IHC 3+ or IHC 2+/ISH+ cancers must have received previous treatment with a HER2-targeting therapy.

Exclusion Criteria:

* Known past or current malignancy other than inclusion diagnosis.
* Known clinically significant cardiac disease.
* Active central nervous system (CNS) metastases, or involvement of the CNS, unless there is a history of at least 3 months of sustained remission.
* Unresolved toxicities from prior anticancer therapy.
* Ongoing uncontrolled systemic infections requiring antibiotic, anti-fungal, or anti-viral therapy.
* History of sensitivity or intolerance to cyclophosphamide or fludarabine.
* Pregnant or lactating females and subjects of both sexes who are not willing to practice birth control from the time of consent through 6 months after administration of the last AB-201 dose.
* Severe disease progression or health deterioration within 2 weeks prior to lymphodepletion regimen.