Study of ACTR T Cell Product in Combination With Trastuzumab in Subjects With HER2-Positive Advanced Solid Tumor Cancers

Inclusion Criteria:

- Signed written informed consent obtained prior to study procedures

- Histologically-confirmed Her2 positive advanced solid tumor malignancy with documented
disease progression during or immediately following the immediate prior therapy, or
within 6 months of completing adjuvant therapy for subjects with breast cancer

- Subjects must have previously received adequate standard therapy for treatment of
their malignancy

- For those with metastatic breast cancer, must have received HER2-directed therapy
including trastuzumab, pertuzumab and ado-trastuzumab in any breast cancer
disease setting

- For those with advanced gastric cancer, adequate prior treatment with
HER2-directed chemotherapy is required

- At least 1 measurable lesion by iRECIST

- Able to provide fresh tumor biopsy or archived block specimen taken since time of most
recent anti-HER2 mAb-directed therapy

- ECOG of 0 or 1

- Life expectancy ≥ 6 months

- LVEF ≥ 50% by MUGA or ECHO

- Absolute neutrophil (ANC) count ≥ 1500/ µL

- Platelet count ≥ 100,000/µL

- Hemoglobin ≥ 9g/dL

- Estimated GFR >30mL/min/1.73m2

Exclusion Criteria:

- glioblastoma multiforme or other primary CNS tumors are excluded

- clinically significant cardiac disease

- clinically significant active infection

- clinical history, prior diagnosis, or overt evidence of autoimmune disease

- current use of more than 5mg/day of prednisone (or an equivalent glucocorticoid)

- Prior treatment as follows:

- prior cumulative doxorubicin dose greater than or equal to 300 mg/m^2 or
equivalent

- chemotherapy within 2 weeks of enrollment

- external beam radiation within 2 weeks of enrollment (28 days if CNS-directed
therapy)

- any monoclonal antibody (mAb) or other protein therapeutic containing Fc-domains
within 4 weeks of enrollment

- pertuzumab within 4 months of enrollment

- Experimental agents within 3 half-lives or 28 days prior to enrollment, whichever
is shorter

- allogeneic hematopoietic stem cell transplant (HSCT)

- prior infusion of a genetically modified therapy

- Pregnant or breastfeeding