Clinical Study to Evaluate the Safety and Anti-Tumor Activity of AB-201

Inclusion Criteria

• •1. Signed informed consent.
• •2. Males or females ≥ 19 years of age at the time of informed consent.
• •3. The ECOG performance status 0 to 1.
• •4. Patients with an expected survival of at least 3 months
• •5. Histologically confirmed HER2-expressed gastric/GEJ cancer ≥IHC 1+ within 36 months prior to study entry.
• •6. Confirmed diagnosis (pathologically documented) of an advanced/unresectable or metastatic HER2+ gastric/GEJ cancer that is refractory to, or intolerable of standard treatment, or for which no standard treatment is available.
• •7. Prior cancer therapies per the National Comprehensive Cancer Network (NCCN) guidelines
• •1. Subjects with gastric/GEJ cancer must have received ≥ 2 prior systemic therapy(ies)
• •2. Subjects with IHC 3+ or IHC 2+/ISH+ cancers must have received previous treatment with a HER2-targeting therapy
• •3. If the investigator determines no standard treatment remains
• •8. Has adequate treatment washout period prior receiving AB-201, defined as:
• •* Major surgery ≥ 4 weeks
• •* Radiation therapy ≥ 4 weeks (if palliative stereotactic radiation therapy without abdominal, ≥ 2 weeks)
• •* Autologous transplantation ≥ 3 months
• •* Chemotherapy (including antibody-drug therapy) ≥ 3 weeks (≥ 2 weeks for 5-fluorouracil-based agents, folinate agents and/or weekly paclitaxel. ≥ 6 weeks for nitrosoureas or mitomycin C, \> 1 week for TKIs approved for the treatment of breast or gastric/GEJ cancers - baseline computed tomography (CT) scan must be completed after discontinuation of TKI)
• •* Hormonal therapy ≥ 3 weeks
• •* Immunotherapy ≥ 4 weeks
• •9. Measurable disease or non-measurable but evaluable disease according to RECIST v1.1, as assessed by computed tomography (CT) or magnetic resonance imaging (MRI), with at least one measurable or non-measurable but evaluable lesion.
• •10. Oxygen saturation via pulse oximeter ≥ 92% at rest on room air
• •11. Left ventricular ejection fraction (LVEF) ≥ 50% and no evidence of pericardial effusion as determined by an echocardiogram (ECHO)/multigated acquisition (MUGA) scan
• •12. Baseline laboratory values fulfilling the following requirements to demonstrate adequate hematologic, renal, and hepatic function:
• •* Absolute neutrophil count (ANC) ≥ 1000/mm3 (1.0 × 109/L)
• •* Platelets (PLT) ≥ 75000/mm3 (75 × 109/L)
• •* Hemoglobin ≥ 8.0 g/dL (transfusions are allowed up to 2 weeks prior to the first AB-201 dose and, as needed, during the treatment period.)
• •* Creatinine clearance ≥ 45 mL/min using the Cockcroft-Gault equation, or an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73m2 per Modification of Diet in Renal Disease (MDRD) equation
• •* Total serum bilirubin \< 2.5 mg/dL (\< 5 mg/dL for subjects with known Gilbert's Syndrome)
• •* Liver transaminases (AST/ALT/ALP) ≤ 3 × ULN; subjects with liver metastases may have AST, ALT, and ALP ≤ 5 × ULN
• •5. Ongoing uncontrolled systemic infections requiring antibiotic, anti-fungal, or anti-viral therapy.
• •7. Live vaccine administration planned or required during the treatment period of the trial.
• •8. History of sensitivity or intolerance to cyclophosphamide or fludarabine.
• •9. Female subjects of childbearing potential, unable or unwilling to use appropriate contraception (e.g., any combination of condom, diaphragm, intrauterine devices \[IUDs\], and hormonal oral contraceptives or male partner vasectomy) for the duration of the trial and for 6 months following the last dose of AB-201.
• •Male subjects must be sterile (biologically or surgically) or commit to the use of a highly effective method of contraception (any approved combination of physical or chemical methods) until at least 6 months following administration of the last AB-201 dose.)
• •10. Currently pregnant or lactating (breast feeding must not be started within 6 months of the last dose of AB 201).
• •11. Any other considerations that might interfere with the assessment of safety or efficacy, or that the investigator deems inappropriate for inclusion.
• •12. History or presence of a clinically relevant CNS disorder such as seizure disorder (e.g., epilepsy), cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, cerebral edema, posterior reversible encephalopathy syndrome (PRES), or any autoimmune disease with CNS involvement.
• •13. Any medical, psychological, familial, or sociological conditions that, in the opinion of the Investigator or Sponsor Medical Monitor, would impair the ability of the subject to receive study treatment or comply with study requirements, including understanding and granting informed consent.
• •14. Severe disease progression or health deterioration within 2 weeks prior to lymphodepletion regimen that, in the opinion of the Investigator, could impair the ability of the subject to receive study treatment or comply with study requirements.
• •15. Subjects who have undergone organ transplantation
• •16. Subjects with a history of receiving one or more immune cell therapy.