GEN-001 in Combination With Avelumab for Patients With PD-L1 Positive Gastric Cancer

Inclusion Criteria:

1. Histologically confirmed unresectable, recurrent, locally advanced or metastatic GC/Gastroesophageal Junction Adenocarcinoma
2. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
3. Have adequate organ functions as defined in the protocol
4. Negative childbearing potential
5. Have experienced documented objective radiographic or clinical disease progression after 2 or above previous lines of standard therapy.
6. PD-L1 positive
7. Measurable disease as per RECIST v1.1 defined as at least 1 lesion
8. Estimated life expectancy of at least 3 months
9. Have ability to swallow and retain oral medication and no clinically significant gastrointestinal abnormalities

Exclusion Criteria:

1. Previously received T-cell coregulatory protein inhibitors
2. Has clinically significant evidence of ascites by physical exam
3. Known prior severe hypersensitivity reactions to monoclonal antibodies or any component in their formulation
4. Has active autoimmune disease that has required systemic treatment in the past 2 years
5. Current use of immunosuppressive medication
6. Have an active infection requiring antibiotics, antifungal or antiviral agents or have received a course of antibiotics within 4 weeks
7. Has received a live vaccine within 4 weeks
8. Known history or any evidence of active for non-infectious pneumonitis
9. Prior solid organ or allogeneic stem cell transplantation
10. Has had any investigational or anti-tumor treatment within 4 weeks or 5 half-life periods of starting study treatment, had any major surgeries within 4 weeks
11. Has received proton pump inhibitors (PPIs) within 2 weeks
12. Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
13. Has clinically significant (i.e., active) cardiovascular disease
14. Has other persisting toxicities
15. Has other severe acute or chronic medical conditions including immune colitis, inflammatory bowel disease, or psychiatric conditions