Inclusion Criteria:
1. Age 18 or older.
2. Patients have newly diagnosed and previously untreated, histologically or radiologically confirmed hepatocellular carcinoma with at least one lesion that is measurable by RECIST 1.1 criteria. A prior HCC lesion that was treated surgically or by radiation is allowed as long as it was at least 2 years or more from the current HCC diagnosis.
3. Patient's cancer must be deemed locally advanced and unresectable
4. Patients must have a Childs-Pugh cirrhosis score of A5 or A6.
5. Eastern Cooperative Oncology Group Performance Status of 0-1.
6. Patients must have bone marrow and organ function as defined below:
* Absolute Neutrophil Count ≥ 1,500/μL
* Platelets ≥ 100,000/μL
* Hemoglobin ≥ 90 g/L (9g/dL)
* Total Bilirubin ≤ 3 x ULN
* AST(SGOT)/ALT(SGPT)/Alkaline Phosphatase ≤ 3 x ULN Or ≤5x ULN if due to liver involvement by tumor
* Creatinine ≤ 2.0 mg/dL
* eGFR (using Cockcroft Gault equation) \> 40ml/min
7. Chemotherapy is harmful to the human fetus. For this reason, sexually active males and females with partners of childbearing potential must agree to use an accepted and effective method of contraception prior to study entry and for the duration of the study.
8. Patients must demonstrate the ability to understand and the willingness to sign a written informed consent document.
9. Men and women, regardless of race, ethnic group, or sexual orientation are eligible for this study.
10. Patient must be able to swallow oral medication.
Exclusion Criteria:
1. Patients with Childs-Pugh B or C cirrhosis.
2. Female patients who are pregnant or breast-feeding.
3. Concomitant illness that would prevent adequate patient assessment or in the investigators' opinion pose an added risk for study participants.
4. Any history or evidence of severe illness or any other condition that would make the patient, in the opinion of the investigator unsuitable for the study. This would include any uncontrolled or untreated viral infection such as HIV, HBV, HCV etc.
5. Subject is enrolled in a separate interventional clinical trial.
6. Active tuberculosis.
7. Significant cardiovascular disease (such as New York Heart Association Class II or greater cardiac disease, myocardial infarction, or cerebrovascular accident) within 3 months prior to initiation of study treatment, unstable arrhythmia, or unstable angina.
8. History of severe allergic anaphylactic reactions to chimeric or humanized antibodies or fusion proteins.
9. Known hypersensitivity to Chinese hamster ovary cell products or to any component of the atezolizumab or bevacizumab formulation.
10. Known fibrolamellar HCC, sarcomatoid HCC, or mixed cholangiocarcinoma and HCC.
11. Uncontrolled tumor-related pain. Patients requiring pain medication must be on a stable regimen at study entry.
12. Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to initiation of study treatment.
13. Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases.
18\. Active, untreated grade 2 or 3 varices. Patients with treated varices to the point that they are grade 1 or less will be allowed.
19\. Patients already on memantine for any reason prior to enrollment will be excluded.
