Atezolizumab and Bevacizumab Pre-Liver Transplantation for Patients With Hepatocellular Carcinoma Beyond Milan Criteria

Inclusion Criteria: 1. Male or female, aged ≥18 years old at the time of signing Informed Consent Form 2. Measurable or evaluable disease per RECIST v1.1 or mRECIST of unresectable HCC outside of Milan criteria 3. Histologically proven HCC, without extrahepatic disease. Patients who consent to a fresh tissue biopsy, and under the discretion of the Investigators, will provide a baseline biopsy sample for diagnosis and correlative studies. Archival tumor tissue may be used to confirm HCC in patients who do not consent to a fresh tissue biopsy. 4. Prior remote LRT is allowed if new lesions or local disease recurrence are present 5. Must be eligible for liver transplantation, defined in Section 10.4 6. Eligible and suited to receive TACE procedure(s) 7. Child-Pugh score ≤A6 8. Eastern Cooperative Oncology Group (ECOG) score 0-1 9. Life expectancy of ≥ 6 months 10. Adequate hematological and end-organ function, defined by the following laboratory test results obtained within 14 days prior to study initiation: 1. Absolute neutrophil count (ANC) ≥ 1.5 x 109/L 2. Lymphocyte count ≥ 0.5 x 10\^9/L (500/uL) 3. Platelet count \> 75 x 109/L 4. Hemoglobin \> 9 g/dL 5. Total bilirubin \< 1.5 x upper limit of normal (ULN) 6. Aspartate transaminase (AST),alanine aminotransferase (ALT), and alkaline phosphatase (ALP) \< 2.5 x ULN 7. Serum albumin \> 2.7 g/dL 8. Serum creatinine \< 1.5x ULN or calculated creatinine clearance \< 50 ml/min 9. Urine dipstick for proteinuria ≥ 2+ unless a 24-hour urine protein \< 1 g of protein is demonstrated 10. International normalized ratio (INR) ≤ 1.5 or partial thromboplastin time (PTT) ≤ 1.5 x ULN for patients not receiving anti-coagulation. The use of full-dose oral or parenteral anticoagulants is permitted as long as the INR or PTT is within therapeutic limits (according to the medical standard of the enrolling institution) and the patient has been on a stable dose of anticoagulants for at least two weeks prior to the first study treatment. 11. No evidence of a Grade 2 or higher esophageal and/or gastric varices. Patients must have an esophagogastroduodenoscopy (EGD) within 6 months prior to initiating the study treatment. See Section 8.7.1.2. 12. No history of hemoptysis (≥ 1/2 teaspoon of bright red blood per episode) within 1 month of study enrollment 13. Negative HIV test at screening or transplant workup 14. Negative hepatitis B surface antigen (HBsAg) test at screening or transplant workup 15. Negative total hepatitis B core antibody (HBcAb) test at screening or transplant workup, or positive total HBcAb test followed by a negative hepatitis B virus (HBV) DNA test at screening or transplant workup. The HBV DNA test will be performed only for patients who have a negative HBsAg test and a positive total HBcAb test. 16. For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods, as defined below: 1. Women must remain abstinent or use contraceptive methods with a failure rate of \<1% per year during the treatment period and for 6 months after the final dose of atezolizumab/bevacizumab Females who receive a LT are required to maintain abstinence or contraception until the End of Study. 2. A woman is considered to be of childbearing potential if she is postmenarchal, has not reached a postmenopausal state (≥12 continuous months of amenorrhea with no identified cause other than menopause), and has not undergone surgical sterilization (removal of ovaries and/or uterus). The definition of childbearing potential may be adapted for alignment with local guidelines or requirements. 3. Examples of contraceptive methods with a failure rate of \<1% per year include bilateral tubal ligation, male sterilization, hormonal contraceptives that inhibit ovulation, hormone-releasing intrauterine devices, and copper intrauterine devices. 4. The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the patient. Periodic abstinence (eg, calendar, ovulation, symptothermal, or postovulation methods) and withdrawal are not adequate methods of contraception. 17. For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use a condom, and agreement to refrain from donating sperm, as defined below: 1. With a female partner of childbearing potential or pregnant female partner, men must remain abstinent or use a condom during the treatment period and for 6 months after the final dose of atezolizumab/bevacizumab to avoid exposing the embryo. Men must refrain from donating sperm during this same period. Males who receive a LT are required to maintain these criteria until the End of Study. 2. The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the patient. Periodic abstinence (eg, calendar, ovulation, symptothermal, or postovulation methods) and withdrawal are not adequate methods of preventing drug exposure. 18. Stated willingness to comply with all study procedures and availability for the duration of the study 19. Women of childbearing potential must have a negative serum or urine pregnancy test result within 14 days prior to initiation of study treatment. Exclusion Criteria: 1. Known fibrolamellar HCC, sacromatoid HCC, or mixed cholangiocarcinoma and HCC 2. Previous systemic therapy for HCC prior to study enrollment 3. Planned or prior multi-organ transplant or prior solid organ or allogeneic stem cell transplantation 4. History of Grade ≥4 venous thromboembolism 5. History or evidence upon physical or neurological examination of central nervous system (eg seizures) unrelated to cancer unless adequately treated with standard medical therapy. Anticonvulsants (stable dose) are allowed. 6. Moderate or severe ascites 7. History of hepatic encephalopathy 8. Inadequately controlled hypertension (defined as systolic blood pressure \>150 mmHg and/or diastolic blood pressure \>100 mmHg) 9. History of hypertensive crisis or hypertensive encephalopathy 10. Significant vascular disease (e.g., aortic aneurysm requiring surgical repair or recent arterial thrombosis) within 6 months prior to drug administration 11. 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 12. History or evidence of inherited bleeding diathesis or significant coagulopathy at risk of bleeding (i.e., in the absence of therapeutic anticoagulation) 13. Surgical procedure (including open biopsy, surgical resection, wound revision, or any other major surgery involving entry into a body cavity) or significant traumatic injury within 28 days prior to initiation of study treatment, or anticipation of need for major surgical procedure during the Treatment Phase of the study • Core biopsy or other minor surgical procedure, excluding placement of a vascular access device within 7 days prior to initiation of study treatment. Placement of a vascular access device should be at least 2 days prior to initiation of study treatment. 14. History of abdominal fistula, gastrointestinal (GI) perforation, intra-abdominal abscess, grade 2 or higher untreated esophageal or gastric varices or active GI bleeding within 6 months prior to treatment 15. Untreated or incompletely treated esophageal and/or gastric varices with bleeding or high risk for bleeding. Patients must undergo an esophagogastroduodenoscopy (EGD), and all size of varices (small to large) must be assessed and treated per local standard of care prior to enrollment. Patients who have undergone an EGD within 6 months prior to initiating the study treatment do not need to repeat the procedure. 16. Serious, non-healing wound, active ulcer, or untreated bone fracture 17. Other malignancy within 5 years prior to randomization, except for localized cancer in situ, such as basal or squamous cell skin cancer 18. Current or recent (\<10 days prior to initiation of study treatment) use of aspirin (\>325 mg/day), or clopidogrel (\>75 mg/day). Note: The use of full-dose oral or parenteral anticoagulants for therapeutic purpose is permitted as long as the INR and/or a PTT is within therapeutic limits (according to institution standards) within 14 days prior to initiation of study treatment and the patient has been on a stable dose of anticoagulants for ≥2 weeks prior to initiation of study treatment. Prophylactic use of anticoagulants is allowed. However, the use of direct oral anticoagulant therapies such as dabigatran (Pradaxa®) and rivaroxaban (Xarelto®) is not recommended due to bleeding risk. 19. Pregnancy (positive pregnancy test) or lactation, or intention of becoming pregnant during study treatment or within 6 months after the final dose of study drugs o Women of childbearing potential must have a negative serum or urine pregnancy test result within 28 days prior to initiation of study treatment. 20. Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently) • Patients with indwelling catheters (e.g., PleurX®) are allowed 21. Uncontrolled or symptomatic hypercalcemia (ionized calcium \> 1.5 mmol/L, calcium \> 12 mg/dL or corrected serum calcium \> ULN) 22. Active or history of autoimmune disease or immune deficiency, including, but not limited to, myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, antiphospholipid antibody syndrome, Wegener granulomatosis, Sjögren syndrome, Guillain-Barré syndrome, or multiple sclerosis, with the following exceptions: * Patients with a history of autoimmune-related hypothyroidism who are on thyroid-replacement hormone are eligible for the study. * Patients with eczema, psoriasis, lichen simplex chronicus, or vitiligo with dermatologic manifestations only (eg, patients with psoriatic arthritis are excluded) are eligible for the study provided all following conditions are met: * Rash must cover \< 10% of body surface area * Disease is well controlled at baseline and requires only low-potency topical corticosteroids * No occurrence of acute exacerbations of the underlying condition requiring psoralen plus ultraviolet A radiation, methotrexate, retinoids, biologic agents, oral calcineurin inhibitors, or high-potency or oral corticosteroids within the previous 12 months 23. History of idiopathic pulmonary fibrosis, organizing pneumonia (eg, bronchiolitis obliterans), drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography (CT) scan. History of radiation pneumonitis in the radiation field (fibrosis) is permitted. 24. Active tuberculosis 25. Any other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding that contraindicates the use of an investigational drug, may affect the interpretation of the results, or may render the patient at high risk from treatment complications 26. Treatment with a live, attenuated vaccine (e.g., FluMist®) within 4 weeks prior to initiation of study treatment, or anticipation of need for such a vaccine during atezolizumab treatment or within 5 months after the final dose of atezolizumab 27. Current treatment with anti-viral therapy for HBV 28. Prior treatment with CD137 agonists or immune checkpoint blockade therapies, including anti-CTLA-4, anti-PD-1, and anti-PD-L1 therapeutic antibodies 29. Treatment with systemic immunostimulatory agents (including, but not limited to, interferon and interleukin 2 \[IL-2\]) within 4 weeks or 5 half-lives of the drug (whichever is longer) prior to initiation of study treatment 30. Treatment with systemic immunosuppressive medication (including, but not limited to, corticosteroids, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-TNF-α agents) within 2 weeks prior to initiation of study treatment, or anticipation of need for systemic immunosuppressive medication during the Treatment Phase, with the following exceptions: * Patients who received acute, low-dose systemic immunosuppressant medication or a one-time pulse dose of systemic immunosuppressant medication (e.g., 48 hours of corticosteroids for a contrast allergy) are eligible for the study after Principal Investigator confirmation has been obtained. * Patients who received mineralocorticoids (eg, fludrocortisone), corticosteroids for chronic obstructive pulmonary disease (COPD) or asthma, or low-dose corticosteroids for orthostatic hypotension or adrenal insufficiency are eligible for the study. 31. History of severe allergic anaphylactic reactions to chimeric or humanized antibodies or fusion proteins 32. Known allergy or hypersensitivity to any component of the Atezlizumab and Bevacizumab formulation, such as a known hypersensitivity to Chinese hamster ovary cell products 33. Inability to comply with study and/or follow-up procedures 34. Active infection requiring IV antibiotics within 2 weeks prior to initiation. * Note: Placement of a vascular access device should be at least 2 days prior to initiation of study treatment. * Patients receiving prophylactic antibiotics (e.g., to prevent a urinary tract infection or chronic obstructive pulmonary disease exacerbation) are eligible for the study. 35. Severe infection within 4 weeks prior to initiation of study treatment, including, but not limited to, hospitalization for complications of infection, bacteremia, or severe pneumonia 36. History of leptomeningeal disease 37. Evidence of abdominal free air that is not explained by paracentesis or recent surgical procedure 38. History of intra-abdominal inflammatory process within 6 months prior to initiation of study treatment, including but not limited to active peptic ulcer disease, diverticulitits, or colitis. 39. Chronic daily treatment with a nonsteroidal anti-inflammatory drug (NSAID). Occasional use of NSAIDs for the symptomatic relief of medical conditions such as headache or fever is allowed 40. Uncontrolled tumor-related pain * Patients requiring pain medication must be on a stable regimen at study entry. * Symptomatic lesions (eg, bone metastases or metastases causing nerve impingement) amenable to palliative radiotherapy should be treated prior to enrollment. Patients should be recovered from the effects of radiation. There is no required minimum recovery period.