A Phase I/II Study to Evaluate AZD5851 in GPC3+ Advanced/Recurrent Hepatocellular Carcinoma

Inclusion Criteria: 1. Participant must be 18 years or older and has voluntarily agreed to participate by giving written informed consent. 2. Participants with confirmed advanced/recurrent or metastatic and/or unresectable HCC based on histopathological findings 3. Completed or were unable to tolerate at least one prior line of standard systemic therapy for HCC and/or participant/investigator decision. 4. GPC3-positive tumour as determined by a central laboratory using an analytically validated IHC assay 5. Barcelona Clinic Liver Cancer Stage B (if not amenable to local treatment/surgery) or C prior to apheresis 6. Child-Pugh score: Grade A 7. Participants with HBV and HCV undergoing management of these infections per institutional practice. Exclusion Criteria: 1. Active or prior documented gastrointestinal (GI) variceal bleed or history of upper GI bleeding, ulcers, or esophageal varices with bleeding within 12 months 2. History of liver transplantation or on waiting list 3. Current clinically significant ascites 4. Main portal vein thrombus, or tumor thrombus invasion of mesenteric vein / inferior vena cava 5. Uncontrolled intercurrent illness 6. Active Infections 7. Positive serology for HIV 8. History of hepatic encephalopathy within 12 months prior to treatment allocation 9. History of chronic or recurrent (within the last year) severe autoimmune or immune mediated disease requiring steroids or other immune-suppressive treatments. 10. Prior treatment with any CAR-T therapy directed at any target or any therapy that is targeted to GPC3. 11. Receipt of the last dose of anticancer therapy (chemotherapy, immunotherapy, endocrine therapy, targeted therapy, biologic therapy, tumour embolisation, or monoclonal antibodies, investigational product) within 5 half-lives or ≤ 21 days (whichever is shortest).