GPC3-Targeted T-Cell Therapy (ECT204) in Adults With Advanced HCC

Inclusion Criteria: * Histologically confirmed HCC, that is unresectable, recurrent, and/or metastatic. * GPC3-positive tumor expression confirmed by immunohistochemistry (IHC). * For the dose-escalation cohort: ≥10-20% tumor cells, ≥2+ IHC. * Beginning with the RP2D confirmatory cohort: ≥ 50% tumor cells, 2+/3+ IHC. * Must have received at least first-line systemic therapy for HCC and have experienced disease progression on, or intolerance to, that therapy. * Life expectancy of at least 4 months per the Investigator's opinion. * Eastern Cooperative Oncology Group (ECOG) performance status 0-1. * Measurable disease by RECIST v1.1. * Child-Pugh score of A6 or better. * Adequate organ function. Exclusion Criteria: * Pre-existing illness (e.g., symptomatic congestive heart failure) that would limit compliance with study requirements. * Active, uncontrolled systemic bacterial, fungal, or viral infection. Subjects with Human Immunodeficiency Virus (HIV), hepatitis B, or hepatitis C are eligible provided their infection is being treated and the viral load is controlled. * History of malignancy other than HCC within 5 years before screening, except adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or other malignancies with low risk of recurrence. * Known brain metastases or other active central nervous system (CNS) involvement, including leptomeningeal disease. Subjects with brain metastases that have been adequately treated (no evident ne…