Partial Immune-boost TACE in unrEseCTable HCC Patients Under Systemic Treatment

Study Objectives： Atezolizumab (anti-programmed death-ligand 1; anti-PD-L1) combined with bevacizumab (anti-vascular endothelial growth factor; anti-VEGF) or Durvalumab (anti-programmed death-ligand 1; anti-PD-L1) combined with tremelimumab (anti-cytotoxic T-lymphocyte-associated protein 4; anti-CTLA4) have recently been established as a standard first-line systemic treatment for unresectable hepatocellular carcinoma (HCC). However, its objective response rate (ORR) is only less than 27% (1, 2), and the majority of patients died of HCC progression and liver failure. Therefore, there is an urgent need to develop a novel combination treatment strategy to overcome resistance to immunotherapy and improve patient outcomes.

Transarterial chemoembolization (TACE) remains the standard treatment for patients with intermediate-stage hepatocellular carcinoma (HCC) (3, 4). However, in our previous retrospective study (5-7), the investigators consistently observed that this combination not only improves therapeutic responses but also significantly prolongs patient survival. The tumor necrosis caused by TACE may enhance the efficacy of systemic therapies by promoting the release of neoantigens, thereby stimulating immune responses (8-14). This concept has been substantiated in two recent trials involving intermediate-stage HCC (15, 16), where the addition of immune checkpoint inhibitors to TACE resulted in improved clinical outcomes. Nevertheless, this promising approach has yet to replace the decades-old standard treatment protocols, underscoring the need for further proof-of-concept studies.

Both immunotherapy (atezolizumab/bevacizumab or durvalumab/tremelimumab) and transarterial chemoembolization (TACE) are approved treatment modalities for unresectable hepatocellular carcinoma (HCC) by the U.S. and Taiwan Food and Drug Administration (FDA). This phase II non-randomized trial is designed to prospectively evaluate the therapeutic efficacy, safety, and immunological responses in patients with unresectable HCC treated with a combination of immunotherapy and TACE. A particular focus of this study is to explore the potential immune-boosting effects of TACE, including its ability to enhance antigen presentation and stimulate anti-tumor immune responses.