PETAL protocol: a phase Ib study of pembrolizumab after transarterial chemoembolization in hepatocellular carcinoma

Maximizing therapeutic outcomes in hepatocellular carcinoma: Insights into combinatorial strategies

In this editorial, we review the article by Ma and colleagues, published in the World Journal of Gastrointestinal Oncology. Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality. Although transarterial chemoembolization (TACE) has been used effectively for several years, particularly in patients with intermediate-stage HCC, the quest for the optimal combination therapy to enhance its efficacy and HCC treatment strategies persists. Combining TACE with tyrosine kinase inhibitors (TKIs) like sorafenib or lenvatinib has shown confusing results in improving both progression-free survival and overall survival. Similarly, combining TACE with immune checkpoint inhibitors (ICIs) has demonstrated potential efficacy by reshaping the tumor microenvironment and activating immune responses. Recent studies suggest combining TACE with TKIs and ICIs may offer synergistic effects. Additionally, combining TKIs and ICIs with other local treatments like microwave ablation or hepatic arterial infusion chemotherapy has shown promise in enhancing efficacy. However, more extensive prospective studies are needed to validate these findings. Overall, these combinations represent a promising direction in HCC management, emphasizing the need for further research to optimize treatment outcomes.

Examining the Efficacy and Safety of Combined Locoregional Therapy and Immunotherapy in Treating Hepatocellular Carcinoma

More than 800,000 people worldwide are diagnosed with HCC (hepatocellular carcinoma) each year, with approximately 700,000 deaths alone occurring in that same year. Treatment of HCC presents complex therapeutic challenges, particularly in intermediate and advanced stages. LRTs such as transarterial chemoembolization (TACE) and ablations have been the mainstay treatment for early to intermediate-stage HCC, and systemic therapies are used to treat intermediate-late-stage HCC. However, novel literature describing combining LRT with systemic therapies has shown promising results. This review explores recent advances in both liver-directed techniques for hepatocellular carcinoma, including bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies in conjunction as well as with systemic therapies, with a focus on combination therapies, patient selection, procedural technique, periprocedural management, and outcomes. Our findings suggest that LRT combined with systemic therapies is a viable strategy for improving progression-free survival and time to progression for patients with intermediate-to-late-stage HCC. However, further investigation is required to refine treatment protocols and define patient cohorts that would benefit the most.

Safety and Preliminary Efficacy of Pembrolizumab Following Transarterial Chemoembolization for Hepatocellular Carcinoma: The PETAL Phase Ib Study

PURPOSE

Transarterial chemoembolization (TACE) may prime adaptive immunity and enhance immunotherapy efficacy. PETAL evaluated safety, preliminary activity of TACE plus pembrolizumab and explored mechanisms of efficacy.

PATIENTS AND METHODS

Patients with liver-confined hepatocellular carcinoma (HCC) were planned to receive up to two rounds of TACE followed by pembrolizumab 200 mg every 21 days commencing 30 days post-TACE until disease progression or unacceptable toxicity for up to 1 year. Primary endpoint was safety, with assessment window of 21 days from pembrolizumab initiation. Secondary endpoints included progression-free survival (PFS) and evaluation of tumor and host determinants of response.

RESULTS

Fifteen patients were included in the safety and efficacy population: 73% had nonviral cirrhosis; median age was 72 years. Child-Pugh class was A in 14 patients. Median tumor size was 4 cm. Ten patients (67%) received pembrolizumab after one TACE; 5 patients after two (33%). Pembrolizumab yielded no synergistic toxicity nor dose-limiting toxicities post-TACE. Treatment-related adverse events occurred in 93% of patients, most commonly skin rash (40%), fatigue, and diarrhea (27%). After a median follow-up of 38.5 months, objective response rate 12 weeks post-TACE was 53%. PFS rate at 12 weeks was 93% and median PFS was 8.95 months [95% confidence interval (CI): 7.30-NE (not estimable)]. Median duration of response was 7.3 months (95% CI: 6.3-8.3). Median overall survival was 33.5 months (95% CI: 11.6-NE). Dynamic changes in peripheral T-cell subsets, circulating tumor DNA, serum metabolites, and in stool bacterial profiles highlight potential mechanisms of action of multimodal therapy.

CONCLUSIONS

TACE plus pembrolizumab was tolerable with no evidence of synergistic toxicity, encouraging further clinical development of immunotherapy alongside TACE.

The efficacy and safety of PD-1 inhibitor combined with TACE in the first-line treatment of unresectable hepatocellular carcinoma

The application of immune checkpoint inhibitors (ICIs) has changed the treatment of advanced hepatocellular carcinoma. Transcatheter arterial chemoembolization (TACE) is a first-line treatment for intermediate hepatocellular carcinoma. Serving as a local treatment modality that can induce immunogenic cell death, the efficacy and safety of combined use with ICI have not been evaluated. Although there have been prospective studies aimed at evaluating the efficacy and safety of ICI combined with TACE in BCLC stage B HCC patients, there are few reports on the evaluation of BCLC stage C patients with distant metastasis or portal vein cancer thrombus. Data of unresectable hepatocellular carcinoma patients received PD-1 inhibitor and TACE were collected in Xijing Hospital from June 2019 to December 2022. The tumor response was evaluated according to the Solid Tumor Modified Response Evaluation Standard (mRECIST), including complete response (CR), partial response (PR), disease stability (SD), disease progression (PD), objective response rate (ORR), and disease control rate (DCR). The progression-free survival (PFS) and overall survival (OS) were used to estimate therapy efficacy. The treatment-related adverse events were evaluated based on National Cancer Institute Common Adverse Event Evaluation Criteria (CTCAE) version 5.0. A total of 42 patients with unresectable hepatocellular carcinoma were included in this study, including 34 males (80.5%) and 8 females (19.5%). The average age is 54.5 years, ranging from 34 to 72. The median follow-up time was 12.3 months, with an ORR of 42.9% and a DCR of 90.5% as of the follow-up time. The median PFS is 7.5 months (95% CI: 5.76-9.23), and the median OS has not yet been reached; 6-month PFS was 62.2%. Safety analysis showed that 41 (97.6%) patients experienced treatment-related adverse reactions, mainly including elevated AST and ALT, fever, elevated bilirubin, hypothyroidism, nausea, abdominal pain, and rash. 40 patients had grade 1/2 adverse reactions, and only one patient had grade 3 adverse reactions, manifested as intolerable rash, nausea, and vomiting. Treatment is terminated when symptomatic treatment and drug suspension cannot be alleviated. In this study, thre patients with unresectable hepatocellular carcinoma were treated with PD-1 inhibitor combined with TACE to achieve good tumor reduction effect and underwent liver cancer resection surgery. For patients with unresectable hepatocellular carcinoma, whether in BCLC stage B or stage C, effective systemic therapy (PD-1 inhibitor) combined with local therapy (TACE) can achieve a high rate of tumor regression and objective response. Some patients may even pursue surgical treatment opportunities, and the treatment-related adverse reactions are controllable, which is expected to provide new options for extending the survival of unresectable hepatocellular carcinoma patients.

Unraveling the Complexities of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Immune checkpoint inhibitors (ICIs) have emerged as effective therapeutics for multiple cancers. Nevertheless, as immunotherapeutic approaches are being extensively utilized, substantial hurdles have arisen for clinicians. These include countering ICIs resistance and ensuring precise efficacy assessments of these drugs, especially in the context of hepatocellular carcinoma (HCC). This review attempts to offer a holistic overview of the latest insights into the ICIs resistance mechanisms in HCC, the molecular underpinnings, and immune response. The intent is to inspire the development of efficacious combination strategies. This review also examines the unconventional response patterns, namely pseudoprogression (PsP) and hyperprogression (HPD). The prompt and rigorous evaluation of these treatment efficacies has emerged as a crucial imperative. Multiple clinical, radiological, and biomarker tests have been advanced to meticulously assess tumor response. Despite progress, precise mechanisms of action and predictive biomarkers remain elusive. This necessitates further investigation through prospective cohort studies in the impending future.