Implications of the TACTICS Trial: Establishing the New Concept of Combination/Sequential Systemic Therapy and Transarterial Chemoembolization to Achieve Synergistic Effects

Systemic Drugs for Hepatocellular Carcinoma: What Do Recent Clinical Trials Reveal About Sequencing and the Emerging Complexities of Clinical Decisions?

Liver cancer was the fourth leading cause of cancer death in 2015 with increasing incidence between 1990 and 2015. Orthotopic liver transplantation, surgical resection and ablation comprise the only curative therapy options. However, due to the late manifestation of clinical symptoms, many patients present with intermediate or advanced disease, resulting in no curative treatment option being available. Whereas intermediate-stage hepatocellular carcinoma (HCC) is usually still addressable by transarterial chemoembolization (TACE), advanced-stage HCC is amenable only to pharmacological treatments. Conventional cytotoxic agents failed demonstrating relevant effect on survival also because their use was severely limited by the mostly underlying insufficient liver function. For a decade, tyrosine kinase inhibitor (TKI) sorafenib was the only systemic therapy that proved to have a clinically relevant effect in the treatment of advanced HCC. In recent years, the number of substances for systemic treatment of advanced HCC has increased enormously. In addition to tyrosine kinase inhibitors, immune checkpoint inhibitors (ICI) and antiangiogenic drugs are increasingly being applied. The combination of anti-programmed death ligand 1 (PD-L1) antibody atezolizumab and anti-vascular endothelial growth factor (VEGF) antibody bevacizumab has become the new standard of care for advanced HCC due to its remarkable response rates. This requires more and more complex clinical decisions regarding tumor therapy. This review aims at summarizing recent developments in systemic therapy, considering data on first- and second-line treatment, use in the neoadjuvant and adjuvant setting and combination with locoregional procedures.

A Phase 2, Prospective, Multicenter, Single-Arm Trial of Transarterial Chemoembolization Therapy in Combination Strategy with Lenvatinib in Patients with Unresectable Intermediate-Stage Hepatocellular Carcinoma: TACTICS-L Trial

INTRODUCTION

Transarterial chemoembolization (TACE) is the standard treatment for unresectable intermediate-stage hepatocellular carcinoma (HCC), but recurrence after TACE is common. The present phase 2, prospective, multicenter, single-arm trial, the TACTICS-L trial, investigated the efficacy and safety of TACE plus lenvatinib (LEN), a drug that more strongly promotes vascular normalization and has a better objective response rate (ORR) than sorafenib (jRCTs031180074).

METHODS

Participants were patients with HCC who had not previously received systemic therapy, hepatic arterial infusion chemotherapy, or immunotherapy and who were ineligible for resection or percutaneous ablation therapy. LEN was to be administered 14-21 days before the first TACE, stopped 2 days before TACE, and resumed 3 days after TACE. Key inclusion criteria were unresectable HCC, Child-Pugh A liver function, 0-2 prior TACE sessions, tumor size ≤10 cm, number of tumors ≤10, and ECOG performance status 0-1. Key exclusion criteria were vascular invasion and extrahepatic spread. The primary endpoint was progression-free survival (PFS) by RECICL, and secondary endpoints were time to untreatable progression, ORR, overall survival (OS), and safety.

RESULTS

A total of 62 HCC patients were enrolled in this trial. The median age was 72 years, 77.4% of patients were men, and 95.2% had PS 0. The primary endpoint of median PFS was 28.0 months (90% confidence interval [CI] 25.1-31.0) after a minimum 24 months of follow-up. The secondary endpoint of median OS was not reached (90% CI 35.5 months-NR). LEN-TACE achieved a high response rate and high complete response (CR) rate (4 weeks after the first TACE: ORR 79.0%, CR rate 53.2%; best response: ORR 88.7%, CR rate 67.7%) by RECICL. Exploratory subgroup analyses showed that the characteristics of responders/nonresponders (ORR and CR rate) were similar and that LEN-TACE would be effective in all subgroups, including the population in whom TACE alone would be less likely to be curative (e.g., patients with the non-simple nodular type or a high tumor burden). The relative dose intensity of LEN before the first TACE was important for achieving higher CR rate/ORR by LEN-TACE. No new safety concerns were observed.

CONCLUSION

The results of this trial provide encouraging evidence, supporting the efficacy and favorable safety profile of LEN-TACE in patients who are ineligible for locoregional therapy.

Treatment Strategy for Intermediate-Stage Hepatocellular Carcinoma: Transarterial Chemoembolization, Systemic Therapy, and Conversion Therapy

Transarterial chemoembolization (TACE) has been standard treatment for intermediate-stage hepatocellular carcinoma (HCC). However, all intermediate-stage HCC patients did not benefit from TACE treatment because intermediate-stage HCC encompasses a wide variety of HCCs. Owing to remarkable progress in systemic therapy, including molecular-targeted therapy for advanced-stage HCC, the standard treatment of HCC has recently shifted to systemic therapy. However, it remains controversial as to which treatment should be initially performed for intermediate-stage HCC. In addition, although curative treatment can be considered when the tumor shrinks, the timing of conversion therapy remains uncertain. This review summarizes the advances of HCC treatment and discusses treatment strategies for intermediate-stage HCC.