Targeted and immune therapies for hepatocellular carcinoma: Predictions for 2019 and beyond.

Systemic therapy for hepatocellular carcinoma (HCC) has markedly advanced since the survival benefit of a molecular targeted agent, sorafenib, were demonstrated in the SHARP and Asia Pacific trials in 2007. Treatment options for patients with advanced HCC increased by sorafenib, and long-term survival for patients with advanced stage HCC has become possible to some extent. However, development of a more potent first-line novel molecular targeted agent replacing sorafenib and a potent second-line agent after disease progression on or intolerant to sorafenib has been warranted because sorafenib lacks tumor shrinking/necrotizing effects and induces relatively severe adverse events such as hand foot skin reaction. Many agents in the 1st line and 2nd line setting were attempted to develop between 2007 and 2016, but all of these clinical trials failed. On the other hand, clinical trials of 4 agents (regorafenib, lenvatinib, cabozantinib, and ramucirumab) succeeded in succession in 2017 and 2018, and their use in clinical practice is possible (regorafenib and lenvatinib) or underway (cabozantinib and ramucirumab). Furthermore, all of 5 clinical trials of combination therapy with transcatheter chemoembolization (TACE) plus a molecular targeted agent failed to date, however, the combination of TACE and sorafenib (TACTICS trials) was reported to be successful and presented at ASCO in 2018. Phase 3 clinical trials of immune checkpoint inhibitors and a combination therapy of immune checkpoint inhibitors and molecular targeted agents are also ongoing, which suggests treatment paradigm of HCC in all stages from early, intermediate and advanced stage, is expected to be changed drastically in the very near future.