Second-line treatment options for hepatocellular carcinoma: current state and challenges for the future

INTRODUCTION

Since the approval of sorafenib for systemic treatment of advanced hepatocellular carcinoma (HCC), many tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) have shown efficacy and tolerability as first-line treatments. On the other hand, these first-line therapies are associated with low objective response and drug resistance. Many drugs have been successfully tested for second-line treatment of advanced HCC. While the rapid proliferation of second-line treatments for advanced HCC brings hope to patients, it also complicates clinical decision-making.

AREAS COVERED

This review aims to facilitate decisions by summarizing the latest guidelines for second-line treatment of HCC in various countries or regions. We then review existing second-line treatment options and discuss challenges that should be addressed in the future. A literature search was conducted in April 2022 of PubMed/Medline, Cochrane library, and abstracts of international cancer meetings.

EXPERT OPINION

There is no standard second-line treatment, especially for the case of sequential treatment after atezolizumab plus bevacizumab (atezo+bev) and further studies focused on sequential treatment are warranted in this setting. The design of clinical trials, different etiologies, and complications or quality of life (QoL) are interesting issues in the second-line setting.

Second-Line Treatment Options for Hepatocellular Carcinoma: Current Landscape and Future Direction

Hepatocellular carcinoma is a leading cause of mortality worldwide, and its incidence is rising. The last few years have witnessed a proliferation of available systemic therapeutic options, with the approval of multiple agents, including immune checkpoint inhibitors and drugs targeting vascular endothelial growth factor, such as cabozantinib, regorafenib, and ramucirumab. Most recently, the combination of atezolizumab plus bevacizumab has resulted in the longest overall survival yet known in hepatocellular carcinoma, therefore changing the preferred first-line treatment from the previous options of sorafenib and lenvatinib. The aim of this review is to summarize the available clinical data for the current second-line systemic treatment options and the future perspectives in the treatment landscape of hepatocellular carcinoma.

Cabozantinib in Advanced Hepatocellular Carcinoma: Efficacy and Safety Data from an International Multicenter Real-Life Cohort

BACKGROUND AND AIMS

The multikinase inhibitor cabozantinib has been approved for hepatocellular carcinoma (HCC) previously treated with sorafenib. We report safety and efficacy data of an international, multicenter, real-life cohort of patients with advanced HCC treated with cabozantinib.

METHODS

Patients with HCC who were treated with cabozantinib were retrospectively identified across 11 centers in Austria, Switzerland, and Germany. Patients' characteristics, adverse events, duration of treatment and overall survival (OS) data were analyzed until April 1, 2020.

RESULTS

Eighty-eight patients from 11 centers were included. The predominant underlying liver diseases were NAFLD/NASH in 26 (30%) and hepatitis C infection in 21 (24%) patients. Seventy-eight patients (89%) were classified as Barcelona clinic liver cancer (BCLC) stage C. Sixty patients (68%) were Child-Pugh A, whereas 22 (25%) were Child-Pugh B, respectively. Cabozantinib was used as systemic second- and third-line or later treatment in 41 (47%) and 46 (52%) patients, respectively. The following best responses under cabozantinib were documented: partial response in 6 (7%), stable disease in 28 (32%), and progressive disease in 28 (32%) patients, respectively. Fifty-two patients (59%) died during follow-up. The median OS from start of cabozantinib treatment was 7.0 months in the entire cohort and 9.7 months in Child-Pugh A patients, while Child-Pugh B patients had a median OS of 3.4 months, respectively. Thirty-seven (42%) patients fulfilled the CELESTIAL inclusion and exclusion criteria, showing a median OS of 11.1 months. Most common adverse events were fatigue (15.6%) and diarrhea (15.6%).

CONCLUSION

Cabozantinib treatment was effective, safe, and feasible in patients with advanced HCC in patients with compensated cirrhosis. Patients in the real-life setting had more advanced liver disease - in which 25% of patients were Child-Pugh B. However, OS in patients with Child-Pugh A cirrhosis was similar to that reported in the phase 3 trial (CELESTIAL).

Cabozantinib: An evolving therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is rising in incidence and remains a leading cause of cancer-related death. After a decade of disappointing trials following the approval of sorafenib for patients with advanced HCC, a number of tyrosine kinase inhibitors (TKIs) and monoclonal antibodies targeting angiogenesis and immune checkpoints have recently been approved. The phase 3 CELESTIAL trial demonstrated improved progression-free and overall survival with the TKI cabozantinib compared to placebo, supporting it as a treatment option for patients with advanced HCC previously treated with sorafenib. Cabozantinib blocks multiple key pathways of HCC pathogenesis, including VEGFR, MET, and the TAM (TYRO3, AXL, MER) family of receptor kinases, and promotes an immune-permissive tumor microenvironment. Here, we review the mechanisms of action of cabozantinib, including effects on tumor growth and its immunomodulatory properties, providing pre-clinical rationale for combination strategies with checkpoint inhibitors. We discuss the design and outcomes of CELESTIAL including improved survival across subgroups defined by age, disease etiology, baseline AFP level, prior therapies (including duration of prior sorafenib), and tumor burden. Cabozantinib had a manageable safety profile with dose modification. Studies combining cabozantinib with atezolizumab (COSMIC-312) and durvalumab (CAMILLA) in the first and second-line settings are ongoing, as well as a neoadjuvant study of cabozantinib with nivolumab. Future investigations are warranted to define the use of cabozantinib in patients with Child-Pugh B liver function and identify markers predictive of clinical benefit. The role of cabozantinib in HCC continues to evolve with an anticipated role in immunotherapy combinations.

The Role of Cabozantinib as a Therapeutic Option for Hepatocellular Carcinoma: Current Landscape and Future Challenges

The systemic treatment of advanced hepatocellular carcinoma (HCC) has significantly changed over the last years, with the introduction of two new standard-of-care first-line treatments (lenvatinib and the combination of atezolizumab and bevacizumab) and the success of several new agents in second line. In particular, after the approval of regorafenib, ramucirumab and cabozantinib, the landscape of second-line treatment has become notably complex, providing a serious challenge in clinical practice. In this review, we focus on cabozantinib, a multikinase inhibitor which was proven effective in improving overall and progression-free survival of patients previously treated with sorafenib in the randomized Phase III CELESTIAL trial. CELESTIAL is the only phase III study to have included patients in the third-line setting and cabozantinib efficacy was confirmed in several post hoc analyses, irrespective of alpha-fetoprotein levels, albumin-bilirubin score, age, and duration of previous sorafenib treatment. The safety profile of cabozantinib in the CELESTIAL trial was comparable with other multikinase inhibitors used for HCC and the most frequent grade ≥3 adverse events were diarrhea, palmar-plantar erythrodysesthesia, fatigue, hypertension, and aspartate aminotransferase increase. Tolerability did not differ between younger and older patients and quality of life was significantly improved compared to placebo during the treatment. In this review, we also make a particular mention to the use of cabozantinib in populations which are normally excluded from clinical trials, such as older patients and Child-Pugh B patients. Finally, we present the new treatment strategies in which cabozantinib is being tested, most notably the combination of cabozantinib and atezolizumab in the first-line setting in the phase III COSMIC-312 trial and the use of cabozantinib after progression on immune-checkpoint inhibitors.

Advances in pharmacotherapeutics for hepatocellular carcinoma

INTRODUCTION

Although hepatocellular carcinoma (HCC) is the most frequent primary liver cancer, there are limited therapeutic options for the advanced stages. Sorafenib was the first tyrosine-kinase inhibitor (TKI) approved for unresectable HCC and remained the only effective choice for a decade. The horizon of systemic treatments drastically expanded in the latest years, opening new interesting possibilities.

AREAS COVERED

In this manuscript, the authors have analysed the recent advances in pharmacotherapy for HCC, discussing their mechanisms of action, the clinical efficacy and the safety profile of currently available first, second-and third-line treatments. The authors have also analysed the role of immune system modulators, in particular immune checkpoints inhibitors (ICIs), based on the limited data published so far.

EXPERT OPINION

The emergence of new targeted therapies, such as lenvatinib, have changed the landscape of HCC therapy. Tumor extension, differences in objective response rates and adverse events profiles should be considered to tailor the choice of the first-line agent. Sorafenib remains the most studied drug, with much real-world data available. The efficacy of second line therapies has only been proven in non-responder or sorafenib-intolerant patients. Unfortunately, studies directly comparing the second-line agents regorafenib, ramucirumab and cabozantinib are still lacking.

Navigating the new landscape of second-line treatment in advanced hepatocellular carcinoma

Sorafenib and lenvatinib are approved for first-line treatment of patients with advanced hepatocellular carcinoma (HCC), and the efficacy of atezolizumab plus bevacizumab has been demonstrated versus sorafenib. Over time, first-line treatment frequently fails, and regorafenib, cabozantinib, ramucirumab (for patients with alpha fetoprotein ≥400 ng/mL), nivolumab, pembrolizumab and ipilimumab plus nivolumab are approved for use after sorafenib (but not lenvatinib) treatment in advanced HCC. Given the considerable complexity in the therapeutic landscape, the objective of this review was to summarize the clinical evidence for second-line agents and provide practical guidance for selecting the best sequential treatment approach. The timing and sequencing of treatment switches are key to optimizing patient outcomes in advanced HCC, and decisions should be informed by reasons for discontinuation of previous therapy and disease progression. It is important not to switch too soon, because sequential treatment benefit may then be lost, nor should switching be delayed too long. Effectiveness, safety and tolerability, patient quality of life, route of administration, dosing regimen, drug class, molecular target and individual patients' characteristics, including comorbidities, inform the selection of second-line systemic treatment, independently of the aetiology of HCC, tumour stage and the response to previous treatment. Biomarkers predictive of treatment effectiveness are of great value, but currently biomarker-driven patient selection is possible only in the case of ramucirumab. The approval of new combination therapies for advanced HCC in the first-line setting will further increase the complexity of decision-making. However, the important factors will remain the individual patient's characteristics and preferences.

Cabozantinib: A Review in Advanced Hepatocellular Carcinoma

Cabozantinib is an inhibitor of multiple receptor tyrosine kinases (RTKs) with roles in cancer pathogenesis. This review focuses on data relevant to the use of cabozantinib tablets (Cabometyx^®) in the treatment of hepatocellular carcinoma (HCC) in patients who have been previously treated with the multi-RTK inhibitor sorafenib, an indication for which cabozantinib tablets are approved in the EU and USA. Approval of cabozantinib in this setting was based largely on the findings of CELESTIAL, a phase 3 trial in adults with advanced HCC who had previously received sorafenib, had progressive disease after at least one systemic therapy and had received up to two systemic treatments for their advanced disease. Compared with placebo in this study, cabozantinib prolonged both overall survival and progression-free survival, with these findings largely unaffected by patient/disease characteristics. The tolerability profile of cabozantinib in CELESTIAL was acceptable and consistent with that of other multi-RTK inhibitors, with adverse events that were manageable with dose modification and supportive care. Thus, cabozantinib is a welcome additional treatment option for use in adults with HCC previously treated with sorafenib.

Targeted agents for second-line treatment of advanced hepatocellular carcinoma

Over the past ten years, sorafenib, a multikinase inhibitor, has been the standard of care for patients with unresectable hepatocellular carcinoma (HCC) and well-preserved liver function. Recently, lenvatinib, a different multikinase inhibitor, was shown to be non-inferior to sorafenib, in terms of survival, while all other agents previously tested failed to prove non-inferiority (or superiority) when compared to sorafenib. Similarly, in the second-line setting, most investigational drugs failed to provide better survival outcomes than placebo. However, in the last 2 years three positive phase III trials have been published in this setting. The RESORCE trial, a phase III study evaluating regorafenib in HCC patients who experienced disease progression after first-line treatment with sorafenib, showed better outcomes with regorafenib compared to placebo. More recently, the phase III CELESTIAL trial demonstrated the superiority of cabozantinib, a multikinase inhibitor targeting vascular endothelial growth factor receptor, MET, and AXL, vs placebo in the second- and third-line setting in patients progressing on or intolerant to sorafenib. The survival benefits of a sustained anti-angiogenic inhibition were demonstrated also with ramucirumab in the phase III REACH-2 trial in patients previously treated with sorafenib and who had high baseline alpha-fetoprotein levels. Overall, the adverse events reported in these trials were in line with the known safety profiles of the tested agents. After nearly a decade of a certain degree of stagnation, we are now witnessing a period of novel therapeutic advances with multikinase inhibitors and monoclonal antibodies that will likely change the treatment scenario of HCC.