Development of sorafenib and other molecularly targeted agents in hepatocellular carcinoma

It is well appreciated that hepatocellular carcinoma (HCC) represents one of the most challenging malignancies of worldwide importance. In fact, HCC is the fifth most common cancer and the third most common cause of cancer-related death globally. The incidence rates for HCC in the U.S. and Western Europe have been rising. Unresectable or metastatic HCC carries a poor prognosis, and systemic therapy with cytotoxic agents provides marginal benefit. Because of the poor track record of systemic therapy in HCC, there has been a sense of nihilism for this disease in the oncology community for decades. However, with the arrival of newly developed, molecularly targeted agents and the success of some of these agents in other traditionally challenging cancers, such as renal cell carcinoma, there has been renewed interest in developing novel systemic therapy in HCC. At the recent Annual Meeting of the American Society of Clinical Oncology, results of a phase 3, randomized, placebo-controlled trial were presented in which sorafenib demonstrated improved survival in patients with advanced HCC. This landmark study represents the first agent that has demonstrated an improved overall survival benefit in this disease and sets the new standard for first-line treatment of advanced HCC. For this review, the author concisely summarized the current status of molecularly targeted agents that are under clinical development in advanced HCC.     

Molecularly targeted therapy for advanced hepatocellular carcinoma in 2012: current status and future perspectives

Improving the overall survival for patients with advanced hepatocellular carcinoma (HCC) requires development of effective systemic therapy. Despite the successful approval and extensive application of sorafenib, the prognosis for patients with advanced HCC remains poor and the benefits with sorafenib are modest. In the past few years, there have been renewed and continued interests and active research in developing other molecularly targeted agents in HCC. While the initial efforts are focusing on anti-angiogenic therapy, other agents targeting the epidermal growth factor-receptor, mammalian target of rapamycin (mTOR), hepatocyte growth factor/c-Met among others have entered HCC clinical trials. Combining different molecularly targeted agents or combining targeted agents with chemotherapy represent other strategies under investigation. This review will attempt to summarize the current status of other molecularly targeted agents or regimens beyond sorafenib under development in advanced HCC and the future perspectives.     

From molecular biology to targeted therapies for hepatocellular carcinoma: the future is now

Hepatocellular carcinoma (HCC) is characterized as a highly chemoresistant cancer with no effective systemic therapy. Despite surgical or locoregional therapies, prognosis remains poor because of high tumor recurrence or tumor progression, and currently there are no well-established effective adjuvant therapies. The molecular biology of carcinogenesis and tumor progression of HCC has been increasingly understood with intense research in recent years. Several important intracellular signaling pathways such as the Ras/Raf/Mek/Erk pathway and PI3k/Akt/mTOR pathway have been recognized, and the role of several growth factors and angiogenic factors such as EGF and VEGF has been confirmed. Effective agents targeting these molecular abnormalities have been developed and widely tested in preclinical studies of HCC cell lines or xenograft models. Several agents have entered clinical trials in HCC patients, and recent data indicated that a multikinase inhibitor targeting Ras kinase and VEGFR-2, sorafenib, is effective in prolonging survival of patients with advanced HCC. The management of advanced HCC is entering the era of molecular targeting therapy, which is of particular significance for HCC in view of the lack of existing effective systemic therapy for this cancer.     

HCC and angiogenesis: possible targets and future directions

Hepatocellular carcinoma (HCC), the most common primary liver tumor, is notoriously resistant to systemic therapies, and often recurs even after aggressive local therapies. HCCs rely on the formation of new blood vessels for growth, and VEGF is critical in this process. A hallmark of new vessel formation in tumors is their structural and functional abnormality. This leads to an abnormal tumor microenvironment characterized by low oxygen tension. The liver is perfused by both arterial and venous blood and the resulting abnormal microenvironment selects for more-aggressive malignancies. Anti-VEGF therapy with sorafenib was the first systemic therapy to demonstrate improved survival in patients with advanced-stage HCC. This important development in the treatment of HCC raises hope as well as critical questions on the future development of targeted agents including other antiangiogenic agents, which hold promise to further increase survival in this aggressive disease.     

Systemic therapy for hepatocellular carcinoma (HCC): from bench to bedside

Primary liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. For patients with early resectable disease, surgical resection or transplantation is considered a potentially curative modality for hepatocellular carcinoma (HCC); on the other hand, for patients with unresectable or metastatic disease, treatment is essentially palliative and prior to the approval of sorafenib, there was no globally approved systemic treatment for patients presenting with unresectable or metastatic HCC. Sorafenib is the only systemic treatment to demonstrate a statistically significant but modest overall survival benefit in a large phase III trial. Thus, novel systemic approaches represent a high unmet medical need in advanced HCC. In this review article, we will try to take a journey through the history of systemic therapeutic options for HCC passing through the current standard options and exploring the potential new systemic options for this disease.     

Hepatocellular Carcinoma: Review of Targeted and Immune Therapies

Background

Hepatocellular carcinoma is the fifth most common cancer globally and the second leading cause of cancer-related mortality worldwide. Despite the established efficacy of screening programs for at-risk individuals, most patients are diagnosed at later stages of disease, wherein the tumor characteristics or liver disease progressions do not allow for curative interventions. Many cytotoxic chemotherapeutic agents have been tested in patients with advanced disease with disappointing outcomes and poor tolerance; therefore, no standard systemic therapy emerged until the approval of sorafenib in 2006.

Conclusion

Despite the toxicity and low response rate, sorafenib had shown a significant survival benefit in phase III clinical trials, thus encouraging clinical research aimed at advancing the field of molecular therapy. Disrupted signaling pathways related to hepatocellular carcinoma (HCC) include the Wnt/β-catenin, Ras/Raf/MAPK, phosphatidyl inositol 3-kinase/Akt/mechanistic target of rapamycin, hepatocyte growth factor/c-mesenchymal–epithelial transition, IGF, vascular endothelial growth factor, and platelet-derived growth factor pathways, and a variety of agents targeting these pathways are currently under investigation. Additionally, better comprehension of the complex mechanisms underlying the ability of tumor cells to escape immune surveillance has led to impressive results with immunotherapy in many types of cancer, and this treatment strategy is currently being developed for HCC patients. Previous and ongoing targeted therapy and immunotherapy trials for HCC are discussed in this review.

     

Novel molecular targets in hepatocellular carcinoma

Globally, hepatocellular carcinoma (HCC) is a leading cause of cancer and cancer-related deaths. The therapeutic efficacy of locoregional and systemic treatment in patients with advanced HCC remains low, which results in a poor prognosis. The development of sorafenib for the treatment of HCC has resulted in a new era of molecular targeted therapy for this disease. However, the median overall survival was reported to be barely higher in the sorafenib treatment group than in the control group. Hence, in this review we describe the importance of developing more effective targeted therapies for the management of advanced HCC. Recent investigations of molecular signaling pathways in several cancers have provided some insights into developing molecular therapies that target critical members of these signaling pathways. Proteins involved in the Hedgehog and Notch signaling pathways, Polo-like kinase 1, arginine, histone deacetylases and Glypican-3 can be potential targets in the treatment of HCC. Monotherapy has limited therapeutic efficacy due to the development of inhibitory feedback mechanisms and induction of chemoresistance. Thus, emphasis is now on the development of personalized and combination molecular targeted therapies that can serve as ideal therapeutic strategies for improved management of HCC.     

Atezolizumab plus bevacizumab versus sorafenib or atezolizumab alone for unresectable hepatocellular carcinoma: A systematic review

BACKGROUNDDespite the use of current standard therapy, the prognosis of patients with unresectable hepatocellular carcinoma (HCC) is poor, with median survival times of 40 mo for intermediate HCC (Barcelona Clinic Liver Cancer [BCLC] stage B) and 6–8 mo for advanced HCC (BCLC stage C). Although patients with early-stage HCC are usually suitable for therapies with curative intention, up to 70% of patients experience relapse within 5 years. In the past decade, the United States Food and Drug Administration has approved different immunogenic treatment options for advanced HCC, the most common type of liver cancer among adults. Nevertheless, no treatment is useful in the adjuvant setting. Since 2007, the multi-kinase inhibitor sorafenib has been used as a first-line targeted drug to address the increased mortality and incidence rates of HCC. However, in 2020, the IMbrave150 trial demonstrated that combination therapy of atezolizumab (anti-programmed death-ligand 1 [PD-L1]) and bevacizumab (anti-vascular endothelial growth factor [VEGF]) is superior to sorafenib, a single anti-programmed death 1/PD-L1 antibody inhibitor used as an anti-cancer monotherapy for HCC treatment.AIMTo conduct a systematic literature review to evaluate the evidence supporting the efficacy and safety of atezolizumab/bevacizumab as preferred first-line drug therapy over the conventional sorafenib or atezolizumab monotherapies, which are used to improve survival outcomes and reduce disease progression in patients with unresectable HCC and non-decompensated liver disease. METHODSA comprehensive literature review was conducted using the PubMed, Scopus, ScienceDirect, clinicaltrials.gov, PubMed Central, Embase, EuropePMC, and CINAHL databases to identify studies that met the inclusion criteria using relevant MeSH terms. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and risk of bias (RoB) were assessed using the Cochrane RoB 2 tool and Sevis.RESULTSIn the atezolizumab/bevacizumab group, an improvement in overall tumor response, reduction of disease progression, and longer progression-free survival were observed compared to monotherapy with either sorafenib or atezolizumab. Hypertension and proteinuria were the most common adverse events, and the rates of adverse events were comparable to those with the monotherapy. Of the studies, there were two completed trials and two ongoing trials analyzed using high quality and low bias. A more thorough analysis was only performed on the completed trials.CONCLUSIONTreatment of HCC with atezolizumab/bevacizumab combination therapy was confirmed to be an effective first-line treatment to improve survival in patients with unresectable HCC and non-decompensated liver disease compared to monotherapy with either sorafenib or atezolizumab.     

分子靶向药物在肝细胞癌治疗中的临床研究进展

肝癌是全球第六大常见的恶性肿瘤,也是第四大肿瘤相关死亡原因,其中肝细胞癌（hepatocellular carcinoma,HCC）占90%,且80%以上的HCC发生在肝炎和肝硬化等患者中。对于HCC的治疗方面,仅20%的HCC患者可进行手术切除、肝脏移植或射频消融治疗,而晚期HCC患者无法进行根治性治疗,其生存率也逐渐下降。近年来,分子靶向药物治疗已成为研究热点,该类药物可通过特异性的与致癌位点靶向结合而发挥抗癌作用。目前,抗HCC的靶向药物主要分为一线药物与二线药物,其中一线药物主要包括索拉非尼、仑伐替尼,二线药物主要包括瑞戈非尼、卡博替尼及雷莫芦单抗等。本文对此类分子靶向药物在HCC治疗中的临床研究进展进行综述。      

A narrative review of systemic treatment options for hepatocellular carcinoma: state of the art review

Hepatocellular carcinoma (HCC) is an aggressive cancer that typically develops in the setting of underlying cirrhosis of the liver. HCC commonly presents in advanced stages and if eligible orthotopic liver transplantation (OLT) and surgical resection/ablation remain as the only curative options. Prior to 2007, no systemic therapy was available that demonstrated an improvement in survival. Underlying cirrhosis and poor synthetic hepatic function provides a major challenge into effective systemic options contributing to the poor success of cytotoxic chemotherapy in HCC. The first drug to achieve clinical success was sorafenib despite the underwhelming overall survival of 3 months. Since then, other targeted therapies have shown modest benefit as well. Most recently, immunotherapy advances have come to the forefront in the management of HCC and combination therapy with immunotherapy and monoclonal antibodies have now surpassed sorafenib as first line treatment. This article will review the various approved and emerging therapies that have had a significant clinical impact and highlight the future directions and ongoing research that will hopefully translate into better outcomes in the treatment approach of advanced HCC.     

Iron depletion enhances the effect of sorafenib in hepatocarcinoma

Human hepatocellular carcinoma (HCC) is known to have a poor prognosis. Sorafenib, a molecular targeted drug, is most commonly used for HCC treatment. However, its effect on HCC is limited in clinical use and therefore new strategies regarding sorafenib treatment are required. Iron overload is known to be associated with progression of chronic hepatitis and increased risk of HCC. We previously reported that iron depletion inhibited cancer cell proliferation and conversely induced angiogenesis. Indeed iron depletion therapy including iron chelator needs to be combined with anti-angiogenic drug for its anti-cancer effect. Since sorafenib has an anti-angiogenic effect by its inhibitory targeting VEGFR, we hypothesized that sorafenib could complement the anti-cancer effect of iron depletion. We retrospectively analyzed the relationship between the efficacy of sorafenib and serum iron-related markers in clinical HCC patients. In clinical cases, overall survival was prolonged in total iron binding capacity (TIBC) high- and ferritin low-patients. This result suggested that the low iron-pooled patients, who could have a potential of more angiogenic properties in/around HCC tumors, could be adequate for sorafenib treatment. We determined the effect of sorafenib (Nexavar®) and/or deferasirox (EXJADE®) on cancer cell viability, and on cell signaling of human hepatocarcinoma HepG2 and HLE cells. Both iron depletion by deferasirox and sorafenib revealed insufficient cytotoxic effect by each monotherapy, however, on the basis of increased angiogenesis by iron depletion, the addition of deferasirox enhanced anti-proliferative effect of sorafenib. Deferasirox was confirmed to increase vascular endothelial growth factor (VEGF) secretion into cellular supernatants by ELISA analysis. In in vivo study sorafenib combined with deferasirox also enhanced sorafenib-induced apoptosis. These results suggested that sorafenib combined with deferasirox could be a novel combination chemotherapy for HCC.     

肝癌的靶向治疗

肝癌（HCC）是全球最富有挑战性的恶性肿瘤之一。HCC需要综合治疗，目前尚无特效的治疗药物。分子靶向药物的发展，使HCC的全身治疗有了新的希望。阐述了分子靶向药物的现状，多激酶抑制剂、抗血管生成和抗表皮生长因子受体药物在临床上的进展，认为索拉芬尼是晚期HCC的新的标准治疗药物。     

Traitement systémique du carcinome hépatocellulaire

Systemic cytotoxic treatments provide marginal benefit in unresectable or metastatic HCC. With the arrival of molecularly targeted agents, there has been renewed interest in developing novel systemic treatments for HCC. For the first time, results of a phase III randomized, placebo-controlled trial were recently presented in which sorafenib demonstrated improved survival in patients with advanced HCC. Therefore, sorafenib is now the new standard for the first-line treatment of advanced HCC. The identification of predictive factors and the search for new molecules remain major challenges for this poor prognostic disease.     

Surgical treatment for hepatocellular carcinoma in cirrhotic patients. Guide to the selection and decision-making process in a context of multimodal strategy

Hepatocellular carcinoma (HCC) is the fifth most frequent malignant tumour and the third leading cause of death due to cancer worldwide [1]. Surgical treatment is the only long-term curative therapy. But the resection rate remains low in cirrhotic patients due to contraindications imposed mainly by hepatic insufficiency and excessively advanced tumoral stages. In recent years, however, due to the extended use of screening programmes in high-risk patients, tumours are smaller at presentation, making treatments easier. In the current context of shortage of organs for transplantation, surgical resection remains the best available treatment option for most patients with HCC in cirrhotic livers. Despite the encouraging results reported by several groups in terms of overall survival, the high recurrence rate is still an unsolved problem. Recently, a large, randomised, placebo-controlled trial has shown that a multikinase inhibitor targeting Ras-kinase and VEGFR-2, sorafenib, improves survival of patients with advanced HCC. Sorafenib was approved by regulatory agencies during 2007 and is likely to become the new standard therapy for HCC patients with advanced disease.     

Targeted therapy for hepatocellular carcinoma: novel agents on the horizon

Hepatocellular carcinoma (HCC) is the most common liver cancer, accounting for 90% of primary liver cancers. In the last decade it has become one of the most frequently occurring tumors worldwide and is also considered to be the most lethal of the cancer systems, accounting for approximately one third of all malignancies. Although the clinical diagnosis and management of early-stage HCC has improved significantly, HCC prognosis is still extremely poor. Furthermore, advanced HCC is a highly aggressive tumor with a poor or no response to common therapies. Therefore, new effective and well-tolerated therapy strategies are urgently needed. Targeted therapies have entered the field of anti-neoplastic treatment and are being used on their own or in combination with conventional chemotherapy drugs. Molecular-targeted therapy holds great promise in the treatment of HCC. A new therapeutic opportunity for advanced HCC is the use of sorafenib (Nexavar). On the basis of the recent large randomized phase III study, the Sorafenib HCC Assessment Randomized Protocol (SHARP), sorafenib has been approved by the FDA for the treatment of advanced HCC. Sorafenib showed to be able to significantly increase survival in patients with advanced HCC, establishing a new standard of care. Despite this promising breakthrough, patients with HCC still have a dismal prognosis, as it is currently the major cause of death in cirrhotic patients. Nevertheless, the successful results of the SHARP trial underscore the need for a comprehensive understanding of the molecular pathogenesis of this devastating disease. In this review we summarize the most important studies on the signaling pathways implicated in the pathogenesis of HCC, as well as the newest emerging drugs and their potential use in HCC management.     

Early development of sunitinib in hepatocellular carcinoma

Sunitinib malate is an oral, multitargeted receptor tyrosine kinase inhibitor of VEGF receptors 1, 2 and 3; PDGF receptors α and β, and other receptor tyrosine kinases implicated in tumor growth, angiogenesis and metastasis. Hepatocellular carcinoma (HCC) is a highly vascular tumor that overexpresses several angiogenic factors; VEGF and PDGF signaling pathways play a key role in HCC. Until recently, treatment options for advanced HCC were limited and conventional therapies have met with poor response rates. Sorafenib provided proof-of-concept for molecularly targeted therapy in advanced HCC and has recently been approved for treatment. However, not all patients can tolerate sorafenib and patients may experience tumor progression; therefore, additional treatment options are warranted. Sunitinib has shown early evidence of anti-tumor activity in Phase II trials in US, European and Asian patients with locally advanced, unresectable and metastatic HCC. A Phase III trial of sunitinib in HCC is ongoing.     

Sorafenib: key lessons from over 10 years of experience

Introduction: In 2005, sorafenib was the first targeted therapy approved for advanced renal cell carcinoma (RCC), transforming treatment. In hepatocellular carcinoma (HCC), for more than a decade, sorafenib remained the only approved systemic therapy to have demonstrated a survival benefit in first-line unresectable HCC. In 2013, sorafenib was the first targeted agent approved for patients with differentiated thyroid cancer (DTC) refractory to radioactive iodine treatment.

Areas covered: This review discusses the development, advances, and challenges associated with sorafenib use in RCC, HCC, and DTC over the past decade. A search was performed on PubMed and key congresses as required, with no time limits.

Expert commentary: Sorafenib has had a lasting impact on the therapeutic landscape of RCC, HCC, and DTC, and remains an important treatment option despite a rapidly evolving treatment landscape. Extensive clinical and real-world experience has been invaluable in improving patient management and maximizing benefit from treatment. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in HCC and DTC. We have no doubt that sorafenib will continue to be an important treatment option in the coming years.     

Sorafenib therapy in advanced hepatocellular carcinoma: the SHARP trial

Until now, no effective systemic treatment options have been available for patients with unresectable advanced hepatocellular carcinoma (HCC). In the Sorafenib Hepatocellular Carcinoma Assessment Randomized Protocol (SHARP), patients with unresectable advanced HCC with Child–Pugh liver function class A and who had not received prior systemic therapy, received either oral sorafenib (400 mg twice daily) or placebo until radiological and symptomatic progression. The two groups of patients were well balanced with respect to baseline characteristics. The study was stopped at the second planned interim analysis because of an advantage in the median overall survival (10.7 vs 7.9 months; hazard ratio: 0.69; 95% CI: 0.55–0.87; p < 0.001) and the median time to radiological progression (5.5 vs 2.8 months; p < 0.001) in the sorafenib arm. However, sorafenib was not able to increase the time to symptomatic progression. In terms of toxicity, there were more cases of diarrhea, weight loss, hand–foot skin reaction and hypophosphatemia among the patients receiving sorafenib, the majority of which were of grade 1 or 2 severity. The SHARP trial has demonstrated that sorafenib is effective in prolonging median survival and time-to-progression in patients with advanced HCC and that it is generally well tolerated with a manageable adverse events profile.     

SC-2001 Overcomes STAT3-mediated Sorafenib Resistance through RFX-1/SHP-1 Activation in Hepatocellular Carcinoma

Hepatocellular carcinoma is the fifth most common solid cancer worldwide. Sorafenib, a small multikinase inhibitor, is the only approved therapy for advanced HCC. The clinical benefit of sorafenib is offset by the acquisition of sorafenib resistance. Understanding of the molecular mechanism of STAT3 overexpression in sorafenib resistance is critical if the clinical benefits of this drug are to be improved. In this study, we explored our hypothesis that loss of RFX-1/SHP-1 and further increase of p-STAT3 as a result of sorafenib treatment induces sorafenib resistance as a cytoprotective response effect, thereby, limiting sorafenib sensitivity and efficiency. We found that knockdown of RFX-1 protected HCC cells against sorafenib-induced cell apoptosis and SHP-1 activity was required for the process. SC-2001, a molecule with similar structure to obatoclax, synergistically suppressed tumor growth when used in combination with sorafenib in vitro and overcame sorafenib resistance through up-regulating RFX-1 and SHP-1 resulting in tumor suppression and mediation of dephosphorylation of STAT3. In addition, sustained sorafenib treatment in HCC led to increased p-STAT3 which was a key mediator of sorafenib sensitivity. The combination of SC-2001 and sorafenib strongly inhibited tumor growth in both wild-type and sorafenib-resistant HCC cell bearing xenograft models. These results demonstrate that inactivation of RFX/SHP-1 induced by sustained sorafenib treatment confers sorafenib resistance to HCC through p-STAT3 up-regulation. These effects can be overcome by SC-2001 through RFX-1/SHP-1 dependent p-STAT3 suppression. In conclusion, the use of SC-2001 in combination with sorafenib may constitute a new strategy for HCC therapy.     

晚期原发性肝癌治疗的研究进展

原发性肝癌位居全球最常见恶性肿瘤的第五位,在癌症相关死亡原因中排名第三位.原发性肝癌治疗方法的选择很大程度上取决于肝脏功能,肿瘤大小,是否存在转移灶和血管侵犯.目前,原发性肝癌的根治方法包括肝切除术和肝移植手术,但是很多患者确诊时已进入晚期,失去了治愈的机会.全身系统性治疗对于晚期原发性肝癌的患者变得尤为重要,其中包括:分子靶向治疗、全身系统性化疗和免疫治疗.本文就近年来晚期原发性肝癌治疗的研究进展作一综述.