3535 POSTER Phase II trial investigating the efficacy and safety of sunitinib in patients with unresectable hepatocellular carcinoma (HCC)

Molecularly targeted therapy in hepatocellular carcinoma

With an annual incidence of over 660,000 deaths, hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally. This disease is often diagnosed at an advanced stage, when potentially curative therapies are not feasible. HCC is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Given the clear need, clinical development of novel therapeutic agents in HCC has begun in earnest. Our recent knowledge of the molecular mechanisms responsible of tumor initiation and progression has identified several potential molecular targets in HCC. These targets are the receptor tyrosine kinase-activated pathways, which include the Raf/MEK/ERK, PI-3K/Akt/mTOR, and Jak/Stat. Sorafenib is the multikinase inhibitor that has shown modest survival benefits in advanced HCC in two randomized controlled trials, supporting the use of molecularly targeted therapies in treatment of HCC. A number of strategies including monoclonal antibodies and tyrosine kinase inhibitors such as erlotinib, sunitinib, vandetanib, cediranib, brivanib, foretinib, and dovitinib have been developed and tested in various phases of clinical trials. The successful development of these novel targeted agents in the future will be dependent on the selection of patient populations that are most likely to derive clinical benefit, optimization of the dose used and schedules, and investigation of combined therapies. This review describes evolving molecular targeted agents, their common adverse side effects, and its potential use in management of HCC.

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.

Treatment options for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is frequently diagnosed at advanced stages and has a high mortality rate. With improved survival of patients with cirrhotic liver disease and increased prevalence of chronic hepatitis C viral infections, a rise in the number of HCC cases is being reported worldwide. Early diagnosis and treatment can significantly improve the prognosis of patients with HCC. Although surgical resection is an important potentially curative therapy for liver tumors, in appropriately selected patients, liver transplantation has been shown to achieve excellent survival rates for a solid tumor. Locally ablative and locoregional therapies in the form of percutaneous ethanol injection, radiofrequency ablation, transcatheter arterial chemoembolization and transcatheter arterial radioembolization (TheraSphere) are viable options in patients with unresectable HCC. Unfortunately, the role of systemic therapy has been very limited in the treatment of these patients. Novel treatment options based on an improved understanding of the molecular pathogenesis of HCC are being explored. These targeted molecular therapies are aimed at growth factors and their receptors, intracellular signal transduction and cell cycle control. A substantial improvement in outcomes of intermediate and advanced stage HCC is expected with the advent of these targeted therapies, used in combination with surgical or locoregional therapies. Recent positive results from a large Phase III study of the receptor tyrosine kinase inhibitor, sorafenib, hold great promise in the treatment of HCC.