Why does every hepatocellular carcinoma clinical trial using molecular targeted agents fail?

Patient-derived precision cut tissue slices from primary liver cancer as a potential platform for preclinical drug testing

BACKGROUND

The exploitation of anti-tumour immunity, harnessed through immunomodulatory therapies, has fundamentally changed the treatment of primary liver cancer (PLC). However, this has posed significant challenges in preclinical research. Novel immunologically relevant models for PLC are urgently required to improve the translation from bench to bedside and back, explore and predict effective combinatorial therapies, aid novel drug discovery and develop personalised treatment modalities.

METHODS

We used human precision-cut tissue slices (PCTS) derived from resected tumours to create a patient-specific immunocompetent disease model that captures the multifaceted and intricate heterogeneity of the tumour and the tumour microenvironment. Tissue architecture, tumour viability and treatment response to single agent and combination therapies were assessed longitudinally over 8 days of ex vivo culture by histological analysis, detection of proliferation/cell death markers, ATP content via HPLC. Immune cell infiltrate was assessed using PCR and immunofluorescence. Checkpoint receptor expression was quantified via Quantigene RNA assay.

FINDINGS

After optimising the culture conditions, PCTS maintained the original tissue architecture, including tumour morphology, stroma and tumour-infiltrated leukocytes. Moreover, PCTS retained the tumour-specific immunophenotype over time, suggesting the utility of PCTS to investigate immunotherapeutic drug efficacy and identify non-responsiveness.

INTERPRETATION

Here we have characterised the PCTS model and demonstrated its effectiveness as a robust preclinical tool that will significantly support the development of successful (immuno)therapeutic strategies for PLC.

FUNDING

Foundation for Liver Research, London.

Metronomic capecitabine versus best supportive care as second-line treatment in hepatocellular carcinoma: a retrospective study

Preliminary studies suggest that capecitabine may be safe and effective in HCC patients. The aim of this study was to retrospectively evaluate the safety and efficacy of metronomic capecitabine as second-line treatment. This multicentric study retrospectively analyzed data of HCC patients unresponsive or intolerant to sorafenib treatment with metronomic capecitabine or best supportive care (BSC).Median progression free survival was 3.1 months in patients treated with capecitabine (95%CI: 2.7-3.5). Median overall survival was 12.0 months (95% CI: 10.7-15.8) in patients receiving capecitabine, while 9.0 months (95% CI: 6.5-13.9) in patients receiving BSC. The result of univariate unweighted Cox regression model shows a 46% reduction in death risk for patients on capecitabine (95%CI: 0.357-0.829; p  =0.005) compared to patients receiving BSC alone. After weighting for potential confounders, death risk remained essentially unaltered (45%; 95%CI: 0.354-0.883; p = 0.013). Metronomic capecitabine seems a safe second-line treatment for HCC patients in terms of management of adverse events, showing a potential anti-tumour activity which needs further evaluation in phase III studies.

Molecular Mechanism and Prediction of Sorafenib Chemoresistance in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide, and prognosis remains unsatisfactory when the disease is diagnosed at an advanced stage. Many molecular targeted agents are being developed for the treatment of advanced HCC; however, the only promising drug to have been developed is sorafenib, which acts as a multi-kinase inhibitor. Unfortunately, a subgroup of HCC is resistant to sorafenib, and the majority of these HCC patients show disease progression even after an initial satisfactory response. To date, a number of studies have examined the underlying mechanisms involved in the response to sorafenib, and trials have been performed to overcome the acquisition of drug resistance. The anti-tumor activity of sorafenib is largely attributed to the blockade of the signals from growth factors, such as vascular endothelial growth factor receptor and platelet-derived growth factor receptor, and the downstream RAF/mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK cascade. The activation of an escape pathway from RAF/MEK/ERK possibly results in chemoresistance. In addition, there are several features of HCCs indicating sorafenib resistance, such as epithelial-mesenchymal transition and positive stem cell markers. Here, we review the recent reports and focus on the mechanism and prediction of chemoresistance to sorafenib in HCC.

Metronomic capecitabine as second-line treatment in hepatocellular carcinoma after sorafenib failure

BACKGROUND

No standard second-line treatments are available for hepatocellular carcinoma patients who fail sorafenib therapy. We assessed the safety and efficacy of metronomic capecitabine after first-line sorafenib failure.

METHODS

Retrospective analysis of consecutive hepatocellular carcinoma patients receiving metronomic capecitabine between January 2012 and November 2014. The primary end-point was safety, secondary end-point was efficacy, including time-to-progression and overall survival.

RESULTS

Twenty-six patients (80% Child-Pugh A, 80% Barcelona Clinic Liver Cancer stage C) received metronomic capecitabine (500 mg/bid). Median treatment duration was 3.2 months (range 0.6-31). Fourteen (53%) patients experienced at least one adverse event. The most frequent drug-related adverse events were bilirubin elevation (23%), fatigue (15%), anaemia (11%), lymphoedema (11%), and hand-foot syndrome (7.6%). Treatment was interrupted in 19 (73%) for disease progression, in 4 (15%) for liver deterioration, and in 1 (3.8%) for adverse event. Disease control was achieved in 6 (23%) patients. Median time-to-progression was 4 months (95% confidence interval 3.2-4.7). Median overall survival was 8 months (95% confidence interval 3.7-12.3).

CONCLUSIONS

Metronomic capecitabine was well tolerated in hepatocellular carcinoma patients who had been treated with sorafenib. Preliminary data show potential anti-tumour activity with long-lasting disease control in a subgroup of patients that warrants further evaluation in a phase III study.

Alteration of Epigenetic Profile in Human Hepatocellular Carcinoma and Its Clinical Implications

Hepatocellular carcinoma (HCC) is a common cancer worldwide and develops against a background of chronic liver damage. A variety of HCC-related genes are known to be altered by genetic and epigenetic mechanisms. Therefore, information regarding alteration of the genetic and epigenetic profiles in HCC is essential for understanding the biology of this type of tumor. Methylation at CpG sites in gene promoters is known to affect the transcription of the corresponding genes. Abnormal regional hypermethylation is observed in the 5' region of several tumor suppressor genes (TSGs) in HCC, and this hypermethylation may promote carcinogenesis through the transcriptional inactivation of downstream TSGs. The DNA damage induced by oxidation is a trigger of abnormal DNA methylation and inactivation of TSGs through recruitment of the polycomb repressive complex to the promoter sequence. Thus, oxidative stress may be responsible for the emergence of HCC from chronic hepatitis and liver cirrhosis through the epigenetic alteration of TSGs. There have been several attempts to apply epigenetic information to the diagnosis and treatment of HCC. The predictive value of selected methylation events on survival in HCC patients has been reported, and the methylation profile of background liver could be associated with recurrence-free survival of HCC patients who have undergone hepatectomy. Another study detected methylated DNA from HCC cells in serum, and the circulating tumor DNA was regarded as a potential tumor marker. In addition, several trials of HCC therapy have targeted the epigenetic machinery and were based upon comprehensive analyses of DNA methylation of this type of tumor. Here, we present an overview of research regarding DNA methylation status in human HCC and describe the clinical application of epigenetic information to HCC.

Drug therapy for advanced-stage liver cancer

Liver cancer was traditionally treated by surgery or interventional ablative treatments, or, if these options were not feasible, by best supportive care. Since 2008, systemic therapy with the multikinase inhibitor sorafenib has become available worldwide and has become the standard of care for unresectable/non-ablatable or advanced-stage hepatocellular carcinoma (HCC). Sorafenib is able to improve the median overall survival by approximately 3 months. Despite this significant advance in the non-surgical/non-interventional management of liver cancer, this improvement in overall survival is only a first step toward more potent, more targeted, and better tolerated oral antitumor treatments. Since the introduction of sorafenib into clinical practice, several attempts have been made to develop even more effective first-line treatments as well as an effective second-line treatment for HCC. None of these endeavors has been successful so far. The development of drug treatments for HCC has been particularly hampered by the unfortunate push to establish the diagnosis of liver cancer by non-invasive imaging alone, without requiring a liver biopsy for histologic confirmation: this precluded the very necessary search for informative biomarkers and the search for molecular targets for drug development in HCC. This important drawback is being increasingly recognized and corrected. Despite several obstacles remaining to be overcome, it seems reasonable to assume that using a rational, data-driven approach, we will be able to develop better drug treatments for liver cancer in the coming years.