Strategies to enhance the response of liver cancer to pharmacological treatments.

In contrast to other types of cancers, there is no available efficient pharmacological treatment to improve the outcomes of patients suffering from major primary liver cancers, i.e., hepatocellular carcinoma and cholangiocarcinoma. This dismal situation is partly due to the existence in these tumors of many different and synergistic mechanisms of resistance, accounting for the lack of response of these patients, not only to classical chemotherapy but also to more modern pharmacological agents based on the inhibition of tyrosine kinase receptors (TKIs) and the stimulation of the immune response against the tumor using immune checkpoint inhibitors (ICIs). This review summarizes the efforts to develop strategies to overcome this severe limitation, including searching for novel drugs derived from synthetic, semisynthetic, or natural products with vectorial properties against therapeutic targets to increase drug uptake or reduce drug export from cancer cells. Besides, immunotherapy is a promising line of research that is already starting to be implemented in clinical practice. Although less successful than in other cancers, the foreseen future for this strategy in treating liver cancers is considerable. Similarly, the pharmacological inhibition of epigenetic targets is highly promising. Many novel "epidrugs," able to act on "writer," "reader," and "eraser" epigenetic players, are currently being evaluated in preclinical and clinical studies. Finally, gene therapy is a broad field of research in the fight against liver cancer chemoresistance, based on the impressive advances recently achieved in gene manipulation. In sum, although the present is still dismal, there is reason for hope in the non-too-distant future.

Efficacy and safety of regorafenib as a first-line agent alone or in combination with an immune checkpoint inhibitor for advanced hepatocellular carcinoma: a retrospective cohort study.

Background: The RESORCE-III trial demonstrated that advanced hepatocellular carcinoma (HCC) patients who progressed on sorafenib and had second-line therapy with regorafenib improved overall survival compared with placebo. Later, immunotherapy with immune checkpoint inhibitors (ICIs) combined with antiangiogenetic antibodies has evolved as the preferred first-line treatment for fit patients. We aimed to explore the efficacy and safety of regorafenib as a first-line agent alone or in combination with ICIs in patients with advanced HCC. Methods: We identified 50 patients with advanced HCC treated with regorafenib as a first-line agent. Two patients were lost to follow-up and excluded. Baseline factors, dosing, concomitant use of ICIs, toxicity and outcome of treatment were recorded from electronic medical records. Results: Twenty-six patients received regorafenib as monotherapy and twenty-two received regorafenib + ICI in combination. In the total cohort, the median progression-free survival (mPFS) was 7.7 months and the median overall survival (mOS) was 16.7 months (P=0.02). Objective response rate (ORR) and disease control rate (DCR) assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 were 21% and 73%. In the regorafenib monotherapy group, mPFS was 5.9 months, and mOS was 13.9 months; in the combination group, mPFS was 7.8 months, and mOS was 23.6 months. ORR and DCR were 15% and 65% in the monotherapy group, and 27% and 82% in the combined treatment group, respectively. Conclusions: Regorafenib used in combination with ICIs had a mild safety profile and resulted in improved response and an almost doubling of mOS compared to monotherapy, warranting further prospective evaluation in a randomized study.

Risk versus Benefit of Tyrosine Kinase Inhibitors for Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Although the treatment landscape has rapidly evolved over the last years, hepatocellular carcinoma (HCC) is one of the most lethal cancers. With recent advances, both immunotherapy and tyrosine kinase inhibitors (TKIs)-based chemotherapy constitute the standard treatment for advanced HCC. A systematic search of randomized clinical trials employing TKIs was performed in 17 databases, obtaining 25 studies evaluating the prognosis, tumor response, and presence of adverse events (AEs) related to TKIs in HCC. Overall effect sizes were estimated for the hazard ratios (HR) and odds ratios (OR) with 95% confidence interval (CI), either extracted or calculated with the Parmar method, employing STATA 16. Heterogeneity was assessed by Chi-square-based Q-test and inconsistency (I2) statistic; source of heterogeneity by meta-regression and subgroup analysis; and publication bias by funnel plot asymmetry and Egger's test. The research protocol was registered in PROSPERO (CRD42023397263). Meta-analysis revealed a correlation between survival and tumor response parameters and TKI treatment vs. placebo, despite detecting high heterogeneity. Combined TKI treatment showed a significantly better objective response rate (ORR) with no heterogeneity, whereas publication bias was only detected with time to progression (TTP). Few gastrointestinal and neurological disorders were associated with TKI treatment vs. placebo or with combined treatment. However, a higher number of serious AEs were related to TKI treatment vs. sorafenib alone. Results show positive clinical benefits from TKI treatment, supporting the approval and maintenance of TKI-based therapy for advanced HCC, while establishing appropriate strategies to maximize efficacy and minimize toxicity.