Sorafenib—a broad tyrosine kinase inhibitor—is the only approved systemic therapy for advanced hepatocellular carcinoma (HCC), but provides limited survival benefits. Recently, immunotherapy has emerged as a promising treatment strategy, but its role remains unclear in HCCs, which are associated with decreased cytotoxic CD8+ T-lymphocyte infiltration in both murine and human tumors. Moreover, we have shown in mouse models that after sorafenib treatment, intratumoral hypoxia is increased and may fuel evasive resistance. Using orthotopic HCC models, we now show that increased hypoxia after sorafenib treatment promotes immunosuppression, characterized by increased intratumoral expression of the immune checkpoint inhibitor programmed death-ligand 1 (PD-L1) and accumulation of T-regulatory cells and M2-type macrophages. We also show that the recruitment of the immunosuppressive cells is mediated in part by hypoxia-induced upregulation of stromal cell-derived 1 alpha (SDF1α). Inhibition of the SDF1α receptor (C-X-C receptor type 4 or CXCR4) using AMD3100 prevented the polarization toward an immunosuppressive microenvironment after sorafenib treatment, inhibited tumor growth, reduced lung metastasis, and improved survival. However, combination of AMD3100 and sorafenib did not significantly change cytotoxic CD8+ T-lymphocyte infiltration into HCC tumors and did not modify their activation status. In separate experiments, antibody blockade of the PD-L1 receptor PD-1 showed anti-tumor effects in treatment-naïve tumors in orthotopic (grafted and genetically engineered) models of HCC. However, anti-PD-1 antibody treatment had additional anti-tumor activity only when combined with sorafenib and AMD3100, and not when combined with sorafenib alone.
Conclusion
Anti-PD-1 treatment can boost anti-tumor immune responses in HCC models. When used in combination with sorafenib, this immunotherapy approach shows efficacy only with concomitant targeting of the hypoxic and immunosuppressive microenvironment with agents such as CXCR4 inhibitors.
Infections ACLF Death Different clinical courses of acutely decompensated cirrhosis Pre-ACLF Unstable decompensated cirrhosis Stable decompensated cirrhosis 0 90 180 270 360 Days Highlights Patients with acutely decompensated cirrhosis without ACLF develop 3 different clinical courses. Patients with pre-ACLF develop ACLF within 90 days and have high systemic inflammation and mortality. Patients with unstable decompensated cirrhosis suffer from complications of severe portal hypertension. Patients with stable decompensated cirrhosis have less frequent complications and lower 1-year mortality risk.
Objective Non-selective β-blockers or endoscopic band ligation (EBL) are recommended for primary prophylaxis of variceal bleeding in patients with oesophageal varices. Additional α-adrenergic blockade (as by carvedilol) may increase the number of patients with haemodynamic response (reduction in hepatic venous pressure gradient (HVPG) of ≥20% or to values <12 mm Hg). Design Patients with oesophageal varices undergoing measurement of HVPG before and under propranolol treatment (80-160 mg/day) were included. HVPG responders were kept on propranolol (PROP group), while non-responders were placed on carvedilol (6.25-50 mg/day). Carvedilol responders continued treatment (CARV group), while non-responders to carvedilol underwent EBL. The primary aim was to assess haemodynamic response rates to carvedilol in propranolol non-responders. Results 36% (37/104) of patients showed a HVPG response to propranolol. Among the propranolol nonresponders 56% (38/67) eventually achieved a haemodynamic response with carvedilol, while 44% (29/67) patients were finally treated with EBL. The decrease in HVPG was significantly greater with carvedilol (median 12.5 mg/day) than with propranolol (median 100 mg/day): −19±10% versus −12±11% ( p<0.001). During a 2 year follow-up bleeding rates for PROP were 11% versus CARV 5% versus EBL 25% ( p=0.0429). Fewer episodes of hepatic decompensation (PROP 38%/CARV 26% vs EBL 55%; p=0.0789) and significantly lower mortality (PROP 14%/CARV 11% vs EBL 31%; p=0.0455) were observed in haemodynamic responders compared to the EBL group. Conclusions Carvedilol leads to a significantly greater decrease in HVPG than propranolol. Using carvedilol for primary prophylaxis a substantial proportion of nonresponders to propranolol can achieve a haemodynamic response, which is associated with improved outcome with regard to prevention of variceal bleeding, hepatic decompensation and death.
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