The oncogenic role of hepatitis delta virus in hepatocellular carcinoma

Hepatitis delta virus (HDV) is a small defective virus that needs hepatitis B virus (HBV) to replicate and propagate. HDV infection affects 20-40 million people worldwide and pegylated interferon (PegIFN) is the only recommended therapy. There is limited data on the contribution of HDV infection to HBV-related liver disease or liver cancer. Evidence from retrospective and cohort studies suggests that HBV/HDV coinfection accelerates progression to cirrhosis and is associated with an increased risk of hepatocellular carcinoma (HCC) development compared to HBV monoinfection. Although the life cycle of HDV is relatively well known, there is only ancillary information on the molecular mechanisms that can drive specific HDV-related oncogenesis. No thorough reports on the specific landscape of mutations or molecular classes of HDV-related HCC have been published. This information could be critical to better understand the uniqueness, if any, of HDV-related HCC and help identify novel targetable mutations. Herein, we review the evidence supporting an oncogenic role of HDV, the main reported mechanisms of HDV involvement and their impact on HCC development.M. Puigvehi received a scholarship grant from Asociación Española para el Estudio del Hígado (AEEH). A. Villanueva was supported by the DoD Translational Team Science Award (CA150272P3). J.M. Llovet was supported by NCI (P30-CA196521), DoD Translational Team Science Award (CA150272P1), European Commission (EC)/Horizon 2020 Program (HEPCAR, Ref. 667273-2), EIT Health (CRISH2, Ref. 18053), Accelerator Award (CRUCK, AEEC, AIRC) (HUNTER, Ref. C9380/A26813), Samuel Waxman Cancer Research Foundation, Spanish National Health Institute (SAF2016-76390), and the Generalitat de Catalunya/AGAUR (SGR-1358)

Molecular markers of response to anti-PD1 therapy in advanced hepatocellular carcinoma.

Single agent anti-PD1 checkpoint inhibitors convey outstanding clinical benefits in a small fraction (∼20%) of patients with advanced hepatocellular carcinoma (aHCC) but the molecular mechanisms determining response are unknown. To fill this gap, we herein analyze the molecular and immune traits of aHCC in patients treated with anti-PD1. Overall, 111 tumor samples from patients with aHCC were obtained from 13 centers prior to systemic therapies. We performed molecular analysis and immune deconvolution using whole genome expression data (n=83), mutational analysis (n=72) and histological evaluation with an endpoint of objective response. Among 83 patients with transcriptomic data, 28 were treated in frontline whereas 55 patients were treated after tyrosine-kinase inhibitors (TKI) either in 2 <sup>nd</sup> or 3 <sup>rd</sup> line. Responders treated in frontline showed upregulated Interferon-γ-signaling and MHCII-related antigen presentation. We generated an 11-gene signature (IFNAP), capturing these molecular features, which predicts response and survival in patients treated with anti-PD1 in frontline. The signature was validated in a separate cohort of aHCC and >240 patients with other solid cancer types where it also predicted response and survival. Of note, the same signature was unable to predict response in archival tissue of patients treated with frontline TKIs, highlighting the need for fresh biopsies prior to immunotherapy. IFN-signaling and MHCII-related genes are key molecular features of HCCs responding to anti-PD1. A novel 11-gene signature predicts response in frontline aHCC - but not in patients pre-treated with TKIs. These results have to be confirmed in prospective studies and highlight the need for biopsies prior immunotherapy to identify biomarkers of response

Quantification of HBsAg to predict low levels and seroclearance in HBeAg-negative patients receiving nucleos(t)ide analogues

BACKGROUND: HBeAg-negative chronic hepatitis B patients require long-term nucleos(t)ide analogues(NAs) because loss of surface antigen (HBsAg) is unusual. Low quantitative HBsAg (qHBsAg) levels can identify patients with higher probability of seroclearance. The aim of our study was to evaluate qHBsAg in HBeAg-negative patients receiving NAs to predict a reduction of HBsAg levels and seroclearance. METHODS: Retrospective analysis of qHBsAg in HBeAg-negative patients before and at years 1, 3, 5, 8 and over of NAs treatment. RESULTS: From 1999 to 2015, HBsAg was quantified in 358 serum samples from 95 HBeAg-negative patients. Low qHBsAg (0.3 log IU/mL showing a positive and negative predictive value of 42% and 100% to identify patients achieving low levels of HBsAg. CONCLUSIONS: Reduction of qHBsAg is slow in HBeAg-negative patients receiving NAs, although low levels or faster qHBsAg decline may occur in 14%. A qHBsAg reduction >0.3 log IU/mL at year 3 can identify patients with a higher probability of achieving low levels and HBsAg seroclearance

Molecular markers of response to anti-PD1 therapy in advanced hepatocellular carcinoma.

BACKGROUND AND AIMS Single agent anti-PD1 checkpoint inhibitors convey outstanding clinical benefits in a small fraction (∼20%) of patients with advanced hepatocellular carcinoma (aHCC) but the molecular mechanisms determining response are unknown. To fill this gap, we herein analyze the molecular and immune traits of aHCC in patients treated with anti-PD1. METHODS Overall, 111 tumor samples from patients with aHCC were obtained from 13 centers prior to systemic therapies. We performed molecular analysis and immune deconvolution using whole genome expression data (n=83), mutational analysis (n=72) and histological evaluation with an endpoint of objective response. RESULTS Among 83 patients with transcriptomic data, 28 were treated in frontline whereas 55 patients were treated after tyrosine-kinase inhibitors (TKI) either in 2nd or 3rd line. Responders treated in frontline showed upregulated Interferon-γ-signaling and MHCII-related antigen presentation. We generated an 11-gene signature (IFNAP), capturing these molecular features, which predicts response and survival in patients treated with anti-PD1 in frontline. The signature was validated in a separate cohort of aHCC and >240 patients with other solid cancer types where it also predicted response and survival. Of note, the same signature was unable to predict response in archival tissue of patients treated with frontline TKIs, highlighting the need for fresh biopsies prior to immunotherapy. CONCLUSION IFN-signaling and MHCII-related genes are key molecular features of HCCs responding to anti-PD1. A novel 11-gene signature predicts response in frontline aHCC - but not in patients pre-treated with TKIs. These results have to be confirmed in prospective studies and highlight the need for biopsies prior immunotherapy to identify biomarkers of response