Background/Aims: Besifovir dipivoxil maleate (BSV), an acyclic nucleotide phosphonate, shows potent antiviral activity against hepatitis B virus. Our previous 48-week trial revealed that BSV has comparable antiviral efficacy to tenofovir disoproxil fumarate (TDF) and better safety profiles in terms of improved renal and bone safety. This extension study evaluated the prolonged efficacy and safety of BSV in treatment-naive chronic hepatitis B patients. Methods: Patients continued to participate in an open-label BSV study after an initial 48-week double-blind comparison of BSV and TDF treatment. The antiviral efficacy and drug safety was evaluated up to 192 weeks in two groups: patients continuing BSV treatment (BSV-BSV) and patients switching from TDF to BSV after 48 weeks (TDF-BSV). Results: Among 197 patients receiving randomized treatments, 170 (86%) entered the open-label phase and 152 (77%) entered the 192-week extension study. Virological response rates over 192 weeks were 92.50% and 93.06% in the BSV-BSV and TDF-BSV groups, respectively (P=0.90). Hepatitis B envelop antigen seroconversion and alanine aminotransferase normalization rates were similar between the groups (P=0.75 and P=0.36, respectively). There were no drug-resistant mutations to BSV. Bone mineral density and renal function were well preserved in the BSV-BSV group, whereas these initially worsened then recovered after switching therapy in the TDF-BSV group. Conclusions BSV maintained potent antiviral efficacy after 192 weeks and showed no evidence of drug resistance. BSV was safe, well tolerated, and effective in patients who switched from TDF to BSV. Trial Registration Number: NCT01937806 (date: 10 Sep 2013).

Background/Aims: The immune-tolerant (IT) phase of chronic hepatitis B (CHB) patients is not generally indicative of antiviral therapy (AVT). We assessed and compared the risk of hepatocellular carcinoma (HCC) during the IT-phase stringently defined by a low fibrosis-4 (FIB-4) index, compared to that in patients undergoing AVT. Methods: Among 125 untreated patients that were hepatitis B e-antigen positive, hepatitis B virus-DNA >20,000 IU/mL, with normal alanine aminotransferase level from 2012 to 2018, those with a FIB-4 index of <1.45 were classified into the IT-group. The cumulative probability of HCC was estimated using Kaplan-Meier analysis. All patients were assessed until HCC development (intention-to-treat [ITT] analysis), whereas those suspected of experiencing CHB phase switch were assessed using the per-protocol (PP) and censored at the time of phase switch. Results: The cumulative probability of HCC at 1-, 3-, and 5-years among the IT-group was zero, compared to AVT-treated patients with FIB-4 indices <1.45 during the same period: 0.2%, 0.6%, and 1.4%, respectively (P=0.264 for ITT and P=0.533 for PP). Among the initially screened 125 untreated patients, those with a FIB-4 index of ≥1.45 had a higher risk of HCC compared to the IT-group (P=0.005). Furthermore, among AVT-treated patients, those with a FIB-4 index of ≥1.45 had a higher risk of HCC compared to their counterpart (P<0.001). Conclusions The risk of HCC was negligible in the IT-group stringently defined by a low FIB-4 index. However, given that a higher HCC risk exists among untreated patients with higher FIB-4, appropriate criteria for AVT should be established.

Background/Aims: We investigated changes in recurrence rates and significant recurrence predictors over time after complete cure of hepatocellular carcinoma (HCC). Methods: A total of 1,491 patients with first-time diagnosis of Barcelona Clinic Liver Cancer stage A HCC, completely cured by treatment between 2007 and 2016, were recruited from two Korean tertiary institutes. Results: The mean age of the population (1,144 men and 347 women) was 58.6 years. Of the total population, 914 patients (61.3%) had liver cirrhosis. Nine-hundred and forty-one (63.1%) and 550 (36.9%) patients were treated with surgical resection and radiofrequency ablation (RFA), respectively. One-year cumulative incidences of HCC recurrence were 14.3%, 9.9%, and 5.1% from the time of treatment, 3 years after treatment, and 5 years after treatment, respectively. Upon multivariate analysis, multiple tumors, maximal tumor size ≥3 cm, and high Model for End-Stage Liver Disease scores were independently associated with increased HCC recurrence risk from the time of treatment and 1 and 2 years after curative treatment (all p<0.05, except for maxi-mal tumor size ≥3 cm for recurrence 2 years after treatment). Meanwhile, liver cirrhosis and RFA were independently associated with the increased HCC recurrence risk for almost all time points (liver cirrhosis: all p<0.05; RFA: all p<0.005 except for recurrence from 5 years after treatment). Conclusions The recurrence rate of HCC after curative treatment gradually decreased over time. Two years after treatment, when tumor-related factors lose their prognostic implications, may be used as a cutoff to define the boundary between early and late recurrence of HCC.

Viral hepatitis is the most important cause of acute and chronic liver disease in Korea.Particularly, hepatitis B virus (HBV) is the leading cause of liver-related mortality. Because of the nationwide vaccinations in the 1980s, hepatitis B surface antigen positive rates substantially decreased from 8% to 3%. Moreover, the introduction of potent nucleoside or nucleotide analogs led to the effective treatment of patients who had already been infected by HBV. The remaining issue has been to develop novel drugs that can cure HBV infection.Hepatitis C virus (HCV), on the other hand, is a hepatotropic virus that is parenterally transmitted. In Korea, the prevalence of HCV is estimated to be approximately 1%. Although no effective vaccine for HCV has been developed yet, highly effective and safe direct-acting antiviral therapy, which has a short treatment duration of 8 – 12 weeks, has made HCV eradication possible globally. Currently, the unsolved issue regarding HCV management is low disease awareness among patients and health care providers. Therefore, nationwide testing for anti-HCV would be a solution to identify patients infected with HCV but with no symptoms. Lastly, the Hepatitis A virus (HAV) is orally transmitted and results in acute hepatitis. In Korea, the young adult population is a high-risk group since this group is not vaccinated against HAV. More active vaccination and improved hygiene would be necessary to prevent HAV infection.

Background: Since September 2015, the initiation of antiviral therapy (AVT) for patients with chronic hepatitis B (CHB)-related cirrhosis has been reimbursed according to the revised Korean Association for the Study of Liver (KASL) guideline, if the patient had hepatitis B virus DNA level ≥ 2,000 IU/L, regardless of aminotransferase or alanine aminotransferase levels. This study investigated whether the KASL guideline implementation reduced the risk of CHB-related hepatocellular carcinoma (HCC) in patients with cirrhosis in South Korea. Methods: A total of 429 patients with CHB-related cirrhosis who initiated AVT between 2014 and 2016 were recruited. The risk of HCC development was compared between patients who initiated AVT before and after September 2015 (pre-guideline [n = 196, 45.7%] vs. postguideline implementation [n = 233, 54.3%]). Results: Univariate analysis showed that AVT initiation before guideline implementation, older age, male gender, and diabetes significantly predicted increased risk of HCC development (all P < 0.05). Subsequent multivariate analysis showed that AVT initiation before guideline implementation (HR = 1.941), older age (HR = 5.762), male gender (HR = 2.555), and diabetes (HR = 1.568) independently predicted increased risk of HCC development (all P < 0.05). Additionally, multivariate analysis showed that AVT initiation before guideline implementation (HR = 2.309), male gender (HR = 3.058), and lower platelet count (HR = 0.989) independently predicted mortality (P < 0.05). The cumulative incidences of HCC and mortality were significantly higher in patients who initiated AVT before guideline implementation than in those who initiated AVT after guideline implementation (all P < 0.05, log-rank test). Conclusion The prognosis of patients with CHB-related cirrhosis who initiated AVT improved after guideline implementation according to the revised KASL guideline.

Background/Aims: Besifovir dipivoxil maleate (BSV), an acyclic nucleotide phosphonate, shows potent antiviral activity against hepatitis B virus. Our previous 48-week trial revealed that BSV has comparable antiviral efficacy to tenofovir disoproxil fumarate (TDF) and better safety profiles in terms of improved renal and bone safety. This extension study evaluated the prolonged efficacy and safety of BSV in treatment-naive chronic hepatitis B patients. Methods: Patients continued to participate in an open-label BSV study after an initial 48-week double-blind comparison of BSV and TDF treatment. The antiviral efficacy and drug safety was evaluated up to 192 weeks in two groups: patients continuing BSV treatment (BSV-BSV) and patients switching from TDF to BSV after 48 weeks (TDF-BSV). Results: Among 197 patients receiving randomized treatments, 170 (86%) entered the open-label phase and 152 (77%) entered the 192-week extension study. Virological response rates over 192 weeks were 92.50% and 93.06% in the BSV-BSV and TDF-BSV groups, respectively (P=0.90). Hepatitis B envelop antigen seroconversion and alanine aminotransferase normalization rates were similar between the groups (P=0.75 and P=0.36, respectively). There were no drug-resistant mutations to BSV. Bone mineral density and renal function were well preserved in the BSV-BSV group, whereas these initially worsened then recovered after switching therapy in the TDF-BSV group. Conclusions BSV maintained potent antiviral efficacy after 192 weeks and showed no evidence of drug resistance. BSV was safe, well tolerated, and effective in patients who switched from TDF to BSV. Trial Registration Number: NCT01937806 (date: 10 Sep 2013).

Background/Aims: The immune-tolerant (IT) phase of chronic hepatitis B (CHB) patients is not generally indicative of antiviral therapy (AVT). We assessed and compared the risk of hepatocellular carcinoma (HCC) during the IT-phase stringently defined by a low fibrosis-4 (FIB-4) index, compared to that in patients undergoing AVT. Methods: Among 125 untreated patients that were hepatitis B e-antigen positive, hepatitis B virus-DNA >20,000 IU/mL, with normal alanine aminotransferase level from 2012 to 2018, those with a FIB-4 index of <1.45 were classified into the IT-group. The cumulative probability of HCC was estimated using Kaplan-Meier analysis. All patients were assessed until HCC development (intention-to-treat [ITT] analysis), whereas those suspected of experiencing CHB phase switch were assessed using the per-protocol (PP) and censored at the time of phase switch. Results: The cumulative probability of HCC at 1-, 3-, and 5-years among the IT-group was zero, compared to AVT-treated patients with FIB-4 indices <1.45 during the same period: 0.2%, 0.6%, and 1.4%, respectively (P=0.264 for ITT and P=0.533 for PP). Among the initially screened 125 untreated patients, those with a FIB-4 index of ≥1.45 had a higher risk of HCC compared to the IT-group (P=0.005). Furthermore, among AVT-treated patients, those with a FIB-4 index of ≥1.45 had a higher risk of HCC compared to their counterpart (P<0.001). Conclusions The risk of HCC was negligible in the IT-group stringently defined by a low FIB-4 index. However, given that a higher HCC risk exists among untreated patients with higher FIB-4, appropriate criteria for AVT should be established.

Background/Aims: We investigated changes in recurrence rates and significant recurrence predictors over time after complete cure of hepatocellular carcinoma (HCC). Methods: A total of 1,491 patients with first-time diagnosis of Barcelona Clinic Liver Cancer stage A HCC, completely cured by treatment between 2007 and 2016, were recruited from two Korean tertiary institutes. Results: The mean age of the population (1,144 men and 347 women) was 58.6 years. Of the total population, 914 patients (61.3%) had liver cirrhosis. Nine-hundred and forty-one (63.1%) and 550 (36.9%) patients were treated with surgical resection and radiofrequency ablation (RFA), respectively. One-year cumulative incidences of HCC recurrence were 14.3%, 9.9%, and 5.1% from the time of treatment, 3 years after treatment, and 5 years after treatment, respectively. Upon multivariate analysis, multiple tumors, maximal tumor size ≥3 cm, and high Model for End-Stage Liver Disease scores were independently associated with increased HCC recurrence risk from the time of treatment and 1 and 2 years after curative treatment (all p<0.05, except for maxi-mal tumor size ≥3 cm for recurrence 2 years after treatment). Meanwhile, liver cirrhosis and RFA were independently associated with the increased HCC recurrence risk for almost all time points (liver cirrhosis: all p<0.05; RFA: all p<0.005 except for recurrence from 5 years after treatment). Conclusions The recurrence rate of HCC after curative treatment gradually decreased over time. Two years after treatment, when tumor-related factors lose their prognostic implications, may be used as a cutoff to define the boundary between early and late recurrence of HCC.

Viral hepatitis is the most important cause of acute and chronic liver disease in Korea.Particularly, hepatitis B virus (HBV) is the leading cause of liver-related mortality. Because of the nationwide vaccinations in the 1980s, hepatitis B surface antigen positive rates substantially decreased from 8% to 3%. Moreover, the introduction of potent nucleoside or nucleotide analogs led to the effective treatment of patients who had already been infected by HBV. The remaining issue has been to develop novel drugs that can cure HBV infection.Hepatitis C virus (HCV), on the other hand, is a hepatotropic virus that is parenterally transmitted. In Korea, the prevalence of HCV is estimated to be approximately 1%. Although no effective vaccine for HCV has been developed yet, highly effective and safe direct-acting antiviral therapy, which has a short treatment duration of 8 – 12 weeks, has made HCV eradication possible globally. Currently, the unsolved issue regarding HCV management is low disease awareness among patients and health care providers. Therefore, nationwide testing for anti-HCV would be a solution to identify patients infected with HCV but with no symptoms. Lastly, the Hepatitis A virus (HAV) is orally transmitted and results in acute hepatitis. In Korea, the young adult population is a high-risk group since this group is not vaccinated against HAV. More active vaccination and improved hygiene would be necessary to prevent HAV infection.

Background: Since September 2015, the initiation of antiviral therapy (AVT) for patients with chronic hepatitis B (CHB)-related cirrhosis has been reimbursed according to the revised Korean Association for the Study of Liver (KASL) guideline, if the patient had hepatitis B virus DNA level ≥ 2,000 IU/L, regardless of aminotransferase or alanine aminotransferase levels. This study investigated whether the KASL guideline implementation reduced the risk of CHB-related hepatocellular carcinoma (HCC) in patients with cirrhosis in South Korea. Methods: A total of 429 patients with CHB-related cirrhosis who initiated AVT between 2014 and 2016 were recruited. The risk of HCC development was compared between patients who initiated AVT before and after September 2015 (pre-guideline [n = 196, 45.7%] vs. postguideline implementation [n = 233, 54.3%]). Results: Univariate analysis showed that AVT initiation before guideline implementation, older age, male gender, and diabetes significantly predicted increased risk of HCC development (all P < 0.05). Subsequent multivariate analysis showed that AVT initiation before guideline implementation (HR = 1.941), older age (HR = 5.762), male gender (HR = 2.555), and diabetes (HR = 1.568) independently predicted increased risk of HCC development (all P < 0.05). Additionally, multivariate analysis showed that AVT initiation before guideline implementation (HR = 2.309), male gender (HR = 3.058), and lower platelet count (HR = 0.989) independently predicted mortality (P < 0.05). The cumulative incidences of HCC and mortality were significantly higher in patients who initiated AVT before guideline implementation than in those who initiated AVT after guideline implementation (all P < 0.05, log-rank test). Conclusion The prognosis of patients with CHB-related cirrhosis who initiated AVT improved after guideline implementation according to the revised KASL guideline.