Application and Impact of Antiviral Therapy for Patients with HBV-Related Hepatocellular Carcinoma Receiving Sorafenib and Lenvatinib Treatment

Overall survival (OS) in patients with advanced hepatocellular carcinoma (HCC) has improved in the era of multi-line sequential therapy. The application of antiviral therapy and its impact on survival for patients with HBV-related HCC needs to be reassessed. The aim of this study was to evaluate the application and impact of antiviral therapy on survival for patients with HBV-related HCC receiving tyrosine kinase inhibitor (TKI) therapy. Patients with advanced HBV-related HCC treated with sorafenib or lenvatinib as first-line therapy with (n = 377) and without (n = 182) nucleos(t)ide analogue (NUC) therapy were retrospectively enrolled. Prognostic factors of OS were evaluated. Secular trends in the increased application of NUC therapy and improved survival were observed in the last decade. The HBV reactivation rate in patients without NUC therapy was 6.6%. By multivariate analysis, baseline low HBV viral load, achieving undetectable HBV DNA after TKI therapy, and ability to receive second-line therapy were found to be independent predictors of OS. In subgroup patients with NUC therapy, starting NUC before TKI was associated with a better OS. In conclusion, the application of antiviral therapy for patients with HBV-related HCC receiving TKI therapy has increased over time. Achieving complete virological suppression may contribute to a better OS in patients with advanced HBV-related HCC.


Introduction
Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths in the world, and chronic hepatitis B virus (HBV) infection is the major cause of HCC, especially in Asia [1]. HBV viral activity has a negative impact on the outcomes in patients with HBV-related HCC, and antiviral therapy has been shown to decrease the risk of HCC recurrence and improve survival in patients with early-stage HCC after curative treatment [2][3][4][5]. In patients with advanced-stage HCC, atezolizumab plus bevacizumab is currently the recommended first-line treatment [6,7], while tyrosine kinase inhibitors (TKI) including sorafenib [8,9] or lenvatinib [10] remain the first-line treatment options in cases where atezolizumab plus bevacizumab is contraindicated.
In patients receiving sorafenib for advanced-stage HCC, previous studies showed that high HBV viral load was associated with a poorer overall survival (OS), whereas antiviral therapy might provide a survival benefit [11][12][13]. Liver function decline is frequently encountered during TKI therapy and was associated with worse survival outcomes [14,15].
The risk of liver function deterioration during TKI therapy might be higher in patients with a high viral load but no antiviral therapy. Furthermore, HBV reactivation is also a specific concern in HBV-infected patients receiving anti-cancer treatment [16,17]. HBV reactivation could also develop in patients with HBV-related HCC receiving TKI therapy, but only a few studies with limited case numbers have been reported [18].
Several second-line treatment options have become available for advanced-stage HCC in the past few years, including regorafenib, cabozantinib, ramucirumab, and immune checkpoint inhibitors (ICIs) [19]. Nevertheless, patients with deteriorated liver function at the time of disease progression may have less chance to receive second-line HCC treatment [20,21]. The OS in patients with advanced HCC gradually improved in the era of multi-line sequential therapy. The application of antiviral therapy and its impact on survival for patients with HBV-related HCC needs to be reassessed. The aim of this study was to evaluate the application and impact of antiviral therapy on survival for patients with HBV-related HCC receiving TKI therapy.

Patients
From June 2012 to January 2022, we retrospectively screened 1276 patients who received sorafenib or lenvatinib as first-line therapy for unresectable HBV-related HCC in Taipei Veterans General Hospital ( Figure 1). Patients were included if they fulfilled the following criteria: (1) age ≥ 20 years; (2) diagnosis of HCC according to the criteria of the American Association for the Study of Liver Diseases (AASLD) guidelines [22]; and (3) Barcelona Clinic Liver Cancer (BCLC) stage C or stage B refractory to transarterial chemoembolization (TACE). The exclusion criteria were as follows: (1) HBsAg-negative (n = 570); (2) died or lost to follow-up within 2 months after starting (n = 72); (3) receiving concurrent immunotherapy during TKI therapy (n = 72); (4) Child-Pugh class C (n = 3). This study adhered to the guidelines Declaration of Helsinki and gained the consent of the Institutional Review Board in Taipei Veterans General Hospital (IRB number: 2022-08-015AC). The Institutional Review Board waived the need for written in-formed consent due to the retrospective nature of the study.
The standard regimen of sorafenib was 400 mg twice daily [20,23,24], while the daily dose of lenvatinib was 12 mg for patients with body weight ≥ 60 kg and 8 mg for patients with body weight < 60 kg [25]. The dosage of sorafenib or lenvatinib was modified upon the development of adverse events. Treatments of sorafenib or lenvatinib were continued until the occurrence of radiologic progression, death, or unacceptable adverse events.

Patient Assessment
Tumor measurements were performed at screening and every 2 months during treatment by contrast-enhanced computed tomography (CECT) or magnetic resonance imaging (MRI), which complied with the regulations of the National Health Insurance Administration, Taiwan. Patients visited the clinic every 2 to 4 weeks for evaluation of liver function and assessment of adverse events [20,23,24]. Detailed demographic profile, tumor characteristics, and biochemistry data at baseline and during follow-up were recorded. These data included age, gender, serum HBV DNA, HBsAg, HBeAg, anti-hepatitis C virus antibody, type of nucleos(t)ide analogues (NUCs) for HBV, BCLC stage, macrovascular invasion, extrahepatic metastasis, serum creatinine, albumin, total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alpha-fetoprotein (AFP) levels, and platelet count. The ALBI score and grade were calculated as previously described [26,27]. HBV DNA levels were measured by the Roche Cobas Taqman HBV DNA assay with detection limit of 20 IU/mL (Roche Diagnostics, Switzerland).

Outcome Assessment
We used the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria to assess radiologic response [24,28]. Disease progression was defined as an increase of at least 20% in the sum of the diameters of viable target lesions evaluated by CECT or MRI every 2 months during TKI treatment. Progression-free survival (PFS) was defined as the time interval between the day of the starting TKI treatment and disease progression. Overall survival (OS) was defined as the time interval between the day of the starting TKI treatment and death.
Patients who started antiviral therapy within 2 months of starting TKI therapy were classified as the NUC therapy group, whereas patients without antiviral therapy, or who started antiviral therapy after 2 months of starting TKI therapy, were classified as the nonantiviral therapy group. The virological response was defined as achieving undetectable HBV DNA after NUC therapy [17]. HBV reactivation was defined according to the AASLD criteria [29].

Statistical Analysis
IBM SPSS Statistics for Windows, Version 22 (IBM, Armonk, NY), was used to perform all statistical analyses. Values were expressed as mean ± standard deviation (SD) or median (interquartile range, IQR) when appropriate. Continuous variables were compared by Mann-Whitney U test. Categorical variables were compared by Pearson chi-square analysis. The survival rate was estimated by the Kaplan-Meier method. The survival curve between patient groups was compared by the log-rank test. The Cox proportional hazards model was used for analysis of survival factors. Factors that achieved p < 0.1 by univariate analysis were subsequently included in the multivariate analysis. A two-tailed p-value < 0.05 was considered as statistically significant.

Patient Characteristics
This study enrolled a total of 559 patients, including 377 patients in the NUC therapy group and 182 patients in the non-antiviral therapy group ( Figure 1). The baseline characteristics of the enrolled patients are shown in Table 1. Most of the patients were in BCLC stage C and Child-Pugh class A. Patients in the NUC therapy group had significant lower serum HBV DNA levels, a higher proportion of patients with undetectable HBV DNA, and lower AFP levels. The BCLC stage, status of portal vein invasion, extrahepatic metastasis, Child-Pugh class, and ALBI grade were comparable between the two groups. In patients with antiviral therapy, the majority of them received NUCs with a high genetic barrier (entecavir, tenofovir disoproxil fumarate, tenofovir alafenamide), and started antiviral therapy before the use of TKI (83.3%).

Main Outcomes in Patients with and without NUC Therapy
The median follow-up period was 14.1 and 11.9 months in the NUC therapy and nonantiviral therapy groups, respectively (p = 0.442). The median duration of sorafenic/lenvatinib treatment was 86 and 73.5 days in those with and without NUC therapy, respectively (p = 0.156). The major outcomes in patients with and without NUC therapy are shown in Table 2. The PFSs were not significantly different in patients with and without antiviral therapy (2.6 vs. 2.4 months, p = 0.914), whereas the OS was significantly longer in the NUC therapy group (9.2 vs. 8.1 months, p = 0.017). Patients in the NUC therapy group had a significantly higher chance of receiving second-line systemic therapy (41.4% vs. 30.8%, p = 0.020). The virological response rate was 82% in patients with NUC therapy. In patients without NUC therapy, 12 (6.6%) cases developed HBV reactivation, and 2 (16.7%) of them died of hepatic decompensation despite immediate NUC therapy after HBV reactivation.  Figure 2B).  Because lenvatinib was introduced in Taiwan in 2019, we compared the PFS and OS between patients receiving lenvatinib and sorafenib during 2019-2022. The median PFS was significantly longer in patients with lenvatinib treatment (4.9 vs. 3.4 months, Figure 2C), while the OS was comparable between patients treated with lenvatinib and sorafenib (14.8 vs. 12.7 months, p = 0.339, Figure 2D).

Discussion
In this study, we evaluated the secular trends in the application of NUC therapy and its impact on survival in patients with advanced HCC receiving TKI. We showed an increased application of antiviral therapy and improved OS over time in the last decade. In particular, achieving complete HBV suppression was identified as an important factor associated with improved survival.
Our data showed that the median OS in patients with advanced HCC receiving TKI therapy significantly improved from 7 months during 2012-2015 to 12.8 months during 2019-2022. The application of NUC therapy and second-line systemic therapy also significantly increased during 2019-2022. A previous study showed that physicians' experience in managing adverse events with tailored sorafenib dosing has improved over time, which has led to increased sorefenib treatment duration and prolonged survival of HCC patients [30]. A recent study from Hong Kong showed that the secular trend of NUC therapy uptake gradually increased in recent years, which may also have contributed to the improved survival in patients with HBV-related HCC [31]. Lenvatinib and regorafenib were reimbursed by the national health insurance program in Taiwan after 2019. Other treatment options, such as immunotherapy, cabozantinib, and ramicirumab, were also available options as second-line therapy in recent years [21,25]. Consistent with the REFLECT trial and recent real-world studies [10,32,33], our data showed that the median OS was comparable between patients receiving lenvatinib and sorafenib during 2019-2022, even though numerically longer by Lenvatinib, while the median PFS was significantly longer in patients with lenvatinib treatment. Our data also showed that patients with NUC therapy were associated with a higher chance of receiving second-line systemic therapy. Our recent study showed that patients who were able to receive regorafenib after sorafenib failure had a median OS of 13.1 months after starting regorafenib treatment [21]. These data suggest that the application of NUC therapy and multi-line sequential therapy may prolong the survival of patients with advanced HBV-related HCC.
The virological response rate after NUC therapy was 81.3%, which was lower than the response rate of NUC prophylaxis for cancer patients undergoing chemotherapy [16,17]. Since patients with advanced HCC generally had higher baseline viral load and shorter OS as compared to cancer patients undergoing chemotherapy, the virological response might not be achieved in the short term after TKI therapy. There were only a few studies that reported the risk of HBV reactivation during TKI therapy for patients with HCC, and a recent systemic review showed that the pooled rate of HBV reactivation was 6.2% after sorafenib therapy [11,18]. In this study, we reported an HBV reactivation rate of 6.6% in patients without antiviral therapy, suggesting a moderate risk of HBV reactivation after TKI therapy for HBV-related HCC.
BCLC stage, ALBI grade, AFP level, and high HBV viral load were identified as independent baseline predictors of OS, while achieving undetectable HBV DNA and the ability to receive second-line therapy were on-treatment predictors of OS. Tumor factors and liver function reserve are well-known prognostic factors of patients with HCC [23,27,34]. HBV viral factors may also have an important impact on the prognosis of HBV-related HCC [3,11,35]. A recent study showed that patients with well-controlled viremia had a significantly better OS after sorafenib treatment [36]. Consistent with this study, our data showed that baseline low HBV viral load or undetectable HBV DNA was associated with a significantly better OS. Furthermore, achieving undetectable HBV DNA during TKI therapy was also an independent predictor of OS. In subgroup patients with NUC therapy, patients who had already received NUC treatment before starting TKI had significantly better OS than those who started NUC treatment after TKI. Patients who started NUC therapy earlier may achieve complete viral suppression earlier, which may lead to better survival after TKI treatment.
There are some limitations in this study. First, this is a retrospective study from a single tertiary medical center. Some patients lacked HBV DNA data at baseline and after TKI therapy. Especially patients with shorter OS may not have the chance to check virological response during follow-up. Second, the case number among patients receiving lenvatinib treatment was relatively small. A significant proportion of patients receiving lenvatinib in our institution had concurrent pembrolizumab use and were excluded from analysis [25]. The impact of NUC therapy in patients with TKI plus immune checkpoint inhibitor therapy also warrants further study. Third, the impact of quantitative HBsAg level and HBV genotype could not be assessed in this study. In Taiwan, the majority of CHB patients were infected with HBV genotype B or C [37,38]. Whether HBsAg level and HBV genotype had a prognostic impact in patients with HCC receiving TKI therapy needs further investigation.
In conclusion, the application of NUC therapy for patients with HBV-related HCC receiving TKI therapy has increased over time. Patients receiving NUC therapy may have a higher chance of achieving complete virological suppression and a higher chance of receiving second-line systemic therapy after first-line TKI failure, which may contribute to a better OS in patients with advanced HBV-related HCC.  Informed Consent Statement: The Institutional Review Board waived the need for written informed consent due to the retrospective nature of the study.

Data Availability Statement:
The data that support the findings of this study are available from the corresponding author upon reasonable request.