Current Antiviral Therapy of Chronic Hepatitis B: Efficacy and Safety

Advances in discovery of novel investigational agents for functional cure of chronic hepatitis B: A comprehensive review of phases II and III therapeutic agents

Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.

A bioinformatics investigation into molecular mechanism of Yinzhihuang granules for treating hepatitis B by network pharmacology and molecular docking verification

Yinzhihuang granules (YZHG) is a patented Chinese medicine for the treatment of hepatitis B. This study aimed to investigate the intrinsic mechanisms of YZHG in the treatment of hepatitis B and to provide new evidence and insights for its clinical application. The chemical compounds of YZHG were searched in the CNKI and PUBMED databases, and their putative targets were then predicted through a search of the SuperPred and Swiss Target Prediction databases. In addition, the targets of hepatitis B were obtained from TTD, PharmGKB and DisGeNET. The abovementioned data were visualized using Cytoscape 3.7.1, and network construction identified a total of 13 potential targets of YZHG in the treatment of hepatitis B. Molecular docking verification showed that CDK6, CDK2, TP53 and BRCA1 might be strongly correlated with hepatitis B treatment. Furthermore, GO and KEGG analyses indicated that the treatment of hepatitis B by YZHG might be related to positive regulation of transcription, positive regulation of gene expression, the hepatitis B pathway and the viral carcinogenesis pathway. Network pharmacology intuitively shows the multicomponent, multitarget and multichannel pharmacological effects of YZHG in the treatment of hepatitis B and provides a scientific basis for its mechanism of action.

Prophylaxis for Hepatitis B Virus Reactivation after Allogeneic Stem Cell Transplantation in the Era of Drug Resistance and Newer Antivirals: A Systematic Review and Meta-Analysis

Patients undergoing allogenic hematopoietic stem cell transplantation (allo-HSCT) are at a very high risk of hepatitis B virus reactivation (HBVr). Lamivudine is commonly used as prophylaxis against HBVr in high-risk patients undergoing allo-HSCT. Unfortunately, its efficacy is diminishing due to the development of HBV mutant drug-resistant strains. With the availability of newer antiviral agents such as entecavir, telbivudine, adefovir, and tenofovir, it is important to assess their role in HBVr prophylaxis. A comprehensive search of 7 databases was performed to evaluate efficacy of antiviral prophylaxis against HBVr in allo-HSCT patients (PubMed/Medline, Embase, Scopus, Cochrane Library, Web of Science, CINAHL, and ClinicalTrials.gov (June 21, 2017)). We identified 10 studies, with 2067 patients undergoing allo-HSCT; these primarily evaluated the use of lamivudine and entecavir as prophylaxis against HBVr in patients undergoing allo-HSCT because there were little or no data about adefovir, telbivudine, or tenofovir as prophylaxis in this specific patient population. Thus, included studies were categorized into 2 main prophylaxis groups: lamivudine and entecavir. Results of our meta-analysis suggest that entecavir is very effective against HBVr, although further clinical trials are required to test efficacy of new antivirals and explore the emerging threat of drug resistance.

Clevudine Induced Mitochondrial Myopathy

Clevudine was approved as an antiviral agent for hepatitis B virus, which showed marked, rapid inhibition of virus replication without significant toxicity. However, several studies have reported myopathy associated with clevudine therapy. Also, we experienced seven patients who suffered from myopathy during clevudine therapy. To characterize clevudine-induced myopathy, we collected previously reported cases of clevudine myopathy and analyzed all the cases including our cases. We searched electronic databases that were published in English or Korean using PubMed and KoreaMed. Ninety-five cases with clevudine myopathy, including our seven cases, were selected and analyzed for the demographic data, clinical features, and pathologic findings. The 95 patients with clevudine-induced myopathy comprised 52 women and 43 men aged 48.9 years (27-76 years). The patients received clevudine therapy for about 14.2 months (5-24 months) before the development of symptoms. Weakness mainly involved proximal extremities, especially in the lower extremities, and bulbar and neck weakness were observed in some cases (13.7%). Creatine kinase was elevated in the majority of patients (97.9%). Myopathic patterns on electromyography were observed in most patients examined (98.1%). Muscle biopsy presented patterns compatible with mitochondrial myopathy in the majority (90.2%). The weakness usually improved within about 3 months after the discontinuation of clevudine. Though clevudine has been known to be safe in a 6-month clinical trial, longer clevudine therapy for about 14 months may cause reversible mitochondrial myopathy. Careful clinical attention should be paid to patients with long-term clevudine therapy.

Factors associated with the decrease in hepatitis B surface antigen titers following interferon therapy in patients with chronic hepatitis B: Is interferon and adefovir combination therapy effective?

The purpose of antiviral therapy in chronic hepatitis B (CHB) is generally to achieve a decrease and ultimately disappearance of HBs antigen (HBsAg). Interferon (IFN) therapy of CHB appears to be less effective in Asian countries than in European countries, and the advantage of IFN and nucleotide(s) analog (NA) combination therapy has yet to be fully investigated. The present study focused on the factors associated with a decrease in HBs antigen following IFN monotherapy or IFN + NA combination therapy. A total of 35 patients with CHB who received IFN-based therapy (mean ± standard deviation age 36.7±8.5 years; 27 males and 8 females) were enrolled in this study. Of the 35 patients, 21 patients received pegylated IFN monotherapy and 14 patients received IFN and adefovir (ADV) combination therapy. We examined the factors associated with reductions in the HBsAg titer of >1.0 log IU/ml from the initial HBsAg titer to the end of treatment and to 24 weeks after treatment. Although 13 patients (37%) had a reduction in HBsAg of >1.0 IU/ml at the end of treatment, it was only maintained to 24 weeks after treatment in 7 patients (20%). The HBV core-related antigen (HBcrAg) titer before treatment was significantly higher in patients with a decrease in HBsAg at the end of treatment than in patients without a decrease in HBsAg (6.56±0.78 vs. 5.30±1.66 log IU/ml, P<0.05). Moreover, an increase in alanine aminotransferase (ALT) of >2 times from baseline occurred significantly more frequently in patients with a decrease in HBsAg (62 vs. 14%, P<0.05). The proportion of patients with a decrease in HBsAg was significantly greater in patients who received IFN monotherapy than in patients who received IFN and ADV combination therapy (43 vs. 29%, P<0.05). The present results revealed that the HBcr antigen titer before therapy and an on-treatment elevation of ALT (indicative of host instruction flare) are important factors associated with a decrease in HBsAg titers after IFN-based therapy. The efficacy of IFN and ADV combination therapy was not apparent in terms of a reduction in the HBsAg titer.

The Efficacy and Safety of Entecavir and Interferon Combination Therapy for Chronic Hepatitis B Virus Infection: A Meta-Analysis

The objective of this study was to evaluate the effectiveness and safety of entecavir (ETV) and interferon (IFN) combination therapy in the treatment of chronic hepatitis B (CHB) mono-infection via a meta-analysis of randomized controlled trials (RCTs). All eligible RCTs evaluating combination therapy for treating CHB were identified from nine electronic databases. A meta-analysis was performed in accordance with the Cochrane Systemic Review handbook. Eleven trials encompassing 1010 participants were included in this meta-analysis. It showed that at 12 and ≥ 96 weeks of therapy, the combination of ETV and IFN was not better than ETV in improving the undetectable HBV DNA (12 weeks: RR=1.12, 95% CI=0.88-1.42; ≥ 96 weeks: RR = 0.64, 95% CI=0.21-1.98, respectively) and HBeAg seroconversion rates (12 weeks: RR=1.35, 95% CI=0.60-3.04; ≥ 96 weeks: RR=1.36, 95% CI=0.75-2.64, respectively). But at 48 weeks of therapy and approximately 2 years of follow up, combination therapy was superior to ETV in improving the undetectable HBV DNA (48 weeks: RR=1.46, 95% CI=1.13-1.90; follow up: RR=2.20, 95% CI=1.26-3.81, respectively) and HBeAg seroconversion rates (48 weeks: RR=1.82, 95% CI=1.44-2.30; follow up: RR=1.92, 95% CI=1.19-3.11, respectively). When compared to IFN group, at 24 and 48 weeks of therapy, combination group showed a greater undetectable HBV DNA (24 weeks: RR=2.14, 95% CI=1.59-2.89; 48 weeks: RR=2.28, 95% CI=1.54-3.37, respectively) and ALT normalization rate (24 weeks: RR=1.56, 95% CI= 1.24-1.96; 48 weeks: RR=1.55, 95% CI = 1.16-2.07, respectively). At 48 weeks of therapy, combination group achieved a greater HBeAg seroconversion rate than IFN (48 weeks: RR=1.58, 95% CI=1.24-2.00). No significant differences were observed in the side effects of the three therapies. So we can conclude that ETV and IFN combination therapy is more effective than ETV or IFN mono-therapy in CHB treatment. ETV, IFN, and the combination of the two are safe in CHB treatment.

Capacity of a natural strain of woodchuck hepatitis virus, WHVNY, to induce acute infection in naive adult woodchucks

Woodchuck hepatitis virus (WHV) is often used as surrogate to study mechanism of HBV infection. Currently, most infections are conducted using strains WHV7 or WHV8 that have very high sequence identity. This study focused on natural strain WHVNY that is more genetically distant from WHV7. Three naive adult woodchucks inoculated with WHVNY developed productive acute infection with long lasting viremia. However, only one of two woodchucks infected with WHV7 at the same multiplicity demonstrated productive liver infection. Quantification of intracellular WHV RNA and DNA replication intermediates; percentages of core antigen-positive hepatocytes; and serum relaxed circular DNA showed that strains WHVNY and WHV7 displayed comparable replication levels and capacities to induce acute infection in naive adult woodchucks. Strain WHVNY was therefore validated as valuable reagent to analyze the mechanism of hepadnavirus infection, especially in co- and super-infection settings, which required discrimination between two related virus genomes replicating in the same liver.

Effects of antiviral therapy on the cellular immune response in patients with chronic hepatitis B

A weak T‑cell immune response to the hepatitis B virus (HBV) is hypothesized to be the primary cause of chronic HBV infection. Emerging evidence suggests that long‑term effective antiviral therapy restores the HBV‑specific T‑cell response from exhaustion. However, the extent to which the cellular immune response can be restored following the persistent suppression of HBV replication by antiviral therapy remains unclear. In order to investigate this question, 46 patients with chronic hepatitis B (CHB) treated with nucleos(t)ide analogues who demonstrated persistent suppression of HBV replication [defined as undetectable HBV DNA, hepatitis B e antigen (HBeAg) negative and adherence to antiviral therapy], 22 untreated CHB patients, 15 patients with acute hepatitis B (AHB) and 10 healthy adults were recruited. HBV‑specific interferon‑γ enzyme‑linked immunospot (IFN‑γ ELISPOT) assay and HBV‑specific T‑cell proliferation analysis were performed with a panel of overlapping peptides covering the envelope and core antigens. Data from this study showed that the HBV‑specific immune responses to the peptide pools of the envelope and core protein in the treated patients were stronger than those in the untreated CHB patients, but significantly weaker than those in the AHB patients and healthy adults. A higher frequency of response to S than C peptide pools was confirmed by the IFN‑γ ELISPOT assay in the treated CHB patients. The restoration of antiviral immunity was clearly associated with a reduction in HBV DNA and the duration of HBV DNA suppression. In conclusion, the HBV‑specific immune responses in the CHB patients can be significantly restored from exhaustion following the persistent suppression of HBV replication as a result of antiviral treatment with nucleos(t)ide analogues.

Prevention of hepatocellular carcinoma in patients with chronic hepatitis B

Patients with chronic hepatitis B are at significant risk for hepatocellular carcinoma (HCC). Globally, over half a million people each year are diagnosed with HCC, with marked geographical variations. Despite overwhelming evidence for a causal role of hepatitis B virus (HBV) infection in the development of HCC and a well-established relationship between high baseline hepatitis B viral load and cumulative risk of HCC, the molecular basis for this association has not been fully elucidated. In addition, a beneficial role for antiviral therapy in preventing the development of HCC has been difficult to establish. This review examines the biological and molecular mechanisms of HBV-related hepatocarcinogenesis, recent results on the effect of modern nucleos(t)ides on the rate of HCC development in high risk HBV cohorts and the potential mechanisms by which long-term antiviral therapy with potent inhibitors of HBV replication might reduce the risk of HCC in patients with chronic hepatitis B. Although evidence from randomized controlled trials shows the favourable effects of antiviral agents in achieving profound and durable suppression of HBV DNA levels while improving liver function and histology, robust evidence of other long-term clinical outcomes, such as prevention of HCC, are limited.

Impact of the rtI187V polymerase substitution of hepatitis B virus on viral replication and antiviral drug susceptibility

A high prevalence of the rtI187V polymerase substitution of hepatitis B virus (HBV) was detected in nucleoside/nucleotide-analogue-naive and -treated chronic hepatitis B (CHB) patients. We aimed at assessing the replicative capacity and susceptibility to lamivudine (LAM) and adefovir (ADV) in vitro of HBV harbouring rtI187V alone or in conjunction with LAM- or ADV-resistant mutations. The reverse transcriptase region of HBV isolates was directly sequenced from a cohort of 300 CHB patients from China. Replication-competent HBV constructs containing rtI187V and combined with LAM-resistant (rtM204I, rtL180M/rtM204V) mutations were generated, and compared with WT, LAM-resistant single (rtM204I) or double (rtL180M/rtM204V) and ADV-resistant (rtN236T) clones. In a Chinese cohort of 300 CHB patients, 8.7 % (26/300) showed substitution of rtI187 with V. Of note, the rtI187V prevalence in HBV genotype B was significantly higher than that in HBV genotype C (95.2 vs 4.8 %). In vitro phenotypic assays showed that the viruses bearing the rtI187V substitution had impaired replication efficacy when compared with the WT and the virus carrying rtI187V combined with LAM-resistant single or double mutations showed even more significantly impaired replicative capacities. Furthermore, rtI187V HBV remained susceptible towards treatment with LAM or ADV in vitro whereas the combination of the rtI187V substitution with LAM-resistant mutations rendered HBV resistant to LAM but still sensitive to ADV. Our study revealed that the rtI187V substitution in the HBV polymerase frequently occurred in CHB patients, particularly those with HBV genotype B. However, the emergence of the rtI187V substitution significantly impaired viral replication but without affecting drug sensitivity in vitro.

The changes of liver stiffness and its associated factors for chronic hepatitis B patients with entecavir therapy

Liver stiffness measurement (LSM) using transient elastography has been proposed to assess liver fibrosis well in various liver diseases. This study was to determine the changes of LSM and its associated factors for chronic hepatitis B (CHB) patients undergoing Entecavir therapy. Consecutive CHB patients underwent Entecavir therapy with two LSMs were enrolled. Patients with aspartate transaminase (AST) and/or alanine transaminase ≧200 IU/L were excluded. The retrospective study enrolled 233 patients including 132 without cirrhosis (group 1) and 101 with cirrhosis (group 2). The mean values of initial liver stiffness were 7.9 and 16.6 kPa for patients in group 1 and group 2, respectively (p<0.001). In addition to the decline of transaminase levels, there was significant reduction of liver stiffness value in a mean interval of 52.8 and 61.9 weeks between the two LSMs for patients in group 1 and 2, respectively (p<0.001). Multivariate analysis showed that higher initial LSM value and presence of hepatitis B e-antigen were associated with a greater decline of LSM value, whereas follow-up AST≧40 IU/L with increased LSM value for group 1 patients. For group 2 patients, longer interval between the two LSMs, higher initial LSM value and AST≧40 IU/L were associated with a greater decline of LSM value, whereas presence of diabetes mellitus (DM) contributed to increased LSM value. In conclusion, CHB patients improved their LSM values after Entecavir therapy. Higher initial LSM value contributed to greater LSM reduction. However, in cirrhotic patients, DM was associated with an increased LSM value after therapy.

Telbivudine versus entecavir for nucleos(t)ide-naive HBeAg-positive chronic hepatitis B: a meta-analysis

BACKGROUND

We performed a meta-analysis to compare the efficacies of entecavir and telbivudine in treatment-naive hepatitis B e-antigen (HBeAg)-positive Asian patients with chronic hepatitis B (CHB).

METHODS

Randomized controlled trials (January 1, 2000 to March 30, 2012) directly comparing entecavir 0.5 mg/d and telbivudine 600 mg/d, used for a minimum of 12 weeks in nucleos(t)ide-naive Asian patients with HBeAg-positive CHB, were searched in the PubMed, Embase, OVID, Cochrane Library, CNKI, VIP and WanFang databases. Publication quality was assessed using the Jadad quality scale. The rates of viral response, biochemical response, HBeAg loss and HBeAg seroconversion were analyzed using forest plots.

RESULTS

Seven eligible articles (867 patients in total) were included in this meta-analysis. With regard to the rates of hepatitis B virus DNA suppression, there were no significant differences between patients treated with entecavir or telbivudine at 12 and 48 weeks, but telbivudine was superior at 24 weeks. Twelve, 24 and 48 weeks after the start of therapy, the rates of alanine aminotransferase normalization were similar between the 2 drugs, and patients treated with telbivudine had higher HBeAg loss and seroconversion rates than patients treated with entecavir.

CONCLUSIONS

In nucleos(t)ide-naive Asian patients with HBeAg-positive CHB, assessed 12, 24, and 48 weeks after beginning treatment, telbivudine was as potent as entecavir in viral suppression, but superior with regard to HBeAg loss and seroconversion. Telbivudine seems to be more effective and suitable for these patients.

Prolonged Combination Therapy is More Effective than Monotherapy in Management of Chronic Hepatitis B Patients With Sustained Virological Response: An Experience From a 'Real-World' Clinical Setting

BACKGROUND

Little is known about the duration of combination therapy for patients with chronic hepatitis B (CHB) and suboptimal response to nucleos(t)ide analogues(NAs) monotherapy.

OBJECTIVES

This study aimed to assess whether monotherapy could be used for treatment of CHB patients, who poorly responded to Adefovir Dipivoxil (ADV) but obtained good responses after at least 12-month lamivudine (LAM) or telbivudine (LdT) add-on therapy.

PATIENTS AND METHODS

Forty-five patients were enrolled, and the baseline time-point was determined according to enrollment data. Twenty-six patients chose to continue combination therapy (LAM+ADV or LdT+ADV, Group A) and 19 patients switched to single-drug maintenance therapy (LAM or LdT or ADV, Group B).

RESULTS

There were no significant differences between two groups in baseline characteristics (P > 0.05). At 12th month, sustained virological response rate was greater in group A compared to group B (96.2% vs. 47.4%, P < 0.001), and the rates of NAs-associated resistance were 0% in group A and 15.8% in group B. Alanine aminotransferase normalization rate was also significantly higher in group A compared with group B (92.3% vs. 36.8%, P < 0.001). Among hepatitis positive patients with Be antigen (HBeAg)-, 40% (4/10) in group A and 9.1% (1/11) in group B achieved HBeAg seroconversion at the 12th month. Of patients in group B with positive-HBeAg before the previous combination therapy and detectable HBV DNA at 6 months of previous combination therapy were associated with high risks of viral relapse after switching to single-drug maintenance therapy.

CONCLUSIONS

Prematurely switching to single-drug maintenance therapy would be resulted in viral relapse, and prolonged combination therapy was effective to maintain sustained responses for patients with initial suboptimal response to ADV.

Association of preexisting drug-resistance mutations and treatment failure in hepatitis B patients

The role of preexisting minority drug-resistance mutations in treatment failure has not been fully understood in chronic hepatitis B patients. To understand mechanisms of drug resistance, we analyzed drug-resistance mutations in 46 treatment-failure patients and in 29 treatment-naïve patients and determined linkage patterns of the drug-resistance mutations in individual viral genomes using a highly sensitive parallel allele-specific sequencing (PASS) method. Lamivudine resistance (LAMr) mutations were predominant in treatment-failure patients, irrespective of the inclusion of LAM in the regimen. The primary LAMr mutations M204V and M204I were detected in 100% and 30% of the treatment-failure patients, respectively. Two secondary LAMr mutations (L180M and V173L) were also found in most treatment-failure patients (87% and 78%, respectively). The linkages containing these three mutations dominated the resistant viruses. Importantly, minority LAMr mutations present in <2% of the viral population were detected in 83% of the treatment-naïve patients. Moreover, the low-frequency same linked LAMr mutations (<0.15%) were detected in 24% of the treatment-naïve patients. Our results demonstrate that the selection of preexisting minority linked LAMr mutations may be an important mechanism for the rapid development of LAM resistance, caution the continuous use of LAM to treat drug-experienced and -naïve hepatitis B patients, and underline the importance of the detection of minority single and linked drug-resistance mutations before initiating antiviral therapy.

Efficacy of entecavir treatment for up to 5 years in nucleos(t)ide-naïve chronic hepatitis B patients in real life

OBJECTIVE

To analyze the efficacy and safety of entecavir (ETV) treatment for up to 5 years in nucleos(t)ide-naïve chronic hepatitis B patients in real life.

METHODS

We retrospectively analyzed 230 nucleos(t)ide naïve chronic hepatitis B patients who received ETV 0.5 mg/day monotherapy for at least 3 months, of whom 113 were HBeAg positive and 117 were HBeAg negative. The primary endpoints was cumulative probability of achieving a virological response (undetectable serum HBV DNA, <100IU/mL). Secondary endpoints were rates of ALT normalization (ALT < upper limit of normal), HBeAg seroconversion, resistance, and safety.

RESULTS

The median follow-up duration was 27.5 months (3-73 months) and mean age was 42 years. With 230, 214, 180, 142, 88, 42 and 11 patients followed-up for at least 3 months,6 months, 1, 2, 3, 4 and 5 years, respectively. In all, Incremental increases were observed in the rates of undetectable HBV DNA. 67.0%, 85.0%, 89.4%, 94.4%, 95.5%, 97.6%, 100% had undetectable HBV DNA at month 3, month 6, 1 year, 2 years, 3 years, 4 years and 5 years. Proportions of patients achieving normal ALT were 73.9%, 85.5%, 82.8%, 89.4%, 80.7%, 85.7%, 100%, respectively. The rate of HBeAg seroconversion reached 21.4% and 15.4% at year2, 3, respectively. One patient achieved HBsAg seroclearance after 1 year, and achieved anti-HBs seroconversion at year 3. Of 180 patients, HBV DNA was detectable (partial virological response, PVR) in 19 patients at year 1 of follow-up, twelve of 14 (85.7%) patients with PVR need more than 1 year of continuous ETV therapy to achieved VR. At baseline, no ETV-resistance was detected in 25 ETV-naïve patients. One patient developed ETV-resistance mutations due to noncompliance. No serious adverse event was reported.

CONCLUSION

Long-term ETV treatment of nucleos(t)ide-naïve was effective and safe in real life. Adjustment of ETV monotherapy in nucleos(t)ide-naïve patients with a partial virological response at 1 year may be unnecessary.

Long-term monitoring drug resistance by ultra-deep pyrosequencing in a chronic hepatitis B virus (HBV)-infected patient exposed to several unsuccessful therapy schemes

The aim of this study was to analyze the spectrum and dynamics of low-prevalent HBV mutations in the reverse transcriptase (rt) and S antigen by ultra-deep pyrosequencing (UDPS). Samples were obtained from a chronically infected patient who was followed throughout a thirteen-year period. This technology enabled simultaneous analysis of 4084 clonally amplified fragments from the patient allowing detecting low prevalent (<1%) mutations during the follow-up. At baseline, HBV sequences were predominately wild-type. Under sequential HBV monotherapies including lamivudine, adefovir and entecavir, a high frequency of rtM204I mutation was detected initially as unique and then coexisting with rtM204V. Both mutations were statistically associated with rtA200V and rtV207I, respectively. Once the entecavir and tenofovir combined therapy was started, polymerase and consequently envelope gene mutations appeared at several positions at a higher frequency than before, including the entecavir resistance-associated mutation rtT184L.

Adherence, persistence, healthcare utilization, and cost benefits of guideline-recommended hepatitis B pharmacotherapy

OBJECTIVE

To compare pharmacotherapy adherence, persistence, and healthcare utilization/costs among US patients with chronic hepatitis B (CHB) initiated on an oral antiviral monotherapy recommended as first-line treatment by current national (US) guidelines vs an oral antiviral not recommended as first-line monotherapy.

RESEARCH DESIGN AND METHODS

In this retrospective cohort study, patients aged 18-64 with medical claims for CHB who initiated an oral antiviral monotherapy for CHB between 07/01/05 and 01/31/10 were identified from a large US commercial health insurance claims database. Patients were continuously enrolled for a 6-month baseline period and ≥90 days follow-up. They were assigned to 'currently recommended first-line therapy' (RT: entecavir or tenofovir) or 'not currently recommended first-line therapy' (NRT: lamivudine, telbivudine, or adefovir) cohorts.

MAIN OUTCOME MEASURES

Multivariate analyses were conducted to compare treatment adherence, persistence, healthcare utilization, and costs for RT vs NRT cohorts.

RESULTS

Baseline characteristics were similar between RT (n=825) and NRT (n=916) cohorts. In multivariate analyses, RT patients were twice as likely as NRT patients to be adherent (OR=2.09; p<0.01) and persistent (mean: RT=361 days, NRT=298 days; p<0.01) and half as likely to have an inpatient stay (OR=0.527; p<0.01). Between the two oral antivirals recommended as first-line treatment, even though pharmacy cost was higher for entecavir, mean total healthcare costs for entecavir and tenofovir were similar ($1214 and $1332 per patient per month, respectively). Similar results were also observed with regard to adherence, persistence, and healthcare use for entecavir and tenofovir.

CONCLUSIONS

A limitation associated with analysis of administrative claims data is that coding errors can be mitigated but are typically not fully eradicated by careful study design. Nevertheless, the current findings clearly indicate the benefits of initiating CHB treatment with an oral antiviral monotherapy recommended as first-line treatment by current guidelines.