Results of Response-Guided Therapy with Pegylated Interferon Alpha 2a in Chronic Hepatitis B and D

Pegylated interferon alpha 2a continues to be used for the treatment of chronic hepatitis D. The reported on-treatment virologic response varies between 17 and 47%, with relapses in more than 50% of these patients. No stopping rules have been defined, and the duration of the treatment is not clearly established, but it should be between 48 and 96 weeks. In total, 76 patients with compensated liver disease treated with peg-interferon according to the Romanian National protocol for the treatment of hepatitis D were retrospectively included. The duration of treatment was up to 96 weeks, with the following stopping rules: less than a 2 log HDV RNA decrease by week 24 and less than a 1 log decrease every 6 months afterwards. Six months after stopping the treatment, it can be restarted for unlimited cycles. The inclusion criteria were aged above 18, HBs Ag-positive, HDV RNA detectable, ALT above ULN and/or liver fibrosis at least F1 at liver biopsy, or Fibrotest and/or Fibroscan higher than 7 KPa and/or inflammation at least A1 at liver biopsy or Fibrotest. We monitored our patients for a total period of 4 years (including those that repeated the cycle). After the first 6 months of treatment, 27 patients (35.5%) had a greater than 2 log HDV RNA decrease, 19 of them achieving undetectable HDV RNA. Seventeen patients (22.3%) had undetectable HDV RNA 24 weeks after stopping 96 weeks of treatment, and none relapsed in the following 2 years. Of these 17 patients, 6 were cirrhotic, and 4 had F3. Undetectable HDV RNA at 24 weeks was the only parameter that predicted a long-term suppression of HDV RNA. In 49 patients, the treatment was stopped after 6 months according to protocol, but it was restarted 6 months later. Five of these patients finished a 48-week course of treatment; none achieved undetectable HDV RNA. During the first course of therapy, 45 patients had at least one moderate adverse reaction to treatment. In one patient, the treatment was stopped due to a serious adverse event (osteomyelitis). Treatment doses had to be reduced in 29 patients. The virologic response at week 24 can select the patients who will benefit from continuing the treatment from those who should be changed to another type of medication when available.

Interferon-based treatment of chronic hepatitis D

Treatment of hepatitis D virus (HDV) infection has been based on the administration of interferon-alfa for more than three decades. First studies to treat HDV-infected patients with type 1 interferons were already performed in the 1980s. Several smaller trials and case series were reported thereafter. During the mid 2000s the use of pegylated interferons for hepatitis D was established. Since then, additional trials were performed in different countries exploring strategies to personalize treatment including extended treatment durations. The overall findings were that about one-quarter to one-third of patients benefit from interferon treatment with persistent suppression of HDV replication. However, only few patients achieve also functional cure of hepatitis B with HBsAg loss. Importantly, several studies indicate that successful interferon treatment is associated with improved clinical long-term outcomes. Still, only a proportion of patients with hepatitis D can be treated with interferons. Even though alternative treatments are currently developed, it is likely that pegylated interferon-alfa will still have an important role in the management of hepatitis D - either alone or in combination. Therefore, better biomarkers are needed to select patients with a high likelihood to benefit from interferon-based treatments. In this review we are discussing basic principles of mode of action of interferon alpha against HDV, summarize previous data on interferon treatment of hepatitis D and give an outlook on potential combinations with novel drugs currently in development.

Treatment endpoints for chronic hepatitis D

Management of chronic hepatitis D (CHD) has entered a new era. In this new era, the virus entry inhibitor bulevirtide has received conditional approval as a treatment for compensated CHD. Three phase 3 studies with two new compounds are ongoing for the treatment of CHD. In this context, surrogate markers of treatment efficacy have been well defined for chronic hepatitis B (CHB) (7) and chronic hepatitis C (8) but not for CHD. The aim of this review is to give a perspective on treatment endpoints in CHD. For this, we took guidance from CHB studies and tried to make suggestions which differed according to finite versus prolonged treatment durations and also took into account the different characteristics of the new compounds.

Emerging drugs for hepatitis D

INTRODUCTION

Chronic hepatitis delta (CHD) is the most severe form of chronic viral hepatitis. Until recently, its treatment consisted of pegylated interferon alfa (pegIFN) use.

AREAS COVERED

Current and new drugs for treating CHD. Virus entry inhibitor bulevirtide has received conditional approval by the European Medicines Agency. Prenylation inhibitor lonafarnib and pegIFN lambda are in phase 3 and nucleic acid polymers in phase 2 of drug development.

EXPERT OPINION

Bulevirtide appears to be safe. Its antiviral efficacy increases with treatment duration. Combining bulevirtide with pegIFN has the highest antiviral efficacy short-term. The prenylation inhibitor lonafarnib prevents hepatitis D virus assembly. It is associated with dose dependent gastrointestinal toxicity and is better used with ritonavir which increases liver lonafarnib concentrations. Lonafarnib also possesses immune modulatory properties which explains some post-treatment beneficial flare cases. Combining lonafarnib/ritonavir with pegIFN has superior antiviral efficacy. Nucleic acid polymers are amphipathic oligonucleotides whose effect appears to be a consequence of phosphorothioate modification of internucleotide linkages. These compounds led to HBsAg clearance in a sizeable proportion of patients. PegIFN lambda is associated with less IFN typical side effects. In a phase 2 study it led to 6 months off treatment viral response in one third of patients.

Future anti-HDV treatment strategies, including those aimed at HBV functional cure

HDV is a defective virus that uses the HBV surface antigen to enter hepatocytes. It is associated with an accelerated course of liver fibrosis progression and an increased risk of hepatocellular carcinoma. Negative HDV RNA 24 weeks after the end of therapy has been proposed as an endpoint but late relapses make this endpoint suboptimal, hence HBsAg loss appears to be more appropriate. Current HBV antiviral agents have poor activity against HDV hence the search for improved therapy. Drugs only active against HDV, such as lonafarnib, have shown efficacy in combination with nucleoside analogues and peginterferon, but do not lead to HBsAg loss. HBsAg loss sustained 24 weeks after the end of therapy with negative HBV DNA is termed functional cure. Agents that are being investigated for functional cure include those that inhibit replication such as entry inhibitors, polymerase inhibitors and capsid assembly modulators but seldom lead to functional cure. Agents that reduce HBV antigen load such as RNA interference and inhibitors of HBsAg secretion are promising. Immunomodulators on their own seldom achieve functional cure, hence these agents in combination to assess the optimal combination are being investigated. Consequently, agents leading to functional cure of HBV are ideal for both HBV and HDV.

Effectiveness of pegylated interferon monotherapy in the treatment of chronic hepatitis D virus infection: A meta-analysis

Chronic HDV infection often is associated with aggressive form of liver disease, compared to chronic HBV mono-infection. However, chronic HDV treatment is challenging because currently there is no approved regimen for affected patients. While standard interferon with/without nucleos(t)ide analogues were reported to be inferior to pegylated interferon (peginterferon) as HDV treatment according to few randomized clinical trials. This meta-analysis will summarize the results of studies on the effectiveness of peginterferon as HDV treatment regimen. An electronic search was performed using PubMed, Cochrane Library, Research Gate, and Medline databases. Studies involving patients who received peginterferon therapy for at least 48 weeks and followed up for 24 weeks post-therapy were included. All analyses were conducted using Review Manager 5.3 designed for Cochrane Reviews. The primary efficacy endpoint was virological response (VR) or HDV-RNA negativity at the end of the follow-up period, whereas secondary efficacy endpoints were biochemical response (BR) or ALT normalization and HBsAg clearance with seroconversion to anti-HBs at the end of follow-up period. Data were abstracted from 13 relevant studies with a total of 475 patients who were treated with peginterferon alpha-2a or -2b. At the end of 24-week post-treatment the pooled VR was achieved in 29% of patients with 95% CI [24%; 34%], BR was reached in 33% of patients [95% CI 27%; 40%] and HBsAg clearance with seroconversion to anti-HBs was achieved in 1% of patients with 95% CI [-0.02; 0.05]. In conclusion, this study showed that peginterferon has limited effectiveness in HDV treatment, since only one-third of chronic HDV patients achieved viral clearance and normalized ALT levels. Morever, HBsAg clearance with seroconversion to anti-HBs has been rarely observed among chronic HDV patients.

LIVER TRANSPLANTATION IN HEPATITIS DELTA: SOUTH AMERICA EXPERIENCE

BACKGROUND

The Amazon region is one of the main endemic areas of hepatitis delta in the world and the only one related to the presence of genotype 3 of the delta virus.

OBJECTIVE

To analyze the profile, mortality and survival of cirrhotic patients submitted to liver transplantation for chronic hepatitis delta virus and compare with those transplanted by hepatitis B virus monoinfection.

METHODS

Retrospective, observational and descriptive study. From May 2002 to December 2011, 629 liver transplants were performed at the Walter Cantídio University Hospital, of which 29 patients were transplanted due to cirrhosis caused by chronic delta virus infection and 40 by hepatitis B chronic monoinfection. The variables analyzed were: age, sex, MELD score, Child-Pugh score, upper gastrointestinal bleeding and hepatocellular carcinoma occurrence before the transplantation, perioperative platelet count, mortality and survival.

RESULTS

The Delta Group was younger and all came from the Brazilian Amazon Region. Group B presented a higher proportion of male patients (92.5%) compared to Group D (58.6%). The occurrence of upper gastrointestinal bleeding before transplantation, MELD score, and Child-Pugh score did not show statistical differences between groups. The occurrence of hepatocellular carcinoma and mortality were higher in the hepatitis B Group. The survival in 4 years was 95% in the Delta Group and 75% in the B Group, with a statistically significant difference (P=0.034). Patients with hepatitis delta presented more evident thrombocytopenia in the pre-transplantation and in the immediate postoperative period.

CONCLUSION

The hepatitis by delta virus patients who underwent liver transplantation were predominantly male, coming from the Brazilian Amazon region and with similar liver function to the hepatitis B virus patients. They had a lower incidence of hepatocellular carcinoma, more marked perioperative thrombocytopenia levels and frequent episodes of upper gastrointestinal bleeding. Patients with hepatitis by delta virus had lower mortality and higher survival than patients with hepatitis B virus.

Addition of nucleoside analogues to peg-IFNα-2a enhances virological response in chronic hepatitis B patients without early response to peg-IFNα-2a: a randomized controlled trial

BACKGROUND

Current treatments for chronic hepatitis B (CHB) include pegylated interferon alpha (PEG-IFN-α) which is an immune modulator, and nucleos(t)ide analogs (NAs) which directly inhibit HBV DNA polymerase. With the limited efficacy of PEG-IFN-α and prolonged treatment periods associated with NAs, there is an urgent need for novel therapeutic strategies, especially for patients with a poor early response to anti-viral therapy.

METHODS

In this study, 178 patients with chronic hepatitis B (n = 131) and compensated (n = 47) HBV-induced cirrhosis were enrolled, 120 patients with HBeAg (+). All the patients were treated for 12 weeks with PEG-IFN-α. Among them, a total of 138 patients with a poor virological response after 12 weeks were treated for an additional 48 weeks with Peg-IFNα-2a (control) (n = 43), with Peg-IFNα-2a + entecavir (ETV) (n = 49), or Peg-IFNα-2a + adefovir dipivoxil (ADV) (n = 46), and were followed for 48 weeks after therapy. Early virological response was defined as undetectable HBV DNA after anti-viral therapy for 12 weeks. Sustained virological response (SVR) was defined as no change in therapeutic effectiveness after 6 months follow-up, and no recurrence.Therapeutic efficacy was determined by evaluating HBV DNA levels, serum and liver HBsAg levels, liver function tests and liver histology.

RESULTS

Patients in the Peg-IFNα-2a + ETV and Peg-IFNα-2a + ADV groups showed a significantly greater decrease in HBV DNA levels over time, and a significantly higher SVR compared to patients receiving Peg-INFα-2a monotherapy (both P values <0.05). Although patients receiving combination therapy had a significantly higher change in serum HBsAg levels compared to the monotherapy group, there was no significant difference in liver HBsAg levels between the three treatment groups.

CONCLUSION

This study demonstrated that in patients with a poor virological response after 12 weeks of treatment with Peg-IFNα-2a alone, addition of ADV or ETV significantly reduced HBV DNA levels, serum HBsAg levels, and increased SVR. Individualization of anti-viral therapy would ensure that only patients who do not respond to Peg-IFNα-2a would receive combination therapy. Our data have important implications for the treatment of CHB patients who fail to show an early response to Peg-IFNα-2a monotherapy.

TRIAL REGISTRATION

This trial was retrospectively registered on 2012 May 24 at the China Clinical Trials Registry (ChiCTR-OCC-12002196).

Long-term therapy of chronic delta hepatitis with peginterferon alfa

BACKGROUND

Chronic delta hepatitis virus (HDV) infection rapidly progresses to cirrhosis. Treatment with peginterferon for up to 2 years is often without durable response.

AIM

To examine the efficacy and safety of long-term peginterferon in achieving a durable response.

METHODS

Treatment was initiated with 180 μg/week of peginterferon alfa-2a with titration to a maximal tolerable dose, for up to 5 years. Liver biopsies and hepatic venous pressure gradients (HVPG) were evaluated at baseline, 1, 3 and 5 years. The primary endpoint was histological improvement or loss of serum HDV and HBsAg at 3 years.

RESULTS

Thirteen patients were treated for a median of 140 weeks (6-260) with an average peginterferon dose of 180 μg/week (90-270). At baseline, most had advanced disease (median Ishak fibrosis = 3) with portal hypertension (HVPG = 10.2 ± 6 mmHg). Five of 13 patients (39%) achieved the primary endpoint, with three seroconverting for HBsAg after 24, 37 and 202 weeks of treatment. Histological inflammation improved after 1 year, (median HAI: 10 vs. 7, P = 0.01) with persistence in 4/5 patients at 3 years (median HAI: 7.5). Greatest improvements occurred in the first year. Baseline bilirubin and HBsAg levels were significantly lower in virological responders than nonresponders. After 12 weeks, virological responders had a significant decline in HBsAg (1.5 log10 IU/mL, P = 0.05).

CONCLUSION

Despite increased doses and duration of therapy, treatment of chronic HDV with peginterferon remains unsatisfactory. Quantitative measures of HBsAg may be an important biomarker of early response to peginterferon therapy in chronic delta hepatitis virus infection.

Treatment of delta hepatitis

Hepatitis delta virus (HDV) is a defective RNA virus that depends on hepatitis B virus (HBV) for its lifecycle. Treatment of chronic HDV infection is difficult as it does not have an enzymatic function as a target, such as polymerases and proteases of HBV and hepatitis C virus. Recently, it has been suggested that farnesyl transferase could be an enzymatic target. Currently, interferon is the only agent against HDV infection. Virological response has risen to 20-47% with pegylated interferon. Monotherapy of nucleos(t)ide analogs are ineffective against the HDV infection, but adefovir and pegylated interferon combination therapy have had some advantages for reduction of HBV surface antigen (HBsAg) levels. Recent studies suggest that measuring HBsAg levels during treatment could be more meaningful than HDV RNA negativity to predict virological response. Prenylation inhibitors that can affect the interactions between the large HDV antigen and HBsAg in the HDV virion are expected treatments for HDV infection. More studies are needed to understand the molecular mechanisms of HDV to manage the disease.