Optimal duration of additional therapy after biochemical and virological responses to lamivudine in patients with HBeAg-negative chronic hepatitis B: a randomized trial

Risks and Benefits of Discontinuation of Nucleos(t)ide Analogue Treatment: A Treatment Concept for Patients With HBeAg-Negative Chronic Hepatitis B

Systematic discontinuation of long-term treatment with nucleos(t)ide analogues (NAs) is one strategy to increase functional cure rates in patients with chronic hepatitis B e antigen (HBeAg)-negative hepatitis B. Currently, available study results are heterogeneous; however, long-term hepatitis B surface antigen (HBsAg) loss rates of up to 20% have been reported in prospective trials. This review proposes criteria that can be used when considering NA discontinuation in patients with chronic hepatitis B virus (HBV). Discontinuing NA treatment frequently results in a virologic and biochemical relapse that runs through different phases: the lag phase, reactivation phase, and consolidation phase. The HBV-DNA flares observed during the reactivation phase are often transient and most likely represent a trigger for inducing a long-term immune control by specific CD8+ T cells, and therefore do not need immediate interventions but close follow-up evaluation. Low HBsAg levels at the time of treatment cessation predict a positive long-term response to NA discontinuation associated with a higher likelihood of HBsAg clearance. Other host and viral biomarkers are currently under evaluation that may prove to be helpful to further characterize the population that may benefit most from the finite NA treatment concept. Potential harmful biochemical flares during the reactivation phase need to be identified early and can be effectively terminated by reintroducing NA treatment. Hepatic decompensation represents a risk to patients with cirrhosis undergoing NA discontinuation. Therefore, the finite NA approach should only be considered after excluding advanced fibrosis and cirrhosis and if a close follow-up of the patient and supervision by an experienced physician can be guaranteed. Conclusion: For selected patients, NA discontinuation has become a powerful tool to achieve control over HBeAg-negative HBV infections. Its significant effect represents a challenge to novel treatment approaches, but it may also serve as their enhancer.

Challenges in the discontinuation of chronic hepatitis B antiviral agents

Long-term antiviral treatment of chronic hepatitis B patients has been proven to be beneficial in reducing liver-related complications. However, lengthy periods of daily administration of medication have some inevitable drawbacks, including decreased medication adherence, increased cost of treatment, and possible long-term side effects. Currently, discontinuation of antiviral agent has become the strategy of interest to many hepatologists, as it might alleviate the aforementioned drawbacks and increase the probability of achieving functional cure. This review focuses on the current evidence of the outcomes following stopping antiviral treatment and the factors associated with subsequent hepatitis B virus relapse, hepatitis B surface antigen clearance, and unmet needs.

Is it possible to stop nucleos(t)ide analogue treatment in chronic hepatitis B patients?

Chronic hepatitis B (CHB) remains a challenging global health problem, with nearly one million related deaths per year. Nucleos(t)ide analogue (NA) treatment suppresses viral replication but does not provide complete cure of the hepatitis B virus (HBV) infection. The accepted endpoint for therapy is the loss of hepatitis B surface antigen (HBsAg), but this is hardly ever achieved. Therefore, indefinite treatment is usually required. Many different studies have evaluated NA therapy discontinuation after several years of NA treatment and before HBsAg loss. The results have indicated that the majority of patients can remain off therapy, with some even reaching HBsAg seroconversion. Fortunately, this strategy has proved to be safe, but it is essential to consider the risk of liver damage and other comorbidities and to ensure a close follow-up of the candidates before considering this strategy. Unanswered questions remain, namely in which patients could this strategy be effective and what is the optimal time point at which to perform it. To solve this enigma, we should keep in mind that the outcome will ultimately depend on the equilibrium between HBV and the host’s immune system. Viral parameters that have been described as good predictors of response in HBeAg(+) cases, have proven useless in HBeAg(-) ones. Since antiviral immunity plays an essential role in the control of HBV infection, we sought to review and explain potential immunological biomarkers to predict safe NA discontinuation in both groups.

Why not to stop antiviral treatment in patients with chronic hepatitis B

Treatment of chronic hepatitis B with entecavir or tenofovir leads to viral suppression in almost all patients. However, prolonged or lifelong treatment is necessary. At present, there is no consensus among the three major guidelines for the treatment of chronic hepatitis B on whether or not to stop antiviral treatment. One of the main reasons for this controversy is that virological relapse has been well documented in patients with chronic hepatitis B who stop treatment. Relapse rate is particularly high in patients who are HBeAg-negative when treatment begins, with reported relapse rates of up to 70% 36 months after treatment discontinuation. Moreover, hepatic decompensation, jaundice and death have been described in patients with cirrhosis after treatment discontinuation. The main reason for stopping antiviral treatment is related to cost, however there is no robust evidence to support treatment discontinuation in most patients.

Stopping long-term treatment with nucleos(t)ide analogues is a favourable option for selected patients with HBeAg-negative chronic hepatitis B

The immune response against the infection is impaired in patients with chronic hepatitis B, and although HBV DNA can effectively be suppressed by nucleos(t)ide analogues (NA), durable immune control is only established in a minority of patients. This especially applies in HBeAg-negative patients who usually must receive lifelong NA treatment. Calculated withdrawal of NA leads to a relapse of HBV DNA in most patients. There is evidence that this sudden exposure of viral antigens can trigger immune control in some patients which may result in HBsAg loss or a form of immune control, then sustained low HBV DNA levels and normal alanine aminotransferase (ALT). In the first prospective randomized trial investigating tenofovir treatment cessation in HBeAg-negative patients, most patients did not need retreatment after NA cessation, although all patients showed a transient relapse in HBV DNA. HBsAg loss was identified in almost 20% nearly 3 years after stopping NA. Further confirmation of these findings is needed in larger randomized trials and patients who are most likely to benefit from finite therapy must be identified to individualize NA stopping strategies. However, these results suggest that in patients without risk factors such as cirrhosis or other severe conditions, NA treatment may be stopped, as long as adequate safety rules for retreatment are followed.

Discontinuation of lamivudine treatment in HBeAg-negative chronic hepatitis B: a pilot study with long-term follow-up

BACKGROUND

Finite treatment of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) with nucleoside/nucleotide analogues (NAs) is important in resource-limited countries. Outcome of treatment discontinuation in patients on long-term lamivudine (LVD) was assessed in a single centre observational pilot study in the current study.

METHODS

Non-cirrhotic patients on LVD for at least 5 years with undetectable HBV DNA on at least two consecutive assessments were offered to stop treatment. Biochemical, serological and virological measures were determined at 3-6 month intervals after treatment discontinuation. Serum quantitative hepatitis B surface antigen (HBsAg) was determined at treatment discontinuation and 5-6 years thereafter. NA treatment was re-instituted in patients with confirmed viral rebound defined as HBV DNA >20,000 IU/ml. Relapser patients were no longer followed but were re-assessed 6 years after treatment cessation.

RESULTS

LVD was discontinued in 23 patients. 8 patients relapsed within 1 year and NA treatment was restarted; 15 patients (65%) were non-relapsers. Thirteen of them were followed for at least 5 years. Two patients had undetectable HBV DNA throughout the follow-up period. In the rest, HBV DNA fluctuated at low levels. Two patients cleared HBsAg 24 and 36 months after stopping treatment. Quantitative HBsAg levels 5-7 years after treatment discontinuation were lower in non-relapser compared to relapser patients (1.21 IU/ml ±0.98 versus 2.71 ±0.76; P=0.002). Of 8 relapser patients 1 patient had HBsAg levels less than 100 IU/ml compared to 11 out of 13 non-relapser patients (P=0.0022).

CONCLUSIONS

These data suggest that cessation of NA treatment is a viable option after a reasonable treatment duration in patients with HBeAg-negative CHB and that HBsAg clearance may become an achievable target in these patients.

Discontinuation of oral antivirals in chronic hepatitis B: A systematic review

The possibility of safe discontinuation of therapy with nucleos(t)ide analogues (NAs) remains one of the most controversial topics in the management of chronic hepatitis B. Therefore, we systematically reviewed the existing data on NA discontinuation in this setting and tried to identify factors affecting the probability of posttherapy remission. A literature search was performed in order to identify all published studies including patients who discontinued NAs in virological remission (VR) and were followed for ≥12 months thereafter. Twenty-five studies with 1716 patients were included. The pooled rates of durable VR remission were 51.4%, 39.3%, and 38.2% at 12, 24, and 36 months, respectively, after NA discontinuation, being relatively higher in initially hepatitis B e antigen (HBeAg)-positive patients (62.5%, 53.4%, 51.5%) than HBeAg-negative patients (43.7%, 31.3%, 30.1%) (P = 0.064). The weighted probability of durable biochemical remission was 65.4%, being numerically higher in HBeAg-positive than HBeAg-negative patients (76.2% versus 56.7%, P = 0.130). The weighted probability of hepatitis B surface antigen loss was 2.0%. The rates of durable VR did not significantly differ according to the VR definition (hepatitis B virus DNA <200, < 2000, < 20,000 IU/mL) or duration of on-therapy VR in HBeAg-positive patients, but they were significantly higher in studies with HBeAg-negative patients and on-therapy VR > 24 than ≤ 24 months (VR at 12 months off-NAs: 75.0% versus 35.6%, P = 0.005). The weighted probability of durable HBeAg seroconversion was 91.9% and 88.0% at 12 and 24 months, respectively, after NA discontinuation without being affected by the duration of on-therapy VR or consolidation therapy (>6 months in all studies).

CONCLUSION

Durable VR seems to be feasible in a substantial proportion of patients who discontinue long-term NA therapy; on-therapy VR > 24 months offers higher chances of off-NA VR in patients with HBeAg-negative chronic hepatitis B.