Comparison of the efficacy of lamivudine and famciclovir in Asian patients with chronic hepatitis B: results of 24 weeks of therapy

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Famciclovir: a focus on efficacy and safety

IMPORTANCE OF THE FIELD

Famciclovir is the prodrug of penciclovir, a guanosine analogue that inhibits viruses of the alpha sub-family of the Herpesviridae, as well as hepatitis B virus. It is indicated for management of mucocutaneous herpes simplex virus disease and acute herpes zoster, and has been investigated for management of hepatitis B virus infection.

AREAS COVERED IN THIS REVIEW

Data for this review were identified by searches of papers published in English on Medline and Scopus, spanning the years 1975 through 1 February 2010 with the key words: 'famciclovir', 'famvir', 'penciclovir', 'herpes', 'oral', 'genital', 'varicella', 'zoster' and 'virus' in association with 'safety', 'toxicity', 'tolerability', 'efficacy' and 'indications'. Relevant references were also obtained from articles acquired through the search strategy.

WHAT THE READER WILL GAIN

Readers are also provided with up-to-date information on the use of famciclovir for infections due to herpes simplex, varicella zoster and hepatitis B viruses. Clinical data pertaining to the safety and tolerability of famciclovir are also reviewed.

TAKE HOME MESSAGE

Famciclovir is a safe, convenient, and well-tolerated drug when used for its approved indications. The most common side effects indicated in the majority of studies were headache and nausea. Data for its use in childhood and pregnancy are limited.

Hepatitis B virus DNA levels at week 4 of lamivudine treatment predict the 5-year ideal response

The best time and hepatitis B virus (HBV) DNA level during an early lamivudine treatment period for predicting the long-term outcome are unknown. We aimed to determine the optimal time and HBV DNA level during an early treatment period for the prediction of the response after a 5-year lamivudine treatment. The HBV DNA levels at the baseline, at weeks 2, 4, 8, 12, 16, 24, and 32, and at yearly intervals until year 5 were measured in 74 hepatitis B e antigen (HBeAg)-positive chronic HBV patients receiving lamivudine treatment. Seventeen patients achieved an ideal response [HBV DNA level < 2000 copies/mL (400 IU/mL), HBeAg seroconversion, normal alanine aminotransferase levels, and absence of tyrosine-methionine-aspartate-aspartate (YMDD) mutations] at year 5. Receiver operating characteristic curves showed good predictions as early as week 4. The areas under the curve for weeks 4 and 16 were 0.89 and 0.94, respectively. Predictive indices revealed 4 and 3.6 log copies/mL (2000 and 800 IU/mL, respectively) to be the best cutoff HBV DNA levels for these 2 times, respectively. All patients with HBV DNA levels lower than these respective cutoff levels at the 2 times achieved an ideal response at year 5. Patients with HBV DNA levels above these cutoff values had 83.8% and 87.7% chances of not achieving an ideal response at year 5, respectively.

CONCLUSION

The measurement of the HBV DNA levels at week 4 of lamivudine treatment should be performed in all patients to predict the long-term outcome. The treatment can be continued for those with HBV DNA levels of less than 4 log copies/mL (2000 IU/mL). The addition of or switch to alternative antiviral agents should be considered for patients who fail to achieve this early target.

Long-Term Lamivudine Therapy Reduces the Risk of Long-Term Complications of Chronic Hepatitis B Infection even in Patients without Advanced Disease

Background

Long-term effects of lamivudine treatment on chronic hepatitis B patients without advanced disease remain unknown. Our aim was to investigate the effects of long-term lamivudine treatment and lamivudine-resistant virus (YMDD) on the development of cirrhosis and hepatocellular carcinoma (HCC) in asymptomatic patients without advanced disease.

Methods

One hundred and forty-two hepatitis B e antigen (HBeAg)-positive patients (median age: 33.9 years) on long-term lamivudine (median treatment duration: 89.9 months) and 124 HBeAg-positive controls (median age: 33.4 years) were prospectively followed up. Patients were monitored for the development of cirrhosis and HCC, liver biochemistry, hepatitis B virus (HBV) DNA levels, HBeAg seroconversion and hepatitis flares. YMDD mutations (YMDD-MT) were determined annually.

Results

Lamivudine-treated patients had a significantly lower cumulative rate of development of cirrhosis and/or HCC compared with controls ( P=0.005). YMDD-MT occurred in 76.3% of patients after 8 years of lamivudine treatment. When compared with controls and patients with YMDD-MT, patients without YMDD-MT had the greatest reduction of HBV DNA and bilirubin levels, slowest decline of albumin level, highest rate of HBeAg seroconversion and lowest risk of hepatitis flare. Patients with YMDD-MT still had a lower risk for developing cirrhosis and/or HCC ( P=0.024) and a greater HBV DNA reduction ( P=0.001) in comparison with controls. Patients with YMDD-MT and controls had a similar chance of hepatitis flares and hepatic decompensation.

Conclusions

Long-term lamivudine treatment was associated with a reduced chance of developing cirrhosis and HCC in patients without advanced disease. Although YMDD-MT reduced the benefits from lamivudine therapy, the outcome of these patients was still better than untreated patients.

Genotypic resistance to lamivudine among hepatitis B virus isolates in Mexico

BACKGROUND

Drug resistance of hepatitis B virus (HBV) is an increasing clinical problem. Resistance to lamivudine in HBV isolates in Mexico has been poorly explored.

OBJECTIVES

To characterize the mutation patterns associated with genotypic resistance to lamivudine and their prevalence among HBV isolates in Mexico.

MATERIAL AND METHODS

Thirty-nine Mexican HBV isolates were analysed by PCR and line probe assay for detection of genetic variants in the polymerase open reading frame domains B and C (INNO-LiPA HBV DR; INNOGENETICS N. V., Ghent, Belgium). This assay detects wild-type and mutations at codons 180, 204 and 207 of the HBV polymerase gene, and at codon positions 171, 172, 195, 196, 198 and 199 of the HBV surface antigen (HBsAg). HBV isolates were obtained from HBsAg-positive serum samples of 15 chronic hepatitis patients, two haemodialysis patients with chronic HBV carriage, 20 men found positive for HBsAg when seeking HIV testing and two AIDS patients with chronic HBV infection. None of the participants had received antiviral therapy.

RESULTS

Overall, HBV wild-type was found in 37 (94.9%) out of the 39 isolates studied. Two (5.1%) out of the 39 isolates showed mixed wild-type and mutant populations. These mutations occurred in isolates from one hepatitis patient and one haemodialysis patient. The isolate from the hepatitis patient showed a double mutation at codon positions 180 (L180M) and 204 (M204V), thus a 2.6% prevalence of genotypic resistance to lamivudine was found. The isolate from the haemodialysis patient showed a single mutation at codon position 180 (L180M). The two HBV mutant isolates were further analysed for genotype and both isolates were genotype H.

CONCLUSIONS

HBV genotypic resistance to lamivudine exists in Mexican isolates. The results highlight the importance of testing for HBV resistance before treatment and have implications for a more rational use of drugs.

Effect of lamivudine therapy on the serum covalently closed-circular (ccc) DNA of chronic hepatitis B infection

OBJECTIVE

To determine the effect of 1-yr lamivudine treatment on serum covalently closed-circular DNA (cccDNA) level.

PATIENTS AND METHOD

Serum total HBV DNA and cccDNA levels at baseline, week 24, and week 52 were measured in 82 lamivudine-treated patients, 17 of whom received 1-yr placebo and acted as controls.

RESULTS

There was a significant reduction in the cccDNA levels from baseline (median 3.0 x 10(6) copies/ml) to week 24 (33,476 copies/ml) and week 52 (48,694 copies/ml) (p < 0.001 for both). The median reduction in cccDNA level at week 24 and 52 were 2.21 and 2.12 logs, respectively, which were significantly greater than those of controls (0.31 log, p < 0.001; 0.2 log, p < 0.001, respectively). Fifteen patients (18.3%) developed YMDD mutations by week 52. Compared to patients without YMDD mutations, patients with YMDD mutations had significantly less median reduction of total HBV DNA level (4.44 vs 3.65 logs, respectively, p= 0.02) and cccDNA level (2.27 vs 1.65 logs, respectively, p= 0.016) at week 24 and significantly less median reduction of cccDNA at week 52 (2.35 vs 0.8 logs respectively, p < 0.001).

CONCLUSIONS

One-year lamivudine treatment decreased serum cccDNA level by 2 logs. The chance of YMDD mutations at week 52 was related to the magnitude of viral suppression at week 24.

HBsAg seroclearance in Chinese patients receiving lamivudine therapy for chronic hepatitis B virus infection

We report two Chinese patients in whom lamivudine treatment resulted in HBsAg seroclearance. One patient received lamivudine, and another patient received 12-week famciclovir treatment followed by lamivudine. Lamivudine was maintained after HBeAg seroconversion. These two patients lost HBsAg at 24 and 27 months (ages, 23 and 19.3 years, respectively) and developed measurable titer of anti-HBs after 65 and 71 months of therapy, respectively. The liver biochemistry was normal after HBeAg seroconversion. The serum hepatitis B virus (HBV) DNA levels were undetectable (<200 copies/ml) both at the time of HBeAg seroconversion and at the last follow-up. Liver biopsy of one patient showed nearly normal histology, with undetectable intrahepatic total HBV DNA and covalently closed circular DNA. In conclusion, lamivudine therapy can result in HBsAg seroclearance at an early age even though the phenomenon is rare.

Long-term follow-up study of Chinese patients with YMDD mutations: significance of hepatitis B virus genotypes and characteristics of biochemical flares

We sought to examine the role of hepatitis B virus (HBV) genotypes in virological breakthroughs and biochemical flares in patients with YMDD mutations during lamivudine therapy. Virologic breakthroughs (i.e., the reappearance of HBV DNA as determined by bDNA assay) and biochemical flares (mild flares = alanine aminotransferase [ALT] between 2 and 10 times the upper limit of normal [ULN]; severe flares = ALT >10 times ULN) were monitored in 154 hepatitis B e antigen-positive patients receiving long-term lamivudine. The HBV genotypes and YMDD mutations were determined. Forty-three patients had virological breakthroughs with YMDD mutations (median follow-up of 29.6 months [range, 22.3 to 61.4]). Twenty patients (47%) patients had mild biochemical flares; seven (16%) had severe flares. Two patients showed an elevation of bilirubin level that is >2 times the ULN. All patients recovered spontaneously. The cumulative risks for biochemical flares were 28, 47, and 58% for the first 3 years, respectively. Patients with biochemical flares compared to those without flares had a significantly higher median pretreatment ALT level (61 U/liter versus 34.5 U/liter [P = 0.012]). There were no differences in the cumulative risk of virological breakthroughs, risk, and severity of biochemical flares between patients with genotypes B (n = 11) and C (n = 32). There was an increase in the percentage of patients with single YMDD mutant at last follow-up compared to that at the time of virological breakthroughs (74% [n = 32] versus 47% [n = 20], respectively; P = 0.015). The chances of YMDD mutations with virological breakthroughs and biochemical flares were similar in patients with genotypes B and C. Biochemical flares were common, with 16% being severe in nature. High pretreatment ALT levels were associated with a higher chance of biochemical flares.

Review article: Nucleoside analogues for the treatment of chronic hepatitis B

Current accepted treatment for chronic hepatitis B uses either the immunomodulator interferon alpha or nucleoside analogues lamivudine or adefovir. Interferon has side effects which mean it is often poorly tolerated. Long-term use of lamivudine is associated with increasing viral resistance for each year it is taken and the rebound viraemia that can occur when the drug is stopped is also of concern to many. Adefovir appears to have less of the resistance issues of lamivudine but is still a relatively new drug and at present its use is principally limited to patients with lamivudine-resistant disease. A number of other nucleoside analogues are currently being developed with some now at the stage of early clinical trials. A proportion share the significant resistance problems of lamivudine but many appear to have more potent anti-viral effect than the drugs currently available. If some of these newer anti-viral agents are approved for use in chronic hepatitis B, the potential for prolonged suppression of hepatitis B virus replication with resultant stabilization or improvement in liver disease may be achieved.

Immune Reconstitution Hepatitis in HIV and Hepatitis B Coinfection, Despite Lamivudine Therapy as Part of HAART

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection occurs commonly. The introduction of antiretroviral therapy can result in immune reconstitution hepatitis. We describe 2 coinfected patients who developed clinical flares of HBV disease, despite the inclusion of lamivudine, a drug with anti-HBV activity, in their HAART regimens. Potential strategies to manage individuals with HBV/HIV coinfection are discussed.

Clinical outcome and virologic profiles of severe hepatitis B exacerbation due to YMDD mutations

BACKGROUND/AIMS

To study the outcome and the virologic profiles of severe hepatitis exacerbations due to YMDD mutants in lamivudine-treated patients.

METHODS

Eighteen lamivudine-treated patients with severe hepatitis exacerbations due to YMDD mutants were recruited. Laboratory and clinical parameters were monitored. Viral genotypes and YMDD mutations were determined.

RESULTS

None of the 18 patients had YMDD wild-type during exacerbations. Three (17%) and 15 (83%) patients had genotypes B and C, respectively. Elevated bilirubin levels and prolonged prothrombin time were found in 11 (61%) and six patients (33%) respectively. Three patients (17%) had adverse outcome with the development of ascites and/or encephalopathy. One of these patients required liver transplantation and one died. Both patients had evidence of cirrhosis before treatment and hepatitis B e antigen (HBeAg) seroreversion from anti-HBe positivity. The remaining 16 patients (89%) have no evidence of pre-existing cirrhosis. Thirty seven percent of patients had normal alanine aminotransferase levels at the last follow-up. The median HBV DNA level at the last follow-up was significantly lower than the pre-treatment level (P=0.009).

CONCLUSIONS

Though the majority of patients with severe hepatitis exacerbations due to YMDD mutants had uneventful course, early liver transplantation should be considered in patients with pre-existing cirrhosis and HBeAg seroreversion.