Is Tenofovir the Best Medication for Hepatitis B Infection?

Two recent studies have suggested that tenofovir may be more effective for hepatitis B virus (HBV) infections.

  • T C-F Yip et al. Gastroenterol 2020; 158: 215-25.
  • J Choi et al. JAMA Oncol 2019; 5: 30-6. (Reviewed in a commentary by P Lampertico, M Colombo. Gastroenterol 2019; 157: 1682-88)

In the first retrospective study from Hong Kong, the authors analyzed 29,350 consecutive treated-patients  (mean age 52.9 years).  1309 were treated with tenofovir disoproxil fumarate (TDV) and 28,041 were treated with entecavir. Key findings:

  • TDF-treated patients were younger (mean age 43.2 years vs. 53.4 years) and had less cirrhosis at baseline (2.9% vs. 13.6%).
  • After a median follow-up of 3.6 years, 8 TDF-treated patients (0.6%) and 1386 (4.9%) of entecavir-treated patients developed hepatocellular carcinoma (HCC).  The authors note that TDF maintained a lower rate of HCC after propensity score weighting (hazard ratio of 0.36)

The second study was a nationwide population cohort database with >24,000 patients –all with ALT >80. Key finding:

  • HCC was significantly lower in TDF group than in the entecavir group, the percent person-years being 0.64 compared to 1.06; though, there was not a lower mortality rate or a lower liver transplantation rate.

The commentary associated with the latter study makes the following points:

  • Both TDF and entecavir could prevent “the incidence and mortality of HCC …in >85% of patients who received [them] for years.”
  • Studies comparing TDF and entecavir have come up with conflicting results.  “Three studies in Korea, the U.S, and Europe reported no differences between NAs even after patient matching by a propensity score.”
  • “Cumulatively, all these studies deliver the reassuring message of a robust risk reduction of liver cancer taking place in patients with chronic hepatitis B who experience prolonged virus suppression after NA therapy, but currently they fail to provide convincing evidence that one NA is superior to the other one in determining such clinical benefit.”

My take: Tenofovir may be better but the answer is not definitive; due to lack of randomization, there may still be confounding variables in which sicker patients are receiving entecavir and this could be contributing to the difference in outcomes.  Also, in patients with bone disease and renal impairment, tenofovir alafenamide (TAF) or entecavir is recommended.

Related blog posts:

From P’tit Train Du Nord Linear Park

Liver Briefs -September 2019

P Rosenthal et al. Hepatology 2019; 69: 2326-37.  This study examined the efficacy and safety of combined entecavir and Peginterferon for immune-tolerant chronic hepatitis B-infected children (n=60). 48 weeks after completing treatment (week 96), 2 children (3%) achieved the primary outcome of undetectable HBeAg with HBV DNA levels <1000 IU/mL.  These two children were also HBsAg negative/anti-HBs positive. In the other children (55 completed study), the ALT and HBV DNA levels were similar to baseline.  37 children experienced adverse events.  My take: Entecavir/peginterferon is not very effective in immune-tolerant children infected with chronic HBV.

DL Thomas. NEJM 2019; 380: 2041-50. This article reviews the pathway to the global elimination of chronic hepatitis.  Currently, it is estimated that hepatitis C virus (HCV) and hepatitis B virus (HBV) kill more than 1 million persons each year. “In fact, by 2040, deaths from chronic hepatitis are projected to exceed the combined mortality associated with HIV infection, tuberculosis, and malaria.”

JR Dillman et al. J Pediatr 2019; 212: 60-5. This study with 41 patients and 13 patients with biliary atresia prospectively assessed ultrasound shear wave elastography (SWE). The authors found that SWE with a cut-off value of >1.84 m/s had 92% sensitivity and 79% specificity.  Also, in their cohort, GGT >320 had a sensitivity of 100% and specificity of 78%.

Z Younossi et al. Hepatology 2019; 69: 2672-82.  This review provides a global perspective of NAFLD.  25% of the world’s population is currently thought to have NAFLD with highest prevalence in South America at 30.45% and lowest in Africa at 13.5%. This article usggest North America to have 24.1% prevalence rate.

Liver Briefs -June 2019

YH Yeo et al. Hepatology 2019; 69: 1385-97.  The prevalence of high risk individuals in the U.S. who are susceptible (not immune) to hepatitis B has decreased from 83% to 69% from 2003 to 2014.  That still leaves 64 million who would benefit from HBV vaccination.

M Sharma et al. Hepatology 2019; 69: 1657-75. This meta-analysis compared therapies for primary prevention of esophageal varices and concluded that nonselective beta-blocker (NSBB) monotherapy may decrease all-cause mortality and carried a lower risk of serious complications than variceal band ligation (VBL). However, the commentary (1382-84 by L Laine) reaches a different conclusion. “Current recommendations for primary prevention with VBL or NSBB or carvediolo still appear to be acceptable…using a shared decision-making approach” to weigh issue such as daily medication or periodic endoscopy.

J Nguyen et al. J Pediatr 2019; 207: 90-6. This study modeled the cost-effectiveness of early treatment with direct-acting antiviral therapy in adolescents with hepatitis C infection.  With pangenotypic agenst, the cost would be $10000 to $21000 per QALY gained.

S Trinh et al. Clin Gastroenterol Hepatol 2019; 17: 948-56. This retrospective hepatitis B study examined the changes in renal function between 239 tenofovir disoproxil fumarte (TDF) treated patients and 171 entecavir treated patients.  Key finding: TDF was not associated with higher risk of worsening renal function in this cohort with a mean followup of 43-46 months in patients with baseline normal renal function.  In patients with renal impairment, deterioration of renal function was noted in TDF-treated patients.  Thus, TDF should be avoided in patients with impaired renal function.

 

Rhododendrom in Sandy Springs

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Comprehensive 2018 AASLD Guidance for Chronic Hepatitis B

NA Terrault et al. Hepatology 2018; 67: 1560-99. Here’s the full link: Update on Prevention, Diagnosis, and Treatment of Chronic Hepatitis B: AASLD 2018 Hepatitis B Guidance

Some of the key points:

Table 4 (pg 1565): provides a refresher on interpretation of serology

Table 5 (pg 1567): Children and Adults Who Are HBsAg Positive:

  • Can participate in all activities, including contact sports
  • Should not be excluded from daycare or school participation and should not be isolated from other children
  • Can share food and utensils and kiss others

Figure 1 (pg 1571) Treatment algorithms.

  • For both HBsAg-positive/HBeAg-positive and HBsAg-positive/HBeAg-negative patients, treatment is recommended if ALT ≥2 x ULN.
  • For both groups, treatment is NOT recommended for those with ALT ≤ULN and low HBV DNA levels (<20,000 IU/mL for HBeAg-positive and <2,000 IU/mL for HBeAg-negative).
  • In those who do not fall into these categories, ongoing monitoring is recommended

Figure 1 from AASLD Guidance Link

Guidance Statements for HCC Screening in HBsAg‐Positive Persons

  • All HBsAg‐positive patients and high risk adults (see page 1574) with cirrhosis should be screened with US examination with or without AFP every 6 months.
  • There are insufficient data to identify high‐risk groups for HCC in children. However, it is reasonable to screen HBsAg‐positive children and adolescents with advanced fibrosis (F3) or cirrhosis and those with a first‐degree family member with HCC using US examination with or without AFP every 6 months.

Treatment: 

  • In adults: The AASLD recommends peg‐IFN, entecavir, or tenofovir (TDF) as preferred initial therapy for adults with immune‐active CHB
  • In children: The AASLD suggests antiviral therapy in HBeAg‐positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV‐DNA levels, with the goal of achieving sustained HBeAg seroconversion.

Perinatal transmission:

  • The AASLD suggests antiviral therapy to reduce the risk of perinatal transmission of HBV in HBsAg‐positive pregnant women with an HBV‐DNA level >200,000 IU/mL..The only antivirals studied in pregnant women are lamivudine, telbivudine, and TDF. Of these 3 options, TDF is preferred to minimize the risk of emergence of viral resistance during treatment. Interim studies show high efficacy of TDF in preventing mother‐to‐child transmission.
  • The infants of all HBsAg‐positive women should receive immunoprophylaxis (HBV vaccination with or without hepatitis B immunoglobulin, per World Heath Organization and Centers for Disease Control and Prevention recommendations)

Treatment & prevention of HBV reactivation in patients receiving immunosuppressive or cytotoxic drugs (section 6 pages 1577-9)

  • HBsAg and anti‐HBc (total or immunoglobulin G) testing should be performed in all persons before initiation of any immunosuppressive, cytotoxic, or immunomodulatory therapy.
  • HBsAg‐positive, anti‐HBc–positive patients should initiate anti‐HBV prophylaxis before immunosuppressive or cytotoxic therapy.
  • HBsAg‐negative, anti‐HBc–positive patients could be carefully monitored with ALT, HBV DNA, and HBsAg with the intent for on‐demand therapy, except for patients receiving anti‐CD20 antibody therapy (e.g., rituximab) or undergoing stem cell transplantation, for whom anti‐HBV prophylaxis is recommended.

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Hepatitis B & C -Winter 2016

The large randomized pediatric entecavir study for Hepatitis B virus (HBV) is now in print: MM Jonas et al. Hepatology 2016; 63: 377-87.  Full link to this study on previous blog: Pediatric Entecavir Data  This study has led to FDA approval for use of entecavir in children as young as 2 years.  One interesting aspect of the study was the 2.6% drug resistance rate in the second year of the study.  This further validates current recommendations to treat children with “immune active” phases (e.g. abnormal transaminases and abnormal histology).

Briefly noted:

H Roberts et al. Hepatology 2016; 63: 388-97.  This study provides prevalence data for chronic HBV, 1988-2012.  During 2011-12, there were approximately 850,000 Americans with chronic HBV infections.  Migration of persons from HBV endemic countries has “largely contributed to prevalence rates remaining constant since 1999.”

JM Wilder et alHepatology 2016; 63: 437-44. This study showed that ledipasvir/sofosbuvir was similarly effective in black and non-black patients, with SVR12 rates of 95% and 97% respectively.  This is important because older interferon-based treatments were much less effective in black patients.

TB Dick et al. Hepatology 2016; 63: 634-43.  This review provides in-depth guidance regarding drug-drug interactions relevant to the new direct-acting antiviral agents used to treat Hepatitis C viral infection.

NY City Data for HIV, HBV, HCV

NY City Data for HIV, HBV, HCV

More on Hepatitis B Treatment in Children

A recent post (New Hepatitis B Treatment Guidelines -AASLD) described the updated treatment recommendations.  When these guidelines were published, a separate review devoted specifically to pediatrics was published (Hepatology 2016; 63: 307-18).

Some of the key points:

  • This pediatric review included 14 studies with 1425 children.  The authors note that 7 of these trials had a high risk of bias.  Also, the studies are limited by relying on surrogate markers of long-term outcomes as clinical outcomes like cirrhosis, HCC, and death are rare in childhood.
  • Among oral agents, entecavir and lamivudine are approved for use in children ≥ 2 years, whereas adefovir and tenofovir are approved for use in children ≥ 12 years.  Both lamivudine and adefovir are associated with frequent development of viral resistance
  • For children with elevated ALT (>1.5 times upper limit of normal [ULN]), treatment is recommended:

9A. The AASLD suggests antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV DNA levels, with the goal of achieving sustained HBeAg seroconversion.

Why not treat everyone?

  • Children with immune-tolerant HBV infection (normal or near-normal ALT [< 1.5-2 times ULN] along with high HBV DNA [>10 million IU/mL]), “are not typically candidates for treatment because treatment with any of the currently available drugs has not been demonstrated to improve HBeAg seroconversion compared with no treatment.”
  • Children with ALT >10 time ULN may be in the process of spontaneous seroconversion “and should be observed for several months before treatment” is initiated.
  • “Prolonged treatment with nucleoside or nucleotide analogs in children who are in immune-tolerant phase has not been associated with substantial benefit and carries a risk of developing antiviral drug resistance…An exception may be those…undergoing immunosuppressive therapy.”
Mina Falls, El Yunque Rainforest

Mina Falls, El Yunque Rainforest

New Hepatitis B Treatment Guidelines

Link to full article: Updated Hepatitis B Treatment Guidelines from AASLD

With regard to pediatrics:

9A. The AASLD suggests antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with both elevated ALT and measurable HBV DNA levels, with the goal of achieving sustained HBeAg seroconversion.

“Most studies required ALT elevation (>1.3 times ULN) for at least 6 months with HBV DNA elevations for inclusion. Given that HBV DNA levels are typically very high during childhood (>106 IU/mL), there is no basis for a recommendation for a lower-limit value with respect to treatment. However, if a level <104 IU/mL is observed, therapy might be deferred until other causes of liver disease and spontaneous HBeAg seroconversion are excluded.”

“Duration of treatment with oral antivirals that has been studied is 1-4 years. It may be prudent to use HBeAg seroconversion as a therapeutic endpoint when oral antivirals are used, continuing treatment for an additional 12 months of consolidation, as recommended in adults. It is currently unknown whether a longer duration of consolidation would reduce rates of virological relapse.”

“Children who stop antiviral therapy should be monitored every 3 months for at least 1 year for recurrent viremia, ALT flares, and clinical decompensation.”

9B. The AASLD recommends against use of antiviral therapy in HBeAg-positive children (ages 2 to <18 years) with persistently normal ALT, regardless of HBV DNA level.

Another nice summary of current treatment recommendations: P Martin et al. Clin Gastroenterol Hepatol 2015; 13: 2071-87.  Table 5 lists recommendations for treatment of HBeAg-positive.

  • The main group needing treatment (entecavir, tenofovir, or PEGinterferon alfa-2a) are those with HBV DNA >2000 IU/mL and elevated ALT.  Table 6 lists recommendations for those with HBeAg-negative.  Main group needing treatment are the same (HBV DNA >2000 IU/mL and elevated ALT).
  • With both groups (HBe-Ag negative and positive), “consider liver biopsy or transient elastography” if elevated HBV DNA >2000 and normal ALT.  If histologic disease present, consider treatment.
  • One point the authors make about therapy regards duration: “Historically, HBeAg seroconversion was considered a durable response, and discontinuation of antiviral therapy was recommended after a period of consolidation therapy of 6-12 months from the time of HBeAg seroconversion. However, patients who discontinue therapy …can experience recurrent viremia and ALT flares.  Thus, long-term therapy is justified.”
  • For HBeAg negative patients who have compensated liver disease, loss of HBsAg for 6-12 months may be discontinued from therapy.

Pediatric Entecavir Data

While entecavir and tenofovir have been in use for many years in adult hepatology for hepatitis B virus (HBV) infection, a well-designed study supporting their use in pediatrics has been lacking until now.  Recently, a study (M Jonas et al. Hepatology 2015; DOI: 10.1002/hep.28015)  has shown that entecavir is effective for pediatric HBV

Link to full study. Randomized Controlled Trial of Entecavir Versus Placebo in Children with HBeAg-positive Chronic Hepatitis B

Here’s the abstract:

This ongoing, randomized phase III study assesses the safety and efficacy of entecavir versus placebo in nucleos(t)ide-naive children (2 to <18 years) with HBeAg-positive chronic hepatitis B (CHB). Blinded treatment was administered for a minimum of 48 weeks. After Week 48, patients with HBeAg seroconversion continued blinded treatment; those without, switched to open-label entecavir. The primary endpoint was HBeAg seroconversion and HBV DNA <50 IU/mL at Week 48. A total of 180 patients were randomized (2:1) and treated. Baseline median age was 12 years, with approximately 50% of children aged >12 to <18, and 25% each aged ≥2 to ≤6 and >6 to ≤12. Rates for the primary endpoint at Week 48 were significantly higher with entecavir than placebo (24.2% [29/120] versus 3.3% [2/60]; P=0.0008). Furthermore, higher response rates were observed with entecavir compared with placebo for the key Week 48 secondary endpoints: HBV DNA <50 IU/mL (49.2% [59/120] versus 3.3% [2/60]; P < 0.0001), alanine aminotransferase normalization (67.5% [81/120] versus 23.3% [14/60]; P < 0.0001), and HBeAg seroconversion (24.2% [29/120] versus 10.0% [6/60]; P = 0.0210). Among entecavir-randomized patients there was an increase in all efficacy endpoints between Weeks 48 and 96, including an increase from 49% to 64% in virologic suppression. The cumulative probability of emergent entecavir resistance through Years 1 and 2 of entecavir was 0.6 and 2.6%, respectively. Entecavir was well tolerated with no observed differences in adverse events or changes in growth compared with placebo. Conclusion: In childhood CHB, entecavir demonstrated superior antiviral efficacy to placebo with a favorable safety profile. These results support the use of entecavir as a therapeutic option in children and adolescents with CHB.

Related blog posts:

From Brooklyn Bridge

From Brooklyn Bridge

 

Hepatitis C -Can We Really Accomplish Widespread Screening?

A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty.  -Winston Churchill

The aforementioned quote leads a recent editorial (Lutchman G, Kim WR, Hepatology 2015; 1455-8) which discusses the challenges of widespread Hepatitis C virus (HCV) screening and avoiding late diagnosis/missed opportunity for timely treatment.  The associated article (Moorman AC et al. Hepatology 2015; 1479-84) reviewed a large cohort of 14,717 patients with HCV and noted that 17% (n=1056) had a ‘late diagnosis’ which resulted in high rates of hospitalization and mortality.  Late diagnosis was defined as having cirrhosis at time of diagnosis or hepatic decompensation within 12 months of initial diagnosis.

The editorialists note that the related article presents data from 2006-11 which models ‘real-life’ practice settings.  Late diagnosis was more common in African-Americans and in patients with Medicare insurance.

With regard to widespread screening, pessimists argue that “we do not have coherent strategies and resources” to implement.

  • there are too few health care providers who are qualified and interested
  • the ‘treat-all” strategy is too expensive.  “For example, in the first 3 months after the release of sofosbuvir, a large commercial health insurance carrier announced that it had spent over $100 million on hepatitis C prescriptions…cause[d] a substantial drop in its stock price”
  • “while prioritizing treatment to patients who are at risk of future problems seems the optimal solution to deliver the most benefits at the lowest costs, the problems lies in the identification of those patients.”

Optimists see the opportunity for early intervention and improved outcomes.

Bottomline: While more effective treatment is available, there are still many questions, especially who should receive treatment and how to identify those most in need.  If/when costs of therapy are reduced, some of the difficult questions will resolve.

Related blog posts:

Briefly noted:

  • “Adding Pegylated Interferon to Entecavir for Hepatitis e Antigen-Positive Chronic Hepatitis B: A Multicenter Randomized Trial (ARES Study)” Brouwer WP et al. Hepatology 2015; 1512-22). “Peg-IFN add-on therapy may facilitate the discontinuation of nucleus(t)ice analogs.”
  • “The Impact of Phlebotomy in Nonalcoholic Fatty Liver Disease: A prospective, randomized, controlled trial.” Adams LA et al. Hepatology 2015; 1555-64).  “Reduction in ferritin by phlebotomy does not improve liver enzymes, hepatic fat, or IR in subjects with NAFLD”
  • “Nonalcoholic Steatohepatitis is the Second Leading Etiology of Liver Disease Among Adults Awaiting Liver Transplantation in the United States.” Wong RJ et al. Gastroenterol 2015; 148: 547-55.
Chattahoochee River

Chattahoochee River

Don’t Give Up Too Soon (with Hepatitis B treatment)

A recent study shows that ongoing treatment with entecavir is usually effective in “primary nonresponders” (Hepatology 2014; 59: 1303-10).

This study retrospectively reviewed a study with 1254 treatment-naive patients who received entecavir (ETV) 0.5 mg/day for >6 months. Only 16 (1.28%) patients were considered “primary nonresponders.”  The latter was defined as a <2 log drop in HBV DNA after 6 months of therapy by AASLD or <1 log drop after 3 months by EASL.

Key findings:

  • The probability of achieving a virologic response (HBV DNA <15 IU/mL) was 95.8% at 54 months among these “nonresponders”
  • Primary nonresponders did not have ETV resistance; however, 13 (1%) of the entire cohort developed ETV resistance.
  • In this treatment cohort, the 5-year cumulative risk of hepatocellular carcinoma (HCC) was 2.5%.  Previous studies have shown that HBV suppression lowers the risk of HCC.

Take-home message: 

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.