Huy N. Trinh

Tenofovir Disoproxil Fumarate versus Adefovir Dipivoxil for Chronic Hepatitis B

BACKGROUND Tenofovir disoproxil fumarate (DF) is a nucleotide analogue and a potent inhibitor of human immunodeficiency virus type 1 reverse transcriptase and hepatitis B virus (HBV) polymerase. METHODS In two double-blind, phase 3 studies, we randomly assigned patients with hepatitis B e antigen (HBeAg)-negative or HBeAg-positive chronic HBV infection to receive tenofovir DF or adefovir dipivoxil (ratio, 2:1) once daily for 48 weeks. The primary efficacy end point was a plasma HBV DNA level of less than 400 copies per milliliter (69 IU per milliliter) and histologic improvement (i.e., a reduction in the Knodell necroinflammation score of 2 or more points without worsening fibrosis) at week 48. Secondary end points included viral suppression (i.e., an HBV DNA level of <400 copies per milliliter), histologic improvement, serologic response, normalization of alanine aminotransferase levels, and development of resistance mutations. RESULTS At week 48, in both studies, a significantly higher proportion of patients receiving tenofovir DF than of those receiving adefovir dipivoxil had reached the primary end point (P<0.001). Viral suppression occurred in more HBeAg-negative patients receiving tenofovir DF than patients receiving adefovir dipivoxil (93% vs. 63%, P<0.001) and in more HBeAg-positive patients receiving tenofovir DF than patients receiving adefovir dipivoxil (76% vs. 13%, P<0.001). Significantly more HBeAg-positive patients treated with tenofovir DF than those treated with adefovir dipivoxil had normalized alanine aminotransferase levels (68% vs. 54%, P=0.03) and loss of hepatitis B surface antigen (3% vs. 0%, P=0.02). At week 48, amino acid substitutions within HBV DNA polymerase associated with phenotypic resistance to tenofovir DF or other drugs to treat HBV infection had not developed in any of the patients. Tenofovir DF produced a similar HBV DNA response in patients who had previously received lamivudine and in those who had not. The safety profile was similar for the two treatments in both studies. CONCLUSIONS Among patients with chronic HBV infection, tenofovir DF at a daily dose of 300 mg had superior antiviral efficacy with a similar safety profile as compared with adefovir dipivoxil at a daily dose of 10 mg through week 48. (ClinicalTrials.gov numbers, NCT00116805 and NCT00117676.)

Three-Year Efficacy and Safety of Tenofovir Disoproxil Fumarate Treatment for Chronic Hepatitis B

BACKGROUND & AIMS Tenofovir disoproxil fumarate (TDF), a nucleotide analogue and potent inhibitor of hepatitis B virus (HBV) polymerase, showed superior efficacy to adefovir dipivoxil in treatment of chronic hepatitis B through 48 weeks. We evaluated long-term efficacy and safety of TDF monotherapy in patients with chronic hepatitis B who were positive or negative for hepatitis B e antigen (HBeAg(+) or HBeAg(-)). METHODS After 48 weeks of double-blind comparison of TDF to adefovir dipivoxil, patients who underwent liver biopsy were eligible to continue the study on open-label TDF for 7 additional years; data presented were collected up to 3 years (week 144) from 85% of participants. Primary efficacy end points at week 144 included levels of HBV DNA and alanine aminotransferase, development of resistance mutations, and presence of HBeAg or hepatitis B surface antigen (HBsAg). RESULTS At week 144, 87% of HBeAg(-) and 72% of HBeAg(+) patients treated with TDF had levels of HBV DNA <400 copies/mL. Among patients who had previously received adefovir dipivoxil and then received TDF, 88% of the HBeAg(-) and 71% of the HBeAg(+) patients had levels of HBV DNA <400 copies/mL; overall, 81% and 74%, respectively, maintained normalized levels of alanine aminotransferase and 34% had lost HBeAg. Amino acid substitutions in HBV DNA polymerase that are associated with resistance to tenofovir were not detected in any patient. Cumulatively, 8% of HBeAg(+) patients lost HBsAg. TDF maintained a favorable safety profile for up to 3 years. CONCLUSIONS TDF was safe and effective in the long-term management of HBeAg(+) and HBeAg(-) patients with chronic hepatitis B.

Renal dysfunction in chronic hepatitis B patients treated with adefovir dipivoxil

Renal dysfunction has been reported in patients treated with adefovir dipivoxil (ADV); however, its incidence and clinical importance may be underappreciated given the lack of long‐term follow‐up and data outside of a clinical trial setting. Our goal was to examine the severity and incidence of renal dysfunction in a real‐life setting for patients treated with ADV and whose baseline estimated glomerular filtration rate (eGFR) was >50 mL/minute. We performed a cohort study of 290 chronic hepatitis B patients: 145 patients treated with 10 mg ADV and 145 patients unexposed to ADV at two community clinics, who were matched for age (±10 years), sex, and baseline eGFR. The exposed and unexposed populations were well‐matched with a similar mean age (46–47 years), proportion of male patients (76.5%), baseline serum creatinine (0.97–0.99 mg/dL), and baseline creatinine clearance (85.0–85.4 mL/minute). The incidence density for renal dysfunction defined by treatment termination and/or development of eGFR ≤50 mL/minute was five cases per 100 patient‐years in the exposed group compared with 1.36 cases per 100 patient‐years in the unexposed group (P = 0.02). The relative risk of exposed to unexposed was 3.68 (95% confidence interval 1.1–19.3). On Cox proportional hazard analysis also inclusive of sex, ADV was a significant predictor of significant renal dysfunction (hazard ratio [HR] 3.94, P = 0.03). There were also significant trends for age >50 years (HR 3.49, P = 0.087), mild renal impairment at baseline (HR 4.49, P = 0.073), and hypertension and/or diabetes mellitus (HR 2.36, P = 0.074). Conclusion: ADV is an independent predictor for significant deterioration of renal function. Patients on ADV should be monitored, especially patients who are older, have baseline renal insufficiency, or have hypertension and/or diabetes mellitus. (HEPATOLOGY 2009.)

Efficacy of Entecavir With or Without Tenofovir Disoproxil Fumarate for Nucleos(t)ide-Naïve Patients With Chronic Hepatitis B

BACKGROUND & AIMS Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent antiviral agents that might have additive or synergistic antiviral activity in treatment of patients with chronic hepatitis B (CHB). We compared the efficacy and safety of ETV monotherapy with those of a combination of ETV and TDF. METHODS We performed a randomized, open-label, multicenter, superiority study of 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive (n = 264) or HBeAg-negative (n = 115) CHB. Subjects were given ETV 0.5 mg (n = 182) or a combination of ETV 0.5 mg and TDF 300 mg (n = 197) for 100 weeks. RESULTS At week 96, comparable proportions of patients in each study arm achieved the primary end point of a level of hepatitis B virus (HBV) DNA <50 IU/mL (83.2% vs 76.4%; P = .088). Among HBeAg-positive patients, a greater proportion given combination therapy achieved levels of HBV DNA <50 IU/mL than those given ETV alone (80.4% vs 69.8%; P = .046). However, this difference was observed only in patients with baseline levels of HBV DNA ≥ 10(8) IU/mL (79% vs 62%) and not in those with baseline levels of HBV DNA <10(8) IU/mL (83% in both arms). Rates of HBeAg loss and HBeAg seroconversion were comparable between groups, whereas the rate of alanine aminotransferase normalization was greater in the ETV monotherapy group. No HBV variants associated with ETV or TDF resistance were detected. Safety profiles were consistent with previous reports of ETV or TDF monotherapy. CONCLUSIONS The antiviral efficacy of ETV monotherapy is comparable to that of ETV plus TDF in a mixed population of nucleos(t)ide-naïve patients with CHB (70% HBeAg positive). The combination therapy could provide an incremental benefit to HBeAg-positive patients with baseline levels of HBV DNA ≥ 10(8) IU/mL.

Significant Prevalence of Histologic Disease in Patients With Chronic Hepatitis B and Mildly Elevated Serum Alanine Aminotransferase Levels

BACKGROUND & AIMS Serum ALT remains the most accessible test available to clinicians for monitoring chronic hepatitis B virus infection, but appropriate action when ALT levels are only mildly elevated is ambiguous in standard guidelines. METHODS A retrospective study was conducted to investigate the prevalence of significant histology in a patient population with mildly elevated serum ALT levels. A total of 193 consecutive patients were selected and divided into 2 groups according to HBeAg status. Patients were further divided into cohorts on the basis of their highest ALT elevation during follow-up and whether it was 1-1.5 times the upper limit of normal (ULN), 1.5-2 times the ULN, or greater than twice the ULN. The ULN that was used is 30 U/L for men and 19 U/L for women. RESULTS In all cohorts there was a substantial fraction of patients with histologic disease as evaluated by liver biopsy. HBeAg-negative patients were older, had lower viral load, and had a higher prevalence of disease. After adjustments for age, HBeAg status and HBV DNA viral load were not predictors of significant histology. Age >35 years, male gender, and increasing ALT levels were predictors for significant histology on multivariate analysis. CONCLUSIONS A substantial proportion of patients with mildly elevated ALT levels have significant histologic disease. The prevalence increased with the higher ALT levels and age.

Long-term efficacy and safety of emtricitabine plus tenofovir DF vs. tenofovir DF monotherapy in adefovir-experienced chronic hepatitis B patients

BACKGROUND & AIMS Suboptimal virologic response to nucleos(t)ide analogs may represent a significant risk factor for resistance development in patients with chronic hepatitis B virus infection; treatment options have not been well studied. We evaluated long-term efficacy and safety of tenofovir alone and in combination with emtricitabine in a prospective, placebo-controlled trial in patients who remained viremic on adefovir therapy. METHODS Hepatitis B e antigen-positive and -negative patients with hepatitis B virus DNA ⩾ 1000 copies/ml despite up to 96 weeks of adefovir were randomized to double-blind tenofovir or emtricitabine/tenofovir for 168 weeks. Patients with hepatitis B virus DNA ⩾ 400 copies/ml (⩾ 69IU/ml) at or after week 24 could switch to open-label emtricitabine/tenofovir. RESULTS Overall, 90/105 (86%) patients (46/53 tenofovir and 44/52 emtricitabine/tenofovir) completed the 168-week study period, including 74/105 (70%) patients (35/53 tenofovir and 39/52 emtricitabine/tenofovir) who completed the study on their initial randomized treatment. Long-term viral suppression (hepatitis B virus DNA <400 copies/ml) was maintained at week 168 in 84% and 82% of patients receiving either emtricitabine/tenofovir combination or tenofovir monotherapy, respectively (non-completer equal to failure analysis). Baseline viral load as well as the presence of lamivudine and/or adefovir resistance-associated mutations at baseline had no impact on long-term treatment response. No resistance to tenofovir was observed through 168 weeks. Both treatments had a favorable safety profile. CONCLUSIONS Tenofovir monotherapy is as effective as emtricitabine/tenofovir combination therapy in maintaining long-term viral suppression in patients with a suboptimal response to adefovir, and is well tolerated in this population.

Clinical course of hepatitis B virus infection during pregnancy.

Background  For women with hepatitis B virus (HBV) infection, little is known about the natural progression of the disease during pregnancy or its impact on pregnancy outcomes.

Higher Rate of Sustained Virologic Response in Chronic Hepatitis C Genotype 6 Treated With 48 Weeks Versus 24 Weeks of Peginterferon Plus Ribavirin

OBJECTIVES:Infection with hepatitis C virus (HCV) genotype 6 is common in patients from parts of China and Southeast Asia. No study to date has examined the treatment response to peginterferon and ribavirin (PEG IFN + RBV) in these patients, or the effects of treatment duration on sustained virologic response (SVR) rates.METHODS:We performed a retrospective study of 190 consecutive Asian-American patients who were diagnosed with HCV genotype 6 at a gastroenterology clinic in northern California between 2001 and 2004, 66 of whom were treatment-naïve and subsequently completed 24 wk of IFN + RBV or PEG IFN + RBV or 48 wk of PEG IFN + RBV therapy. The primary outcome was SVR.RESULTS:There was no statistical difference in SVR of 31 patients treated with 24 wk of IFN + RBV and in 23 patients treated with 24 wk of PEG IFN + RBV (51.6% vs 39%, P = 0.363). The SVR in 12 patients treated with 48 wk of PEG IFN + RBV was significantly higher than that in those treated for only 24 wk (75% vs 39%, P = 0.044).CONCLUSIONS:Treatment-eligible patients with HCV genotype 6 should be treated with a full course of 48 wk as tolerated. Larger prospective studies of patients with HCV genotype 6 are needed to confirm the optimal treatment duration with PEG IFN + RBV.

High frequency of recurrent viremia after hepatitis B e antigen seroconversion and consolidation therapy.

Background: The primary treatment endpoint for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B is HBeAg seroconversion; however, data on the durability of response are inconsistent. Goals: Our goal was to investigate the rate of recurrent viremia after HBeAg seroconversion and subsequent discontinuation of therapy. Methods: We retrospectively studied 88 consecutive Asian American patients who achieved HBeAg seroconversion [loss of HBeAg and development of antibody to HBeAg (anti-HBe)] among 458 HBeAg-positive patients who received oral antiviral therapy at 3 US clinics between March 1998 and November 2010. Recurrent viremia was defined as reappearance of detectable serum hepatitis B virus DNA (>100 IU/mL) on 2 consecutive laboratory tests from previously undetectable levels. Results: Antiviral medications used at the time of HBeAg seroconversion included: lamivudine (23%), adefovir (34%), entecavir (36%), tenofovir (4%), and combination therapy (3%). Antiviral therapy was continued after HBeAg seroconversion in 49 patients (group I) and discontinued in the other 39 patients after consolidation therapy [median=12 months (range, 1 to 55 mo)] (group II). No patients in group I experienced recurrent viremia, whereas 90% in group II did. Elevated alanine aminotransferase also occurred in 38% of group II patients [median peak alanine aminotransferase 249 IU/mL (range, 93 to 1070 IU/mL)]. Conclusions: Despite consolidation therapy, almost all patients who discontinued therapy after achieving HBeAg seroconversion and complete viral suppression experienced recurrent viremia, and close to half also experienced biochemical flares. HBeAg seroconversion does not seem to be a durable treatment endpoint for many patients, and they should be monitored carefully for virologic relapse and biochemical flares if antiviral therapy is withdrawn.

Histological disease in Asian-Americans with chronic hepatitis B, high hepatitis B virus DNA, and normal alanine aminotransferase levels.

OBJECTIVES:At present there is no clear consensus on how patients with chronic hepatitis B (CHB), high serum hepatitis B virus (HBV) DNA, and normal alanine aminotransferase (NLALT) levels should be managed. This study hypothesizes that a significant proportion of such patients may have histological disease.METHODS:We carried out a retrospective study of 101 consecutive treatment-naive patients with CHB who underwent liver biopsies at a community gastroenterology clinic and had high HBV DNA and NLALT (≤40 U/l) levels at the time of biopsy. All patients were Asians. ALT levels were observed for a period of time before liver biopsy and were used to classify patients into two groups, namely those with only NLALT levels and those with fluctuating ALT (FLALT) levels. All patients had at least two ALT measurements during this period of time. Significant histology was defined as stage ≥2 fibrosis or stage 1 fibrosis plus grade ≥2 inflammation using the Batts–Ludwig scoring system.RESULTS:In patients with NLALT levels, the proportions of those with significant histology were 0, 22, and 45% for age ≤35, 36–50, and >50 years, respectively (n=11, n=27, n=19; P=0.033). In patients who had FLALT levels, the corresponding proportions were 22, 42, and 69% (n=9, n=22, n=13; P=0.091). After adjustments for gender, hepatitis B e antigen (HBeAg) status, and mean pre-biopsy HBV DNA levels, significant predictors of histological disease were older age (odds ratio (OR)=6.2 for age 36–50 years and OR=17.6 for age >50 years compared with age ≤35 years, P=0.041 and P=0.003, respectively) and FLALT levels (OR=3.6, P=0.008). Sub-analysis of patients with NLALT levels using lower cutoffs (30 U/l for men and 19 U/l for women) showed similar trends.CONCLUSIONS:Patients with CHB, high HBV DNA, and NLALT levels and aged more than 35 years or those with FLALT levels may have significant histological disease (22–70%).