Kelly Kaita

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.

Fatty infiltration of liver in hyperlipidemic patients

Hyperlipidemia is a known risk factor for fatty infiltration of the liver, a condition that can progress to cirrhosis and liver failure. The objectives of this study were to document the prevalence of fatty infiltration in the livers of hyperlipidemic patients and to identify the predictor variables associated with this condition. Over an 18-month recruitment period, clinical, biochemical, and radiologic assessments were performed in a cross-sectional manner in 95 adult patients referred to an urban hospital-based lipid clinic for evaluation and management of hyperlipidemia. The mean (±sd) age of the patients was 55 ± 13 years. Forty-eight (51%) were male. Fifty-two patients (55%) had hypercholesterolemia, 25 (26%) severe hypertriglyceridemia, 14 (15%) mixed hyperlipidemia, and 4 (4%) moderate hypertriglyceridemia. Obesity and diabetes were present in 36 (38%) and 12 (12%) of cases, respectively. A total of 61 (64%) patients had elevated liver enzyme tests. The most common enzyme abnormalities were an elevated serum ALT in 45 (47%) and GGT in 43 (45%) of patients. Ultrasound findings revealed diffuse fatty liver in 47 patients (50%), of which 21 cases (22%) were mild, 18 (19%) moderate, and 8 (9%) severe. The majority of patients with hypercholesterolemia [35/52 (67%)] had normal ultrasounds, whereas severe hypertriglyceridemia and mixed hyperlipidemia were frequently associated with radiologic evidence of fatty liver (odds ratios 5.9 and 5.1 respectively, P < 0.01). Independent predictors of fatty liver were; AST (P = 0.001), hyperglycemia (P = 0.02), and age (P = 0.04). In a model incorporating known risk factors for fatty liver, diabetes was the only risk factor other than hypertriglyceridemia that was significantly associated with fatty infiltration. No such effect was seen with age, gender, obesity, or alcohol consumption. In conclusions, the results of this study indicate that ultrasonographic evidence of fatty infiltration of the liver is evident in approximately 50% of patients with hyperlipidemia. Hypertriglyceridemia is the lipid profile most often associated with this condition. Serum AST values, hyperglycemia, and age independently predict the presence of fatty infiltration, while hypertriglyceridemia and diabetes are the only risk factors that significantly increase the risk of fatty infiltration in hyperlipidemic patients.

Historical epidemiology of hepatitis C virus (HCV) in selected countries

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6 358 000 cases in 2008 and Brazil with 2 106 000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV‐infected populations are critical for addressing HCV‐related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

Strategies to manage hepatitis C virus (HCV) disease burden

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV‐related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3–5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

Albinterferon alfa-2b dosed every two or four weeks in interferon-naïve patients with genotype 1 chronic hepatitis C†‡

The efficacy and safety of albinterferon alfa‐2b (alb‐IFN), a novel recombinant protein consisting of interferon alfa‐2b genetically fused to human albumin, was evaluated in a phase 2b, open‐label study of patients with genotype 1, chronic hepatitis C. In all, 458 IFN‐alfa treatment‐naïve patients were randomized to 48‐week treatment with peginterferon alfa (PEG‐IFNα)‐2a 180 μg one time per week (qwk), or alb‐IFN 900 or 1,200 μg once every two weeks (q2wk), or 1,200 μg once every four weeks (q4wk), administered subcutaneously, plus weight‐based oral ribavirin 1,000 or 1,200 mg/day. Hepatitis C virus RNA was measured by real‐time polymerase chain reaction (limit of detection: 10 IU/mL). The primary efficacy endpoint was sustained virologic response (hepatitis C virus RNA <10 IU/mL 24 weeks after the end of treatment). By intention‐to‐treat analysis, sustained virologic response rates were 58.5% (69/118) with alb‐IFN 900 μg q2wk, 55.5% (61/110) with 1,200 μg q2wk, and 50.9% (59/116) with 1,200 μg q4wk, and 57.9% (66/114) with PEG‐IFNα‐2a (P = 0.64 for overall test). Discontinuation rates due to adverse events were 9.3% with alb‐IFN 900 μg q2wk, 18.2% with 1,200 μg q2wk and 12.1% with 1,200 μg q4wk, and 6.1% with PEG‐IFNα‐2a (P = 0.04). Hematologic reductions were lowest in the q4wk group and comparable across other groups. At week 12, mean treatment‐associated missed workdays were significantly lower with alb‐IFN 900 μg q2wk versus PEG‐IFNα‐2a (1.1 versus 4.3 days; P = 0.006). Conclusion: Alb‐IFN administered q2wk or q4wk may offer comparable efficacy, with an improved dosing schedule, compared with PEG‐IFNα‐2a. (HEPATOLOGY 2008;48:407–417.)

Burden of disease and cost of chronic hepatitis C virus infection in Canada

BACKGROUND: Chronic infection with hepatitis C virus (HCV) is a major cause of cirrhosis, hepatocellular carcinoma and liver transplantation.

Peginterferon alfa-2a (40KD) plus ribavirin in chronic hepatitis C patients who failed previous interferon therapy

Background: The management of patients with chronic hepatitis C who have relapsed or failed to respond to interferon based therapies is an important issue facing hepatologists. Aims: We evaluated the efficacy and safety of peginterferon alfa-2a (40KD) plus ribavirin in this population by conducting a multicentre open label study. Patients: Data from adults with detectable serum hepatitis C virus (HCV) RNA who had not responded or had relapsed after previous conventional interferon or conventional interferon/ribavirin combination therapy were analysed. Methods: Patients were retreated with peginterferon alfa-2a (40KD) 180 µg/week plus ribavirin 800 mg/day for 24 or 48 weeks at the investigators’ discretion. The study was conceived before the optimal dose of ribavirin (1000/1200 mg/day) for patients with genotype 1 was known. The primary endpoint was sustained virological response (SVR), defined as undetectable HCV RNA (<50 IU/ml) after 24 weeks of follow up. The analysis was conducted by intention to treat. Results: A total of 312 patients (212 non-responders, 100 relapsers) were included. Of these, 28 patients were treated for 24 weeks and 284 for 48 weeks. Baseline characteristics between non-responders and relapsers were similar although more non-responders had genotype 1 infection (87% v 69%). Overall SVR rates were 23% (48/212) for non-responders and 41% (41/100) for relapsers. When data were analysed by genotype, SVR rates were 24% (61/253) in genotype 1 and 47% (28/59) in genotype 2/3. Conclusions: These results in a large patient cohort demonstrate that it is possible to cure a proportion of previous non-responders and relapsers by retreating with peginterferon alfa-2a (40KD) plus ribavirin.

Serum immunoglobulins predict the extent of hepatic fibrosis in patients with chronic hepatitis C virus infection

Summary.  Recently, we documented that immunoglobulins stimulate the proliferative activity of rat hepatic stellate cells in vitro. The aim of the present study was to determine whether there is any association between serum immunoglobulin levels and hepatic fibrosis in patients with chronic hepatitis C virus (HCV) infection. Charts from 116 patients with biochemical, serologic, virologic and histologic evidence of chronic hepatitis C infection and serum immunoglobulin levels (IgA, IgG, IgM and total) were reviewed. The mean (±SD) age of the study population was 46 ± 11 years and 67 (58%) were male. There were significant correlations between serum IgA (r = 0.39, P = 0.00001), IgG (r = 0.49, P = 0.000002) and total (r = 0.51, P = 0.000003) immunoglobulin levels and the stage of hepatic fibrosis. When serum immunoglobulin levels were included into logistic regression analysis with variables known to be associated with advanced disease (male gender, age >40 years at onset of infection, duration of infection beyond 20 years and concurrent alcohol abuse) only IgA, IgG and total immunoglobulin levels (P < 0.05, <0.05 and <0.005, respectively) emerged as independent predictors of hepatic fibrosis. Our data indicate a strong association between serum immunoglobulin levels (IgA, IgG and total) and hepatic fibrosis in patients with HCV infection. This finding supports the need to further investigate whether immunoglobulins independently promote disease progression in patients with chronic HCV infection.

Glecaprevir–Pibrentasvir for 8 or 12 Weeks in HCV Genotype 1 or 3 Infection

BACKGROUND Glecaprevir and pibrentasvir are direct‐acting antiviral agents with pangenotypic activity and a high barrier to resistance. We evaluated the efficacy and safety of 8‐week and 12‐week courses of treatment with 300 mg of glecaprevir plus 120 mg of pibrentasvir in patients without cirrhosis who had hepatitis C virus (HCV) genotype 1 or 3 infection. METHODS We conducted two phase 3, randomized, open‐label, multicenter trials. Patients with genotype 1 infection were randomly assigned in a 1:1 ratio to receive once‐daily glecaprevir–pibrentasvir for either 8 or 12 weeks. Patients with genotype 3 infection were randomly assigned in a 2:1 ratio to receive 12 weeks of treatment with either glecaprevir–pibrentasvir or sofosbuvir–daclatasvir. Additional patients with genotype 3 infection were subsequently enrolled and nonrandomly assigned to receive 8 weeks of treatment with glecaprevir–pibrentasvir. The primary end point was the rate of sustained virologic response 12 weeks after the end of treatment. RESULTS In total, 1208 patients were treated. The rate of sustained virologic response at 12 weeks among genotype 1–infected patients was 99.1% (95% confidence interval [CI], 98 to 100) in the 8‐week group and 99.7% (95% CI, 99 to 100) in the 12‐week group. Genotype 3–infected patients who were treated for 12 weeks had a rate of sustained virologic response at 12 weeks of 95% (95% CI, 93 to 98; 222 of 233 patients) with glecaprevir–pibrentasvir and 97% (95% CI, 93 to 99.9; 111 of 115) with sofosbuvir–daclatasvir; 8 weeks of treatment with glecaprevir–pibrentasvir yielded a rate of 95% (95% CI, 91 to 98; 149 of 157 patients). Adverse events led to discontinuation of treatment in no more than 1% of patients in any treatment group. CONCLUSIONS Once‐daily treatment with glecaprevir–pibrentasvir for either 8 weeks or 12 weeks achieved high rates of sustained virologic response among patients with HCV genotype 1 or 3 infection who did not have cirrhosis. (Funded by AbbVie; ENDURANCE‐1 and ENDURANCE‐3 ClinicalTrials.gov numbers, NCT02604017 and NCT02640157.)