Comparable efficacy with entecavir monotherapy and tenofovir-entecavir combination in chronic hepatitis B patients.

OBJECTIVES: The long-term goal for chronic hepatitis B patients is to maintain viral suppression in order to reduce disease progression risk. Because patients with previous treatment failure may have multiple viral resistance mutations, finding effective therapy is challenging. Because recent studies have shown that the combination of entecavir and tenofovir is effective in achieving virological response in many patients with prior treatment failure and multiple drug resistance mutations, we compared outcomes with this combination versus monotherapy. METHODS: With a retrospective chart review we compared results in 35 patients with previous treatment failure treated with the entecavir-tenofovir combination to results in patients treated with entecavir monotherapy. RESULTS: Although combination therapy resulted in significantly faster achievement of DNA negativity compared to entecavir monotherapy, the modest ten-week advantage is unlikely to be important for most patients since entecavir resistance develops extremely slowly. Significantly more patients on combination therapy experienced viral breakthroughs, most of which were attributed to non-adherence due to difficulties with the combination regimen. CONCLUSIONS: Our findings of reasonably comparable efficacy over time in the combination and monotherapy arms combined with the increased costs and compliance issues related to combination therapy weigh in favor of entecavir monotherapy in patients with previous treatment failure. However, because our study was a retrospective analysis of a small patient population, it will be important to confirm these findings with a randomised, controlled trial that compares these treatment approaches in treatment-experienced patients.

High rate of core promoter and precore mutations in patients with chronic hepatitis B.

BACKGROUND: The prevalence of precore (PC) and core promoter (CP) mutations in patients with chronic hepatitis B virus (HBV) infection (CHB) and their impact on liver disease is incompletely defined in the United States. METHODS: A retrospective chart review using a cross-sectional approach of 1,186 CHB patients was conducted. RESULTS: Of 926 patients tested for HBV e antigen (HBeAg), 37% were HBeAg+. Of 194 patients tested for mutations, 80% had PC or CP mutations or both; 89% of HBeAg-negative and 56% of HBeAg+ patients had PC or CP mutations or both (p < 0.001). The mean log10 ALT was significantly lower in patients with both mutations compared to patients without mutations. The mean log10 HBV DNA was significantly lower in patients with only PC mutations (4.82) compared to patients without mutations (5.71, p = 0.019). With the study population divided into four subgroups based on ALT level at time of diagnosis, cirrhosis incidence was significantly higher in patients with ALT 1-2 × ULN and ALT > 2 × ULN compared to patients with ALT ≤ 0.5 × ULN. CONCLUSIONS: Our finding that PC and CP mutations may be associated with milder liver disease in some patients could serve as the basis for longitudinal studies to help delineate treatment need and duration in patients with these mutations. If confirmed, the finding of an association between ALT 1-2 × ULN and increased incidence of cirrhosis could call into question guidelines which only recommend treatment with ALT > 2 × ULN.

Coinfection with hepatitis B and D: epidemiology, prevalence and disease in patients in Northern California.

BACKGROUND AND AIMS: With no report on the overall prevalence and ramifications of hepatitis Delta virus (HDV) infection in the United States for more than two decades, the characteristics of chronic hepatitis B virus (CHB) patients coinfected with HDV, including clinical presentation, rate of hepatitis C virus tri-infection, and HDV viral load, were assessed. METHODS: At California Pacific Medical Center, a retrospective chart review was conducted on all CHB patients. RESULTS: Of 1191 CHB patients, 499 had been tested for HDV, with 42 (8%) determined to be coinfected; half of these were also hepatitis C virus-infected. Cirrhosis was present in 73% of the coinfected, 80% of the tri-infected, but only 22% of the monoinfected. Twenty-nine patients (69%) were Caucasian non-Hispanic; 10 (24%) were Asians and Pacific Islanders. Of 39 patients for whom HBV-DNA quantification at time of HDV presentation was available, 22 (56%) had undetectable levels; four (10%) had levels > 100 000 IU/mL. CONCLUSIONS: HDV affects individuals of all ages and various ethnic groups. Although HBV viral loads are lower, rates of cirrhosis are higher in coinfected patients and higher still in the tri-infected. Our data support revising screening guidelines to advocate for all patients with HBV to be screened for HDV in order to both give the individual patient important information related to the possible need for treatment and to support the public health goal of reducing transmission by educating HDV-negative patients about the need for protection against superinfection and HDV-infected patients about the need to protect against transmission to others.

Similar risk of renal events among patients treated with tenofovir or entecavir for chronic hepatitis B.

BACKGROUND & AIMS: Tenofovir is a nucleotide reverse-transcriptase inhibitor approved for treatment of human immunodeficiency virus infection, as well as chronic hepatitis B (CHB). We evaluated nephrotoxicity among patients with CHB treated with tenofovir. METHODS: We performed a community-based, retrospective cohort study of 80 patients with CHB who received tenofovir, alone or in a combination regimen; they were matched for age and sex with 80 CHB patients who received only entecavir. Incidences of serum creatinine (SCr) increase ≥0.2 mg/dL and new SCr levels of 1.5, 2.0, or 2.5 mg/dL were assessed. Patients with an estimated glomerular filtration rate (eGFR) <60 mL/min, calculated using the Modification of Diet in Renal Disease or Cockcroft-Gault formula, or who had ≥20% decrease in eGFR were also recorded. RESULTS: More patients given entecavir had increases in SCr ≥2.5 mg/dL (1 vs 6; P = .053), whereas more patients given tenofovir had a new Cockcroft-Gault eGFR of <60 mL/min (15 vs 6; P = .022) and at least 1 dose adjustment (13 vs 4; P = .021). By multivariate analysis, the only significant factors associated with an increase in SCr were a history of organ transplantation (adjusted odds ratio, 6.740; 95% confidence interval, 1.799-28.250; P = .005) and pre-existing renal insufficiency (adjusted odds ratio, 10.960; 95% confidence interval, 2.419-48.850; P = .002). No factors, including therapy assignment, were associated with a new eGFR <60 mL/min. CONCLUSIONS: Markers of renal function indicated that patients who received tenofovir were no more likely to have changes in renal function than patients treated with entecavir. History of transplant and pre-existing renal insufficiency were the only factors independently associated with increases in SCr.

Mechanism of entecavir resistance of hepatitis B virus with viral breakthrough as determined by long-term clinical assessment and molecular docking simulation.

The mechanism by which entecavir resistance (ETVr) substitutions of hepatitis B virus (HBV) can induce breakthrough (BT) during ETV therapy is largely unknown. We conducted a cross-sectional study of 49 lamivudine (LVD)-refractory patients and 59 naïve patients with chronic hepatitis B. BT was observed in 26.8% of the LVD-refractory group during weeks 60 to 144 of ETV therapy. A line probe assay revealed ETVr substitutions only in the LVD-refractory group, i.e., in 4.9% of patients at baseline, increasing to 14.6%, 24.4%, and 44.8% at weeks 48, 96, and 144, respectively. Multivariate logistic regression analysis adjusted for age, gender, HBV DNA levels, and LVD resistance (LVDr) (L180M and M204V, but not M204I) indicated that T184 substitutions and S202G (not S202C) were a significant factor for BT (adjusted odds ratio [OR], 141.12, and 95% confidence interval [CI], 6.94 to 2,870.20; OR, 201.25, and 95% CI, 11.22 to 3608.65, respectively). Modeling of HBV reverse transcriptase (RT) by docking simulation indicated that a combination of LVDr and ETVr (T184L or S202G) was characterized by a change in the direction of the D205 residue and steric conflict in the binding pocket of ETV triphosphate (ETV-TP), by significantly longer minimal distances (2.2 A and 2.1 A), and by higher potential energy (-117 and -99.8 Kcal/mol) for ETV-TP compared with the wild type (1.3 A; -178 Kcal/mol) and LVDr substitutions (1.5 A; -141 Kcal/mol). Our data suggest that the low binding affinity of ETV-TP for the HBV RT, involving conformational change of the binding pocket of HBV RT by L180M, M204V plus T184L, and S202G, could induce BT.