Anti-HBV DNA vaccination does not prevent relapse after discontinuation of analogues in the treatment of chronic hepatitis B: a randomised trial--ANRS HB02 VAC-ADN.

OBJECTIVE: The antiviral efficacy of nucleos(t)ide analogues whose main limitation is relapse after discontinuation requires long-term therapy. To overcome the risk of relapse and virological breakthrough during long-term therapy, we performed a phase I/II, open, prospective, multicentre trial using a HBV envelope-expressing DNA vaccine. DESIGN: 70 patients treated effectively with nucleos(t)ide analogues for a median of 3 years (HBV DNA <12 IU/mL for at least 12 months) were randomised into two groups: one received five intramuscular injections of vaccine (weeks 0, 8, 16, 40 and 44) and one did not receive the vaccine. Analogues were stopped after an additional 48 weeks of treatment in patients who maintained HBV DNA <12 IU/mL with no clinical progression and monthly HBV DNA for 6 months. The primary endpoint was defined as viral reactivation at week 72 (HBV DNA >120 IU/mL) or impossibility of stopping treatment at week 48. RESULTS: Reactivation occurred in 97% of each group after a median 28 days without liver failure but with an HBV DNA <2000 IU/mL in 33%; 99% of adverse reactions were mild to moderate. Immune responses were evaluated by enzyme-linked immunosorbent spot and proliferation assays: there was no difference in the percentage of patients with interferon-γ secreting cells and a specific T-cell proliferation to HBcAg but not to HBsAg after reactivation in each group. CONCLUSIONS: Although it is fairly well tolerated, the HBV DNA vaccine does not decrease the risk of relapse in HBV-treated patients or the rate of virological breakthrough, and does not restore the anti-HBV immune response despite effective viral suppression by analogues. TRIAL REGISTRATION NUMBER: NCT00536627.

Hyperlactataemia in HIV-infected subjects initiating antiretroviral therapy in a large randomized study (a substudy of the INITIO trial).

OBJECTIVE: The aim of the study was to evaluate the predictive value of clinical and molecular risk factors, including peripheral blood mononuclear cell (PBMC) mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA), for the development of lactic acidosis (LA) and symptomatic hyperlactataemia (SHL). METHODS: In a substudy of a large multicentre, randomized trial of three antiretroviral regimens, all containing didanosine (ddI) and stavudine (d4T), in antiretroviralnaïve, HIV-1-infected patients, patients with LA/SHL ('cases') were compared with those without LA/SHL in a univariate analysis, with significant parameters analysed in a multivariate model. In a molecular substudy, PBMC mtDNA and mtRNA from cases and matched controls at baseline and time of event were examined. RESULTS: In 911 subjects followed for a median of 192 weeks, 24 cases were identified (14 SHL and 10 LA). In univariate analysis, cases were more likely to be female (P=0.05) and to have a high body mass index (BMI) (P=0.02). In multivariate analyses, only BMI remained an independent predictor of the development of LA/SHL (P=0.03). Between cases and controls there was no significant difference in mtDNA copy number at baseline (389 vs. 411 copies/cell, respectively; P=0.60) or at time of event (329 vs. 474 copies/cell, respectively; P=0.21), in the change in mtDNA copy number from baseline to event (-65 vs. +113 copies/cell, respectively; P=0.12), in mtRNA expression at baseline or time of event, or in the change in mtRNA expression from baseline to event. CONCLUSION: The development of LA/SHL was associated with increased BMI, but PBMC mtDNA and mtRNA did not predict LA/SHL. This demonstrates the ineffectiveness of routine measurement of PBMC mtDNA in patients on ddI and d4T as a means of predicting development of LA/SHL.

Gag mutations can impact virological response to dual-boosted protease inhibitor combinations in antiretroviral-naïve HIV-infected patients.

ANRS 127 was a randomized pilot trial involving naïve patients receiving two dual-boosted protease inhibitor (PI) combinations. Virological response, defined as a plasma HIV RNA level of <50 copies/ml at week 16, occurred in only 41% patients. Low baseline plasma HIV RNA level was the only significant predictor of virological response. The purpose of this study was to investigate the impact on virological response of pretherapy mutations in cleavage sites of gag, gag-pol, and the gag-pol frameshift region. The whole gag gene and protease-coding region were amplified and sequenced at baseline and at week 16 for 48 patients still on the allocated regimen at week 16. No major PI resistance-associated mutations were detected either at baseline or in the 26 patients who did not achieve virological response at week 16. Baseline cleavage site substitutions in the product of the gag open reading frame at positions 128 (p17/p24) (P = 0.04) and 449 (p1/p6(gag)) (P = 0.01) were significantly more frequent in those patients not achieving virological response. Conversely, baseline cleavage site mutation at position 437 (TFP/p6(pol)) was associated with virological response (P = 0.04). In multivariate analysis adjusted for baseline viral load, these 3 substitutions remained independently associated with virological response. We demonstrated here, in vivo, an impact of baseline polymorphic gag mutations on virological response in naïve patients receiving a combination of two protease inhibitors. However, it was not possible to link the substitutions selected under PI selective pressure with virological failure.

Influence of alpha-1 glycoprotein acid concentrations and variants on atazanavir pharmacokinetics in HIV-infected patients included in the ANRS 107 trial.

Atazanavir is an HIV-1 protease inhibitor with high protein binding in human plasma. The objectives were first to determine the in vitro binding characteristics of atazanavir and second to evaluate whether plasma protein binding to albumin and alpha-1 glycoprotein acid (AAG) influences the pharmacokinetics of atazanavir in HIV-infected patients. For the in vitro study, atazanavir protein binding characteristics were determined in AAG- and albumin-containing purified solutions. Atazanavir was found to bind AAG on a high-affinity saturable site (association constant, 4.61x10(5) liters/mol) and albumin on a low-affinity nonsaturable site. For the in vivo study, blood samples from 51 patients included in trial ANRS 107--Puzzle 2 were drawn prior to drug intake at week 6. For 10 patients included in the pharmacokinetic substudy, five additional blood samples were collected during one dosing interval at week 6. Atazanavir concentrations were assayed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Albumin concentrations, AAG concentrations, and phenotypes were also measured in these patients. Concentrations of atazanavir were modeled using a population approach. A one-compartment model with first-order absorption and elimination best described atazanavir pharmacokinetics. Atazanavir pharmacokinetic parameters and their interindividual variabilities were as follows: absorption rate constant (ka), 0.73 h(-1) (139.3%); apparent clearance (CL/F), 13.3 liters/h (26.7%); and apparent volume of distribution (V/F), 79.7 liters (27.0%). Atazanavir CL/F decreased significantly when alanine aminotransferase and/or AAG levels increased (P<0.01). The ORM1*S phenotype also significantly increased atazanavir V/F (P<0.05). These in vivo results indicate that atazanavir pharmacokinetics is moderately influenced by its protein binding, especially to AAG, without expected clinical consequences.