Cross-study analysis of the relative efficacies of oral antiviral therapies for chronic hepatitis B infection in nucleoside-naive patients

BACKGROUND AND OBJECTIVE

Lamivudine and adefovir were approved for treatment of chronic hepatitis B virus (HBV) infection based on placebo-controlled trials, and entecavir was recently approved on the basis of its superiority over lamivudine in phase II/III trials; however, to date, these three therapies have not been compared head to head.

METHODS

To evaluate the relative efficacy of these therapies, we applied a predefined protocol of established statistical techniques to compare data from phase III entecavir trials with published clinical trial results with lamivudine, adefovir and placebo in nucleoside-naive hepatitis B e antigen (HBeAg)-positive and -negative populations.

RESULTS

A comprehensive literature search identified 612 publications/data sources, of which 28 satisfied predefined inclusion criteria. Independent reviewers extracted week 48-52 histological, virological, biochemical and serological endpoints from these sources, which were analysed with a fixed-effects model. For each of the three histological endpoints in HBeAg-positive patients (Histological Improvement, Ranked Assessment of Necroinflammation [RA-N] and Ranked Assessment of Fibrosis [RA-F]), entecavir was superior to adefovir. Entecavir was superior to lamivudine for Histological Improvement and comparable to lamivudine for RA-N and RA-F. With respect to reducing HBV DNA levels, entecavir (-6.98 log(10) copies/mL) was more effective than lamivudine (-5.46 log(10) copies/mL, p < 0.0001) and adefovir (-3.60 log(10) copies/mL, p < 0.0001), and lamivudine was more effective than adefovir (p < 0.0001). The parallel goals of HBV DNA reduction below the limit of quantitation (LOQ) [by polymerase chain reaction] and ALT normalisation were achieved more often with entecavir (69% and 67% of patients, respectively) than with lamivudine (38% and 59%, respectively; p < 0.0001 and p < 0.05, respectively) or adefovir (21% and 48%, respectively; both p < 0.0001), and more often with lamivudine than with adefovir (p < 0.0001 and p < 0.05, respectively). HBeAg seroconversion rates were higher with entecavir (21% of patients) and lamivudine (18%) than with adefovir (12%, p < 0.01 and p < 0.05, respectively). For each of the three histological endpoints in the HBeAg-negative population, entecavir was comparable to adefovir. Entecavir was superior to lamivudine for Histological Improvement, and comparable to lamivudine for RA-N and RA-F, and all three antivirals were superior to placebo. Entecavir proved superior to lamivudine and adefovir in lowering HBV DNA levels (-5.20 vs -4.66 vs -3.91 log(10) copies/mL, respectively; p < 0.0005 and p < 0.0001, respectively) and in suppressing HBV DNA below the LOQ (91% vs 73% vs 51% of patients, respectively; both p < 0.0001); in the latter respect, lamivudine was in turn superior to adefovir (p < 0.0001). Entecavir was also superior to lamivudine in normalising ALT (76% vs 69% patients, respectively; p < 0.05).

CONCLUSIONS

Over a 12-month treatment period, this analysis predicts that the antiviral efficacy of entecavir would be superior to that of lamivudine, which in turn would be superior to that of adefovir, in nucleoside-naive patients with chronic HBV infection.

Immunosuppressive effect of nucleoside-nucleotide-free diet in rat allogeneic small intestinal transplantation

BACKGROUND

We evaluated the effects of nucleosides (NS) and nucleotides (NT) on the rejection of rat allogeneic small intestinal transplants.

METHODS

A 2-cm segment of jejunum from fetal Fischer rats (RT-1(lvl)) was transplanted at day 19 of gestation into the abdominal wall of 7-week-old Lewis rats (RT-1(l)) by a nonvascular technique. Two weeks before transplantation, recipient rats were separated into an NS-NT-free group and an NS-NT-supplemented group. At 2 days after transplantation, histologic study of the grafts was performed with hematoxylin-eosin staining and interleukin-2 (IL-2) production estimated in recipient blood using an ELISA method. The morphologic findings were graded in a blind fashion on a scale of 0 to 4, with 0 indicating an intact intestinal structure.

RESULTS

Mean plasma IL-2 levels of the NS-NT-free group were significantly lower than those of the NS-NT-supplemented group. The mean rejection score of the NS-NT-free group was also significantly lower than that of the NS-NT-supplemented group.

CONCLUSIONS

Administration of an NS-NT-free diet reduces acute rejection in rat small intestinal transplantations.

Family studies on nucleoside phosphorylase and the short arm of chromosome 14

A family with two nucleoside phosphorylase-deficient patients has been scored for the segregation of NP0 and the variable region 14p. The mose likely 14p:NP recombination fraction is 0.15 in males and 0.30 in females. There is no family data to assign the Pi:Gm linkage group to chromosome 14, but as immunoglobulin heavy chain has been assigned to this chromosome by somatic cell methods the most likely gene order is 14p:NP:Pi:Gm with Pi in 14q2 and Gm in 14(q23 leads to q32), but the order 14p:NP:Gm:Pi with Pi in 14(q24 leads to qter) and Gm in 14(q22 leads to q24) is not excluded. The available linkage data between biochemical markers on acrocentric chromosomes and their short arm markers suggest that there may be more recombination towards the ends of human chromosomes whether or not those ends carry centromeres.