PEG-IFN Plus Adefovir or Tenofovir Results in Reduction in Hepatitis B Surface Antigen: Presented at EASL
April 28th, 2015
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Conference Dispatch adefovir dipivoxil interferon alfa-2a tenofovir Cirrhosis Hepatitis Liver Cancer Infectious Diseases Internal Medicine EASL
By Chris Berrie
VIENNA, Austria -- April 28, 2015 -- Combinations of pegylated interferon alfa-2a (PEG-IFN) with the acyclic nucleoside phosphonate analogues adefovir or tenofovir provide small but significant hepatitis B surface antigen (HBsAg) loss in patients with chronic hepatitis B (CHB) and a low viral load, according to a study presented here at the International Liver Congress, the 50th Annual Meeting of the European Association for the Study of the Liver (EASL).
Patients with a low viral load comprise the largest group of hepatitis B virus (HBV) infections, but they are currently not eligible for treatment, despite being at risk of developing cirrhosis or hepatocellular carcinoma.
“There is a rationale behind starting combination therapy for patients who actually already have a lower viral load and lower HBsAg levels,” said Louis Jansen, MD, Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, The Netherlands, on April 25.
Treatment with PEG-IFN combined with adefovir has shown HBsAg loss in patients with CHB who were hepatitis B e antigen (HBeAg) negative and had low baseline serum HBsAg, and a study of PEG-IFN combined with tenofovir indicated high rates of HBsAg loss.
The primary aim of this prospective open-label trial was to determine the rate of HBsAg loss in patients with CHB with low viral load being treated with PEG-IFN plus adefovir or tenofovir.
The researchers enrolled patients with CHB and HBV RNA <20,000 IU/mL who were HBsAg positive, HBeAg negative, and anti-HBe positive for >6 months. The patient baseline characteristics were similar across these treatments, with 44% female, mean age 43 years, 96% PEG-IFN naive, and HBsAg and HBV DNA of 3.20 and 2.74 log10 IU/mL, respectively.
The patients were randomised to no treatment (control, n = 43) or to PEG-IFN with adefovir (n = 46) or tenofovir (n = 45) for 48 weeks.
For this interim intention-to-treat analysis at week 48, 4 (4.4%) of the patients on combination therapy had achieved HBsAg loss (AxSYM <0.05 IU/mL), 1 on adefovir and 3 on tenofovir. They were HBV genotypes A (n = 1), B (n = 1), and indeterminate (n = 2).
Although there was a low response rate, a larger proportion of patients had declines in HBsAg levels to almost negative. In a per-protocol analysis, the HBsAg levels showed significant median log reductions in the control (-0.08; P = .02), adefovir (-0.33; P < .001), and tenofovir (-0.22; P < .001) arms.
Furthermore, although there was no significant difference between the combination arms, both showed significant median log reductions over the control arm (P < .001 and P = .004; respectively). Strong significant HBsAg declines of >0.5 and >1.0 log10 IU/mL were seen for 25 (31%) and 17 (21%) of the patients in the adefovir and tenofovir arms, respectively, with no decline in the control arm (P < .001 for each).
Dr. Jansen indicated that should these data follow the researchers’ previous data for patients with CHB and high viral load, a further increase in the rates of HBsAg loss during treatment-free follow-up would be likely. This information will be available at the week 72 follow-up.
Funding for the study was provided by Roche (NL).
[Presentation title: A Randomised Prospective Open-Label Trial Comparing Peginterferon + Adefovir and Peginterferon + Tenofovir Versus No Treatment in HBeAg Negative Chronic Hepatitis B Patients With Low Viral Load: Analysis of Week 48 Results. Abstract LP29]