BOSTON – Adding pegylated interferon alfa-2a to entecavir increased the likelihood of long-term viral suppression of chronic hepatitis B infections in a randomized trial of 160 patients with chronic hepatitis B virus infections.
Loss of the hepatitis B e antigen (HBeAg) and hepatitis B viral (HBV) DNA levels below 200 IU/mL after 48 weeks of therapy occurred in 18% of patients who were randomized to entecavir (Baraclude) and pegylated interferon alfa-2a (Pegasys), compared with 8% of patients on entecavir monotherapy, but this difference was not significant, Dr. Milan J. Sonneveld reported at the annual meeting of the American Association for the Study of Liver Diseases.
However, after adjustment for baseline HBV serum antigen levels, analysis showed that pegylated interferon alfa-2a (PEG IFN) as an add-on was independently associated with response at 48 weeks (P = .01).
"Adding peginterferon alfa-2a to a potent nucleoside analogue appears to be a possibility to increase the probability of finite treatment in e-antigen–positive chronic hepatitis B patients," said Dr. Sonneveld of the department of gastroenterology and hepatology at Erasmus University Medical Center in Rotterdam, the Netherlands.
Investigators at 15 sites in Europe and China enrolled 184 patients with HBeAg-positive infections with compensated liver disease. The patients were randomized to either entecavir alone at a dose of 0.5 mg daily for 48 weeks, or 24 weeks of entecavir monotherapy, after which 24 weeks of PEG IFN alfa-2a 180 mcg weekly were added.
All patients were assessed at weeks 12, 24, 36, and 48. Those with a response – a loss of the HBeAg with HBV DNA less than 200 IU/mL at 48 weeks – received an additional 24 weeks of consolidation therapy with entecavir and then discontinued therapy, whereas those without a response were continued on entecavir through week 72.
At week 48, there were 77 patients assigned to entecavir and PEG IFN and 83 assigned to entecavir alone.
There were no significant differences in response rates between the treatment arms, but patients who received the PEG IFN add-on had a greater decline of HBV DNA (6.33 vs. 5.91 log IU/mL; P = .05), HBeAg (1.99 vs. 1.56 log IU/mL; P = .01) and HBV serum antigen (0.84 vs. 0.32 log IU/mL; P less than .001) at week 48.
HBV serum antigen clearance was seen in only one patient at week 48; he had been assigned to the PEG IFN add-on group.
In a multivariate analysis adjusted for differences in baseline serum antigen levels, the addition of PEG IFN was independently associated with response at week 48 (adjusted odds ratio, 3.78; P = .012).
There were no differences in anemia between the two groups, but patients on the entecavir plus PEG IFN combination had significantly more leukopenia (8% vs. 0%; P = .01), neutropenia (23% vs. 0%; P = .001), and thrombocytopenia (P = .01).
The study was supported by Bristol-Myers Squibb, which manufactures entecavir, and Roche, which manufactures pegylated interferon alfa-2a. Dr. Sonneveld reported receiving speakers fees and educational support from Roche.