AASLD 2012: Adding Pegylated Interferon to Entecavir Improves HBV Treatment Response

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Intensifying entecavir (Baraclude) treatment for hepatitis B by adding pegylated interferon lowers HBV viral load and increases the likelihood of hepatitis B "e" antigen (HBeAg) loss, according to a report at the American Association for the Study of Liver Diseases Liver Meeting (AASLD 2012) last month in Boston. A related study found that hepatitis B surface antigen (HBsAg) levels during treatment can be used to predict response to interferon.

Nucleoside/nucleotideanalog antivirals that interfere with the hepatitis B virus (HBV) lifecycle are standard treatment for chronic hepatitis B. They perform well for lowering HBV DNA levels, but serological response, including HBeAg and HBsAg loss or seroconversion, occurs in only a minority of patients.

Interferon -- long the mainstay of hepatitis C treatment -- stimulates the natural immune response against viral infections and may contribute to improved outcomes for hepatitis B as well.

Milan Sonneveld from Erasmus University Medical Center in Rotterdam and the ARES study team conducted a controlled trial that enrolled 184 HBeAg positive patients with compensated liver disease at 15 sites in Europe and China. About 60% were of Asian ethnicity and all major HBV genotypes were represented.

One group was randomly assigned to take 0.5 mg/day entecavir monotherapy for 48 weeks; the other group received the same dose of entecavir, but after 24 weeks of monotherapy they added 180 mcg/week pegylated interferon alfa-2a (Pegasys) and continued on triple therapy through week 48.

Results

o   HBsAg level at baseline: odds ratio 0.42, indicating that a lower level raised the likelihood of response;

o   Addition of pegylated interferon: odds ratio 3.78, or nearly quadruple the likelihood of response.

"Addition of pegylated interferon alfa-2a to entecavir monotherapy increases HBV DNA, HBeAg, and HBsAg decline," the reseachers concluded. "Addition of pegylated interferon alfa-2a to potent [nucleoside/nucleotide] analogue therapy may increase chances of finite therapy."

HBsAg Response-guided Therapy

In another presentation during the same oral session, Sonneveld described findings from a study of response-guided interferon therapy using stopping rules based on HBsAg levels (< 1500, 1500-20,00 or > 20,000 IU/mL) or HBsAg decline (yes or no) at 12 and 24 weeks.

As background, the researchers noted that several factors are associated with response to interferon treatment, including HBV genotype, baseline viral load, ALT level, and possibly variants of the IL28B gene, which plays a role in interferon responsiveness and predict response to interferon-based therapy for hepatitis C. Serum HBsAg levels appear to reflect the amount of covalently closed circular DNA(cccDNA) in the liver, a byproduct of viral replication.

This pooled analysis included 803 participants in 3 trials. Treatment response was defined as a combination of HBV DNA < 200 IU/mL and HBsAg loss at 24 weeks after the end of treatment. A majority of patients (75%) were men and about 80% were Asian. Nearly half (48%) had HBV genotype C, followed by 25% with genotype B. 58% used pegylated interferon monotherapy while the rest used pegylated interferon plus lamivudine (Epivir-HBV).

Results

o   45% with HBsAg < 1500 IU/mL;

o   22% with HBsAg 1500-20,000 IU/mL;

o   6% with HBsAg > 20,000 IU/mL

o   26% with HBsAg decline at 12 weeks;

o   14% with no HBsAg decline at 12 weeks.

o   46% with HBsAg < 1500 IU/mL;

o   16% with HBsAg 1500-20,000 Iu/mL;

o   3% with HBsAg > 20,000 IU/mL

o   25% with HBsAg decline at 12 weeks;

o   12% with no HBsAg decline at 12 weeks.

Overall, the best stopping rule was HBsAg > 20,000 IU/mL at week 24 of treatment, supporting a recommendation that all patients with HBsAg > 20,000 IU/mL at that point should discontinue treatment.

12/11/12

References

MJ Sonneveld, Q Xie, N-P Zhang, et al. Adding peginterferon alfa-2a to entecavir increases HBsAg decline and HBeAg clearance - first results from a global randomized trial (ARES study). 63rd Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2012). Boston, November 9-13, 2012. Abstract 19.

MJ Sonneveld, BE Hansen, T Piratvisuth, et al. Response-guided peginterferon therapy in HBeAg-positive chronic hepatitis B using serum hepatitis B surface antigen levels: a pooled analysis of 803 patients. 63rd Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2012). Boston, November 9-13, 2012. Abstract 23.