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AASLD 2011: Upping Entecavir Dose Does Not Improve Hepatitis B Treatment Response

Doubling the usual dose of entecavir (Baraclude) did not increase its effectiveness for treating chronic hepatitis B, according to a study presented at the 62nd Annual Meeting of the American Association for the Study of Liver Disease (AASLD 2011) this month in San Francisco.

The standard dose recommendation for entecavir is 0.5 mg daily for patients with previously untreated chronic hepatitis B virus (HBV) infection, and 1.0 mg daily for treatment-experienced people who did not achieve sustained response to lamivudine (Epivir-HBV). Treatment is not always effective, however, leading researchers to explore different regimens.

Nghiem Ha from Stanford University Medical Center and colleagues performed a case-control study to compare the safety and efficacy of 0.5 mg versus 1.0 mg daily entecavir for treatment-naive patients.

The analysis included 40 consecutive chronic hepatitis B patients at 3 clinics in San Jose, CA, who were treated for the first time with 1.0 mg daily entecavir between 2005 and 2010. A control group included 40 patients treated with 0.5 mg daily entecavir at the same clinics during the same period.

While this was not a randomized controlled trial, participants in both groups were well matched for age (median 36 years), sex (55% men), ethnicity (majority Asian), baseline ALT level, and baseline HBV viral load. All were hepatitis B "e" antigen (HBeAg) positive. Patients in the 0.5 mg entecavir group were treated for a median of 20 months while those taking 1.0 mg were treated for a median of 25 months.

Results

• At 24 weeks, rates of viral suppression (HBV DNA <100 IU/mL) were the same in the 0.5 mg and 1.0 mg entecavir groups.
• At 48 week, more people in the 0.5 mg group achieved viral suppression (36% vs 22%), but the difference did not reach statistical significance.
• Mean HBV DNA levels over time in the 0.5 mg and 1.0 mg groups were also similar:
  • Baseline: 7.64 vs 7.71 log IU/mL, respectively;
  • Week 24: 3.24 vs 3.31 log IU/mL, respectively;
  • Week 48: 2.17 vs 3.03 log IU/mL, respectively.
• Fewer patients in the 0.5 mg entecavir group achieved biochemical response, or ALT normalization, compared with the 1.0 mg group:
  • Week 24: 50% vs 90%, respectively;
  • Week 48: 72% vs 92%, respectively.
• 3 people in the 0.5 mg entecavir group and none in the 1.0 mg group achieved HBeAg seroconversion by week 48.
• No participants in either group achieved hepatitis B surface antigen (HBsAg) seroconversion or loss.

Based on these findings, the researchers concluded "Complete viral suppression rate was similar in patients treated with entecavir 0.5 mg daily or the higher daily dose of 1.0 mg at 24 and 48 weeks."

Investigator affiliations: Division of GI and Hepatology, Stanford University Medical Center, Palo Alto, CA; Pacific Health Foundation, San Jose, CA; San Jose Gastroenterology, San Jose, CA.

11/29/11

Reference

NB Ha, NB Ha, HN Trinh, et al. Similar Virologic Response to Entecavir 0.5 mg or 1.0 mg Daily in Treatment-Naïve Chronic Hepatitis B Patients: A Case-Control Study. 62nd Annual Meeting of the American Association for the Study of Liver Disease (AASLD 2011). San Francisco, November 4-8. 2011. Abstract 1461.