Virologic response and resistance to adefovir in patients with chronic hepatitis B.

Abstract

BACKGROUND:

The incidence and risk factors for adefovir-resistant HBV have not been clearly defined.

AIMS:

To characterize the virologic response to adefovir, to determine the rate of adefovir resistance and to explore factors associated with initial virologic response (IVR) and adefovir resistance.

METHODS:

All hepatitis B patients who received adefovir for > or =6 months at our center were prospectively monitored for virologic response and adefovir resistance.

RESULTS:

Forty three patients were included; mean treatment duration was 18 months (range 6-45). Thirty four (79%) patients had prior lamivudine. IVR was observed in 44% patients and associated with higher pretreatment ALT (P = 0.05) and the absence of HBeAg (P = 0.02). Six (14%) patients were found to have adefovir-resistant mutations. The cumulative probability of genotypic resistance to adefovir at month 24 was 22%. Patients with adefovir resistance were more likely to have been switched from lamivudine to adefovir monotherapy (P = 0.01), to be older (P = 0.04), and to be infected with HBV genotype D (P = 0.02).

CONCLUSIONS:

Roughly 50% of patients failed to achieve IVR on adefovir. The cumulative probability of adefovir resistance at 2 years was 22%. Our data suggest that combination of lamivudine and adefovir may prevent emergence of adefovir resistance in patients with lamivudine-resistant HBV.

• Authors: Scott K Fung, Hee Bok Chae, Robert J Fontana, Hari Conjeevaram, Jorge Marrero, Kelly Oberhelman, Munira Hussain, Anna S F Lok
• Journal: Journal of hepatology (J Hepatol) Vol. 44 Issue 2 Pg. 283-90 (Feb 2006) ISSN: 0168-8278 [Print] Netherlands
• PMID: 16338024 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antiviral Agents
• DNA, Viral
• Organophosphonates
• Lamivudine
• adefovir
• Adenine

Topics

• Adenine (analogs & derivatives, therapeutic use)
• Antiviral Agents (therapeutic use)
• DNA, Viral (genetics)
• Drug Resistance, Viral (genetics)
• Female
• Follow-Up Studies
• Genotype
• Hepatitis B virus (drug effects, genetics)
• Hepatitis B, Chronic (drug therapy, virology)
• Humans
• Lamivudine (therapeutic use)
• Male
• Middle Aged
• Mutation
• Organophosphonates (therapeutic use)
• Polymerase Chain Reaction
• Retrospective Studies
• Treatment Outcome