Source: DGNews  |  Posted 6 years ago

By Crystal Phend

SAN FRANCISCO, CA -- November 21, 2005 ? Long-term use of adefovir dipivoxil (Hepsera) as an add-on to lamivudine appears effective in hard-to-treat, lamivudine-resistant patients who are co-infected with hepatitis B virus and HIV, researchers said.

Lead author Vincent Thibault, PhD, Pathologist, H?pital Piti?-Salpetri?re, Paris, France, presented results of a 5-year follow-up study of the combination here at the annual meeting of the American Association for the Study of Liver Diseases (AASLD).

During his presentation on November 14[^]th[], Dr. Thibault said that about 10% of HIV patients seen at the hospital are co-infected with hepatitis B. The small study included 35 such patients, who received 10 mg of adefovir dipivoxil once daily in addition to lamivudine and other anti-HIV medications.

Patients were evaluated every 4 weeks for 1 year and then every 12 weeks for up to 5 years for hepatitis B viral load, HIV viral load, CD4 cell counts, and liver function (alanine transaminase levels).

The hepatitis B virus polymerase gene was sequenced at least once a year to identify treatment-resistance mutations.

Twenty-five patients completed the full 5 years of follow up. Of these, 11 maintained hepatitis B viral suppression to undetectable levels (55%), all but three of these patients maintained well-controlled HIV.

Nine patients had detectable hepatitis B DNA, which the researchers suspected was due to poor treatment compliance.

Five had been switched from adefovir to tenofovir disoproxil fumarate (Viread). Poor compliance was suspected in all but one of these patients, who seemed compliant and had a viral load progression compatible with adefovir resistance. This patient's virus gene sequencing showed a mutation not previously described as causing adefovir resistance.

"The role of this new mutation needs to be confirmed in vitro," Dr. Thibault said.

No known adefovir resistance mutations were seen over the 5 year period.

The researchers concluded that adefovir as add-on to lamivudine was effective, and that the bigger issue appeared to be compliance to therapy.

"Before talking about resistance, we should be careful about compliance," he said.

[Presentation title: Long-Term Experience of Adefovir Dipivoxil Add-on Therapy in Chronic Hepatitis B Patients Co-infected with HIV and Lamivudine-Resistant HBV: Absence of Adefovir Resistance Mutation Selection. Abstract 979]