Reuters Health Information (2004-04-09): Tenofovir active against lamivudine-resistant HBV in HIV-infected patients
Tenofovir active against lamivudine-resistant HBV in HIV-infected patients
Last Updated: 2004-04-09 15:00:08 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The nucleotide analogue tenofovir disoproxil fumarate (tenofovir DF) offers potent HBV suppression in antiretroviral-experienced and -na�ve patients coinfected with HIV-1 and hepatitis B virus (HBV), according to the results of new study.
Moreover, tenofovir DF has "potent activity against lamivudine-resistant HBV strains in people with HIV/HBV coinfection," lead researcher Dr. Gregory J. Dore told Reuters Health.
HIV/HBV coinfection increases the risk of HBV-associated progressive liver disease, Dr. Dore, from the University of New South Wales in Sydney, Australia, and colleagues note in the April 1st issue of The Journal of Infectious Diseases. And while lamivudine has significant anti-HBV activity in coinfected patients, lamivudine-resistance mutations in HBV often develop, highlighting the need for other anti-HBV agents in this population.
Dr. Dore's team studied the safety and efficacy of tenofovir DF in 23 HIV/HBV coinfected patients with (n = 12) and without (n = 11) prior ART exposure who were participating in two phase 3 randomized HIV trials.
The 12 ART-experienced patients were randomized to tenofovir DF or placebo, while the 11 ART-na�ve patients were randomized to receive ART regimens that included lamivudine plus tenofovir DF or lamivudine alone as agents against HBV.
In the ART-experienced group, 10 tenofovir-treated subjects saw a 4 log10 mean reduction in HBV DNA after 24 weeks compared with a mean 1.2 log10 increase in the 2 placebo-treated patients (p = 0.041). The mean decrease in HBV DNA during tenofovir treatment was similar in patients with wild-type and lamivudine-resistant HBV strains.
In the ART-na�ve group, the 6 lamivudine-treated patients saw a 3.0 log10 fall in HBV DNA after 48 weeks, compared with a 4.7 log10 reduction in the 5 patients treated with lamivudine plus tenofovir DF (p = 0.055).
"This study shows that tenofovir provides control of HBV replication in people with HIV/HBV coinfection, in those with and without prior antiretroviral therapy," Dr. Dore said. These findings support results of a previous study (see Reuters Health report, January 21, 2003).
Of note, 4 patients, all in the lamivudine-only arm, developed lamivudine-resistance mutations in HBV. This finding, Dr. Dore said, "provides preliminary evidence that a combination of lamivudine and tenofovir in antiretroviral therapy-naive HIV/HBV coinfected patients will delay the onset of HBV resistance."
"In people with HIV/HBV coinfection and evidence of active and/or progressive liver disease, tenofovir should be included as a component of their highly active antiretroviral therapy regimen," the researcher said.
J Infect Dis 2004;189:1185-1192.