• Tenofovir in the Treatment of Individuals Co-Infected With HIV and Hepatitis B (Abstract H-1740)
  Authored by M.R. Nelson, A. Barr, M. Fisher, B.G. Gazzard
  Poster Presentation: View the original abstract

It has been noted for several years that in addition to its activity against HIV, tenofovir (TDF, Viread) is active against the hepatitis B virus. Data from several cohorts suggest that about 10 percent of those with HIV infection also have active hepatitis B infection. Prior to the availability of tenofovir, the only oral drug clearly active against both HIV and hepatitis B was lamivudine (3TC, Epivir). As with HIV, there has been concern that whenever possible, we treat hepatitis B with more than one active agent, a goal that has been impossible until the arrival of newer agents. This is one of a few studies that documents the impact of adding tenofovir to those dually infected with both HIV and hepatitis B infection.

The study was conducted by the colorful and well-known group at the Chelsea and Westminster Hospital in London. They reported on 20 persons, all of whom have hepatitis B "e" antigen and received the standard dose of 300 mg of tenofovir as part of their standard regimen. Most also had prior (and concomitant) lamivudine, but had evidence of ongoing hepatitis B viral replication as measured by hepatitis B DNA. They noted that 15 out of 20 of the patients in the study had prior lamivudine use, and most had evidence of resistance to this drug. The impact was measured in a variety of ways, but primarily by monitoring a fall in the hepatitis B DNA, including the percentage of patients who became hepatitis B "e" antigen "undetectable" over time, defined as less than 10,000 units.

The baseline hepatitis B DNA was about 181 million units. The hepatitis B viral load dropped by about four logs over this time period. By week 24, about half of the patients in the study (55 percent) were able to establish an undetectable hepatitis B DNA (i.e., below 10,000 units). There was a trend suggesting a slower hepatitis B DNA decline in those with baseline lamivudine resistance. The researchers noted that all of the study's participants tolerated tenofovir, and all maintained HIV suppression as well.

The researchers concluded that anyone co-infected with HIV and hepatitis B be considered a candidate for adding tenofovir to their regimen. Studies are ongoing to define the comparative role of lamivudine, tenofovir and adefovir, given that all are now available as hepatitis B treatments. Until then, these data add to other observations suggesting yet another role for tenofovir in the treatment of HIV infection.