Coverage of CROI 2008 (Conference on Retroviruses and Opportunistic Infections)

February 4–6, 2008, Boston, MA

Apricitabine shows some promise

February 5, 2008

A poster presented at CROI shows potential for the experimental NRTI, apricitabine. The results came from the AVX-201 study, which Project Inform reported about earlier. AVX-201 compared apricitabine to Epivir (lamivudine) in people with HIV that harbors the M184V mutation, which is associated with resistance to Epivir and Emtriva (emtricitabine).

In the first phase of the study, people on failing Epivir regimens were randomly assigned to either stay on Epivir or switch to apricitabine. After 21 days everyone was switched to a background regimen made up of the best available HIV drugs. Results from this second phase were presented at CROI.

After 24 weeks there was a trend toward better outcomes for people taking apricitabine, but the difference wasn’t significant. The authors speculated that the potency of the background regimens and the small number of people in the study made this difference too small to be significant. There were more treatment related side effects among people taking apricitabine than Epivir. This is not surprising as everyone in the study had experience taking Epivir.

The development for apricitabine is unclear, as it is for some other HIV drugs. Many people have developed resistance to either Epivir or Emtriva, so a viable option is needed for them. Avexa, the developer of apricitabine, will need to show that its drug is potent and well tolerated in larger trials before we know if it can be that option.