In the news ... 2006 archive

Truvada in the News

April 7, 2006

In the past few weeks there have been three news stories about the fixed dose combination pill, Truvada [Viread (tenofovir) + Emtriva (emtricitibine)], developed and manufactured by Gilead Sciences. This is a brief update on each story.

Truvada gets PREPed
At the 2006 CROI, researchers presented results from experiments testing Truvada as a way to prevent HIV infection. The animal study looked at a pre-exposure prevention (PREP) approach, which involves an HIV-negative person taking anti-HIV drugs before an HIV exposure in hopes of preventing infection. [This is different from post-exposure prevention (PEP), which involves intervening with anti-HIV drugs after a possible exposure in hopes of preventing the establishment of infection.]

In the study, two groups of monkeys were exposed to an HIV-like virus, called SHIV. One group was given Truvada before being exposed to SHIV and throughout the study. The other group was not given Truvada. Both groups were exposed to the virus 14 times. None of the monkeys who received Truvada were infected by the virus, while most of the monkeys who didn’t receive Truvada did get infected.

This study does not prove that Truvada is safe or effective in preventing HIV infection in humans, though it does offer evidence that the concept of prevention by use of therapeutic drugs is valid. More research will need to be done before it is known whether Truvada is a safe and effective prevention measure for people at high risk of HIV infection. There are already several studies looking at using a single drug, Viread (tenofovir) in this way—Viread is one of the drugs in the Truvada combination pill. Investigators from one study being done in Botswana will switch to using Truvada. Investigators in another study being conducted in San Francisco and Atlanta have no plans to switch.

Traditional Approval for Truvada:
In March 2006 the FDA granted traditional, or ‘full,’ approval for Truvada. This action was based primarily on data from a study of more than 500 people comparing Sustiva (efavirenz) plus either Truvada or Combivir [AZT (zidovudine, Retrovir) + 3TC (Epivir, lamivudine)]. After 48 weeks, more of the people taking Truvada and Sustiva had undetectable viral loads than those taking Combivir + Sustiva (84 % vs. 73%). People taking the Truvada-based combination also reported fewer side effects. Truvada was granted accelerated approval status in 2004. The FDA’s ruling will allow Gilead to include data from this study in their packaging information and marketing. The change in the approval status of the drug will not impact most people’s access to the drug, but these results are important in confirming the benefits of Truvada.

Truvada/Sustiva Combo Coming?
As reported here, the makers of Truvada (Gilead Sciences) have been working with the makers of Sustiva (efavirenz, Bristol Myers Squibb and Merck) to develop the first one-pill, once-a-day HAART regimen. After several unsuccessful attempts at co-formulation, the companies settled on a layering approach. The companies are expected to file for FDA approval in the second quarter of 2006. The FDA administration typically takes about six months to issue a ruling after the paperwork is filed.

For more information about Truvada, click here.

For more information about Sustiva, click here.

For more information about Combivir, click here.