After three decades, major developments in HIV treatment and prevention are finally moving forward at a steady pace – two studies and one extraordinary patient have captured the attention of doctors and scientists, and made the idea of a cure less fantastical.
Doctors say American Timothy Ray Brown was indeed cured of HIV in Germany. The “Berlin Patient” was being treated for leukemia when he was given a bone marrow transplant using the stem cells of a HIV resistant donor. More than two years after the transplant, his bloodstream is now free of HIV even though he´s not taking antiretroviral drugs.
Many of us view this as a unique case that´s not relatable to people doing very well on medications, says Peter Anton, a professor of medicine at the University of California, Los Angeles. However, it does provide proof that it´s possible to eradicate HIV from the body. Until now we haven´t had that proof because of concerns that there are hidden reservoirs of HIV as well as low levels of HIV replication we cannot detect.
There is also much excitement over microbicides, a new type of prevention method in the form of a gel applied vaginally or rectally to prevent infection, especially after last year´s announcement that a vaginal gel containing the antiretroviral drug tenofovir had a 39% success rate among South African women. Further advances could boost those numbers, and more studies are under way. Human trials of rectal microbicide will likely begin in two to three years.
If you go to a bar nad ask how many people know what a microbicide is, most people won´t raise their hand, Anton says. We want to change that.
Another breakthrough came out of a study on pre-exposure prophylaxis, PrEP. Results showed that regular doses of the antiretroviral pill Truvada cut HIV infection rate by 44% among a group of HIV-negative, specially men and transgender women who have sex with men. While Anton is heartened by the findings, he offers caveats, specially about people preemptively taking PrEP without further confirmation of its success. The second major PrEP worry involves those who contract HIV while taking the regimen – there´s a chance they could become resistant to other antiretroviral drugs.
There are so many people who do not know their diagnosis, Anton says. If they end up taking prevention medicines but are already HIV-positive, they could be utilizing single-drug therapy, which is a big NO-NO. To avoid drug resistance, HIV-positive people need combination-drug therapy.
As studies on PrEP continues, regiment refinement is likely on the horizon.
One of the efforts on the PrEP side was to study preventive use in a controlled setting so we could document whether you need it daily or weekly, Anton says. This is going to be looked at further so we can give more informed guidelines than those out now.