December 18, 2012
Every year, new research gives us a deeper understanding of what it will take to achieve greater successes in HIV prevention, treatment, patient care and the search for a cure. While most of the legwork gets overlooked, HIV conferences allow researchers to present their study results to a broader audience -- and to attract the attention of sites like TheBodyPRO.com and its readers.
Here we count down the 10 conference stories we covered this year that proved to be most popular with our readership.
Early study results presented at CROI 2012 showed that GS-7340 (tenofovir alafenamide, TAF), a new oral prodrug, was well tolerated and had better antiviral activity at lower doses than tenofovir disoproxil fumarate (Viread, TDF). The study found that in 38 people over 10 days, 25 mg of GS-7340 outperformed 300 mg of the currently approved tenofovir formulation. Along with fewer side effects, GS-7340 showed higher potency, which could mean longer and better viral suppression over time.
(Follow-up results, which reinforced these initial findings, were later presented at ICAAC 2012.)
In this study presented at CROI 2012, some seroadaptive behaviors appeared to be even more effective than condom use at reducing the risk of HIV acquisition, but with important caveats.
While having a single, uninfected partner or being an exclusive "top" (i.e., the insertive partner) seemed to reduce risk more than never having unprotected anal intercourse, lead researcher Snigdha Vallabhaneni, M.D., attributed this to an over-reporting of condom use. "Serosorting itself is twice as risky as not having unprotected anal sex. But it has a 38% risk reduction when compared to having no strategy at all -- so it may be a harm reduction strategy for those engaging in the highest risk behavior," Vallabhaneni told TheBodyPRO.com.
At the XIX International AIDS Conference, HIV advocate Jeff Taylor met with Jacob P. Lalezari, M.D., the director of Quest Clinical Research, to talk about the coupled optimism and cautiousness regarding the search for an HIV cure.
During the interview, Lalezari explains each of the primary paths being explored toward the development of a cure, while describing the progress that has been made to date -- as well as some of the challenges the field still faces.
This year's CROI was typical in that it featured many noteworthy presentations highlighting new research on HIV drugs in development, the treatment of HIV/HCV coinfection, metabolic complications and malignancies for people living with HIV. Jeff Berry, editor of Positively Aware, sat down with HIV researchers Cal Cohen, M.D., and Richard Ellion, M.D., to get their perspectives on the breaking research.
While people who lack CCR5 receptors on their CD4+ cells are typically immune to most forms of HIV, these rare individuals can actually become infected.
A group of researchers from the Autonomous University of Barcelona identified an individual with CCR5 mutation who had been infected by a CXCR4-tropic virus, which is a strain of HIV that enters CD4 cells via the CXCR4 receptor instead of the typical CCR5 receptor.
HIV and wellness expert Nelson Vergel wrote about the CROI 2012 poster that spotlighted this discovery.
During ICAAC 2012, researchers in France presented data that provided a potential explanation for why some patients have a persistently low CD4+ cell count despite being virally suppressed.
The researchers used a qPCR assay to look for HIV DNA in the CD4+ cell cytoplasm, which has a short half-life and could be a reliable marker of recent CD4+ cell infection. Of the 35 study participants, 10 were found to have HIV DNA in the CD4+ cell cytoplasm. Average CD4+ cell counts for these 10 individuals were lower than the rest of the group, suggesting that ongoing HIV infection could be responsible.
This simple assay could help assess how well antiretroviral drugs are working for patients, and may help clinicians determine which patients may need stronger regimens.
In the wake of CROI 2012, Jeff Berry reported on the HIV drugs that were at the front of the antiretroviral pipeline. In a phase-3 study, the once-daily regimen elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild), also known as the "Quad," was found to be non-inferior to efavirenz/tenofovir/emtricitabine (Atripla) after 48 weeks. (It was approved by the U.S. Food and Drug Administration later in 2012.)
Berry covered other drug developments in the article, including phase-2b study results of the new integrase inhibitor doultegravir, which was shown to be superior to efavirenz (Sustiva), with no emergent resistance mutations after 96 weeks.
During the XIX International AIDS Conference, a study published in Nature highlighted the apparent ability of a histone deacetylase (HDAC) inhibitor known as vorinostat to disrupt the HIV reservoir. The results showed that when eight patients, all of whom were already on antiretroviral therapy, received vorinostat, HIV was flushed out of the hidden reservoir -- at least for a moment.
Co-author David Margolis, M.D., stated during an interview at the International AIDS Conference, "This is proof of the concept, of the idea that the virus can be specifically targeted in a patient by a drug, and essentially opens up the way for this class of drugs to be studied for use in this way."
At the first-ever IDWeek, Joseph Eron, M.D., director of the University of North Carolina Center for AIDS Research, provided an overview of current HIV cure research. He highlighted the three "functionally" cured patients of which we are currently aware (more on two of those patients in a moment), all of whom serve as proof of concept.
While Eron pointed out the barriers that block us from a practical cure, he also discussed the potential cure strategies being developed. These include targeting the HIV reservoir with HDAC inhibitors such as vorinostat, artificially disrupting the CCR5 receptor on CD4+ cells using zinc finger nucleases, and other areas currently under investigation.
During the XIX International AIDS Conference, case results were presented that suggested two more individuals had potentially been cured of HIV. Daniel Kuritzkes, M.D., from Brigham and Women's Hospital in Boston discussed the promising method that led to the results, which targeted the elusive HIV reservoir.
Two patients had undergone allogeneic stem cell transplantation for the treatment of lymphoma. Unlike "Berlin patient" Timothy Brown, their donor cells did not lack the CCR5 receptor and were fully susceptible to HIV. But because they remained on antiretroviral therapy during the transplant period, the donor cells were not infected with HIV.
Although both men are still on HIV treatment, neither shows traces of HIV in his blood. They are also showing a significant decline in HIV antibodies, suggesting a lack of HIV replication.
Warren Tong is the research editor for TheBody.com and TheBodyPRO.com.
Follow Warren on Twitter: @WarrenAtTheBody.