This Week in HIV Research: Spotlight on HIV Cure Research, and TAF vs. TDF in Triple-Drug Regimens
This week, we look at a special issue of The Journal of Infectious Diseases that highlighted HIV cure research. A study finds that those taking a triple-drug regimen containing tenofovir alafenamide (TAF) had similar rates of viral suppression as those taking a triple-drug regimen containing tenofovir disproxil fumarate (TDF). And another finds that Framingham score is not enough to screen for heart disease in people with HIV. To beat HIV, you have to follow the science!
Special Issue on HIV Cure Research
There is hope that "eradication of infection is possible in a gradually growing number of people across the world," David M. Margolis, M.D., of the University of North Carolina wrote in the introduction to a special supplement of The Journal of Infectious Diseases about HIV cure research.
The issue was written by scientists who work with the Martin Delaney Collaboratories for HIV Cure Research. It examines the challenges of measuring persistent HIV infection, recently identified virus particles that remain in the latent HIV reservoir, the development of latency-reversing agents to reactivate that reservoir for better clearance of the virus, the use of gene-modified T-cells or immunotherapy to control the virus, and animal studies in cure research.
Margolis explained the two definitions for an HIV cure: complete eradication of the virus from the body, or sustained viral control and lack of transmission without antiretroviral treatment. In the near term, the distinction between these definitions will be irrelevant, he noted, since only time can tell whether the virus will resurface in a person.
TAF Just as Effective for Viral Suppression as TDF
Study participants who took a fixed-dose combination of emtricitabine, rilpivirine and tenofovir alafenamide (Odefsey) had the same rates of viral suppression as those who took the single-tablet regimen of emtricitabine, rilpivirine and tenofovir disproxil fumarate (Complera), a multi-country phase 3b trial published in The Lancet HIV found.
More than 600 people whose viral loads had been below 50 copies/mL for at least six months prior to the study were randomized to one of the two medications. By week 48, 94% of participants in each study arm were still virally suppressed, but the rate of study-drug related adverse events was twice as high in the TAF arm compared to the TDF group.
Those in the TAF arm also had better markers of bone mineral density and kidney function than participants who took TDF. However, cholesterol levels were higher among those on TAF than on TDF. This result is consistent with previous studies that found TDF to reduce plasma cholesterol levels. The study was sponsored by Gilead Sciences, which manufacturers both study drugs.
Framingham Score Inadequate for Screening People Living With HIV
Stress echocardiography or computed tomography coronary angiography (CTCA) should be used to screen people living with HIV for coronary artery disease (CAD), the authors of an expert opinion published in HIV Medicine (via MedScape) proposed.
People living with HIV (PLWH) face up to twice the risk of developing CAD than does the general population. Yet, HIV is not included as an independent factor in tools that assess the risk for acute coronary syndrome (ACS). The Framingham score, which is traditionally used to assess cardiovascular risk, does not adequately account for the role of chronic inflammation and oxidative stress associated with HIV, or the effect of antiretroviral therapy on ACS risk, the authors noted. They advocated for stress echocardiography in PLWH whose HIV is optimally managed.
CTCA should be used for people with suboptimally managed virus to detect "soft" coronary plaque, which is more common among people with HIV, they added.
Large Discrepancies in the HIV Care Continuum Among Countries in Europe and Central Asia
At 88%, the overall percentage of PLWH who are virally suppressed on antiretroviral treatment in Europe and Central Asia is close to the UNAIDS target of 90%, according to data from the European Centre for Disease Prevention and Control. However, that figure varies widely among countries, ranging from 97% in Switzerland to 32% in Albania and Tajikistan.
The region is further away from reaching the other two UN goals, 90% of people with HIV aware of their serostatus and 90% of these on antiretroviral treatment. Three-quarters of people with HIV across the region have been diagnosed, and 77% of them are on treatment. Here, too, the range is huge: Romania surpassed the first goal (98%), while Tajikistan lags far behind with 38% diagnosed.
Malta and the United Kingdom had the highest rates of people with HIV on treatment (96%), while in Latvia only 27% of those who know that they are living with HIV are receiving antiretrovirals. Report authors called for "country-specific measures" to reach the UNAIDS 90-90-90 targets.