This Week in HIV Research: Tenofovir Alafenamide (TAF) Single-Tablet Regimen; Retention in Care; and Better Resistance Test

This week we read updated results on a single-tablet HIV regimen containing tenofovir alafenamide (TAF). We also read how a better organized HIV care system could save hundreds of thousands of lives and billions of dollars. Plus, a new HIV drug resistance test is faster and more accurate than current ones. And researchers describe how rectal microbicide formulated as enemas might help prevent new infections.

To beat HIV, you have to follow the science!


Tenofovir Alafenamide (TAF) Single-Tablet Regimen Shows Good Efficacy With Improved Kidney and Bone Safety

A new single-tablet coformulation containing tenofovir alafenamide (TAF) continued to be non-inferior to elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild) after 96 weeks, with fewer kidney and bone toxicities, according to a study presented at the European AIDS Conference 2015.

The new regimen of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide, which will be marketed as Genvoya, continues to show strong results for TAF, which has better potency at lower doses than tenofovir disproxil fumarate (TDF). Additionally, TAF is broken down within the cells, which leads to improved kidney and bone safety.

After 96 weeks, the TAF regimen continued to have high viral suppression at 87% in study participants, which was similar to elvitegravir/cobicistat/emtricitabine/tenofovir at 85%, according to a report by Aidsmap.

The U.S. Food and Drug Administration (FDA) is set to make a decision regarding approval of the new TAF regimen by Nov. 5, 2015.

In the Clinic

Better Organized HIV Care Could Save Lives and Billions of Dollars, Computer Model Predicts

The most important intervention in reducing new HIV infections over the next 20 years could be strengthening retention in care for those living with HIV, according to a new study from Johns Hopkins. The study used a computer model to estimate potential new HIV infections and AIDS deaths that could be avoided in the United States over the next 20 years.

The computer model examined interventions including: annual testing for high-risk individuals, testing every three years for the general population between the ages of 25 and 65, raising linkage to care within three months for newly diagnosed patients, and an increased effort toward retention in care with re-engagement for those who drop out of care.

Retention and re-engagement in care was the most cost-effective intervention; however, a combination of all the interventions could avert 752,000 new HIV infections and 276,000 AIDS deaths at a cost of $96 billion over 20 years, according to the study press release. By contrast, continuing with current strategies would lead to 1.39 million new HIV infections and 435,000 AIDS deaths over the next 20 years, and cost $256 billion, the model predicts.

"Despite having good treatments available, current reports suggest that fewer than half of individuals who need therapy are actually getting appropriate HIV medicine to control their virus, leading to more transmission of disease," said lead study author Maunank Shah, M.D., Ph.D., according to the study press release.

Researchers Describe Rapid, Sensitive Test for HIV Mutations

A new test could detect HIV drug resistance more quickly and accurately than current tests, according to a study by Brown University researchers. The newly developed test analyzes HIV RNA directly, rather than the current method of waiting for the reverse transcription of RNA to DNA, which can lead to errors, according to the study press release.

The new test, known as the LRA (ligation on RNA amplification) test, was able to detect a common mutation in concentrations as low as one mutant per 10,000 strands of viral RNA, and do that in as little as two hours, compared to other tests that can take as long as eight hours.


Researchers Propose Novel Solution to HIV Prevention

For men who have sex with men (MSM) and transwomen, using a rectal microbicide formulated as an enema could help prevent HIV, according to a study by researchers at University of California, Riverside.

The study found that douching was common among MSM and transwomen in Peru, but that the practice could damage the tissue lining in the rectum and make HIV transmission easier.

"A douche-based rectal microbicide that is safe and effective could play an important role by providing another HIV prevention option for these highly vulnerable groups," said lead researcher Brandon Brown, according to the study press release.

The researchers noted that oral pre-exposure prophylaxis (PrEP) may not be available or agreeable for everybody, and that rectal microbicide enemas could be another option.

Is there a development this week in HIV research that you think we missed? Send us a tip!