Virus World

There is a “window of opportunity” in the weeks after someone is infected with HIV where treatment may lead to better control later on, researchers say. Treatment for human immunodeficiency virus (HIV) four weeks after infection may make it possible to control the virus without medication in the long term, a new study has shown. The finding reinforces the importance of detecting HIV early, according to researchers from the French Institut Pasteur, CEA, Inserm, University of Paris Cité, and the University of Paris-Saclay. Treatment for HIV is called antiretroviral therapy (ART) and can be taken as a pill or an injection. The goal is to reduce a person’s viral load to an undetectable level so the person has no risk of transmitting HIV.

This therapy is now so effective that it can fully control the virus, with researchers even exploring ways to cure it. This latest study looked at the impact of early treatment on primates with simian immunodeficiency virus (SIV), which is closely related to HIV. The researchers found that very early treatment for two years led to controlling the virus even after treatment was interrupted. “We show an association between early treatment and control of the infection after treatment is stopped, and our study indicates the existence of a window of opportunity to promote remission of HIV infection,” Asier Sáez-Cirión, head of the Institut Pasteur’s viral reservoirs and immune control unit and co-senior author of the study, said in a statement. A previous 2013 study in humans had shown a similar possibility, suggesting that early treatment could allow people to stop treatment, with the virus in a “state of remission”. The latest study also showed that the benefits of early treatment were lost if therapy was started just five months later. The findings were published in the scientific journal Nature Communications.

 New evidence released today at the 10th IAS Conference on HIV Science (IAS 2019) highlights important advancements in antiretroviral therapy, including new and more efficient regimens with the potential to change the treatment landscape.
 
“New drugs and novel treatment regimens have the potential to improve long-term tolerability and reduce costs and pill sizes,” IAS President and IAS 2019 International Scientific Chair Anton Pozniak said.

Moving from three- to two-drug regimens 
Two studies presented the safety and efficacy of dolutegravir (DTG) plus lamivudine (3TC) in two-drug therapy: for people starting treatment for the first time; and for people who switch after being virally suppressed on another regimen. The new analysis includes 96 weeks of data. It finds that the two-drug regimen remains non-inferior to the three-drug regimen over this two-year period.

A new HIV treatment drug
 IAS 2019 also featured promising data on MK-8591, the first drug in a new class of treatments known as nucleoside transcriptase translocation inhibitors (NRTTIs). The authors presented 48-week data from a Phase 2B, randomized trial in which MK-8591 was used as part of first-line therapy. After 48 weeks of treatment, rates of viral suppression were similar in all study arms, ranging from 78% to 90% in patients receiving MK-8591, and 84% in those on the three-drug combination without MK-8591.

Every other day antiretroviral maintenance strategy
 Another analysis focused on reducing the number of pills that a person living with HIV must take. Specifically, this open-label, randomized Phase III study compared the use of typical three-drug regimens taken four days per week with daily use.  After 48 weeks of treatment, the four-days-per-week approach was found to be non-inferior to everyday treatment, in terms of maintaining viral suppression. These findings offer further evidence that newer HIV treatment drugs can be used in innovative ways.

At an all-day meeting for investors last month in a posh Manhattan event space, executives at Merck couldn’t have been more excited about a new HIV drug, MK-8591. They mentioned it 25 times, calling it “a game changer” and talking up its “remarkable properties.”   Why? If effective, it could be used in a new drug combination that might have fewer side effects, the company says. More excitingly, it might be fashioned into an implant that could be given only once a year to prevent patients at high risk from contracting HIV, a boon to public health.

The first results on both approaches are being presented this week in Mexico City at the annual meeting of the International AIDS Society. The data on the implant is being released Tuesday, and the drug combination data will be presented on Wednesday.

One of the benefits of MK-8591 is that it builds up in the body, and it could be given as an implant that might only need to be replaced once a year. By contrast, Gilead’s HIV pill Truvada, given to patients at high risk of HIV, is a once-a-day pill. Researchers randomly assigned four patients to receive a placebo implant, six to receive an implant with a 54-milligram dose of MK-8591, and six with a 62-mg dose, and followed them for four months. Based on blood levels of the drug, the researchers predicted that the 54-mg implant could prove effective for between eight and 10 months, and the 62-mg implant should protect against HIV infection for a year. Larger, longer studies will need to be completed to see if that promise bears out.

The drug also got a new name this week: islatravir. It is the first drug with the root “travir,” an indication, Merck said, that the medicine is a new drug class, called a nucleoside reverse transcriptase and translocation inhibitor.