More conference news
This edition of HIV Weekly has more news from the recent Conference on Retroviruses and Opportunistic Infections (CROI), one of the most important HIV conferences of the year.
HIV Weekly subscribers received daily updates from the conference, and if you’d like to look back at these you can click here.
Once-daily anti-HIV therapy
Anti-HIV therapy doesn’t cure HIV, but it can lower the amount of HIV in the blood to such low levels that it cannot be detected using tests (this is normally called an undetectable viral load). Lowering the amount of HIV in the body allows the immune system, measured by key CD4 cells, to increase allowing the body to fight infections.
For HIV treatment to work properly it needs to be taken properly – adherence is the term that is often used for taking the correct dose of medication, at the right time and in the right way.
To make adherence easier, anti-HIV treatments have been developed that only need to be taken once-daily, and can be taken with or without food. Very popular once-daily combinations involve the NNRTI efavirenz (Sustiva) with either tenofovir and FTC (Truvada), or abacavir and 3TC (Kivexa).
There is some evidence to suggest that nevirapine (Viramune), the other licensed NNRTI, can also be used once-daily, but there are some lingering concerns about how safe and effective this drug is when used in this way.
Now a study presented to the recent Conference on Retroviruses and Opportunistic Infections (CROI) has found that people who took a once-daily combination consisting of nevirapine, tenofovir and 3TC, had lower falls in their viral load than those who took nevirapine twice-daily with AZT and 3TC. High rates of resistance to NNRTIs were seen in people who had a poor response to treatment.
The researchers behind the study commented: “The once-daily 3TC, tenofovir and nevirapine regimen resulted in unexpected high rates of early nonresponse with a high incidence of [resistance]. The reasons for failures remain currently unclear”.
It's worth adding that a combination of nevirapine, tenofovir and 3TC is quite unusual and wouldn't normally be considered for first-line HIV therapy.
Experimental drug doing well
There are over 20 approved anti-HIV drugs, and many more are in development. Some of these drugs attack HIV in a ways different to the classes of drugs that are currently available and look like they might provide important treatment options for people who have taken a lot of anti-HIV treatment before, have drug-resistant HIV, and have very limited treatment options.
Drugs called integrase inhibitors are a new class of anti-HIV drug and some promising drugs from this class are currently having their safety and effectiveness checked in clinical trials.
Interim results from a trial involving one such drug, elvitegravir (previously known as GS-9137) were recently presented to CROI.
The anti-HIV effects of the drug are boosted by using it along with a small dose of ritonavir
The trial into the drug is planned to last 48 weeks, and researchers presented results from the first 16 and 24 weeks of the study. The study involves people who have taken a lot of anti-HIV drugs and have very limited treatment options. Results so far suggest that a 125mg once-daily dose of the drug, boosted by 100mg of ritonavir was the most effective. The drug only provided lasting suppression of HIV when it could be combined with at least one other effective anti-HIV drug.
One of the researchers involved in the study told the conference: “We have a potent drug, but it is only good if there are other companion drugs to use with it.”
Encouraging results were also presented to CROI from a study involving another integrase inhibitor, raltegravir.
Lipodystrophy
Anti-HIV therapy can mean a longer and healthier life. Indeed, many doctors now believe that people who start taking HIV treatment before their immune systems have suffered too much damage because of HIV, who take their treatment properly, and who aren’t coinfected with hepatitis B virus or hepatitis C virus, will have a more or less normal life-expectancy.
But anti-HIV drugs do have side-effects, some of the most concerning being the increases in blood fats and sugars that some drugs can cause. In the longer term these changes in the body’s metabolism can increase the risk of developing serious illness like heart disease.
Exercise, not smoking, and eating a healthy diet can help reduce the risk of heart disease whether or not you are taking anti-HIV treatment. A recent US study compared the diets and levels of blood fats in a group of HIV-positive patients and a control group of HIV-negative individuals. This found that people with HIV were eating more food with high levels of saturated fat and cholesterol (like full-fat milk, cream, butter, cheese, red meat, cakes and biscuits).
The HIV-positive people had higher levels of fats and sugars in their blood than the HIV-negative people.
“Increased saturated fat intake should be targeted for dietary modification in this population”, the researchers concluded.