New HIV treatment

An investigative integrase inhibitor, dolutegravir, suppresses viral load and is safe, according to results of a two-year study.

This type of drug targets a protein in HIV called integrase and stops the virus from integrating into the DNA of human cells.

The once-daily drug doesn’t require any boosting and has no food restrictions. It appears unlikely to interact with other anti-HIV drugs and has a good resistance profile.

The study was intended to find the best dose of the drug for investigation in further trials. After a year, 88-91 per cent of people treated with dolutegravir had an undetectable viral load, compared to 82 per cent taking efavirenz (Sustiva). The best responses were seen in people taking a 50mg dose of dolutegravir, which will now be investigated further.

The incidence of side-effects was comparable for dolutegravir and efavirenz. However, mild kidney dysfunction was associated with dolutegravir.

A ‘pro-drug’ of tenofovir is more potent, results of a small study show.

A pro-drug is an inactive drug that is converted into an active therapeutic drug in the body. In this case, people taking the pro-drug achieved greater reductions in viral load, and the 25mg and 40mg doses were superior to the standard dose (300mg) of tenofovir.

The pro-drug was well tolerated, with no evidence it caused kidney or bone toxicities, known to be side-effects of the current form of tenofovir. Investigators are hopeful that it will be suitable for co-formulation with other anti-HIV drugs.

A pill known as Quad, containing a complete HIV treatment combination, has been shown to be as effective as the widely used Atripla combination pill. The Quad combination also matched boosted atazanavir (Reyataz) in a separate study.

Quad, a four-in-one combination, contains an experimental integrase inhibitor (elvitegravir), a boosting agent (cobicistat), emtricitabine (FTC) and tenofovir (commonly combined as Truvada and also contained in Atripla).
The participants, starting treatment for the first time, took either the Quad pill or Atripla (efavirenz, tenofovir and emtricitabine).

After 48 weeks of treatment, the two groups had similarly good results for reduction in viral load and increase in CD4 count.

Proportions of participants reporting side-effects were similar. People taking Quad were more likely to report nausea. In the Atripla group, several other side-effects were reported more often, including abnormal dreams, insomnia, dizziness and rash.

A parallel trial compared the Quad to a current combination of atazanavir (Reyataz), ritonavir (Norvir), tenofovir and emtricitabine (FTC). Again the Quad combination produced similarly good results to the atazanavir combination.

Based on these findings, Quad has been submitted for regulatory approval in Europe, the US, Australia and Canada, with a decision from the US Food and Drug Administration expected by August 2012.