Given to HIV-positive people who are treatment-experienced, ViiV Healthcare’s investigational integrase inhibitor dolutegravir has proved superior to Isentress (raltegravir), an approved drug in the same class of antiretrovirals (ARVs), aidsmap reports. Investigators conduced a 48-week, Phase III trial comparing the two drugs in 724 people with HIV who were on failing ARV regimens and had ongoing viral replication. They announced their findings at the 7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2013) in Kuala Lumpur and also published their study online in The Lancet.

Everyone in the study had drug resistance to two or more classes of ARVs and had not yet taken an integrase inhibitor. At the outset of the study, the median CD4 count was about 200, and 30 percent of the people had a viral load greater than 50,000. The participants were randomly divided into two groups: One was given once-daily dolutegravir, the other twice-daily Isentress. All participants took background regimens selected by the investigators including no more than two ARVs, with at least one of the drugs fully active against the virus.

After 48 weeks, 71 percent of those taking dolutegravir had an undetectable viral load, compared with 64 percent of the participants in the Isentress group. This was a statistically significant difference, meaning it was unlikely to have occurred by chance. Six percent of the dolutegravir group experienced virologic failure, a figure that was doubled for those taking Isentress, at 12 percent. Just 1 percent of those on dolutegravir developed mutations resistant to integrase inhibitors, compared with 5 percent of those in the Isentress group.

CD4 gains between the two groups, however, were about equivalent, with levels increasing by a respective 162 and 153 cells in the dolutegravir and Isentress groups.

To read the aidsmap story, click here.

To read the conference abstract, click here.

To read the Lancet abstract, click here.