According to ViiV Healthcare, two large studies have found that people taking the two-drug combination of Tivicay (dolutegravir) and Edurant (rilpivirine) achieve rates of HIV suppression comparable to those on three- or four-antiretroviral (ARV) regimens.

At this time, the pharmaceutical collaborative between GSK (GlaxoSmithKline), Pfizer and Shiongi Limited has released only the fact that the trials achieved their primary endpoint—non-inferiority in the rates of viral suppression between those who remained on three- or four-drug combinations and those who switched from such regimens to the two-drug combo. In this context, “non-inferior” essentially means “as good as.”

ViiV will release more comprehensive details about the trials at a future medical conference, presumably the Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle, which takes place in February.

The SWORD Phase III clinical trials included two identical studies, SWORD-1 and -2, in which participants were all virally suppressed and taking a three- or four-drug integrase inhibitor–, non-nucleoside reverse transcriptase inhibitor (NNRTI)– or boosted protease inhibitor–based ARV regimen. They either stayed on their original regimen or switched to ViiV’s integrase strand transfer inhibitor Tivicay and Janssen’s NNRTI Edurant, which were given as individual tablets (as opposed to in a fixed-dose combination tablet).

The studies are set to run for 148 weeks. First and foremost, the researchers looked at the rates of those with an undetectable viral load after 48 weeks of treatment. These rates were comparable between those who continued to take their original regimens and those who switched to Tivicay and Edurant.

The investigators are also evaluating any viral resistance that might emerge among the participants, the safety and tolerability of the regimens, and any changes in indicators of kidney, bone and cardiovascular health. They will also look at changes in quality of life and participants’ willingness to switch regimens as well as their adherence to them.

The safety profiles of Tivicay and Edurant were consistent with their respective product labels.

No two-drug HIV regimen, including Tivicay and Edurant, is currently approved for use. Given the apparent success of the SWORD trials, ViiV will likely apply for approval for the Tivicay and Edurant regimen as a single tablet in 2017.

To read a press release about the study, click here.