ViiV Healthcare has reported that the Phase III ATLAS-2M clinical trial of its long-acting, two-drug regimen developed to treat HIV infection met its primary endpoint.

The regimen comprises ViiV’s cabotegravir and Janssen’s rilpivirine.

ATLAS-2M compared the antiviral activity and safety of the long-acting regimen given every eight weeks to the regimen given every four weeks. The 48-week study enrolled HIV-1 patients with suppressed viral load and no resistance to either drug.

According to the headline results, the long-acting regimen showed non-inferiority at week 48 to cabotegravir and rilpivirine administered every four weeks.

Non-inferiority was determined by comparing the proportions of patients having plasma HIV-RNA ≥50 copies per millilitre with the FDA Snapshot algorithm.

“The long-acting regimen showed non-inferiority at week 48 to cabotegravir and rilpivirine administered every four weeks.”

The overall safety, virologic response and drug resistance data for the every eight-week, long-acting regimen was found to be consistent with that observed in the Phase III ATLAS trial.

ViiV Healthcare Research & Development head Kimberly Smith said: “We are excited to report that for the first time since the AIDS epidemic started more than 30 years ago, our ATLAS-2M study has demonstrated that it is possible to maintain suppression of the HIV virus with an injectable regimen containing two drugs administered every two months.

“The ATLAS-2M study results mean that people living with HIV could maintain viral suppression with six total treatments per year, instead of a daily oral treatment 365 times per year.”

ATLAS-2M is part of ViiV’s clinical trial programme for two-drug regimens.

The Phase III randomised, open-label, active-controlled, multi-centre, parallel-group study is being performed in 13 countries including the US, Canada, and Australia.

In the US, Canada, and Europe, the company is seeking regulatory approval for the long-acting, injectable regimen of cabotegravir and rilpivirine to treat patients with HIV.