A study into a long-acting, injectable two-drug regimen to treat HIV has met its primary endpoint ViiV healthcare and Janssen Sciences have announced.

The positive headline results come from the phase III ATLAS (Antiretroviral Therapy as Long-Acting Suppression) study. ATLAS was designed to establish if HIV-1-infected adult participants who had maintained viral suppression for at least six months, on a daily oral regimen comprised of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a third agent, maintained similar rates of viral suppression upon switching to the investigational, two-drug, long-acting, injectable regimen of cabotegravir and rilpivirine, compared with continuing the three-drug oral regimen.

The study showed long-acting cabotegravir and rilpivirine, injected once a month, had similar efficacy to a standard of care, daily, oral three-drug regimen at week 48. The injectable treatment regimen met the primary endpoint for non-inferiority (the proportion of participants with plasma HIV-1 RNA ≥50 copies per milliliter [c/mL] using the FDA Snapshot algorithm at Week 48. Overall safety, virologic response and drug resistance results for the injectable regimen were consistent with results from the phase II LATTE and LATTE-2 studies.

John C. Pottage, Jr, MD and Chief Scientific and Medical Officer of ViiV Healthcare, said: “This novel approach is another step towards potentially reducing the treatment burden for people living with HIV.

“The data from ATLAS suggest a long-acting, injectable 2DR of cabotegravir and rilpivirine may offer an alternative to daily, oral three-drug therapy for people who have previously achieved viral suppression. If approved, this regimen would give people living with HIV one month between each dose of antiretroviral therapy, changing HIV treatment from 365 dosing days per year, to just 12.”

Detailed results from the study will be presented at an upcoming scientific meeting.

Headline results from FLAIR, a second pivotal trial designed to evaluate a long-acting, injectable regimen of cabotegravir and rilpivirine in treatment-naïve individuals, are expected later this year.