Long-acting Cabotegravir and Rilpivirine Shown Effective in HIV-1 Infected Adults

New data sheds light on efficacy of longer periods between dosing.

A recent finding from 48-week results of a clinical study have shown that dosing with long-acting intramuscular cabotegravir and rilpivirine every 8 weeks was very similar to dosing every 4 weeks. Longer periods of time between dosing can be more convenient and cost effective for people living with the HIV-1 virus. HIV-1 is the most common form of Human Immunodeficiency Virus.

The results of the Phase IIIb, Randomized, Multicenter, Parallel-group, Non-inferiority, Open-label Study, published in The Lancet, saw that the safety profiles and efficacy of dosing with cabotegravir and rilpivirine every 8 weeks, in comparison with every 4 weeks, were almost indistinguishable. This supports the belief that the use of the two therapies as a therapeutic option administered every 2 months can be just as effective for HIV-1.

Antiretroviral Therapy as Long-Acting Suppression every 2 Months (ATLAS-2M) is an ongoing clinical trial taking place in 13 countries, including Australia, Argentina, Canada, France, Germany, Italy, Mexico, Russia, South Africa, South Korea, Spain, Sweden, and the USA. The study is designed to demonstrate the non-inferior antiviral activity and safety of cabotegravir and rilpivirine administered twice a month instead of once a month over a 48-week treatment period.

The study included 1,045 participants with a median age of 42 years old, who were randomly assigned 1:1 to receive cabotegravir and rilpivirine long-acting every 8 weeks or every 4 weeks. In order to be eligible for the trial, the participants must have received an uninterrupted first or second oral standard-of-care regimen for at least 6 months without virological failure.

The findings demonstrated that Cabotegravir plus rilpivirine long-acting every 8 weeks was non-inferior to dosing every 4 weeks (HIV-1 RNA ≥50 copies per mL; 2% vs 1%). During the trial, there were eight (2%, every 8 weeks group) and two (<1%, every 4 weeks group) confirmed virological failures (two sequential measures ≥200 copies per mL). However, the safety profile between the dosing periods was found to be virtually identical and none of the 1,045 participants had any adverse events.

“Seeing the longer-term data is really exciting. It confirms that the long-acting, 2-drug regimen of cabotegravir and rilpivirine has maintained its efficacy and has the potential to be a generally well-tolerated alternative to the standard-of-care, daily, oral pill,” Chloe Orkin, MD, consultant physician and clinical professor at Queen Mary University of London said. “For some people living with HIV, reducing their dosing schedules…may be a realistic option in the future.”