Insights on Cabotegravir Rilpivirine and HIV Treatment Studies

Clinical Studies of Cabotegravir and Rilpivirine

Several clinical trials have evaluated the effectiveness and safety of this combination. The FLAIR and ATLAS Phase 3 studies included almost 1,200 participants with HIV who were already virally suppressed or achieved suppression before receiving the injectable regimen. The studies compared long acting cabotegravir and rilpivirine with continued oral antiretroviral treatment. The results supported the ability of the injectable regimen to maintain viral suppression in appropriately selected participants.

Important studies include:

• FLAIR: Evaluated long acting cabotegravir and rilpivirine after participants first achieved viral suppression with oral therapy.
• ATLAS: Compared monthly injectable cabotegravir and rilpivirine with continued standard oral antiretroviral therapy.
• ATLAS 2M: Studied whether injections administered every two months could maintain suppression compared with monthly injections.
• LATTE 2: Provided earlier evidence supporting the development of injectable cabotegravir and rilpivirine as a long acting treatment strategy.

The ATLAS 2M study is particularly relevant because it evaluated less frequent administration. FDA-reviewed data reported confirmed virologic failure through Week 48 in 1.7% of participants receiving injections every two months and 0.4% of those receiving monthly injections. These figures illustrate why adherence to the injection schedule and clinical monitoring remain important.

Eligibility and Treatment Considerations

Long acting cabotegravir and rilpivirine are not intended to replace the need for clinical assessment. Current NIH guidance states that the regimen can be used to replace an existing oral regimen when specific conditions are met, including sustained viral suppression for at least three months and no documented or suspected resistance to either cabotegravir or rilpivirine. Active hepatitis B infection also requires consideration because this two drug regimen does not provide the same hepatitis B treatment coverage as certain tenofovir containing regimens.

Before switching, clinicians generally consider:

• The person's HIV viral load and duration of viral suppression.
• Previous treatment history and resistance results.
• Hepatitis B infection status.
• Pregnancy or plans for pregnancy.
• Current medicines and potential drug interactions.
• The ability to attend scheduled injections and monitoring appointments.

Resistance is another important area of study. FDA data from longer term FLAIR and ATLAS analyses documented confirmed virologic failures in a small proportion of participants, with several failures associated with resistance-associated substitutions affecting rilpivirine and or cabotegravir. This highlights the importance of appropriate patient selection and maintaining effective drug exposure.

Cabotegravir and rilpivirine therefore represent an important development in long acting HIV treatment research. The FLAIR, ATLAS, and ATLAS 2M studies provide evidence that injectable therapy can maintain viral suppression in appropriately selected people with HIV. At the same time, the regimen has specific eligibility requirements, resistance considerations, interaction issues, and scheduling requirements. Treatment decisions should be based on an individual's medical history, laboratory results, treatment experience, and discussion with a qualified HIV care professional.