Cabotegravir-Rilpivirine  Investigational

Cabotegravir plus rilpivirine is a dual antiretroviral combination being studied for HIV treatment. Cabotegravir is an investigational integrase strand transfer inhibitor (INSTI) that is also being studied for HIV prevention (preexposure prophylaxis). Rilpivirine is a non-nucleoside reverse transcriptase inhibitor; an oral formulation of rilpivirine has been approved by the US Food and Drug Administration (FDA) and is already available.

The primary interest in the cabotegravir plus rilpivirine combination is in the long-acting, injectable, nanoformulations, which are being developed and which have been studied as a two-drug combination for maintenance antiretroviral therapy. In the clinical trials of long-acting intramuscular cabotegravir plus rilpivirine, individuals must achieve an undetectable HIV RNA levels before switching to the long-acting, injectable combination, which is administered every 4 or 8 weeks. Individuals also must take oral versions of cabotegravir and rilpivirine before switching to the long-acting formulations in order to confirm tolerability.

Both long-acting cabotegravir and long-acting rilpivirine remain present in the plasma at detectable but sub-therapeutic levels for many months after an intramuscular injection, which could potentially create risk for drug resistance if an individual discontinues the medications or misses doses. Therefore, upon discontinuation of the long-acting agents, a person likely will need a course of standard oral antiretroviral therapy to prevent development of resistance.