- If on a protease inhibitor based regimen, participant must be switched to a non-protease inhibitor-based regimen based on lack of any prior drug resistance or antiretroviral-treatment failure, and be willing to remain on indefinitely unless a change is medically necessary. Participants who need to be switched must have been on a stable cART regimen for at least 3 months prior, and must have an eligible HIV-1 RNA result post change in cART.