<qa>  What is the name of the regimen that is switched to?This pilot study will provide data on the safety and efficacy of the combination of Raltegravir RAL 400mg BID Atazanavir ATV 300 mg BID in Antiretroviral ARV-experienced subjects that have a suppressed HIV viral load on a Ritonavir RTV boosted Protease Inhibitor PI based regimen who are then switched to a regimen of RAL 400mg BID ATV 300mg BID. 