- switch from Protease Inhibitor to Raltegravir in patients on Abacavir and lamivudine, switch from any Nucleoside analog reverse-transcriptase inhibitors (NRTI) combination to abacavir and lamivudine in patients on raltegravir, switch to raltegravir plus abacavir and lamivudine from any other combination will all allow the inclusion in the study