4.1.6 Receiving a stable antiretroviral regimen consisting of 3 or more drugs belonging to two or more classes, one of which must be a protease inhibitor, an integrase inhibitor, or a non-nucleoside reverse transcriptase inhibitor, without any changes due to virologic failure in the past 24 weeks, and with no plans to change antiretroviral regimen in the 40 weeks following enrollment. If the regimen includes a protease inhibitor, ritonavir or an approved boosting agent known to increase trough levels of the protease inhibitor by at least 50% must also be a part of the regimen.