PHPT-3 was a study comparing a CD4 based antiretroviral monitoring and switching strategy with the standard viral load based monitoring strategy among immunocompromised antiretroviral naive adults receiving antiretroviral treatment in Thailand.

Due to the limited number of antiretroviral drugs belonging to few classes which share resistance mutations, toxicities, intolerance, the actual number of drug combinations available is restricted. This study addresses the following questions:

• What is the most efficient strategy for the use of available antiretroviral drugs?
• On which criteria should antiretroviral drug regimens be modified?

721 adult HIV infected patients were enrolled in 21 sites spread over Thailand. They had not received prior antiretroviral treatment and they were immunocompromised (CD4 count between 50 and 250 cells/mm3).

The clinical follow up is completed and analysis is ongoing (publication expected in 2012).

The analysis will be based on the occurrence of  clinical failures defined as confirmed CD4 below 50 cells/ml, new AIDS-defining event or death. Secondary analyses will take into account the number of drugs exhausted (taking into account cross-resistance mutations) and safety.

For further information please refer to ClinicalTrials.gov.