 - Total prior antiretroviral experience of at least three months and documented genotypic or phenotypic resistance to at least one compound in each of the following classes of antiretrovirals: NRTIs includes NtRTI TDF, NNRTIs, and PIs. Resistance mutations must be at least one major mutation according to the current International AIDS Society-USA Drug Resistance Mutations Group refer to study reference manual SRM. Resistance testing may be current e.g. screening results andor historical with verifiable documentation in source documents. 