Inclusion Criteria:

Patients meeting the following criteria will be eligible for participation in th is study:

1. Human Immunodeficiency virus 1 (HIV-1) infected males or females >=18 years of age.
2. Screening genotypic resistance report indicating both of the following: at least one primary protease Inhibitor (PI) mutation at the following sites:

30N, 46I/L, 48V, 50V, 82A/F/L/T, 84V or 90M, and no more than two protease mutations on codons 33, 82, 84, or 90.

3. At least 3 consecutive months experience taking antiretrovirals (ARVs) from each of the classes of nucleoside reverse transcriptase inhibitors(NRTI(s)), non-nucleoside reverse transcriptase inhibitors(NNRTI(s)), and protease inhibitors (PIs) at some point in treatment history,with at least 2 protease inhibitor (PI)-based regimens, one of which must be the current regimen, and current protease inhibitor (PI)-based antiretroviral (ARV) medication regimen for at least 3 months prior to randomization.

4. Human Immunodeficiency Virus 1 (HIV-1) viral load >=1,000 copies/mL at screening.

Exclusion criteria:

Patients with any of the following criteria are excluded from participation in t he study:

1. Antiretroviral (ARV) medication naïve.
2. Patients on recent drug holiday, defined as off antiretroviral (ARV) medications for at least 7 consecutive days within the last 3 months.
3. alanine aminotransferase (ALT) >=3.0x upperlimit of normal (ULN) and aspartate aminotransferase(AST) >=2.5x upper limit of normal (ULN) (>=Division of AIDS(DAIDS) Grade 1) at either screening visit.