Eligibility Criteria:
Inclusion Criteria:
* Male or female. Females of child-bearing potential, must have a documented negative pregnancy test and be willing to utilize double-barrier contraception through-out the study period.
* Have HIV-1-infection.
* Have a screening plasma HIV-1 RNA value, measured by the Roche Amplicor assay, of 2,000 - 250,000 copies/ml (inclusive).
* Have documented evidence of genotypic resistance in their medical records (at screening) or have resistance at screening by genotype to any major mutation from the IAS-USA list of resistance drug mutations, defined as: NRTI resistance: M41L, K65R, D67N, K70R, K70E, L74V, Y115F, M184V, M184V/I, L210W, T215Y/F, K219Q/E; NNRTI resistance: L100I, K103N, V106M, V106A/M, V108I, Y181C, Y181C/I, Y188L, Y188C/L/H, G190S/A, G190A, P225H; Major PI resistance: D30N, V32I, L33F, M46I/L, I47V/A, G48V, I50L, I50V, I54M/L, L76V, V82A/F/T, V82A/F/T/S, V82L/T, I84V, N88S, L90M
* Be receiving an antiretroviral therapy regimen containing at least 3 drugs (regimens containing ritonavir must not exceed a total daily dose of 400 mg) which has been unchanged for at least 8 weeks prior to initial screening.
* Be able to receive an optimized background regimen.
* Be free from any acute infection or serious medical illness within 14 days prior to study entry.
* Be informed of the nature of the study and provide written informed consent.
* Be willing to comply with the meal requirements described in the protocol.
Exclusion Criteria:
* Current opportunistic infection characteristic of AIDS
* Patients unable or unwilling to comply with the dosing schedule and protocol evaluations.
* Patients with malabsorption syndromes affecting drug absorption.
* Patients with systolic blood pressure \< 90 mmHg or \> 140 mmHg or diastolic blood pressure \< 60 mmHg or \> 90 mmHg measured in a semi-recumbent position after at least 10 minutes of rest at the screening or qualification visit.
* A history of seizures (excluding pediatric febrile seizures), migraines, cluster and/or chronic headaches, cerebrovascular accident (CVA) or transient ischemic attacks (TIA).
* Patients with abnormal Hemoglobin (\< 10.0 g/dL for men and \< 9.0 g/dL for women), Neutrophil count (\< 1000/mm3), Platelet count (\< 100,000/mm3), AST or ALT \> 2.5 times the upper limit of normal (patients with a positive HBV surface antigen or HCV antibody test at screening must have AST and ALT no more than 1.5 times the upper limit of normal)
* Patients who have received radiation therapy or cytotoxic chemotherapeutic agents, immunomodulating agents, HIV immunotherapeutic vaccine, an investigational drug or product, or participation in a drug study within 4 weeks prior to the first dose of study drug.
* A history of alcoholism or drug addiction within the past 1 year (unless enrolled in a treatment program and approved by the sponsor). Recent use of any recreational drugs (except marijuana).
* A history of difficulty donating blood or inadequate venous access.
* The donation of blood or plasma within 30 days prior to receiving study medication.
Note: patients with a CD4 count \<100 cells/mm3 will be considered for enrollment following discussion and agreement between the Investigator and the Sponsor.