A Simplification Study of Unboosted Reyataz With Epzicom (ASSURE)

This study is designed to compare the efficacy and safety of simplifying therapy from a regimen of atazanavir (ATV) + ritonavir (RTV) + tenofovir/emtricitabine (TDF/FTC) to a regimen of ATV + abacavir sulfate/lamivudine (ABC/3TC) without RTV in virologically suppressed, HIV-1 infected, HLA-B\*5701 negative subjects for 48 weeks.

A prospective, randomized, multicenter, open-label study to compare the efficacy and safety of simplifying from a regimen of atazanavir (ATV) + ritonavir (RTV) + tenofovir/emtricitabine (TDF/FTC) to ATV + abacavir sulfate/lamivudine (ABC/3TC) without RTV for 48 weeks in virologically suppressed, HIV-1 infected, HLA-B\*5701 negative subjects.

ViiV Healthcare is the new sponsor of this study, and GlaxoSmithKline is in the process of updating systems to reflect the change in sponsorship.

Eligibility Criteria:
Inclusion Criteria:

* Subject is an adult (greater than or equal to 18 years) with documented HIV-1 infection
* Subject is a male or female of non-childbearing potential (physiologically incapable of becoming pregnant, is pre-menarchal or post-menopausal) or child-bearing potential with a negative pregnancy test who agrees to avoid pregnancy by sexual abstinence or utilization of a highly effective method of birth control throughout the study period
* Subject is receiving a once-daily regimen of ATV (300mg) + RTV (100mg) + TDF/FTC (300mg/200mg) for at least 6 months prior to or by the first day of screening. ATV + RTV + TDF/FTC must be the subejct's INITIAL regimen or FIRST or SECOND SWITCH regimen. If ATV + RTV + TDF/FTC is subject's first or second switch regimen, then subject may ONLY have received the following prior regimens: a) any currently licensed non-nucleoside reverse transcriptase inhibitor (NNRTI) + TDF/FTC or ZDV/3TC; b) RTV-boosted PI with TDF/FTC or ZDV/3TC; or c) an alternative regimen not listed above after approval by Sponsor.
* Subject is virologically suppressed on ATV + RTV + TDF/FTC defined as HIV-1 RNA \</=75 copies/mL at 2 consecutive timepoints, one of which is at Screening and the other at least 28 days prior to Screening

Exclusion Criteria:

* Subject has evidence of virologic failure
* Subject has any known HIV genotyping results indicating HIV virus contains any of the following resistance mutations in reverse transcriptase including K65R, K70E, L74V, M184I/V or Y115F, a combination of two or more thymidine analog mutations including M41L, D67N, K70R, K219Q or E that include changes at either L210 or T215), or 3 or more of the following HIV-1 protease mutations associated with atazanavir resistance: D30, V32, M36, M46, I47, G48, I50, I54, A71, G73, V77, V82, I84, N88, and L90
* Subject is HLA-B\*5701 positive
* Subject has hypersensitivity to any component of the study drugs
* SUbject is pregnant or breastfeeding
* Subject is enrolled in one or more investigational drug protocols within 30 days of screening
* Subject has an active Center for Disease Control and Prevention (CDC) Category C disease, except cutaneous Kaposi's sarcoma not requiring systemic therapy during the trial
* Subject has ongoing clinically relevant hepatitis at screening and/or positive for Hepatitis B (+ HbsAg)
* Subject has a creatinine clearance \<50 mL/min via the Cockcroft-Gault method
* Subject has a verified Grade 4 laboratory abnormality at screening unless the Investigator can provide a compelling explanation (e.g. elevated CPK due to exercise) for the laboratory result(s) and has the assent of the Sponsor
* Subject has any other laboratory abnormality or medical condition at screening, which, in the opinion of the investigator, would preclude the subject's participation in the study
* Subject has had an immunization within 30 days prior to first dose of investigational product
* Subject has had any exposure to treatment with immunomodulating agents (such as systemic corticosteroids, interleukins, or interferons) or receipt of an HIV-1 immunotherapeutic vaccine within 90 days prior to screening. Subjects using inhaled corticosteroids or short-course systemic corticosteroids (less than or equal to 14 days) are eligible for enrollment.
* Subject has had treatment with radiation therapy or cytotoxic chemotherapeutic agents within 90 days prior to screening, or has an anticipated need for these agents within the study period
* Subject has had treatment within 30 days prior to first dose of investigational product for or an anticipated need during the study of any medications which can have interactions with the study medications, TDF, FTC, ABC, 3TC, ATV and/or RTV, as described in current product labelling
* Subject has had treatment with any previous abacavir-containing regimen