Randomized, Double-Blind, Placebo-Controlled Trial, Followed by Single-Arm Treatment of PRO 140

Inclusion Criteria

• •1. Males and females, age ≥ 18 years
• •2. Exclusive CCR5-tropic virus at Screening Visit
• •3. Have a history of at least 3 months on current antiretroviral regimen
• •4. Treatment-experienced HIV-infected patients with documented genotypic or phenotypic resistance to at least one ART drug within three drug classes
• •OR
• •Treatment-experienced HIV-infected patients with documented genotypic or phenotypic resistance to at least one ART drug within two drug classes and have limited treatment options. The options may be limited as a result of drug antiretroviral class cross-resistance or documented treatment intolerance.
• •5. Be willing to remain on treatment without any changes or additions to the OBT regimen, except for toxicity management or upon meeting criteria for treatment failure.
• •6. Plasma HIV-1 RNA ≥ 400 copies/mL at Screening Visit and documented detectable viral load (HIV-1 RNA \>50 copies/ml) within the last 3 months prior to Screening Visit.
• •7. Laboratory values at Screening of:
• •* Absolute neutrophil count (ANC) ≥ 750/mm3
• •* Hemoglobin (Hb) ≥ 10.5 gm/dL (male) or ≥ 9.5 gm/dL (female)
• •* Platelets ≥ 75,000 /mm3
• •* Serum alanine transaminase (SGPT/ALT) \< 5 x upper limit of normal (ULN)
• •* Serum aspartate transaminase (SGOT/AST) \< 5 x ULN
• •* Bilirubin (total) \< 2.5 x ULN unless Gilbert's disease is present or subject is receiving atazanavir in the absence of other evidence of significant liver disease
• •* Creatinine ≤ 1.5 x ULN
• •8. Clinically normal resting 12-lead ECG at Screening Visit or, if abnormal, considered not clinically significant by the Principal Investigator
• •9. Both male and female patients and their partners of childbearing potential must agree to use 2 medically accepted methods of contraception (e.g., barrier contraceptives \[male condom, female condom, or diaphragm with a spermicidal gel\], hormonal contraceptives \[implants, injectables, combination oral contraceptives, transdermal patches, or contraceptive rings\], and intrauterine devices) during the course of the study (excluding women who are not of childbearing potential and men who have been sterilized). Females of childbearing potential must have a negative serum pregnancy test at Screening visit and negative urine pregnancy test prior to receiving the first dose of study drug.
• •10. Willing and able to participate in all aspects of the study, including use of SC medication, completion of subjective evaluations, attendance at scheduled clinic visits, and compliance with all protocol requirements as evidenced by providing written informed consent.
• •Note: Subjects diagnosed with either substance dependence or substance abuse or any history of a concomitant condition (e.g., medical, psychologic, or psychiatric) may be enrolled if in the opinion of site investigator these circumstances would not interfere with the subject's successful completion of the study requirements.