An Extension Protocol for Subjects Who Successfully Completed PRO140_CD02 Study

Inclusion Criteria: Potential subjects are required to meet all of the following criteria for enrollment into the study.

1. Subjects who have completed 24 weeks of treatment in PRO 140_CD 02 study, and Investigator believes subject requires continued access to PRO 140 in order to continue deriving clinical benefit and maintain HIV-1 viral suppression
2. HIV-1 RNA ≤ 50 copies/ml at T23 Visit in PRO140_CD02 study

3. 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 urine pregnancy test prior to receiving the first dose of study drug.

4. 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.

Exclusion Criteria: Potential subjects meeting any of the following criteria will be excluded from enrollment.

1. Not currently enrolled in PRO 140_CD 02 study
2. Any active infection or malignancy requiring acute therapy (with the exception of local cutaneous Kaposi's sarcoma)
3. Females who are pregnant, lactating, or breastfeeding, or who plan to become pregnant during the study
4. Any other clinical condition that, in the Investigator's judgment, would potentially compromise study compliance or the ability to evaluate safety measures