Safety and Tolerability of PRO 140 in HIV Uninfected Male Volunteers

The purpose of the study is to determine the safety and tolerability of PRO 140, an investigational anti-HIV drug, administered via intravenous infusion. Study hypothesis: Single intravenous doses of PRO 140 can be safely administered to humans and will result in measurable concentrations of the product in serum.

PRO 140 is a man-made monoclonal antibody to the chemokine receptor CCR5, which serves as a co-receptor for HIV. In numerous preclinical models of HIV infection, PRO 140 broadly and potently blocks CCR5-mediated HIV entry without blocking the natural activity of CCR5. PRO 140 is being developed for therapy of HIV infected individuals. The purpose of this study is to evaluate the safety and tolerability of PRO 140 in HIV uninfected male volunteers. The pharmacokinetics and pharmacodynamics of PRO 140 will also be assessed in this study. Participants in this study will be randomly assigned to receive a single dose of one of several possible doses of PRO 140 or placebo. Participants will remain in the clinic for observation and evaluation for 24 hours after the single-dose administration. Follow-up visits will occur at 2, 3, 5, 7, 10, 14, 28, 42, and 60 days post-treatment. Physical exams, electrocardiograms (ECGs), vital signs measurement, adverse event reporting, and blood and urine collection will occur at most visits.