Despite an increase in the variety of anti-retroviral agents in the market, there remains a need for novel agents to treat HIV 1 infected individuals, in order to overcome existing problems with adherence, toxicities, drug interactions and viral resistance. In this article, we will describe Pro 140, one of the recently developed class of anti-retroviral agent, the CCR5 co-receptor inhibitor. We will also describe several preclinical and clinical studies that have evaluated the efficacy, tolerability and toxicity profiles of Pro 140. We will also look at how its mechanism of action and mode of delivery may change the way patients take highly active anti-retroviral therapy. There are some promising patents discussed in this short review for the use of PRO 140 as CCR5 co-receptor inhibitor.