Rectal pre-exposure prophylaxis (PrEP)

• This article summarizes the role of rectal pre-exposure prophylaxis in global HIV prevention.
• It provides justification of need and an overview of the current status of rectal microbicide research.
• It summarizes preclinical evaluation and product development issues specific to rectal microbicides.
• It presents current gaps in knowledge and future directions for science in the field.

Rectal pre-exposure prophylaxis (PrEP) will be a critical component of HIV prevention products due to the prevalence of unprotected receptive anal intercourse among men who have sex with men and heterosexual couples. Given the biological considerations of this compartment and the complexity of HIV infection, design of a successful rectal microbicide product faces a number of challenges. Important information is being compiled to begin to address deficits in knowledge toward design of rectal PrEP products for men and women. Aspects of formulation development and preclinical and clinical evaluation of rectal products studied to date are summarized in this review. This article is based on a presentation at the “Product Development Workshop 2013: HIV and Multipurpose Prevention Technologies,” held in Arlington, Virginia on February 21–22, 2013. It forms part of a special supplement to Antiviral Research.