Griffithsin-based Rectal Microbicide for PREvention of Viral ENTry (PREVENT)

A microbicide is a drug or agent designed to prevent transmission of HIV. Griffithsin, or "GRFT", is an investigational product that is being developed as a microbicide. GRFT is a naturally occurring protein originally isolated from the red alga Griffithsia found in the South Pacific Ocean. GRFT is one of the most powerful, broad-spectrum antivirals ever tested and its activity is under study for potential therapeutic applications against several viral pathogens including HIV, herpes simplex virus type-2, human papillomavirus (HPV), and hepatitis C. GRFT can be formulated into a number of delivery vehicles including gels, films, suppositories and even simple enemas or rinses. The product is intended for use prior to sexual activity by people who practice receptive anal intercourse (RAI), and thus represent the population most vulnerable to HIV-1 transmission due to the high concentration of HIV target cells in the rectal mucosa and the presence of mucosal trauma commonly associated with RAI. For the purposes of this study GRFT has been genetically modified to produce a more stable compound less prone to oxidation, Q-GRFT. Up to 21 HIV-uninfected individuals between the ages of 18 - 45 years will be enrolled in this study at the University of Pittsburgh, the only study site. Participants will be screened to exclude those with HIV infection, and anorectal sexually transmitted infections (STIs) (Visit 1). Up to 28 days after screening, eligible participants will return for a baseline visit (Visit 2), be assigned to a study arm, and undergo sample collection including flexible sigmoidoscopy with collection of colorectal biopsies. The first 3 participants will be assigned to Arm 1 and receive a clinician administered single dose exposure of open-label Q-GRFT. Once the participants in Arm 1 complete Visit 4, study activity will be paused while the study Protocol Safety Review Team (PSRT) conducts an interim review of the clinical and laboratory data. In the absence of any significant safety concerns, the PSRT will be asked to approve enrollment of Study Arms 2 and 3. The remaining 18 participants will be assigned 2:1 in a randomized and blinded fashion to either Study Arm 2 (Q-GRFT) or 3 (placebo), respectively. At Visit 3, participants will receive a clinician-administered single-dose exposure followed by flexible sigmoidoscopy with collection of colorectal biopsies at 1-hr and PK sampling of blood and rectal fluid at 1-hr and 4-hr. Participants will return to clinic the next day (Visit 4) for colorectal biopsies and 24-hr PK sampling. Participants in Arm 1 will additionally return for PK sampling including colorectal biopsies at 48 hrs (Visit 4a) following Visit 3. Participants will be contacted by study staff approximately 3 days after Visit 4 to collect safety information. Participants will return for a final study visit, Visit 5, 4 weeks +/- 1 week after Visit 4/4a to collect blood samples for PK and immunogenicity assessments. A final study exit call for safety will occur within one week after the final study visit.