MTN-037 was a Phase I study that evaluated whether a microbicide gel called PC-1005 is safe for use in the rectum. PC-1500 is the only product designed for vaginal and rectal use targeting HIV, herpes simplex virus (HSV) and human papillomavirus (HPV) simultaneously that has undergone Phase 1 testing to date. MTN-037 was the first study of PC-1005 used rectally. PC-1005 contains an antiretroviral drug called MIV-150; zinc acetate dihydrate, an agent that acts against HSV type 2 (HSV-2); and carrageenan, a potent anti-HIV agent and gellant. The study, which included 12 HIV-negative cisgender and transgender men and women at two sites in the U.S., found the gel was safe and well-tolerated with low systemic MIV-150 exposure. Through tissue sampling, researchers also concluded that a longer-acting formulation or higher dose of MIV-150 would be required to deliver an adequate amount of the drug for it to be effective at preventing the rectal transmission of HIV. Results of MTN-037 were reported in February 2021 during the virtual HIV R4P conference.
MTN-037 Study Protocol