MTN-033

Intermittent dosing of a rectal microbicide gel associated with sexual activity may be a more feasible strategy for long-term usage. Data are needed on the pharmacokinetics, safety, and acceptability of applying dapivirine gel as a lubricant in at-risk men who have sex with men (MSM) and transgender females who have sex with men.

MTN-033 was a Phase 1, randomized, open label, single-site trial designed to evaluate the pharmacokinetics of dapivirine gel (0.05%) when administered rectally via HTI vaginal applicator and a coital simulation device to healthy, HIV-1 uninfected men and transgender women. MTN-033 enrolled 16 participants ages 18 and older. Participants administered a single dose of dapivirine gel (DPV 0.05%) in each study sequence. They were randomized to one of two product application sequences. Product sequences included the application of a single dose of study product via applicator (2.5 g) and administration of up to 10 g of dapivirine gel applied via a coital simulation device (to simulate receptive anal intercourse); order of administration was randomly selected. A washout period occurred between each product application visit. This design allowed for the collection of valuable pharmacokinetic (PK) data from those exposed to a single dose of dapivirine gel rectally (which may be representative of episodic or coital dosing) with and without the use of a coital simulation device. The ideal coital-dosing regimens for dapivirine gel applied rectally are not yet known.

The study completed follow-up on December 5, 2018. Primary results were presented at the HIV Research for Prevention (HIVR4P) conference held virtually on January 27-28 and February 3-4, 2021. The primary manuscript is currently in development.