Tenofovir Rectal Douche to Prevent HIV Transmission

On demand and behaviorally-congruent forms of HIV pre-exposure prophylaxis (PrEP) have long been demanded by communities at great risk of HIV, especially men who have sex with men (MSM). The DREAM Program is developing a tenofovir (TFV) douche for on demand PrEP use prior to receptive anal intercourse (RAI), given that the vast majority of MSM very commonly douche prior to RAI (behaviorally-congruent). DREAM-01 established a range of safe and acceptable TFV rectal douche formulations administered as a single dose which also achieved desired tissue concentrations of drug. DREAM Behavioral Survey data established that a series of 3 cleansing douches are typical prior to RAI in MSM. To more closely simulate actual douching practice prior to RAI, the investigators propose the study of 3 douche product sequences to approximate the highest (3 TFV douches \[Sequence A\]) and lowest (only one TFV douche at the beginning \[Sequence B\] or end \[Sequence C\] of 2 other non-medicated douches) number of TFV doses in a typical repeated cleansing douche sequence. Study objectives including safety, pharmacokinetics (PK), pharmacodynamics (PD), and acceptability of repeated douching with TFV and non-medicated solutions, are essential to inform the design of an extended safety study of a TFV douche in outpatient pre-RAI contexts. DREAM-03 is an early phase 1, open label study to compare the safety, PK, PD, and acceptability of 3 sequences of TFV and non-medicated douches. Each participant will undergo a Screening Visit to evaluate eligibility. Baseline Visit will assess pre-dose safety, PK, PD, and behavioral points of reference. Three sequences described above (Sequences A, B, and C) occur sequentially within each subject. Safety, PK, PD, and behavioral readouts are assessed at specified times over 8 hours after each dose, followed by a minimum 14 day washout period before the next sequence. The TFV douche to be used, previously known as Product C from the DREAM-01 study, consists of TFV 660 mg in 125 mL half-normal saline (TFV 5.28 mg/mL). Sequence A includes 3 TFV douches and sequence B and C include only one TFV douche at the beginning or the end, respectively. In sequence B and C the other douches (2 per sequence) will be non-medicated solutions (tap water). Sequence A, proportional accumulation of all 3 TFV douches, would represent a 3-fold increase in TFV dose relative to the highest single dose used in DREAM-01 (Product C, 660 mg/125 mL half-normal saline \[TFV 5.28 mg/mL\]). Sequence B and C, with only 1 TFV douche dose either preceded by or following two non-medicated douches, are expected to exceed the tissue exposure of the lowest dose used in DREAM-01 (Product A, TFV 220 mg/125 mL normal saline). Participant accrual will take approximately 6 months and each participant will be on study for approximately 6 months. Total study duration is about 1 year.