A Multiple Dose Phase 1 Assessment of Rilpivirine Long Acting in a Model of Preexposure Prophylaxis Against HIV

The MWRI-01 study characterized the safety, acceptability, pharmacokinetic (PK), and pharmacodynamic (PD) profile of rilpivirine (RPV) long acting (LA) in a model of preexposure prophylaxis (PrEP). Prospective, open-label Phase 1 study. The safety and acceptability of three repeated doses of RPV LA were monitored. Blood, tissue (rectal, cervical, and vaginal), and biological fluids (vaginal and endocervical) were collected at baseline and at 1- to 2-month intervals throughout the study for PK and PD assessment. Eight women and four men received three intramuscular doses of 1,200 mg of RPV LA given 8 weeks apart. There were a total of 195 adverse events (AEs) reported, of which 138 (70.8%) were Grade 1 and 55 (28.2%) were Grade 2. The most common AE was injection site pain. Geometric mean (90% confidence interval) plasma RPV concentrations at 56 days after the first and third doses were 39 (33-45) ng/mL (female)/29 (17-40) ng/mL (male) and 59 (45-62) ng/mL (female)/40 (30-51) ng/mL (male), respectively. Exposure to RPV LA was associated with significant inhibition of HIV-1_BaL viral replication in the ex vivo rectal explant model (p < .0001) that persisted for up to 4 months after the third dose of RPV LA. In contrast, no viral suppression was seen in cervicovaginal tissue. Multiple dose administration of RPV LA was safe and well tolerated, and was associated with prolonged suppression of viral replication in rectal explant tissue.