Findings for Extended Dapivrine Delivery Phase 1 Trial Reported

In looking at HIV prevention, there are a number of different therapies and now methods of delivery for patients. This latter portion is being examined in injectables, implants, and vaginal rings (VR).

Within these pre-exposure prophylaxis (PrEP) studies using these various methods of delivery, there is the hope these various options will create convenience and aid in adherence.

Duration studies have been done looking at extended usage for PrEP. In a multisite phase 1 trial studying dapivrine (DPV) vaginal rings (VR), 49 HIV-negative participants were randomized (1:1:1) trial comparing 2 extended duration (100 or 200 mg DPV) VRs used continuously for 13 weeks to a monthly 25 mg DPV VR.

“Across timepoints, plasma and cervicovaginal fluid (CVF) DPV concentrations were higher in the 100 and 200 mg VR arms compared with the 25 mg arm,” the investigators wrote. “Additionally, the peak concentration (Cmax) and Area Under the Concentration-Time Curve (AUC) for 0-28 days were 1.5 to 2 times higher for the extended duration VRs vs. monthly VR.”

Their findings were presented during the Conference on Retroviruses and Opportunistic Infections (CROI) 2021 virtual sessions.

Eighty-two percent reported being fully adherent, and no statistically significant differences were found between groups.

“The extended duration DPV VRs were well-tolerated and achieved higher DPV concentrations compared with the monthly DPV VR, likely translating into at least equal efficacy,” the investigators reported. “These findings support further evaluation of 3-month DPV VRs for HIV prevention in women.”