Preexposure prophylaxis (PrEP) using FDA-approved antiretroviral (ARV) drugs is emerging as a promising strategy for the prevention of sexual HIV infection. There is growing consensus that a combination of ARV agents, analogous to highly active antiretroviral therapy (HAART), likely is essential for optimally effective PrEP (1, 2). Oral administration of tenofovir disoproxil fumarate (TDF) plus emtricitabine (FTC) (Truvada; Gilead Sciences, Inc.) is the first regimen approved by the FDA to reduce the risk of HIV infection in uninfected individuals (http://www.fda.gov/NewsEvents/Newsroom /PressAnnouncements/ucm312210.htm). Three recent clinical trials demonstrated that oral ARV regimens using the combination of TDF and FTC can be effective in susceptible men, women, and partners of HIV-infected individuals (3-5). However, the relative risk reduction in these trials varied widely (from 44 to 75%), and a study in which women used a daily oral TDF-FTC regimen was stopped early due to futility. A critical factor driving success in these trials appears to involve sustaining high levels of adherence to frequent dosing (6).It is well established across different delivery methods that adherence to therapy is inversely related to the dosing period (7-10). Controlled topical delivery of ARV drugs using intravaginal rings (IVRs) is thought to improve adherence (11) and to provide sustained mucosal levels independent of coitus and daily dosing (12). The delivery of two or more ARV drugs from conventional IVR designs involves significant technological and manufacturing hurdles. To meet these challenges, we have developed a novel IVR technology, the pod-IVR (13), that enables rapid development of devices capable of delivering multiple agents over a wide range of target delivery rates and aqueous solubilities (14-16). We recently published the design and 28-day pharmacokinetic (PK) evaluation in sheep of a five-drug pod-IVR as a proof-of-concept, advanced multipurpose prevention technology (MPT), combining three ARV drugs from different mechanistic classes (tenofovir [TFV], nevirapine, and saquinavir) with a proven estrogen-progestogen contraceptive for prevention of HIV infection and unintended pregnancy (17).Here we present the first report of an IVR delivering TDF and FTC, as well as the first report of a triple-combination IVR delivering TDF, FTC, and maraviroc (MVC) (an entry inhibitor/antagonist of chemokine receptor 5 [CCR5]). Preliminary local safety and pharmacokinetic (PK) findings for these devices were determined in pig-tailed macaques, which are considered by many to represent the most relevant animal model for HIV vaginal PrEP studies (15,18,19). Steady-state drug levels for all three ARV agents in vaginal fluids were sustained over the 28-day study period, with corresponding vaginal tissue concentrations suggesting putative efficacy in preventing HIV infection.