Dapivirine

[1] The International Partnership for Microbicides has held exclusive worldwide rights to dapivirine since 2014,[2] building upon a 2004 royalty-free license to develop dapivirine-based microbicides for women in resource-poor countries.

[3] A monthly intravaginal ring containing dapivirine has been developed as a way of preventing infection by human immunodeficiency virus in women.

Two phase 3 clinical trials of intravaginal dapivirine rings for HIV prevention were completed in 2015 and results were announced at the 2016 Conference on Retroviruses and Opportunistic Infections.

[4] The Ring Study (IPM-027) reported a 31% reduction in HIV acquisition (95% CI 0.9-51.5%, p=0.040) also with a trend toward greater efficacy in women over age 21.

[5] In both trials, more than 80% of returned rings showed signs of drug depletion indicating at least some use, and more than 80% of blood samples from participants in the active arm had levels of dapivirine consistent at least 8 hours of continuous use preceding the blood test.