Microbicides

CAPRISA 004, a Phase IIb clinical trial of tenofovir gel used as a coitally-dependent microbicide, reported results on July 19. 2010. Tenofovir is an ARV-based nucleotide reverse transcriptase inhibitor (NRTI). The study found tenofovir gel used in a dosing regimen timed before and after sex reduced HIV infections by 39 percent, a finding that is statistically significant. CAPRISA provided the first evidence that the use of the antiretroviral (ARV) drug tenofovir in the form of a vaginal gel can reduce the risk of HIV infection in women.  The “test of concept” trial tested the effectiveness of 1% tenofovir gel, used before and after sex, among urban and rural South African women at high risk of HIV via vaginal sex. The International Partnership for Microbicides’ (IPM) most clinically advanced candidate, a long-acting monthly dapivirine ring, continues to progress and is scheduled to enter Phase III evaluation in 2011. Dapivirine is an ARV-based non-nucleoside reverse transcriptase inhibitor (NNRTI). The evaluation would cost approximately US$ 90 million.