Viread (Gilead Sciences) dropped from HIV prevention trial

Viread gel (tenofovir disoproxil fumarate), from Gilead Sciences, has been dropped from the VOICE trial. The decision to discontinue use of the anti-retroviral (ARV) gel was made after a routine review of study data concluded Viread was not effective in preventing HIV in the women enrolled in the trial. VOICE is evaluating two ARV-based approaches for preventing the sexual transmission of HIV in women � daily use of one of two different ARV tablets or the gel. The review, conducted by the National Institute of Allergy and Infectious Diseases independent Prevention Trials Data and Safety Monitoring Board identified no major safety concerns with either Viread or the oral Truvada tablet, a combination of tenofovir and emtricitabine. In fact, VOICE is continuing to test the safety and effectiveness of Truvada. The other oral tablet, tenofovir, was discontinued from the study after a routine DSMB review in September determined that although the tenofovir tablets were safe, they were no better than placebo in preventing HIV in the women assigned to that study group. VOICE was designed with five study groups: Viread, an inactive placebo gel, oral tenofovir, oral Truvada and an inactive placebo tablet. The women in each group (about 1,000) were asked to take their assigned study product daily. The DSMB recommended that VOICE discontinue Viread and placebo gel arms, because there was no difference in effect between them in preventing HIV infection. The HIV incidence rates in the two groups were nearly identical, with a 6.1 percent incidence rate in the placebo gel group and 6.0 percent in the Viread group. Following the promising results of CAPRISA 004, which found Viread 39 percent more effective than placebo gel when used before and after sex, the FDA indicated that it would review data from VOICE as the second pivotal trial to support possible licensure of Viread. Now VOICE has provided clear evidence that the gel was not effective. FACTS 001, a Phase III trial testing the same regimen of tenofovir gel used in CAPRISA 004, plans to continue its study with results expected in 2014.