VOICE Study Discontinues Tenofovir Gel Arm

November 25, 2011 —

Today, the Microbicide Trials Network (MTN) announced a change to its VOICE study, a clinical trial evaluating the safety and effectiveness of two different antiretroviral (ARV)-based methods women can use to protect themselves from sexually transmitted HIV — daily use of tenofovir vaginal microbicide gel or daily use of the oral ARV tablet Truvada.

VOICE will discontinue use of tenofovir gel in the trial, but continue testing oral Truvada.

The decision follows an independent interim review of the study data, which concluded that tenofovir gel is not effective in preventing HIV in the women enrolled in the VOICE trial.

No safety concerns are cited. Please see MTN’s website for its   statement and Q&A about today’s news.

Following an earlier DSMB review conducted in September, the VOICE study had discontinued the oral tenofovir tablet arm, also due to futility.

Once the VOICE study concludes, MTN will review all the data it gathered to help understand why tenofovir gel and oral tenofovir did not prevent HIV infection in the study.

This research will provide invaluable information as the field continues its work to develop safe and effective HIV prevention tools for women.

While today’s news is disappointing, VOICE will continue to test the effectiveness of oral Truvada, with results expected in 2013.

In addition, data from the recently initiated FACTS 001 trial in South Africa may help us to better understand the disparity between results from the 2010 CARPRISA 004 trial, which showed efficacy for tenofovir gel when used before and after sex, and today’s data. Results from FACTS are expected in 2013.

IPM praises the VOICE study team for its work implementing this trial and its unwavering commitment to developing products women urgently need to protect themselves against HIV. 

Our deep gratitude goes out to the women of South Africa, Uganda and Zimbabwe who have volunteered for VOICE to advance these technologies and women’s health — in their communities and around the world.

We look forward to future results from this important ongoing study and to working in collaboration with MTN on the dapivirine ring licensure program.