Quick Links


Understanding the results from trials of the PRO 2000 microbicide candidate

PRO 2000 is a candidate microbicide that has been studied in two large-scale effectiveness trials: HPTN 035 and MDP 301.

The results from HPTN 035 were announced in February 2009 (click here for AVAC's update on the HPTN 035 trial and its result) and showed that there were 30% fewer new HIV infections among women who used the 0.5% strength of PRO 2000 plus the standard prevention package (condoms, STI treatment, behavior change counseling) compared to women who received the placebo gel plus a standard prevention package alone. This finding fell short of statistical significance—meaning that scientists could not say with certainty that the lower number of infections in the PRO 2000 arm was due to gel use and not a chance finding. For additional background on HPTN 035, visit www.mtnstopshiv.org/news/studies/hptn035.
MDP 301 enrolled 9,404 sexually active, HIV-negative women at six sites in South Africa, Tanzania, Uganda, and Zambia. Participants enrolled in the study between October 2005 and August 2008. It was conducted by the Microbicides Development Programme (MDP), a partnership of African and European researchers. MDP 301 was funded by the UK Department for International Development (DFID) and the UK Medical Research Council.
The study was originally designed to test two strengths of PRO 2000 gel, but the 2% dose was discontinued in February 2008 when the study’s Independent Data Monitoring Committee concluded that the higher dose gel was not likely to show benefit in reducing acquisition of HIV.

On December 14, 2009, MDP announced that their trial found no evidence that PRO 2000 reduces the risk of HIV infection in women.

While this trial did not result in an effective product, it was a successful trial – it gave a clear result, even if that result is disappointing. In many ways, this trial should serve as a model for future HIV prevention trials as it will provide critical scientific information as well as important lessons from the extensive social science component and the comprehensive community engagement and preparation undertaken by the trial staff. The principal investigators and trial staff developed several innovative integrated approaches for working with participants and communities to ensure retention in the trial and to track women’s use of the product.

AVAC will be releasing a new report that will help advocates understand these results and the implications for next steps.

For additional background on both the HPTN 035 and MDP 301 trials, please visit:
Media coverage, understanding the initial results:
Microbicides Media and Communications Initiative, December 14, 2009
Disappointment as microbicide fails to protect against HIV - NAM, December 14, 2009
Anti-HIV gel hopes dashed by trial results - The Guardian, December 14, 2009

Bookmark and Share

AVAC: Global Advocacy for HIV Prevention
101 West 23rd Street   ·  New York, NY  
+1 212.796.6423 (main)   ·  avac@avac.org
Copyright 2014, All rights reserved.
Design by Lomangino Studio | Powered by Orchid Suites Orchid ver. 4.7.6.