On 1 February 2007, the International AIDS Society (IAS) issued a press release to the halting of two large Phase III studies of the HIV microbicide candidate Ushercell. Ushercell is a cellulose sulfate based topical gel that was being developed for HIV prevention in women by Polydex Pharmaceuticals.

This was because preliminary results at some sites indicating potential increased risk for HIV among women who use the compound. The findings of increased risk were identified at some sites in a trial sponsored by CONRAD, a research agency of USAID in the United States. The CONRAD trial was being conducted in South Africa, Benin, Uganda and India.

Family Health International, sponsor of the second halted trial in Nigeria, had not found similar results but halted the trial as a precautionary measure, given the preliminary results in the CONRAD trial. At this point, it is not clear why the use of cellulose sulfate was associated with increased risk for HIV infection among women in the CONRAD-sponsored trial. Earlier trials of the same compound involving 500 participants did not indicate safety concerns.

“While extremely disappointing, this setback is also an opportunity to learn why some women who used Ushercell were found to be at increased risk of HIV infection,” said Dr. Pedro Cahn, President of the IAS and Director of Fundación Huesped in Buenos Aires, Argentina. “This will strengthen future microbicide research and increase our overall knowledge of how such compounds work.”

“The importance of developing a safe and effective microbicide to protect women from HIV infection cannot be understated,” said Dr. Cahn. “We must give women the tools to protect themselves, independent of their partners’ actions.”

The halted trials were two of six Phase III microbicide trials underway at the start of 2007. Four additional Phase III trials of other candidates are ongoing.

Source:

IAS and Polydex press releases
http://www.ias.se

and

Polydex Pharmaceuticals reports
http://www.polydex.com/v2/news/07-01-31.html