Cellulose sulfate

Cellulose sulfate was a candidate microbicide that had been stopped for regulatory approval to be used therapeutically in the prevention of the spread of sexually transmitted diseases.

On February 1, 2007, the International AIDS Society announced that two phase III trials of cellulose sulfate had been stopped because preliminary results suggested a potential increased risk of HIV in women who used the compound.

At present, there is no explanation as to why cellulose sulfate was associated with a higher risk of HIV infection than placebo.

Although the halting of the the two trials was a disappointing setback for microbicide research, the investigators received praise for acting quickly as soon as an adverse effect had become apparent.

According to a review of microbicide drug candidates by the World Health Organization on March 16, 2007 a large number of compounds - more than 60 at the start of 2007 - are in the development pipeline. And at the beginning of that year, five phase III trials testing different formulations were under way.

As for these remaining late-stage microbicide trials, if they prove successful, first-generation products could be available by 2009. If they fail, second-generation products could become available by 2012.