Ushercell is a cellulose sulfate-based topical microbicide gel. Polydex said that it was cellulose sulfate that could have lead to a potential increased risk of HIV infection in these women. The trial was being conducted in South Africa, Benin, Uganda, and India.
Simultaneously, Family Health International (FHI) has halted a second phase III cellulose sulfate trial in Nigeria as a precautionary measure.
Polydex said that it is not yet clear why use of cellulose sulfate was associated with an increased risk of HIV infection. An independent data monitoring committee will conduct a detailed review of the data to better understand the findings, and help determine any implications for other microbicide studies.
“While the findings are unexpected and disappointing, we will learn scientifically important information from this trial that will inform future HIV prevention research,” stated Dr Lut Van Damme, principal investigator of the trial.
Polydex said that it would continue to evaluate the findings to help determine the biological cause of an increased sero-conversion rate detected in the preliminary analysis at some of the trial sites. Additionally, the company plans to evaluate the product for its potential use as a contraceptive product.
The company commented that its income has not been adversely affected by the halting of these trials.