CONRAD, a reproductive health research organization, halted a Phase III trial of Polydex Pharmaceuticals’ candidate for HIV prevention in women as it seemed to instead increase the risk of HIV. Ushercell, a cellulose sulfate-based topical microbicide gel, was being tested in women and trials were underway in South Africa, Benin, Uganda, and India.
The company opened traded at $3.18, representing a 52.25% drop in price.
"Ushercell has shown a consistent safety profile up to this point, having undergone 11 rigorous clinical safety and contraceptive trials involving more than 500 participants before entering the HIV prevention trial," states Polydex president and CEO, George Usher. "CONRAD will continue to evaluate the findings to help us determine the biological cause of an increased sero-conversion rate detected in the preliminary analysis at some of the trial sites."
Simultaneously, Family Health International (FHI) stopped a second Phase III cellulose sulfate trial in Nigeria. Although the FHI trial did not detect an increased HIV risk associated with cellulose sulfate, the decision was made as a precautionary measure, given CONRAD trial data.
Cellulose sulfate was one of four microbicides currently in effectiveness trials for prevention of HIV and other sexually transmitted infections. At this point, it is not clear why use of cellulose sulfate was associated with an increased risk of HIV infection in the CONRAD trial.