Funded by the US Agency for International Development (USAID), the trial was part of an international effort to evaluate microbicides as a tool to reduce the risk of HIV infection in people at high risk.
After observing a lower than expected rate of HIV seroconversion in the trial, which was less than half of the expected rate, and after examining the trial’s data, the Data Monitoring Committee (DMC) indicated that continuation of the trial was not warranted due to a lack of statistical significance in the data.
The company said that the low seroconversion rate was possibly due in part to procedures designed to ensure ethical trial design, including counseling on HIV prevention and distribution of condoms.
The Savvy trial in Nigeria began screening volunteers in September 2004 and completed planned enrollment with 2,152 women in June 2006. Half of the women were given Savvy gel, and half were given a placebo gel to be inserted vaginally with pre-filled applicators before each act of intercourse. At monthly visits during a year-long follow-up, each participant was tested for HIV and reported on use of the gel and condoms, and any side effects or medical problems.
At trial initiation, the anticipated annual rate of new HIV infections in this population was 3.7%. Almost two years into the study, annual HIV incidence among study participants was less than 2%.
“We are disappointed that the Savvy African trial ended early. Savvy has proven to be a safe drug in its use by over 4,000 women. The low incidence of infection was due to many factors resulting in not enough power in the statistical plan,” said Mr Richard Williams, Cellegy’s chairman and interim CEO.