Final HIV Result of Ushercell Trial Presented at IAS Conference in Sydney

July 25, 2007
Arlington, VA

Today, at the International AIDS Society Conference in Sydney, Australia, Dr. Lut Van Damme of CONRAD, principal investigator of the Phase III clinical trial of Ushercell, reported further analysis of HIV results from the trial. This trial of Ushercell, a potential microbicide also known as cellulose sulfate (CS), was halted in January of this year due to a higher number of HIV infections in the group of women using cellulose sulfate than in the group using a placebo product.

Final analysis of the data from the CONRAD study showed that the difference in HIV seroconversions between the CS group and the placebo group was not statistically significant. There were more seroconversions in the CS group, but the difference was not large enough to exclude the possibility that it could have occurred by chance. Out of 1,425 women who were enrolled in the trial, 41 seroconverted — 25 using CS and 16 on the placebo.

A further exploratory analysis using a subset of the data that excluded women after they stopped using the gel — for example, because of pregnancy — showed that there were more infections among women using CS than there were among those using the placebo product, and that difference was statistically significant. In this secondary analysis, there were 34 seroconversions —23 among those using CS and 11 among those using the placebo. This alternative analysis suggests that the use of CS gel may increase a woman’s susceptibility to HIV infection. However, in a study conducted by Family Health International (FHI) and collaborating investigators in Nigeria, and also presented today in Sydney, CS use had no effect on the risk of HIV transmission.

Taken together, these analyses confirm that CS is not effective against HIV infection. In order to try to find a scientific explanation for the higher number of seroconversions in the cellulose sulfate group in one of the two studies, CONRAD will support a number of activities over the next six months: additional analyses on the datasets from these two Phase III trials, additional data gathering in ongoing animal studies of CS, additional in vitrotesting, and initiation of a small study in women at two U.S. sites to explore specific vaginal responses to CS.                                  

Dr. Van Damme said, “The well being of the women who participate in clinical trials is, and always will be, our top priority, and we made the right decision to err on the side of caution when we halted the trial in January.” Ushercell had undergone 11 safety and tolerance trials prior to the start of the Phase III trials to determine whether it might be effective at preventing HIV in humans. “While we are disappointed that cellulose sulfate was not found to be effective for HIV prevention,” Dr. Van Damme continued,  “with a globally devastating epidemic such as HIV, it is crucial to continue to evaluate a variety of potential prevention methods, particularly those that are female-initiated.”

Each new infection that occurred during the trials must be viewed in the context of a truly devastating pandemic. The studies were conducted in countries and communities hard-hit by the HIV epidemic. In South Africa, for example, 50 percent of the women who volunteered to participate in CONRAD’s trial were unable to participate because they were already HIV-positive at the time of their initial screening visit. In Uganda, the infection rate was 32 percent at screening.

During the course of the trials, each woman received medical care, HIV/STI prevention counseling, and free condoms to help her avoid contracting HIV. Women who nevertheless tested HIV-positive during these studies also have been assured access to HIV care and antiretroviral treatment when needed.

CONRAD is a cooperating agency of the U.S. Agency for International Development (USAID) committed to improving reproductive health by expanding the contraceptive choices of women and men and by helping to prevent the transmission of HIV and other sexually transmitted infections. CONRAD is administered through the Department of Obstetrics and Gynecology at Eastern Virginia Medical School (EVMS) in Norfolk, VA and headquartered in Arlington, VA.

Family Health International (FHI) is a nonprofit organization dedicated to improving lives, knowledge, and understanding worldwide through a highly diversified program of research, education, and services in family health and HIV/AIDS prevention and care. Since its inception in 1971, FHI has formed partnerships with national governments and local communities in countries throughout the developing world to support lasting improvements in the health of individuals and the effectiveness of entire health systems. FHI has 1700 staff and offices in 40 countries.

For more information, contact:
Family Health International 
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Tel: 919-405-1461

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