Nonoxynol-9 Not Effective Microbicide, Trial Shows
Search Continues for Effective Product, UNAIDS Chief Says
June 13, 2000
An international multi-site trial of the spermicide nonoxynol-9 in gel form has shown that the product is not effective in protecting women from HIV infection. This spermicide is on the market in the USA and China under the trade name "Advantage S."
"We are clearly disappointed at the results of the trial," said Dr. Peter Piot, Executive Director of the Joint United Nations Programme on HIV/AIDS (UNAIDS). "But the search for an effective microbicide doesn't end here. With over 5 million people a year becoming infected with HIV, we have to push ahead with multiple trials in order to find a product that protects against infection with the virus." Microbicides are chemical substances -- in the form of gel, cream, suppository or film -- which kill viruses and bacteria when applied vaginally or rectally before sexual intercourse.
The large-scale efficacy trial -- known as a Phase III trial -- was sponsored jointly by UNAIDS and US-based Columbia Laboratories, beginning in 1996. The participants were female sex workers in Benin, Côte d'Ivoire, South Africa and Thailand.
"Prior to the start of the Phase III trial we conducted several safety studies. We found that this formulation of nonoxynol-9 did not have any of the side effects associated with other formulations of the product, such as genital sores and irritation," said Dr. Joseph Perriëns, who heads the UNAIDS microbicide effort. "This paved the way for the Phase III trial. Now, we will have to continue our search for an effective product using other compounds."
At least 36 other compounds are now at the pre-clinical testing stage, while 20 are ready for early safety trials in human volunteers and 3 additional compounds are being considered for large-scale trials. Meantime, the preliminary results raise questions about the continuation of the two other nonoxynol-9 trials that are currently taking place.
Finding an effective microbicide would be a major breakthrough in preventing the spread of HIV, especially for women. "A microbicide can allow women to protect themselves and their partners from infection without necessarily having to secure male cooperation," said Dr. Awa Coll-Seck, Director of UNAIDS Policy, Strategy and Research.
One positive outcome of the trial is that fewer of the sex workers who participated became infected with HIV, compared with sex workers who did not participate at all in the study. Apart from receiving the trial microbicide or a placebo, sex workers in the study received classical HIV prevention support -- free condoms, free treatment for sexually transmitted infections, counselling and peer support. The resulting lower rate of new infections, and the detailed final outcome of the trial, will be discussed during the XIII International AIDS Conference in Durban, South Africa, on 12 July 2000.
This article was provided by UNAIDS. Visit UNAIDS' website to find out more about their activities, publications and services.