Media statement

Phase III trial of cellulose sulfate microbicide for HIV prevention closed

USA organisation, CONRAD reported today that a study of a potential vaginal microbicide, cellulose sulfate, had to halt immediately upon learning that the preliminary results indicated that cellulose sulphate could lead to an increased risk of HIV infection in women who use the compound. The trial is being conducted in South Africa by the Medical Research Council's HIV Prevention Research Unit in Durban, as well as in Benin, Uganda and India.
 
At this point it is not clear why the use of cellulose sulphate was associated with an increased risk of HIV infection in the trial. The Independent Data Monitoring Committee (IDMC), an independent advisory group of experts overseeing the trial, will conduct a detailed review of the data to better understand the findings, and help determine any implications for other microbicide studies.
 
The findings were unexpected as 11 earlier safety and contraceptive trials of cellulose sulfate involving more than 500 participants in Africa, India and the USA, identified no safety concerns.
 
Recruitment for the CONRAD Phase III study began in July 2005.  The study was conducted in areas of the world where HIV risk is greatest, and where infection occurs primarily through heterosexual intercourse.   Half of the participating women were given cellulose sulfate, and half a placebo gel, in a double-blinded randomized trial design.  All participants received intensive HIV prevention counselling at each monthly visit and all women were given high-quality condoms free of charge.  Participants received regular testing and treatment for sexually transmitted infections.  Pregnant women were not included in the study.  
 
Participants were only admitted to the study after receiving detailed information about the purpose of the study and the possible health benefits and risks. During this process, their understanding of the study was assessed through comprehension testing prior to signing a consent form. In addition, participants were informed of the unknown effect of the product and advised on behavioural change and provided with condoms, regular HIV testing and counselling, and safe-sex counselling was done.
 
Each trial site is linked to local organizations that provide care for women who become HIV-infected during the trial.  As part of the trial preparation, CONRAD set aside funding for women who become HIV-positive during the trial to ensure adequate health care, including HIV antiretroviral treatment when needed.
 
Given the high number of HIV infections among women, we need to be cognizant that cellulose sulfate is just one product and not the entire field of microbicides. We should continue with the hard work and dedication to ensure that other products are tested with rigorous safety monitoring until we find something for women worldwide, as women do not have many options other than male/female condoms, which she may not always be in a position to negotiate with her partner.