Microbicide Trials Network

HPTN 035 is four-arm, multi-center Phase II/IIb randomized controlled trial that aims to determine the safety and effectiveness of two different candidate microbicides, BufferGel® and PRO 2000 (0.5% PRO 2000/5 Gel (P)) for the prevention of HIV in women. Participants are randomly assigned to one of four study groups: BufferGel, PRO 2000 gel, placebo gel, and no gel. Women assigned to the three gel groups apply gel up to one hour before sexual intercourse using pre-filled applicators. Because all three gels and applicators look the same, neither researchers nor participants know who has been assigned to use which gel for the duration of the study. Participants in all four groups receive free condoms, HIV risk reduction counseling, and routine testing and treatment for sexually transmitted infections. The study enrolled its first participant in February 2005. Accrual was completed in July 2007 at which time a total of 3,100 sexually active HIV-negative women had been enrolled at seven sites in Malawi, South Africa, Zambia, Zimbabwe, and the United States. Each study participant is followed for at least one year. Follow-up is expected to be completed in July 2008, and results of the study available in 2009.