Safety and effectiveness of BufferGel and 0.5% PRO2000 gel for the prevention of HIV infection in women
Abdool Karim, S.S.; Richardson, B.A.; Ramjee, G.; Hoffman, I.F.; Chirenje, Z.M.; Taha, T.; Kapina, M.; Maslankowski, L.; Coletti, A.; Profy, A.; Moench, T.R.; Piwowar-Manning, E.; Mâsse, Bît.; Hillier, S.L.; Soto-Torres, L.
Aids 25(7): 957-966
2011
ISSN/ISBN: 0269-9370 PMID: 21330907 DOI: 10.1097/qad.0b013e32834541d9Document Number: 220807
To determine the safety and effectiveness of BufferGel and 0.5% PRO2000 microbicide gels for the prevention of male-to-female HIV transmission. Phase II/IIb, randomized, placebo-controlled trial with three double-blinded gel arms and an open-label no gel arm. Study participants from Malawi, South Africa, Zambia, Zimbabwe, and the USA were instructed to apply study gel up to 1 h before each sex act and safety, sexual behavior, pregnancy, gel adherence, acceptability, and HIV serostatus were assessed during follow-up. The 3101 enrolled women were followed for an average of 20.4 months with 93.6% retention and 81.1% self-reported gel adherence. Adverse event rates were similar in all study arms. HIV incidence rates in the 0.5% PRO2000 gel, BufferGel, placebo gel, and no gel arms were 2.70, 4.14, 3.91, and 4.02 per 100 women-years, respectively. HIV incidence in the 0.5% PRO2000 gel arm was lower than the placebo gel arm (hazard ratio = 0.7, P = 0.10) and the no gel arm (hazard ratio = 0.67, P = 0.06). HIV incidence rates were similar in the BufferGel and both placebo gel (hazard ratio = 1.10, P = 0.63) and no gel control arms (hazard ratio = 1.05, P = 0.78). HIV incidence was similar in the placebo gel and no gel arms (hazard ratio = 0.97, P = 0.89). The 0.5% PRO2000 gel demonstrated a modest 30% reduction in HIV acquisition in women. However, these results were not statistically significant and subsequent findings from the Microbicide Development Programme (MDP) 301 trial have confirmed that 0.5% PRO2000 gel has little or no protective effect. BufferGel did not alter the risk of HIV infection. Both products were well tolerated.