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December 15, 2009

Disappointment as microbicide fails to protect against HIV

"PRO 2000 microbicide gel failed to protect women against HIV infection in the largest microbicide study to date, partners in the Microbicide Development Programme’s 301 study have announced. ...

"The study recruited 9385 women, compared to 3099 women in the HPTN 035 study, and because of the larger number of participants, more infections took place in the study. As a result MDP 301 has much greater power to detect differences in infection rates.

"However, after one year of microbicide use, there was no significant difference in the risk of infection between women who received PRO 2000 or the placebo gel. PRO 2000 failed to show a protective effect (hazard ratio 1.05 [95% confidence interval 0.82 – 1.34], p=0.172).

"There were 130 HIV infections out of 3,156 women who were given 0.5% PRO 2000 gel (4.5 per 100 person years), and 123 HIV infections out of 3,112 given the placebo gel (4.3 per 100 person years). ...

"The future

"The full results of MDP 301 are likely to be presented and published early in 2010, and the field is now awaiting the results of a South African study of a microbicide containing the antiretroviral drug tenofovir.

"That study, the CAPRISA 004 trial, is testing the use of tenofovir gel in women in KwaZulu-Natal, and the results are expected to be presented in the summer of 2010.

"CAPRISA 004 is a pilot study, and will be followed by results from the VOICE study, which is directly comparing a tenofovir gel with oral tenofovir pre-exposure prophylaxis (PrEP) in 4200 women at 10 sites in South Africa, Malawi, Uganda, Zambia and Zimbabwe."

Read more in Aidsmap, December 14, 2009.