Study Shows Drug Combo Effective as HIV Prevention

(USA.gov)

A new study called iPrEx shows that individuals at high risk for HIV infection who took a once-a-day commercially-available tablet containing two widely used HIV medications experienced fewer HIV infections than those who received a placebo pill. The researchers say that the clinical trial, reported in the New England Journal of Medicine, is the first evidence that this HIV prevention method, called pre-exposure prophylaxis or PrEP, reduces HIV infection risk in people.

A total of 2,499 individuals at high risk of HIV infection participated in the six-country Iniciativa Profilaxis Preexposicion or Prexposure Prophylaxis Initiative (iPrEx) study. All study participants received a comprehensive package of prevention services designed to reduce their risk of HIV infection throughout the trial, including HIV testing, intensive safer sex counseling, condoms and treatment and care for sexually transmitted infections. Half of study participants also received the PrEP pill, while the other half received a placebo.

The findings show patients taking the tablet with the drugs emtricitabine and tenofovir, experienced an average of 43.8% fewer HIV infections than those who received a placebo. The average reduction in HIV infection risk of 43.8% includes all study participants—even those who did not take the daily pill consistently. Some 64 HIV infections were recorded among the 1,248 study participants who received a placebo pill, while 36 HIV infections were recorded among the 1,251 participants who received the study drug.

The study also found that PrEP was more protective among those who reported taking the pill more regularly. Levels of the PrEP drug measured in the blood of study participants also indicated that those participants who were protected against HIV infection were likely taking the study drug more regularly.

The drug used in the iPrEx study, a single-tablet combination of emtricitabine (200 mg) and tenofovir (300 mg), is marketed by Gilead Sciences Inc. under the brand name Truvada, and is available generically in many countries. Gilead Sciences provided the drugs for the iPrEx study, but did not otherwise take part in the study design, implementation, or analysis.

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