Peter Anderson

Peter Anderson, PharmD, professor, Skaggs School of Pharmacy and Pharmaceutical Sciences, contributed to the latest findings on the effectiveness of an HIV prevention drug.

Working in the Colorado Antiviral Pharmacology Laboratory at the CU School of Pharmacy, Anderson and his colleagues developed a way to test the effectiveness of the drug, Truvada (a combination of tenofovir/emtricitabine). It is taken once daily to prevent HIV infection.

The research findings were presented last month during the AIDS 2014 Conference. And the work also was published in ​​The Lancet Infectious Diseases on the efficacy and safety of prophylactic use of Truvada to protect against HIV infection, which relied on the test developed at the school.

The test developed at CU measures the amount of tenofovir-diphosphate (a metabolite of tenofovir) in red blood cells, using a dried blood spot. Because of a long half-life, high amounts of the metabolite in the dried blood spot correspond with consistent dosing of Truvada and low amounts correspond with inconsistent dosing.

The new test was used in the iPrEx open label extension study (iPrEx OLE) published in The Lancet Infectious Diseases to estimate patterns of tablet use during the study.

The new test showed a continuous gradient of increasing efficacy (fewer HIV infections) with increasing drug concentrations. 

“Participants in the study who had tablet use consistent with four or more tablets per week, as determined by the new test, had no HIV infections (estimated 100 percent efficacy),” Anderson said. 

The U.S. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) recently issued guidelines recommending the use of antiretroviral medicines as an additional method of preventing HIV infection.

Findings from iPrEx OLE are particularly important in relation to emerging guidelines recommending widespread use of PrEP, according to Protocol Chair Robert Grant, MD, PGH of the Gladstone Institutes, the University of California at San Francisco and the San Francisco AIDS Foundation.

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