Brandon Gufford, PharmD, PhD, received an $85,000 Campbell Foundation grant to study a strategy to boost the effectiveness and lower the cost of Truvada as on-demand PrEP, a pre-exposure prophylaxis to prevent acquiring HIV.

Gufford, a researcher at the Indiana University School of Medicine, and his team will collaborate with scientists at the University of Colorado in a study that combines Truvada with Probenecid (PRO), an oral drug that could increase the length of time Truvada is active in the body.

As a Campbell Foundation press release explains, although Truvada is a proven HIV prevention pill, the medication is eliminated quickly from the body by the kidneys. As such, it must be taken daily, which increases its cost as well as the possible damage to the kidneys—what’s more, some people have a harder time sticking with a daily regimen.

Researchers hope that adding Probenecid to Truvada will require less frequent dosing for on-demand PrEP, which is the strategy of taking PrEP only when you have sex, as opposed to every day (regardless of sexual activity).

“A boosted single dose strategy given before anticipated sexual activity, instead of the four doses of Tenofovir [one of the drugs in Truvada] given before and after currently being implemented, would be more practical and may possibly improve adherence,” said Gufford in the press release. “Thus, this strategy should improve PrEP efficacy and compliance.”

“On-demand PrEP can be improved,” Ken Rapkin, executive director of the Campbell Foundation, which supports nontraditional, laboratory-based HIV research. “This team from Indiana University may be able to show that adding this already-approved drug to the current PrEP medication can reduce damage to the kidneys, a problem that doctors and patients have been aware of for some time,” Rapkin said. “Hopefully, the results also will lead to increased protection, thereby reducing pill burden on those taking PrEP around the globe.”

For more about on-demand PrEP, click here. And for a collection of POZ articles, click #PrEP and #Prevention.