TAMPA — HIV infections are rising more rapidly among young gay and bisexual males than any other group, the latest figures show. Now University of South Florida researchers are joining a national study to learn how well a new daily pill may protect this high-risk population.
From Tampa to San Francisco, 14 communities are involved in the youth trial of Truvada, which received federal approval in July as an HIV preventive drug. But earlier trials on its effectiveness and safety didn't include sufficient numbers of younger males who have gay sex.
This month, the U.S. Centers for Disease Control and Prevention reported that new HIV infections rose 22 percent among 13- to 24-year-old males who have sex with other males. That's the only group to show a significant increase between 2008 and 2010, the most recent data available. Young black males are particularly affected.
Reversing this trend is critical to addressing the nation's rate of newly acquired HIV infections, which has remained stubbornly steady even as treatment advances have helped many with the disease to live far longer. According to the CDC, about 50,000 new cases have been reported annually for the past decade.
"If we could curb HIV in this population, we could really get a handle on the epidemic," said Dr. Diane Straub, chief of the division of adolescent medicine at USF, the principal local investigator for the trial. "We would love to get rid of HIV, but we are not going to be able to do that unless we have multiple weapons to attack it," she added.
But using Truvada as a preventive measure for healthy people remains controversial — and expensive, with a daily dose costing as much as $14,000 per year.
The drug contains two antiretroviral medications that have been used for years in people infected with HIV, the human immunodeficiency virus that without treatment almost always develops into AIDS.
Truvada helps prevent HIV from establishing itself and multiplying in the body. This summer, federal regulators approved Truvada for preventive use — in combination with condoms and safer sex measures — after studies showed it significantly reduced the risk of new HIV infection.
A trial sponsored by the National Institutes of Health, involving 2,500 healthy gay and bisexual men, showed that daily use of Truvada helped reduce the risk of HIV infection by more than 40 percent. The pill was even more effective among people who consistently took it every day, as proved by blood tests.
In another study, Truvada reduced the risk of HIV infection by 75 percent among 4,800 heterosexual couples in which one partner was HIV positive and the other was not.
The drug's power is encouraging, but the protection it offers is not perfect — particularly if not taken daily — which is why people who take the drug still must practice safe sex.
Many within the HIV-AIDS community thought the approval of Truvada for prevention was premature, said William Harper, executive director of the AIDS Service Association of Pinellas Inc., or ASAP, an affiliate of Suncoast Hospice.
"What we're afraid of at this point is people will have unprotected sex," he said. "They will think that they can pop a pill and they will think it's all good."
Harper is pleased that more research is being conducted, especially among younger males. In this population, he is especially concerned about maturity issues — whether young people will take the drug regularly, and how a prevention pill may change their sexual behavior.
These are among the questions that researchers hope to answer with a national study involving hundreds of young men who have sex with other men. These 18- to 22-year-old study participants could identify themselves as homosexual and bisexual, or even consider themselves primarily heterosexual, but also engage in gay sex.
USF will begin recruiting 25 participants in January at its new Ybor Youth Clinic, which serves at-risk young people.
"We need to prove the science," Straub said. "We are looking to see if it's feasible for a young person to take a medication as (prevention), if it's safe, and if it changes their behavior."
Truvada's rare but serious side effects include kidney problems and loss of bone density, which could be especially concerning in healthy youths.
The study, called Project PrEPare (which stands for Pre-Exposure Prophylaxis), will examine the use of Truvada within a broad HIV-prevention strategy. Participants will also receive free condoms, safe-sex counseling and monthly HIV testing.
Researchers will monitor the blood work of participants for evidence of side effects and will administer two bone-density scans over the yearlong study. The young men involved will be paid for their time.
If any become HIV-infected, or develop health issues that may be related to Truvada, they may be monitored for a second year.
Straub noted that the at-risk youth targeted often lack emotional and financial support at home and in the community.
"This is such a marginalized group of people. I'm really excited to be able to provide something that actually helps them," Straub said.
"For many years, (HIV prevention efforts) just tried to decrease behavioral risk, and that has not shown to be sufficient."
Times researcher Natalie Watson contributed to this report. Letitia Stein can be reached at firstname.lastname@example.org or (727) 893-8330.