HIV-preventing drug holds up under study

Paul Marcelin pauses near his home in Alameda, Calif. where he often exercises Monday August 31, 2015. Paul Marcelin has been taking a drug called Truvada as part of a study of people not infected with HIV in San Francisco. Researchers at Kaiser Permanente found no new HIV infections from 650 people taking a drug known as PrEP, but also sold under the brand name Truvada. less Paul Marcelin pauses near his home in Alameda, Calif. where he often exercises Monday August 31, 2015. Paul Marcelin has been taking a drug called Truvada as part of a study of people not infected with HIV in ... more Photo: Brant Ward, The Chronicle Buy photo Photo: Brant Ward, The Chronicle Image 1 of / 9 Caption Close HIV-preventing drug holds up under study 1 / 9 Back to Gallery

Truvada, a daily pill that holds the hope of eliminating the risk of contracting HIV, appears to be living up to its promise.

In the first real-world study of the prescription drug, Kaiser researchers found no new HIV infections among the more than 650 people they followed over nearly three years, beginning just after the drug was approved by the U.S. Food and Drug Administration in 2012.

A clinical trial leading up to the FDA approval had shown that Truvada, made by Foster City’s Gilead Sciences, nearly eliminated the risk of getting infected by the AIDS virus. But no evaluations of the drug, also known as PrEP, for pre-exposure prophylaxis, had been published outside the tightly regulated clinical trial setting.

In the new study, participants were sexually active. Many did not use condoms for prevention, and half of them were diagnosed with other sexually transmitted diseases within a year of starting the study. But no new HIV infections turned up, researchers said.

“This is really compelling data that shows that PrEP works in a real-world setting,” said Dr. Jonathan Volk, a San Francisco Kaiser physician and epidemiologist and lead author of the study, which was published Wednesday in the medical journal Clinical Infectious Diseases.

Truvada, which contains the antiviral drugs emtricitabine and tenofovir, was originally created as an anti-retroviral drug used to treat HIV, but it has been shown to reduce the risk of HIV infection in people who are at high risk by up to 92 percent when taken consistently, according to the U.S. Centers for Disease Control and Prevention.

Drug has its critics

Still, the drug, which costs Kaiser patients about $50 a month, is not without controversy. PrEP was criticized early on by health providers and other advocates over concerns that the drug would encourage unsafe sex because of a false sense of security. In fact, the Kaiser study did find a significant decrease in condom use among the participants.

One of the loudest critics has been Michael Weinstein, president of the AIDS Healthcare Foundation in Los Angeles, who has publicly called Truvada a “party drug.” While PrEP may be an option for high-risk individuals who don’t use condoms, he said last month, it should not be used as community-wide public health intervention strategy.

But the CDC and public health advocates disagree.

The CDC last summer recommended the drug as a prophylactic for those at highest risk of becoming infected — sex workers, men with HIV-positive partners or those who engage in high-risk behaviors, such as IV drug use — and under careful watch by their doctors. San Francisco health advocates have also recognized Truvada as an important tool for the city’s Getting to Zero program, which aims to make the city the first in the country to have no new HIV infections, deaths or stigma.

“We have a fantastic new tool we can be using to help our patients protect themselves from HIV,” Kaiser’s Volk said. “I don’t think PrEP is right for everybody. But for the folks who need it, it works.”

No new infections seen

To test the effectiveness of the drug, Kaiser researchers identified 657 Kaiser San Francisco patients and followed them over 32 months without requiring anything after their initial screening other than regular testing for sexually transmitted diseases and completing an occasional questionnaire. The average age was 37, and 99 percent were men who have sex with men.

The study did not have a control group for the sake of comparison, but the participants clearly weren’t abstinent. After six months, about 30 percent of the PrEP users had been diagnosed with at least one sexually transmitted infection, with that number rising to 50 percent after a year. But there were no HIV infections, the study found.

When the participants were asked about any changes in behavior, 74 percent reported no change in their number of sexual partners, while 15 percent reported a decrease and 11 percent said the number increased. Condom use was unchanged in 51 percent of the participants, while 41 percent said they had decreased their condom use and 3 percent had increased the use of condoms.

“We know adherence to the medication is a really importance piece,” Volk said. “The fact we had no new HIV infections is very encouraging, but we still have more to learn about how people are using this medication.”

‘At high-risk phases’

For study participant Paul Marcelin, a San Francisco Kaiser patient who lives in Alameda, the drug allows him to protect himself while maintaining his relationship with his HIV-positive boyfriend. “I felt very comfortable that we don’t worry the same way that some couples might,” he said.

Marcelin, 40, a database expert, participated in a separate PrEP study conducted in 2013 by the San Francisco Department of Public Health and stayed on the drug for the Kaiser study. He said he thinks any hesitancy about Truvada is starting to dissipate, and people are accepting it as another prevention option.

“PrEP is something you can choose to use when at high-risk phases in your life,” he said. “I’m in a phase of my life I need to use it, but I won’t always be.”

Victoria Colliver is a San Francisco Chronicle staff writer. E-mail: vcolliver@sfchronicle.com Twitter: @vcolliver