Kaiser PrEP Users See No New HIV Infections

No new HIV infections have occurred among more than 500 Kaiser Permanente members using pre-exposure prophylaxis -- better known as PrEP -- but condom use appears to be declining among a subset of gay men, according to a small survey presented at a forum commemorating World AIDS Day.

"PrEP is provided for the purpose of preventing HIV infections, and we're seeing that hold true," Bradley Hare, Kaiser's director of HIV care and prevention, told the Bay Area Reporter .

Hare described preliminary findings from a survey of Kaiser members who started taking Gilead Sciences' Truvada (tenofovir and emtricitabine) combination pill to prevent HIV.

The Food and Drug Administration approved Truvada for PrEP in July 2012, based in part on data from the iPrEx trial of mostly gay and bisexual men. This trial showed that once-daily Truvada reduced the risk of HIV infection by 42 percent overall, rising to 92 percent among participants with blood drug levels indicating regular use. In an open-label extension of iPrEx, none of the men who took Truvada at least four times per week became infected. In May the Centers for Disease Control and Prevention recommended that people at substantial risk for HIV infection should consider PrEP.

The Kaiser survey was only recently initiated and so far has received responses from approximately 90 members -- less than 20 percent of PrEP recipients -- mostly men who have sex with men. The survey is intended to help Kaiser providers learn more about their patients taking PrEP in an effort to provide better clinical care, Hare said.

Such preliminary results presented at an informal forum normally would not be major news. But the AIDS Healthcare Foundation -- which has waged a media campaign against PrEP -- issued a news release December 8 calling attention to an article in the San Francisco Business Times highlighting one number from Hare's presentation: 45 percent of survey respondents reported using condoms less often since they started PrEP.

"This Kaiser study confirms the fears of organizations like AHF that have expressed caution and skepticism about the wisdom of the community's wholesale embrace -- as well as the CDC's recommendation -- of the widespread scale up of PrEP," stated AHF President Michael Weinstein. "This study should serve as a warning and may one day be seen as the canary in the coal mine of unintended -- but predictable -- consequences of a poorly thought out public health strategy."

Explaining the survey findings in more detail, Hare told the B.A.R. that among the 90 people who chose to answer the survey -- a group that may not be representative of Kaiser's PrEP users overall -- half said their condom use had remained the same, 45 percent said it had decreased, and 5 percent said it had increased since they went on PrEP.

Hare emphasized that they do not have baseline data about how often respondents used condoms before starting PrEP, and there is no control group of men not using PrEP for comparison. However, the fact that the men chose to go on PrEP suggests they likely were already having sex without condoms at least some of the time.

"We don't know if we took [condom use] from 100 percent to zero, or from 50 percent to 40 percent," Hare said. "With the extra protection provided by PrEP, some may have decided to forego condoms" -- including people in monogamous relationships with HIV-positive partners, he suggested.

The survey did ask about changes in the number of sex partners, and found that this did not increase. "It's not the case that people are having a lot of unprotected sex with a lot of new partners" after starting PrEP, Hare said.

PrEP clinical trials generally have not seen evidence of so-called risk compensation -- engaging in more risky behavior or reducing use of other prevention methods. But anecdotal reports suggest that many men find dispensing with condoms to be one of the major benefits of PrEP.

"Is anyone actually surprised that once PrEP starts settling in as a safer sex strategy, some guys who use it are going to use condoms less?" asked London-based PrEP advocate Gus Cairns. "The important question is not whether they are using condoms less. It's are they protected from HIV better or worse than they were before they started PrEP?"

As Weinstein noted, PrEP critics fear that a reduction in condom use could lead to a rise in other sexually transmitted diseases.

"We are seeing a high number of STDs in people on PrEP," Hare told the B.A.R., but again he said there is no control group of people not taking PrEP to use for comparison.

These STDs include the "usual suspects" syphilis, gonorrhea, and chlamydia, he said, but Kaiser providers have also seen two cases of acute hepatitis C in HIV-negative gay men who were not injection drug users.

While concern about STDs is well founded, the goal of PrEP is to prevent HIV, Hare emphasized.

"We've seen zero cases of HIV among more than 500 guys on PrEP," he said. "Behavior and STDs are important things to watch to be able to prescribe it responsibly, but PrEP is prescribed to prevent HIV, and it's working."