(Reuters Health) - An HIV-prevention drug pill, dubbed PrEP, dramatically reduced new infections in a large group of high risk gay men, Australian researchers report.

Although HIV pre-exposure prophylaxis (PrEP) had been shown to be effective in past clinical trials, the Australian researchers write in The Lancet HIV that the current study looks at the impact of the medication in a more real-world situation.

The researchers found that new diagnoses in gay men across one Australian state dropped by nearly a third, from 295 cases in the year prior to the study to 221 cases in the year after the drug was widely distributed.

“Our trial examined whether large scale, targeted and rapid introduction of PrEP in a big population would reduce the incidence of HIV in the whole population,” said lead author Andrew Grulich, head of the HIV Epidemiology and Prevention Program at the Kirby Institute at the University of New South Wales.

“Our key finding was a 32 percent decline in new infections in the state of New South Wales - whose population is greater than seven million - within one year of recruiting our initial target of 3,700 mostly gay and bisexual men.”

The men in the study were age 18 or older and had a history of high-risk sex. Ultimately, 3,645 of the men received PrEP. The men were required to be tested for HIV at one month and three months after starting the drug regimen, then every three months thereafter. They were also tested every three months for other sexually transmitted infections.

After a year, just two of the men had become HIV positive, and those two had not taken their medication as instructed.

“Our results show that rapid scale-up of targeted PrEP can lead to rapid reductions in HIV at a population level,” Grulich said by email. “This should be an urgent priority in any setting with an epidemic predominantly affecting men who have sex with men.”

“(This is) a really important study because it documents the benefit of HIV prevention pills at a population level,” said Dr. Jeffrey D. Klausner of the University of California, Los Angeles, who wasn’t involved in the new research. “Numerous studies since it was FDA approved in 2012 have shown that it prevented HIV in individuals taking the drug. This shows when you scale it up to a large enough level you can protect an entire population of people. It’s a call to action for other cities and governments to scale up.”

The issue for some people in the U.S. may be getting access to the medication. “It’s expensive,” said Klausner. “Public and private insurance does cover it, but there are different levels of co-pays.”

It’s important to get the medication in the hands of at-risk men who are uninsured, Klausner said. “While the manufacturer does have a medical assistance program, it will not cover the costs of the required lab testing. To be on PrEP, you need to be tested every three months and that can be expensive. But it’s important to monitor for any other sexually transmitted diseases, like chlamydia, gonorrhea or syphilis.”

There can be other barriers to those who might benefit from the medication, said Dr. Ken Ho of the University of Pittsburgh.

“Some providers are more interested in preventing ‘bad behavior,’” said Ho, who also was not involved in the new research. “They don’t want condom-less sex, so they’re not going to put you on PrEP. The reality is that there are a lot of people who don’t use condoms anyway. It’s just a case of being realistic about the world in front of us.”

While PrEP is highly effective, it won’t wipe out HIV by itself, Ho said. “I think that no individual intervention is going to eradicate HIV. But if you approach the problem from a multimodal perspective, then we can aim to get to zero.”

SOURCE: bit.ly/2AfCk4g and bit.ly/2P9viGc The Lancet HIV, online October 17, 2018.