The Road to HIV Prevention Using an Injectable Prophylaxis

Can a prophylactic therapy eliminate HIV transmission in the most vulnerable populations?

With vast strides in research and treatment since the early days of the global HIV pandemic back in the 1980s, it’s safe to say the outlook for living with the disease is much more positive than it used to be. Much has changed.

But there is much, too, that hasn’t.

The populations most vulnerable to HIV infection — men who have sex with men, Black and Latino populations, transgender women — are still most vulnerable, especially young people.

“And despite decades of talking about barrier protection and safer sex, we’ve done little to slow the number of new infections,” says adolescent and HIV medicine specialist Daniel Reirden, MD, Medical Director of the Youth Immunodeficiency Program at Children’s Hospital Colorado.

Making pre-exposure HIV prophylaxis practical

One promising avenue for improving those stats is pre-exposure prophylaxis therapy, or PrEP. A combination of the HIV antivirals tenofovir and emtricitabine, it’s 99% effective preventing HIV when taken in pill form every day.

But for vulnerable populations, that’s often not possible or practical — for precisely the same reasons safe sex education hasn’t been effective.

“Taking a daily pill is difficult for any age group,” says Dr. Reirden, “but particularly for young adults and adolescents. And in some settings, asking a partner to use barrier protection or having a partner see you take a pill every day could put you at risk for interpersonal violence.”

Reaching hard-to-reach populations affected by HIV

The development of a long-acting injectable form of PrEP was a potentially promising solve. For clinical investigators like Dr. Reirden, the crucial component would be to test its effectiveness in those vulnerable populations.

One of three pediatric hospitals in the U.S. to participate in worldwide clinical trials, Children’s Colorado was tasked with bringing in a younger demographic, 18 to 24. The recruitment goal was a 50% Black, 10% transgender women sample.

“These are populations that have historically had reasons to be suspect of medical research,” Dr. Reirden notes. “In order for them to participate, they had to feel safe.”

Community study design

From the outset, Dr. Reirden and his team set up advisory boards that included members of the Black and transgender communities, who had a say in the protocol and study design. They helped reach out to participants and weighed in on inclusive language for the questions. They helped choose study sites around the world.

The research team recruited coordinators and volunteers to help participants navigate the healthcare system. They adjusted systems to make sure preferred pronouns would always be used. They hit their recruitment goals — and made some positive institutional changes in the process.

“This study actually began before Children’s Colorado created an Epic module to more easily use a person’s preferred pronouns and name,” says Dr. Reirden. “So some of the experience from this study informed how to roll out those chart enhancements effectively and consistently in our clinical populations.”

Establishing a PrEP routine

Administered every two months, the injectable therapy proved so effective the investigation team made the call to stop the trial.

“Oral PrEP is still effective. People taking either medication were seeing very few new cases,” says Dr. Reirden. “But the data analysis determined the injectable form was significantly more effective. We’re working to secure the injectable form for everybody in the study while the FDA goes through the process of approving this for clinical use.”

There’s more work to be done. The trial focused on those assigned male at birth; there will need to be trials for cisgender women as well. Studies in that population, and in younger adolescents ages 15 to 18, are ongoing.

But if those trials continue to show the same rates of success, Dr. Reirden hopes therapies like these will become a routine part of healthcare for sexually active teens and adults: get tested, get birth control, get PrEP.

“This is a fantastic first step,” says Dr. Reirden. “It’s an extremely important development in reaching the goal of eliminating HIV infection.”