Clinical Trial shows twice a year injection more effective with HIV prevention

As often the case with treating or preventing medical conditions, consistency is key with prescription drugs. Specifically, when dealing with a new HIV infection, only by taking regular doses of oral antiretrovirals, more commonly referred to as PrEP (pre-exposure prophylaxis), can patients expect to have an effective defense against HIV. Missing even a daily dose of medications, such as Truvada, could mean greatly compromising an otherwise reduced risk in contracting the virus.

However, in a recent Gilead-funded clinical trial led by physicians at Emory University and the Grady Health System, results have been found that a twice-yearly injection of a new drug called Lenacapavir would offer a 96 percent reduced risk of infection overall, making the medication significantly more effective than the daily oral PrEP.

In the randomized, double-blind, Phase III clinical trial comparing the efficacy of the two medications, Lenacapavir and Truvada, 99 percent of the participants in the Lenacapavir group did not acquire an HIV infection. Of the 2,179 people the group comprised, only two participants contracted an HIV infection. Compared to the nine new HIV infections in the Truvada group, which had 1,086 people, the trial showed that adherence to the injectable was higher than of the daily oral pill.

“Seeing these high levels of efficacy, at almost 100 percent, in an injectable that people only have to take every six months is incredible,” says Colleen Kelley, MD, lead author of the study and professor in the School of Medicine at Emory University. “This is a considerable and profound advancement in medicine, especially for people whose circumstances don’t allow them to take a daily oral medication, and for those among populations disproportionately impacted by HIV.” 

Kelley, also the co-director of the Emory Center for AIDS Research, and associate dean for research for Emory at Grady added that while PrEP is incredibly effective at preventing infection, part of what made the injection more effective in the clinical trial was the challenges associated with adherence to a daily oral pill.

The trial groups included cisgender men and gender-diverse people at 88 sites in Peru, Brazil, Argentina, Mexico, South Africa, Thailand and the United States. The inclusion of racially, ethnically and gender-diverse participants in the clinical trial, all with different circumstances In being able to access daily medication, is notable because it was representative of populations disproportionately impacted by HIV in real time.

“What we see over time is that about half of people who start taking daily oral PrEP stop within a year due to various factors,” says Kelley, referencing healthcare disparities in general. “Having an effective injectable that is only needed twice annually is very significant for people who have trouble accessing healthcare or staying adherent to daily, oral pills.”