New HIV injection approved in the US with near 100% effectiveness.

247 - The U.S. Food and Drug Administration (FDA) this week authorized the use of the drug lenacapavir — trade name Yeztugo, from the pharmaceutical company Gilead Sciences — as a new method of pre-exposure prophylaxis (PrEP) for HIV. This information comes from the InfoMoney website.

The treatment represents a significant advance in combating the transmission of the virus, being administered by injection only twice a year, with proven efficacy of up to 100% in clinical studies. Unlike the daily oral PrEP currently available, including in the Brazilian Unified Health System (SUS) since 2017, lenacapavir offers a less demanding alternative with the potential to increase adherence, especially among vulnerable populations.

Six-monthly treatment can expand preventive coverage.

The new formulation was approved in EUA For use in adults and adolescents weighing at least 35 kilograms. For Daniel O'Day, president and CEO of Gilead, the release represents "a historic day in the decades-long fight against HIV" and marks a concrete chance to "help end the epidemic."

Experts also highlight the impact of the new protocol. Carlos del Rio, professor at Emory University and co-director of the institution's AIDS Research Center, reinforces that lenacapavir "can be a powerful tool" by resolving obstacles such as stigma and difficulties with adherence. "A twice-yearly injection could very well resolve the main barriers [...] We also know that, in research, many people who need or want PrEP prefer less frequent dosing," he said.

Clinical results are impressive in terms of preventive effectiveness.

Lenacapavir was initially approved under the trade name Sunlenca to treat cases of HIV Resistant to multiple drugs. The new preventive application was tested in two large clinical studies.

The first study, called Purpose-1, involved 5,3 cisgender women in South Africa and Uganda. During the follow-up period, none of the participants who used the medication became infected, while 55 infections occurred among those who used daily oral PrEP.

The second study, Purpose-2, included 3,3 diverse participants—including cisgender men and transgender people—at research centers in Latin America, Asia, Africa, and the US. Two cases of infection were recorded among lenacapavir users and nine among those using oral treatment. When compared to a control population of 4,6 people without access to PrEP, the data indicated 96% efficacy of the new drug.

Both studies were published in the scientific journal New England Journal of Medicine.

Economic barriers and the debate on global access

Despite approval in the United States, the high price of lenacapavir still represents an obstacle to its widespread distribution. Currently, the annual cost of the drug is approximately US$40 per patient, which is around R$220. Studies published in The Lancet HIV estimate that generic versions could be produced for between US$35 and US$46.

In October, Gilead announced agreements with six manufacturers to produce generic drugs destined for 120 low- and middle-income countries with a high incidence of HIV — however, Brazil was left off the list.

UNAIDS Executive Director Winnie Byanyima urged the pharmaceutical company to adopt measures to expand access. "If this revolutionary drug remains inaccessible, it will change nothing. I urge Gilead to do the right thing. Lower the price, expand production, and ensure the world has a chance to end AIDS," she declared.

Mitchell Warren, CEO of the AVAC organization, reinforced: “Scientific progress only matters if the innovation actually reaches people [...] Otherwise, the world risks wasting this opportunity with PrEP, as has already happened with other options in the last 12 years.”

AVAC also noted that the journal Science named lenacapavir the "discovery of the year" in 2024, given the promising initial data.

Why isn't it considered a vaccine?

Although it works in preventing HIV infection, lenacapavir is not a vaccine. The main difference lies in the mechanism of action: while vaccines stimulate the immune system to produce lasting defenses, lenacapavir acts as an antiviral, blocking the multiplication of the virus directly. Therefore, it needs to be continuously present in the body, which requires periodic applications.

If administration is interrupted, protection against HIV disappears, unlike the immunological memory generated by traditional vaccines. To date, there is no HIV vaccine approved for human use.