Dear HIV, Meet Your Remedy??

Just recently, scientists made a groundbreaking discovery that may prove an invaluable ally in our decades-long fight against the HIV epidemic that plagues much of the world. 

Gilead Sciences' Lenacapavir has achieved considerable results and received the final nod of approval from the US Food and Drug Administration (FDA). Global health leaders have even begun cautiously talking about the end of the war against HIV, which has claimed about 600,000 people every year.

How Does This Wonder Drug Work?

Firstly, it’s worth highlighting that this drug, Lenacapavir, is an injectable HIV-1 capsid inhibitor and is a pre-exposure prophylaxis (PrEP).

In English, the drug is administered through a shot, not a pill. As a matter of fact, one of Lenacapavir's biggest advantages is that it only needs to be injected once every 6 months, unlike the daily pills used in traditional HIV treatment or prevention. This feat might make the drug especially useful in low-resource or high-risk communities.

Now, moving on to the science: A HIV virus’s genetic material is contained within a “capsid”, which is effectively a protective shell; Lenacapavir is a capsid inhibitor, meaning it rigidifies that protective shell, which stops the virus from copying itself and infecting more cells in the body. This is what makes Lenacapavir different from older HIV drugs, making it useful even if the HIV virus becomes resistant to other treatments.

(This development comes through many years of research into the structure and function of the HIV's capsid protein.)

However, as a PrEP, patients must take medicine before they’re exposed to a virus, to prevent infection. 

What are the Results?

Thus far, Lenacapavir as a PrEP has been effectively used by people at risk of HIV infection to stay HIV-negative.

Within a Lenacapavir trial called PURPOSE 1, early results shockingly indicated 100% efficacy. Yes, that’s right. In a study that involved 5,300 cisgender women in South Africa and Uganda, Gilead Sciences revealed that not a single woman who had received the drug had contracted HIV.

Within PURPOSE 2, a study sponsored by Gilead Science, the drug was found to be 96% effective in preventing HIV infections in the newly released results of a clinical trial of more than 3,200 cisgender men, transgender men, transgender women and gender non-binary individuals. The study was geographically diverse as it was conducted across sites in Argentina, Brazil, Mexico, Peru, South Africa, Thailand and the United States.

Not the First … But Still!

Technically, the current standard of care for HIV prevention - taking a pill called Truvada every day - has also been shown to be 99% effective in blocking HIV infections from sex in clinical trials. This type of drug is also a pre-exposure prophylaxis (PrEP).

In 2021, the FDA had also previously approved an injectable form of PrEP medication called cabotegravir, but patients needed to receive it every two months, and a health care provider needed to administer an intramuscular dose into the buttocks. 

Lenacapavir itself is not even a new drug: It's been approved by the FDA in the United States for multi-drug resistant HIV treatment since 2022. Back when Lenacapavir was used in combination with other drugs to fully suppress the HIV virus, Lenacapavir also lacked an equally durable drug to build a complete twice-yearly regimen and had to be used with daily oral antiretrovirals. However, what is new is that the  PURPOSE 1 and PURPOSE 2 clinical trials were the first to specifically test Lenacapavir for HIV prevention. According to Gilead Sciences, the data from these two trials will now be used to support a series of global regulatory filings which will begin by the end of 2024, which could launch this game-changing drug onto the market by this year!

The Catch?

The most promising thing about PrEP drugs is: Should we reach a critical threshold regarding usage in a population, it can significantly reduce overall transmission rates, especially when targeted to those at highest risk. 

(Think of how vaccines work by triggering the immune system to destroy pathogens before they can spread; if enough people are immune, the disease has nowhere to go—this is classic herd immunity. While PrEP like Lenacapavir doesn’t eliminate the virus or make people immune, it still protects the individual from infection while they are taking it, so widespread use of PrEP reduces new infections, especially in high-transmission networks!)

However, current CDC data show that the US population is not yet using PrEP at rates that could end transmission of the virus; sadly, the data points to barriers including adherence challenges, stigma and low awareness of existing PrEP options by healthcare providers and consumers.

Even so, it is possible that Lenacapavir, a twice-yearly injection that requires less frequent dosing, could address the key barriers above like adherence and stigma. This could particularly help individuals who were previously on more frequent PrEP dosing regimens, especially daily oral PrEP.

Reference List‌

aidsmap.com. (2025). Lenacapavir plus broadly neutralising antibodies could be twice-yearly HIV treatment. [online] Available at: https://www.aidsmap.com/news/mar-2025/lenacapavir-plus-broadly-neutralising-antibodies-could-be-twice-yearly-hiv-treatment.

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American Association for the Advancement of Science (AAAS). (2025). The Road to Lenacapavir, a Breakthrough HIV Treatment | American Association for the Advancement of Science (AAAS). [online] Available at: https://www.aaas.org/news/road-lenacapavir-breakthrough-hiv-treatment.

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clinicalinfo.hiv.gov. (2024). Lenacapavir - | NIH. [online] Available at: https://clinicalinfo.hiv.gov/en/drugs/lenacapavir/patient.

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Cox, D. (2024). This drug is the ‘breakthrough of the year’ -- and it could mean the end of the HIV epidemic. [online] NPR. Available at: https://www.npr.org/sections/goats-and-soda/2024/12/12/g-s1-37662/breakthrough-hiv-lenacapavir.

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Gilead.com. (2025). Yeztugo Lenacapavir Is Now the First and Only FDA Approved HIV Prevention Option Offering 6 Months of Protection. [online] Available at: https://www.gilead.com/news/news-details/2025/yeztugo-lenacapavir-is-now-the-first-and-only-fda-approved-hiv-prevention-option-offering-6-months-of-protection.

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Jarvis, L. (2025). HIV Scientific Drug Lenacapavir Breakthrough Isn’t Enough. [online] Bloomberg.com. Available at: https://www.bloomberg.com/opinion/articles/2025-07-06/hiv-scientific-drug-lenacapavir-breakthrough-isn-t-enough?cmpid=070625_morningapac&utm_medium=email&utm_source=newsletter&utm_term=250706&utm_campaign=morningapac [Accessed 11 Jul. 2025].