When lenacapavir test results were presented at a World AIDS Conference in July 2024, experts were thrilled: Lenacapavir was hailed as a long-awaited breakthrough in the fight against HIV/AIDS.

"I [was] totally thrilled," said Clara Lehmann, who heads the German Center for Infection Research (DZIF) at the University Hospital of Cologne. "When these data were presented, there was an electrifying atmosphere in the hall. This was simply terrific."

What is special about lenacapavir?

Lenacapavir is an antiretroviral drug that is said to be almost 100% effective in the prevention and treatment of HIV infections.

As a preventative drug, also known as a prophylactic, it only needs to be injected twice a year, which makes administration much easier. Other prophylactics, such as cabotegravir (CAB), are injected every one to two months; Truvada has to be taken daily as a tablet.

But lenacapavir is also considered more discreet. Astrid Berner-Rodoreda, a post-doc researcher at the Heidelberg Institute of Global Health, said a twice-a-year injection can be a great relief for people who face stigmatization or where care constraints make it difficult for a person to take tablets every day.

Lenacapavir could, for example, benefit women and young girls for whom the HIV incidence is still extraordinarily high in some regions, according to UNAIDS.

How does lenacapavir work?

Lenacapavir is a so-called capsid inhibitor: The active ingredient disrupts the function of a vital protein of the virus so that it stops replicating.

And it works — in contrast to most antiretroviral agents — in several phases in the life of the HI-virus.

But lenacapavir can also cause "serious side effects," according to the US-government website, clinicalinfo.hiv.gov. These can include changes in your immune system. So, you should always consult a medical professional.

When will lenacapavir be available?

Lenacapavir has been approved in the US and EU for the treatment of HIV. But the drug has so far only been used in special circumstances and cannot yet be bought or freely prescribed as a prophylactic.

The manufacturer, Gilead, says it is waiting for approval of the drug as antiviral pre-exposure prophylaxis (HIV-PrEP), and this is expected to happen soon.

It is still unclear, however, whether lenacapavir will be that long-awaited turning point in the fight against AIDS. Experts say that lenacapavir will only become a breakthrough if it is used widely. And for that to happen, it would have to be much more affordable, they say.

How much will lenacapavir cost?

Gilead charges more than €37,870 (about $40,000) per person per year for the treatment. By comparison, other prophylactic HIV medication costs an average of €50-60 per month, or about €600-700 euros per year.

The pharmaceutical company says it needs to recoup its development costs for the drug. But experts and AIDS activists disagree. Astrid Berner-Rodoreda, for example, refers to calculations done by a British pharmacologist, Andrew Hill, at the University of Liverpool.

Hill has said that even with a profit margin of 30%, lenacapavir could be sold for as little as $40 per year — that's one thousandth of what Gilead wants to charge.

Where will lenacapavir be available?

Gilead is negotiating licenses with several generic drug manufacturers to produce and sell the drug more cheaply in low-income countries. The licenses could include 120 countries, including some in sub-Saharan Africa.

But some countries, such as Argentina, Brazil, Mexico and Peru, may not be part of this special licensing area, even though Gilead tested the drug in those regions. Berner-Rodoreda said this raises ethical and legal questions. The deputy director of UNAIDS, Christine Stegling, takes a similar view.

Presenting the 2024 UNAIDS report, Stegling said that such "groundbreaking innovations will only lead us to a real decline in new infections if we ensure that all people have access to them."

How big is the global HIV risk?

Health experts want to end the HIV epidemic by 2030. But we are a long way from that: More than 40 million people worldwide still live with the virus. Around 30 million are in treatment. That means a quarter of all known infections are untreated.

The number of new HIV infections worldwide fell by 22% between 2010 and 2021 — infections fell most in sub-Saharan Africa and South Asia.

But according to the new UNAIDS report, there were about 1.3 million people new infections in 2023. Infection rates continued to rise in Central and Eastern Europe, Central Asia, North Africa and the Middle East.

"We haven't made much progress in prevention, you have to say that really openly. If we really want to end the AIDS epidemic by 2030, then we would have to reduce the number of new infections to 370,000 next year," said Berner-Rodoreda.

HIV-related deaths fell by almost 40% between 2010 and 2021. In 2023, around 630,000 people died of AIDS-related illnesses. This is the lowest level since 2004.

What are the alternatives to lenacapavir?

Despite intensive research, there is still no vaccination against HIV. But there are some highly effective pre-exposure prophylactics that prevent HIV infection.

Although they are not quite as convenient to use as lenacapavir, existing PrEP medication has significantly reduced HIV rates in some countries.

But "[o]nly 15% of people who need PrEP received it in 2023," according to the UNAIDS report.

In poorer countries, some of which have the highest HIV rates, HIV prophylactics are often just too expensive.

Primary source:

UNAIDS: Take the right path to end AIDS - World AIDS Day report 2024 https: //www.unaids.org/sites/default/files/media_asset/take-the-rights-path-to-end-aids_en.pdf

This article was originally published in German.