{UAH} A NEW DRUG TO EFFECTIVELY PREVENT HIV INFECTION

'Huge relief' as new drug found to effectively prevent HIV infection

Story by DPA International

An employee of the aid organisation Doctors Without Borders (MSF) in Nambiri in South Sudan explains the basics of how the HI virus works. Worldwide, 39.9 million people are living with the virus, the majority in sub-Saharan Africa, according to the UN programme UNAIDS. Anna Kerber / dpa© DPA International

Avaccination with the drug lenacapavir offers an effective protection against a HIV infection, according to newly published research from the pivotal phase-three study "Purpose 2".

The option to vaccinate against HIV only every six months is a genuine breakthrough, said Astrid Berner-Rodoreda from the University Hospital of Heidelberg in response to the finding, published in the New England Journal of Medicine (NEJM).

Lenacapavir, a relatively new drug, provides lasting protection against HIV infection and requires a booster injection be given every six months. This marks a stark contrast to current HIV pre-exposure prophylaxis (PrEP) drugs such as Truvada, which have to be taken daily as a tablet.

Having to be vaccinated twice a year is much more convenient than having to remember to take a tablet every day, says Berner-Rodoreda.

Tablets raise suspicions

In addition, tablets have been known to attract attention. Especially in some countries severely affected by HIV, there is a risk that others will assume you are HIV-positive when you start taking tablets daily.

An injection administered only twice a year is much easier to keep secret. Therefore, there is no question that lenacapavir is a "huge relief" for many people, Berner-Rodoreda said.

Like the previous study, Purpose 1, the evaluation was terminated early due to the promising results, in order to be able to make the drug available to all subjects, according to the manufacturer Gilead.

The company now plans to apply for approval of lenacapavir as HIV protection in numerous countries. Efforts are also being made to ensure that it is available in poorer countries.

Similar protection level

The drug will be offered prophylactically to people at high risk of HIV infection. It inhibits the life cycle of the virus at several stages of infection.

Max von Kleist from the Free University of Berlin explained that in terms of efficiency, lenacapavir is comparable to Truvada. Both offer excellent, almost complete protection.

The results of the two "Purpose" studies suggest that there are proportionately more infections in the control groups that were given tablets, but the data is misleading, explained the head of the Mathematics for Data Science research group.

In many cases, the tablets were not taken regularly or were not taken at all, especially towards the end of the study period. It is not surprising that infections then occur.

Lenacapavir is already approved in the EU for the antiviral treatment of certain patients who are already infected, but has not been launched by Gilead for preventative purposes. It is currently unclear in exactly which countries it will be available in this capacity.

In any case, it is of great importance, especially for poorer countries, such as for women in sub-Saharan Africa.

Will it be affordable for those who need it most?

There is a problem in terms of cost, however. When used to treat existing infections, lenacapavir costs around $42,000 per year in the US. At this price, it would be beyond unaffordable for people in poorer countries.

It is crucial that access nevertheless be provided for such countries where the drug is really urgently needed, says Berner-Rodoreda. Activists have been protesting against Gilead, arguing they are leveraging a monopoly on HIV drugs for profit.

The question of who should be given lenacapavir and under what circumstances must be carefully considered in each case, von Kleist says.

This is because there is a risk of a drug resistance developing, as there generally is with such active ingredients. The particular problem with lenacapavir is that the active ingredient can still be detected in the body for about a year after vaccinations have been stopped. "This promotes the development of resistances."

A pathogen can become resistant if the dose of an active ingredient is insufficient to eliminate it.

Follow-up treatment

It may be necessary to continue taking Truvada for a year after stopping lenacapavir to prevent the development of resistance in the event of infection during this period, according to von Kleist.

The risk of this happening with Truvada is low. It disappears from the body within a week of stopping treatment.

"Purpose 2" included almost 3,300 HIV-negative people who had sex frequently. Two people in the lenacapavir group (approx. 2,200 subjects) and nine in the group treated with Truvada for comparison (approx. 1,100 subjects) became infected with HIV, according to the journal.

Lenacapavir thus reduced the risk of infection by 96% compared to the background incidence. Both drugs were generally well tolerated.

In July, promising results from the Phase III "Purpose 1" study were presented at the International AIDS Conference in Munich and in the NEJM.

Around 5,300 HIV-negative girls and young women in South Africa and Uganda were involved in the study. Among the 2,100 participants who were injected with lenacapavir twice a year, there were no infections.

In control groups with around 3,200 participants who had taken other drugs for prevention, there were 55 HIV infections.

Cure still not possible

The HI virus weakens the immune system and makes the body susceptible to various illnesses. The resulting condition is called AIDS. With early diagnosis and treatment, those infected have a practically normal life expectancy.

However, in most cases the infection cannot be completely eliminated, which is why lifelong use of virus-inhibiting medication is necessary.

According to a UN report presented on Tuesday, the number of HIV infections is increasing in 28 countries. Worldwide, 39.9 million people are living with the virus, the majority in sub-Saharan Africa, according to the UN programme UNAIDS.

In 2023, 630,000 people died in connection with AIDS and 1.3 million people were newly infected with the HI virus.