A large clinical trial in
The trial tested whether the six-month injection of lenacapavir would provide better protection against HIV infection than two other drugs, both daily pills. All three medications are pre-exposure prophylaxis (or PrEP) drugs.
Physician-scientist
Tell us about the trial and what it set out to achieve
The Purpose 1 trial with 5,000 participants took place at three sites in
Lenacapavir (Len LA) is a fusion capside inhibitor. It interferes with the HIV capsid, a protein shell that protects HIV's genetic material and enzymes needed for replication. It is administered just under the skin, once every six months.
The randomised controlled trial, sponsored by the drug developers
The first was whether a six-monthly injection of lenacapavir was safe and would provide better protection against HIV infection as PrEP for women between the ages of 16 and 25 years than Truvada F/TDF, a daily PrEP pill in wide use that has been available for more than a decade.
Secondly, the trial also tested whether Descovy F/TAF, a newer daily pill, was as effective as F/TDF. The newer F/TAF has superior pharmacokinetic properties to F/TDF. Pharmacokinetic refers to the movement of a drug into, through, and out of the body. F/TAF is a smaller pill and is in use among men and transgender women in high-income countries.
The trial had three arms. Young women were randomly assigned to one of the arms in a 2:2:1 ratio (Len LA: F/TAF oral: F/TDF oral) in a double blinded fashion. This means neither the participants nor the researchers knew which treatment participants were receiving until the clinical trial was over.
In eastern and southern
During the randomised phase of the trial none of the 2,134 women
By comparison, 16 of the 1,068 women (or 1.5%)
The results at a recent independent data safety monitoring board review led to the recommendation that the trial's "blinded" phase should be stopped and all participants should be offered a choice of PrEP.
This board is an independent committee of experts
What is the significance of these trials?
This breakthrough gives great hope that we have a proven, highly effective prevention tool to protect people from HIV.
There were 1.3 million new HIV infections globally in the past year. Although that's fewer than the 2 million infections seen in 2010, it is clear that at this rate we are not going to meet the HIV new infection target that UNAIDS set for 2025 (fewer than 500,000 globally) or potentially even the goal to end Aids by 2030.
PrEP is not the only prevention tool.
PrEP should be provided alongside HIV self-testing, access to condoms, screening and treatment for sexually transmitted infections and access to contraception for women of childbearing potential.
In addition, young men should be offered medical male circumcision for health reasons.
But despite these options, we haven't quite got to the point where we have been able to stop new infections, particularly among young people.
For young people, the daily decision to take a pill or use a condom or take a pill at the time of sexual intercourse can be very challenging.
HIV scientists and activists hope that young people may find that having to make this "prevention decision" only twice a year may reduce unpredictability and barriers.
For a young woman
What happens now?
The plan is that the Purpose 1 trial will go on but now in an "open label" phase. This means that study participants will be "unblinded": they will be told whether they have been in the "injectable" or oral TDF or oral TAF groups.
They will be offered the choice of PrEP they would prefer as the trial continues.
A sister trial is also under way: Purpose 2 is being conducted in a number of regions including some sites in
It's important to conduct trials among different groups because we have seen differences in effectiveness. Whether the sex is anal or vaginal is important and may have an impact on effectiveness.
How long until the drug is rolled out?
We have read in a
The
We hope then that this new drug will be adopted into
We also hope we may begin to see the drug being tested in more studies to understand better how to incorporate it into real world settings.
Price is a critical factor to ensure access and distribution in the public sector where it is badly needed.
In an ideal world, governments will be able to purchase this affordably and it will be offered to all
Copyright 2024 The Conversation Africa. All rights reserved. Distributed by AllAfrica Global Media (allAfrica.com)., source