A new drug to prevent HIV infection is showing hugely promising results in clinical trials when injected every six months.
In this episode of The Conversation Weekly podcast, we speak to South African HIV doctor and scientist Linda-Gail Bekker about her involvement in one of the trials for lenacapavir and why she thinks it could be so groundbreaking.
Thanks to advancements in prevention and treatment, global HIV infection rates have dramatically declined in recent years. But HIV still affects over 38 million people around the world.
Today, women are disproportionately affected by HIV, with young women at the highest risk. In 2022, adolescent girls and young women in sub-Saharan Africa represented over 77% of new infections among people aged 15 to 24.
One of the most important medical breakthroughs in the fight against HIV has been the use of antiretroviral treatments for prevention. Called pre-exposure prophylaxis (PrEP), this is commonly taken as a pill a day, and has been proven to reduce infection rates.
But the pill must be taken every day to be effective, which can be difficult for some people, as Linda-Gail Bekker, professor of medicine at the University of Cape Town in South Africa, explained.
Young people do talk about the rattling pills: 'I walk out of the clinic with a bunch of pill boxes that look like antiretrovirals, and it causes a stir, or my family want to know what's going on, or my boyfriend wants to know why don't I trust him.'
Bekker has been involved in a phase III, randomised control trial of a new drug, called lenacpaovir, taken as an injection every six months. The Purpose I study, sponsored by the drug manufacturer Gilead Sciences, included 5,000 women aged 16 and 25 years in Uganda and South Africa, and tested lenacapavir against two other PrEP drugs taken as a pill every day, called Truvada and Descovy.
We had such a good on-time injection rate that really this population of young women were never without their antiviral protection ... It was like always driving with your seat belt on, and always stopping at every stop sign.
Read more: HIV breakthrough: drug trial shows injection twice a year is 100% effective against infection
And it worked. None of the women who received lenacapavir during the randomised control part of the study contracted HIV, making it 100% efficient. This compared to 1.5% of those who took Truvada getting infected with HIV and 1.8% who took Descovy. Bekker said when she got the results she was astonished.
One has high hopes, but one does not imagine zeros, right? No infections in the lenacapavir arm literally reduced me to tears.
The results were so good that the safety monitoring board for the trial recommended unblinding it and offering everybody on the trial lenacapavir if they wanted it.
Initial results published in September by Gilead Sciences for a separate, Purpose 2 trial of men who have sex with men, transgender and non-binary people assigned male at birth showed 99% protection rates, with only two new cases of HIV among 2,180 people given lenacapavir.
While lenacapovir is approved as treatment of people with HIV, it's not yet approved for HIV prevention by medical regulators. The drug is currently priced at around US$42,000 (£31,600) a year if used as a treatment and Gilead Sciences is under pressure to lower the price.
The company has said $42,000 will not be a reference for the price of the drug if it gets approval for HIV prevention and that it's committed to develop a strategy that enables "broad, sustainable access globally".
In early October, Gilead signed licensing agreements with six generic drug manufacturers to make low-cost versions of lenacapavir for 120 countries, and said it would begin filing for regulatory approval for the drug by the end of 2024.
Listen to Linda-Gail Bekker talk more about the trial and the potential for a drug like lenacapavir on The Conversation Weekly podcast, plus an introduction from Nadine Dreyer, health and medicine editor at The Conversation Africa.
A transcript of this episode is available on Apple Podcasts.
This episode of The Conversation Weekly was written and produced by Mend Mariwany. Sound design was by Michelle Macklem, and our theme music is by Neeta Sarl. Gemma Ware is the executive producer.
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Gemma Ware, Host, The Conversation Weekly Podcast, The Conversation