On the eve of the International AIDS conference in Munich, scientists report that another person has been cured of AIDS via a stem cell transplant and impressive success in HIV prevention via trials of long-action injectable pre-exposure medication – yet funding cuts threaten global HIV goals.

UNAIDS economist Erik Lamontagne said that HIV could cost low- and middle-income countries (LMICs) over $10,000 per person by 2050, with almost 35 million new HIV acquisitions and nearly 18 million AIDS-related deaths between 2021 and 2050 without “bold action”.

The projections are based on the failure of 114 key LMICs to meet the “95-95-95” targets – 95% of people who are living with HIV knowing their HIV status, 95% of these people on antiretroviral treatment, and 95% of those on treatment being virally suppressed.

Seventh AIDS cure via stem cell transplant

Christian Gaebler of Charité Universitätsmedizin Berlin told a media briefing on Thursday  that a seventh person had been cured of AIDS following a stem cell transplant with from a donor carrying genes that are partially resistant to HIV. 

The Berlin-based patient had leukaemia and HIV. and his doctors looked for a donor with the particular gene mutuation – referred to as double, CCR5-delta32 mutation – known to have cleared HIV in other patients.

“In 2015 when it became clear that our patient required the stem cell transplantation for his cancer treatment, the clinical team began searching for donors with this rare genetic mutation known as the homozygous CCR5-delta32 mutation, because we know that this mutation provides natural resistance to HIV, and it has been a crucial part in the successful HIV cure cases,” said Gaebler.

However, the clinical team was only able to find a donor carrying one functional as well as one copy of the CCR5-delta32 mutation, known as a heterozygous donor, he added.

The transplant went ahead and the patient, who has asked to be anonymous, has been AIDS free since 2018, almost six years.

This is the seventh recorded case of a person being cured of HIV via a stem cell transplant, the first being the “Berlin patient”, who later revealed himself as Timothy Brown.

“The next Berlin Patient’s experience suggests that we can broaden the donor pool for these kinds of cases, although stem cell transplantation is only used in people who have another illness, such as leukaemia. This is also promising for future HIV cure strategies based on gene therapy, because it suggests that we don’t have to eliminate every single piece of CCR5 to achieve remission,” said Sharon Lewin, President of the International AIDS Society, and co-director of the conference, which begins in Munich on Monday.

Prevention advances with PrEP

Last month, news broke that none of the over 2,000 young women and girls injected twice a year with a new drug, lenacapavir, had contracted HIV in one of the most important advances in HIV prevention ever.

Gilead Sciences announced the preliminary results of its Phase 3 PURPOSE 1 trial of lenacapavir as pre-exposure prophylaxis (PrEP) conducted in South Africa and Uganda involving 2,134 women and girls aged 16-25.

The trial was so successful that it was stopped early, and details of the trial will be released at the AIDS conference next week.

Results of another, smaller PrEP study of the antiretrovial cabotegravir – where participants were given a choice between pills or an injection  – showed that many participants preferred a long-acting injection rather than daily pills.

The study recruited young men and women aged 15 and older in rural Uganda and Kenya who were vulnerable to HIV infection.

Ugandan scientist Jane Kabani told the media briefing that participants two-thirds of participants opted for the long-acting injection as they did not want to be questioned about why they were taking pills. Some also feared the side effects of pills.

“Long-acting PrEP has the potential to strengthen HIV prevention progress worldwide. I hope these results will accelerate efforts to make long-acting injectable cabotegravir available and accessible to all those who can benefit,” Lewin said.

PrEP to prevent STIs

Another study using the antibiotic doxycycline to prevent sexually transmitted diseases (STIs) showed impressive results in a small study in Canada, as presented by Tony Grennan of the British Columbia Centre for Disease Control.

The study recruited 52 gay, bisexual and other men who have sex with men living with HIV in Vancouver and Toronto. Half took 100 milligrams of doxycycline daily for the prevention of STIs and the other took a placebo for 48 week. 

“There was an 80% reduction in any of the three STIs we were looking” said Grennan. “Breaking it down by specific infection, there was a 79% reduction in syphilis, a 92% reduction in chlamydia and a 68% reduction in gonorrhea in the Doxy PrEP arm.”

He added that there was “no signal of concern” about antibiotic resistance “but the numbers were very, very small, so it’s really hard to draw any definitive conclusions”.

“We’re seeing impressive innovation across the entire spectrum of HIV research,” noted 

Lewin. “For these advances to have a real-world impact, we must put people first and keep delivery and access concerns front and centre.”

Image Credits: UNICEF Zimbabwe, NIAID/Flickr.