SA researchers make major breakthrough in HIV prevention

In a multi-country trial which involved Kenya and Uganda, researchers from South Africa’s University of the Witwatersrand have made a major breakthrough in the prevention of new HIV/Aids infections.

The university’s Reproductive Health and HIV Institute has developed an injectable preventative treatment lasting eight weeks and which has been found to be at least 90 per cent effective in halting new infections.

The new treatment, which has been tested on men and women separately, allows those having intimate relations with people living with HIV not to take daily preventative medications, ensuring much higher levels of compliance in treatment, another huge advantage of the new method.

Initial results from clinical trials show that taking an injection of PrEP and CAB LA once every eight weeks is more effective than taking a daily pill to prevent HIV among women.

Affordability

But researchers are grappling with how to make it widely accessible to people who might not be able to afford it, though final pricing has yet to be established.

“The company that makes cabotegravir (the name of the new treatment drug) has not allocated a cost yet. But what they have articulated is the importance of access, particularly in low and middle-income countries in the region where HIV is more prevalent,” said Prof Sinead Delany-Moretlwe, Director of the RHI at the University of the Witwatersrand in Johannesburg.

Researchers also warn that it will take some months before the drug is available.

“We are not looking at something that is going to be available immediately. But this is going to be fast-tracked, both from the clinical research point of view and the manufacturing side,” said Prof Helen Rees, an internationally renowned vaccine, HIV and reproductive health expert who also worked on the study.

“Access in a country like ours, with such high numbers (of new HIV infections) every year, could be a game-changer. But we will have to have a little bit of patience,” she added.

The research was conducted in several countries including South Africa, Kenya, Uganda, Botswana, Malawi, Swaziland and Zimbabwe.

The intention is to roll out the new treatment across the entire Sub-Saharan region before taking it to other countries.

The trial of the pre-exposure prophylaxis regimen of long-acting cabotegravir (CAB LA) injections, once every eight weeks, was found to be both safe and superior to daily oral tenofovir/emtricitabine (TDF/FTC), currently used for HIV prevention among women in Sub-Saharan Africa.

Nine times more effective

The injectable treatment was shown to be up to nine times more effective in preventing new HIV infections, even though the oral treatment, when taken regularly, is still considered ‘highly effective’ in preventing HIV transmission.

The study, known as the HPTN 084 trial, headed by Prof Delany-Moretlwe, has been reviewed by an independent data and safety monitoring board which recommended that the study’s sponsor – the National Institute of Allergy and Infectious Diseases (NIAID), part of SA’s National Institutes of Health – stop the blinded phase of the trial, which was originally designed to continue through 2022, and share the results.

This is an unusual step with wide scale safety and efficacy tests, and one only taken when the treatment involved shows such clear efficacy, and there are so few or minor negative reactions to it, that continuing with a trial, in which half of the people receive a non-effective ‘placebo’, is considered unethical.

The NIAID accepted those recommendations and has released the results in the broader public interest, it said.

Additional option

“The results … are incredibly important for women in Africa where lowering HIV incidence remains a priority,” said Prof Delany-Moretlwe.

“We know that adherence to a daily pill continues to be challenging, and an effective injectable product such as long-acting CAB is a very important additional HIV prevention option for them,” she added.

“These results are a milestone for prevention of HIV among women at risk of HIV worldwide and especially for women in Sub-Saharan Africa,” said Prof Rees.

Wits University has long been recognised as a global leader in HIV research and has contributed substantially to the fight against the pandemic.

“This incredible breakthrough will certainly save the lives of many women living in Sub-Saharan Africa, and beyond,” said Prof Zeblon Vilakazi, Vice-Chancellor and Principal Designate of Wits University.