“
crucial in

widening African

children’s access

to antiretrovirals

”

Bringing antiretroviral drugs to children

The CHAPAS trials have ensured that many more children with HIV have benefited
from life-saving antiretrovirals.

The challenge

Young women are twice as likely as young men to acquire HIV. Every year since 2010, they have accounted for two thirds of new infections among adolescents. In some parts of sub-Saharan Africa, women are up to eight times more vulnerable to HIV than young men.

Pre-emptive use of antiretroviral drugs – pre-exposure prophylaxis (PrEP) – can be a highly effective way to prevent HIV infection. However, results with women have been inconsistent, mainly because of a lack of adherence to the daily drug-taking that PrEP requires.

To provide women with an improved option for PrEP, the CAPRISA 018 study is evaluating an innovative sustained-release antiretroviral implant. A new implant is being developed incorporating tenofovir alafenamide (TAF), a highly potent antiretroviral with fewer unwanted side effects than earlier drugs.  

The CAPRISA 018 team is evaluating an implant that would last six months. It will carry out preparatory studies to examine the safety, acceptability and pharmacokinetics of the TAF implant, and to gather initial data on its efficacy for HIV prevention. A randomised controlled trial will then be carried out on nearly 500 at-risk women.  

The project

The later CHAPAS-3 trial compared the efficacy and safety of three fixed-dose combinations including two without stavudine (found to have some long-term side effects in adults, leading to a recommendation that its use be discontinued in children). The trial the first of its kind in Africa studied nearly 500 children at four sites in two African countries.

The CAPRISA 018 study will create a safe intervention that enables women to take control of HIV prevention. Positive results in the initial trial would pave the way to a large-scale phase III trial that would provide definitive evidence of the ability of a TAF implant to prevent HIV infection. As sub-dermal implants are already widely available through family planning service in several sub-Saharan African countries, implementation could be relatively straightforward. 

ratios forfixed-dose combinations and on appropriatedosage according to weight. 

The CHAPAS-3 trial confirmed the effectiveness of fixed-dose combinations, providing further impetus to the rollout of antiretrovirals to children. Its evidence on abacavir informed the WHO recommendation of abacavir-containing combinations for first-line therapy in children. Trial data have also been used to support applications for regulatory approval for new scored efavirenz tablets.

Impact