The results of the CHAPAS-3 trial were presented by Victor Musiime at the 6th International Workshop on HIV Pediatrics in Melbourne on 19 July. CHAPAS-3 looked into the safety and effectiveness of three different drugs used as part of a combination to treat children with HIV in Africa. One of the main findings from the trial was that children respond very well to HIV treatment, regardless of which specific treatment they receive, echoing the results of the ARROW trial.
There are more than 3 million children living with HIV, but only a third of those in need of treatment were receiving it by the end of 2012. This is well below the coverage of adults in need of HIV treatment. One of the problems with treating children is that there are fewer antiretroviral drugs available for children, particularly in acceptable formulations that small children can easily swallow. Children’s bodies absorb drugs at different rates to adults, so doses that work in adults may not be right for children. Children are also growing and developing, meaning that the same drugs may not always be suitable for adults and children.
HIV is usually treated with a combination of drugs from different classes, which target different stages of the virus’ life cycle. CHAPAS-3 set out to test three different drugs from the NRTI class. The current World Health Organisation guidelines for treatment of both adults and children recommend a combination of two NRTI drugs, together with a drug from another class. In CHAPAS-3, children were randomly allocated to one of three groups, to receive either:
abacavir + lamivudine + a drug from another class (NNRTI)
or zidovudine + lamivudine + a drug from another class (NNRTI)
or stavudine + lamivudine + a drug from another class (NNRTI)
The trial was carried out in Uganda and Zimbabwe, and 478 children took part. Three quarters of these children were starting HIV treatment for the first time, while the others had already been on stavudine-based treatment for a while. The average age of those children starting HIV treatment for the first time was 2.6 years. Children who had already been on treatment for a while had an average age of 6.8 years. The children were followed up for around 2.3 years.
Most of the children in the CHAPAS-3 trial did very well. Only 6% had to change any of their initial drugs through the course of the study due to side-effects. Only 1% had to change to a completely new combination due to the drugs no longer working. Less than 4% of children in the study died, all of whom were starting HIV treatment for the first time, which would be expected as some children were very sick with HIV when they started treatment.
The trial found no difference between the groups in terms of the number of illnesses and side-effects the children had over the 2.3 years. Most of these were infections such as colds, chest infections, pneumonia, malaria or sepsis. There were very few side-effects, and even fewer serious side-effects, and rates were similar in all three groups. There was also no difference in the numbers whose HIV disease worsened during the trial.
All three combinations of drugs did well at preventing the virus levels from increasing. Almost 100% of children who were already on treatment at the start of the trial, and the majority of those starting treatment for the first time, having very low virus levels at the end of the trial, regardless of which specific drugs they took.
The CHAPAS-3 trial has shown that HIV treatment which includes abacavir, zidovudine or stavudine , given as fixed-dose combination tablets, has low side-effects and works well. This echoes the results of the ARROW trial. Children respond well to HIV treatment, and the researchers are now urging national governments and donors to make sure all who need it can access HIV treatment.