A monitoring board stopped the HIV Prevention Trials Network’ (a global collaborative network to find and test HIV interventions) study of the drug, called cabotegravir, early, per a news release from the World Health Organization (WHO).
The study involved over 3,200 women across seven countries in sub-Saharan Africa, and randomized participants into one of two study arms: an injection of cabotegravir every eight weeks and a daily, oral placebo, or an injected placebo plus a daily prophylaxis tablet that’s proven to prevent HIV infection.
The trial design pitted the two interventions against each other to compare their effectiveness.
Ultimately, the cabotegravir drug was 89% effective in preventing HIV infections in the study participants, who were aged 18 to 45. More specifically, 38 women developed HIV infections – but 34 of them were receiving the injected placebo. In other words, only four patients receiving the injected drug went on to still develop HIV infections.
“These results show that [the injected drug] is significantly more effective in preventing HIV acquisition than oral PrEP [the tablet] in an intention-to-treat analysis from this trial,” per the release.
Both interventions were well tolerated, per the WHO, with only mild or moderate adverse effects cropping up.
While the daily oral drug “has proven benefits in preventing HIV infection,” reads a separate study, the WHO noted that some women have a hard time keeping up with a daily tablet – which diminishes its effect. However, when women do take the oral drug consistently every day, it remains highly effective, per the WHO.
“Women in the countries where the trial was conducted and across East and southern Africa continue to experience high HIV incidence,” reads the WHO release. “More effective and acceptable HIV prevention choices for women are needed.”
For now, the drug will only be available to study participants until it undergoes further approval, per the WHO.
Following the results, the Joint United Nations Programme on HIV/AIDS (UNAIDS), also working to end HIV, said it was “strongly encouraged.”
“These results are hugely significant. UNAIDS has long been calling for additional, acceptable and effective HIV prevention options for women, and this could be a real game-changer,” said Winnie Byanyima, executive director of UNAIDS. “If donors and countries invest in rolling out access of injectable [pre-exposure prophylaxis] PrEP to women at higher risk of HIV, new infections could be dramatically reduced.”