HIV Prevention Drug from ViiV Healthcare Disguised Infections

A re-examination of blood samples taken during a clinical trial found that ViiV Healthcare’s investigational HIV prevention drug cabotegravir actually cloaked infections and fueled infection resistance in rare cases, according to a study published in Nature.

While the bi-monthly injection kept nearly all participants in the 4,570-person clinical trial free of the infection, four people contracted HIV.

Researchers believe the drug suppressed the virus enough to prevent HIV tests from detecting it during early stages of infection. Sensitive tests that measure RNA from HIV later showed that the participants had been infected for six to 16 weeks before regular, monthly HIV diagnostics identified the infection. Additionally, the four patients developed resistance to cabotegravir and similar therapies.

The study findings come just as several other potent HIV preventative drugs — called pre-exposure prophylaxis or PrEP drugs — are entering clinical trials.