Once-weekly HIV pill matches daily therapy in phase 3 trial

An experimental once-weekly HIV tablet maintained viral suppression as effectively as standard daily treatment over 48 weeks in a large international phase 3 trial. If approved, the islatravir-lenacapavir combination could become the first complete oral HIV regimen taken weekly, reducing dosing for eligible patients from about 365 times a year to 52.

The trial involved 626 adults at 100 sites across 14 countries and territories. Among 314 participants who switched to the weekly tablet, one had a viral load of at least 50 copies per millilitre after 48 weeks. That compared with four of the 312 participants who remained on daily therapy. Median adherence to the weekly regimen was 100 percent, and those who switched reported greater treatment satisfaction and a lower perceived burden.

The findings apply to a carefully selected group. All participants already had suppressed HIV, had received treatment for at least six months and had no history of treatment failure. The study therefore offers less evidence about people beginning treatment, those with detectable virus or those with drug resistance.

Treatment-related side effects were more common with the weekly pill, affecting 18 percent of recipients compared with less than 1 percent on daily therapy. Most were mild or moderate, including headache, nausea and diarrhoea. The treatment remains investigational, with participants being followed through 96 weeks for longer-term results.