An experimental pill to treat Covid developed by pharmaceutical giants, Pfizer cuts the risk of hospitalisation or death by 89% in vulnerable adults, the company has announced.
The drug – Paxlovid – is intended for use soon after symptoms develop in people at high risk of severe disease.
Pfizer says it stopped trials early as the initial results were so positive.
The positive news comes a day after the UK medicines regulator approved a similar treatment from Merck Sharp and Dohme (MSD).
The UK has already ordered 250,000 courses of the new Pfizer treatment along with another 480,000 courses of MSD’s molnupiravir pill.
The Pfizer drug, known as a protease inhibitor, is designed to block an enzyme the virus needs in order to multiply. When taken alongside a low dose of another antiviral pill called ritonavir, it stays in the body for longer.
Three pills are taken twice a day for five days.
Unlike the Pfizer drug, the Merck pill introduces errors into the genetic code of the virus.
Pfizer said it plans to submit interim trial results for its pill to US drug regulator, the FDA, as part of the emergency use application it started last month.
