A tale of two antiviral targets — and the COVID-19 drugs that bind them
COVID-19, for all of the problems it has created, has shown the unprecedented speed with which drug developers can move. Vaccines and bespoke antibodies were among the first responders on the COVID-19 scene, authorized just under 11 months from the release of the SARS-CoV-2 sequence. Now oral antivirals, from Pfizer and Merck & Co., are set to make their mark.
Pfizer’s contender, paxlovid, went from a compound in a freezer and optimization ideas on a drawing board to a regulatory submission in just 20 months. “It was a quick journey,” says Mikael Dolsten, Pfizer’s chief scientific officer. “In the normal development of a small-molecule programme, that would take 8–10 years,” he notes.
Merck’s molnupiravir was already a preclinical candidate when COVID-19 struck, but also a beneficiary of a development sprint.
The FDA is now considering both drugs for Emergency Use Authorization (EUA). An FDA advisory committee voted 13 to 10 in favour of an EUA for molnupiravir on November 30th, preparing the way for an approval decision in the coming weeks. The EMA is reviewing molnupiravir too, and an application from Pfizer there is imminent.
Preliminary data suggest that both offer benefits over Gilead’s remdesivir — an intravenously injected antiviral that secured an EUA in May 2020 and full FDA approval in October 2020 for hospitalized patients. This antiviral had already been derisked in clinical trials before the pandemic started. It is not widely used outside the USA.
The arrival of oral antivirals that can be used in non-hospitalized patients is raising the hopes of infectious diseases experts.
