US FDA authorises Merck's at-home antiviral Covid-19 pill

MARYLAND - The United States Food and Drug Administration (FDA) on Thursday (Dec 23) authorised Merck & Co's antiviral pill for Covid-19 for certain high-risk adult patients, a day after giving the go-ahead to a similar treatment from Pfizer Inc for high-risk patients above the age of 12.

Merck's drug, molnupiravir, developed with Ridgeback Biotherapeutics, was shown to reduce hospitalisations and deaths by around 30 per cent in a clinical trial of high-risk individuals early in the course of the illness.

The agency authorised the oral drug for the treatment of mild-to-moderate Covid-19 in adults who are at risk for severe disease, and for whom alternative Covid-19 treatments are not accessible or clinically appropriate.

The decision follows a narrow vote in favor of authorisation by a panel of advisers to the FDA on Nov 30.

Both the Merck and Pfizer pills could be promising tools for those who are sick with Covid-19, especially in the face of the fast-spreading Omicron variant, which is now dominant in the US.

"As new variants of the virus continue to emerge, it is crucial to expand the country's arsenal of Covid-19 therapies using emergency-use authorisation," said Ms Patrizia Cavazzoni, director of the FDA's Centre for Drug Evaluation and Research.

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The drug is not authorised for use in patients younger than 18 because molnupiravir may affect bone and cartilage growth, the FDA said. Pfizer's drug was authorised on Wednesday for people aged 12 and older.

Pfizer's antiviral regimen, Paxlovid, was nearly 90 per cent effective in preventing hospitalisations and deaths in patients at high risk of severe illness, according to trial data.

The lower efficacy of Merck's drug compared with Pfizer's treatment could hurt future sales.

The US government's contract for 10 million courses of the Pfizer drug at a price of US$530 (S$720) per course compares to the deal with Merck for as many as five million courses of molnupiravir at a price of US$700 per course.