US FDA authorises Pfizer’s Covid-19 pill as Omicron surges

WASHINGTON – The United States yesterday authorised Pfizer’s anti-Covid-19 pill for high-risk people aged 12 and up, as a surge of cases driven by the highly infectious Omicron variant threatened holiday plans and Americans struggled to find tests.

Paxlovid, which comprises two types of tablets, was granted an emergency use authorisation by the Food and Drug Administration (FDA) after it was shown in a clinical trial to reduce the risk of hospitalisations and deaths among at-risk people by 88%.

“Today’s action is a testament to the power of science and the result of American innovation and ingenuity,” President Joe Biden said in a statement, promising to invoke a law that would help Pfizer ramp up production quickly.

The US has spent $5.3 billion (RM22.3 billion) procuring 10 million courses of the treatment, with the first 265,000 to be delivered in January next year, and the rest by late summer, White House Covid-19 coordinator Jeff Zients told reporters on a call.

The FDA stressed the treatment should complement rather than replace vaccines, which remain the frontline tool against the coronavirus.

But pills that are available at pharmacies should be much easier to access than synthetic antibody treatments, which require infusions administered by drip at hospitals or specialised centres.

The European Union’s drug regulator last week allowed member states to use Pfizer’s Covid-19 treatment ahead of formal approval, as an emergency measure to curb an Omicron-fueled wave.

Omicron wave

The authorisation comes as cases are surging across the United States, driven by Omicron, the most infectious variant seen to date – and testing remains a challenge, with long lines reminiscent of the early part of the pandemic seen across US cities.

Companies including Amazon, Walgreens and CVS have capped how many home tests customers can buy. The Biden administration has promised to ship half a billion of the tests starting from next month, but experts have said that figure is too little and too late.

About 150,000 Americans are getting infected, 7,800 are being hospitalised and 1,200 are dying every day, according to the latest Centres for Disease Control and Prevention (CDC) data.

The highly mutated variant accounts for 90% of all cases in some US regions, CDC director Rochelle Walensky told reporters.

It is better able to bypass prior immunity, and health authorities are urging the public to get boosted with mRNA vaccines in order to restore a higher degree of protection.

Unlike vaccines, the Covid-19 pill does not target the ever-evolving spike protein of the coronavirus, which it uses to invade cells. It should therefore in theory be more variant-proof, and Pfizer has said preliminary lab studies have backed up that hypothesis.

Paxlovid is a combination of a new molecule, nirmatrelvir, and HIV antiviral ritonavir, that are taken as separate tablets.

Nirmatrelvir blocks the action of an enzyme the virus needs to replicate, while ritonavir slows down nirmatrelvir's breakdown, so it remains in the body for longer and at higher levels.

Synthetic antibody treatments developed by Eli Lilly and Regeneron are not effective against Omicron, top scientist Anthony Fauci told reporters, but an antibody treatment by GlaxoSmithKline (GSK) and a prophylactic antibody drug by AstraZeneca remain protective.

The US has bought a million courses of the GSK treatment, with 300,000 expected ready by January, and half a million doses of the AstraZeneca drug, which can be given preventatively to immune-compromised people who don’t respond as well to vaccines.

Authorisation is still awaited for another Covid-19 pill, developed by Merck, which is also taken over five days and has been shown to reduce hospitalisations and deaths by 30% among high-risk people.

Independent experts voted in favour of that treatment by a narrow margin, but expressed concerns surrounding its safety, such as potential harm to foetuses and possible damage to DNA.

The two treatments work in different ways inside the body, and Pfizer’s pill is not thought to carry the same level of concerns. – AFP, December 23, 2021