Pfizer’s at-home pill to treat Covid cuts risk of dying by nearly 90%, firm says

Pfizer today claimed its Covid pill cuts the risk of severe illness by nearly 90 per cent, potentially providing the UK with another weapon to combat the pandemic. 

Its twice-a-day antiviral was shown in clinical trials to slash the risk of hospitalisation or deaths by 87 per cent in vulnerable and elderly patients.

The pharmaceutical giant stopped its study of the drug — known as Paxlovid —early because of the promising results. 

The findings appear to surpass those seen with Merck’s rival pill molnupiravir, which data showed halved the risk of death or hospitalisation.

Paxlovid can be taken at home and is given in combination with an older antiviral called ritonavir, which is used to treat HIV/AIDS. 

Pfizer, which described its findings as a ‘game-changer’ now plans to apply for approval from American medical regulators in the coming days. 

The firm will likely also seek approval in the UK, where the Government has already purchased 250,000 courses.

It comes after Britain became the first country in the world to approve Merck’s antiviral on Thursday, which will be rolled out on the NHS within weeks.

The combination treatment, which will have the brand name Paxlovid, consists of three pills given twice daily.

The planned analysis of 1,219 patients in Pfizer’s study looked at hospitalizations or deaths among people diagnosed with mild to moderate Covid with at least one risk factor for developing severe disease, such as obesity or older age.

It found that 0.8 per cent of those given Pfizer’s drug within three days of symptom onset were hospitalised and none had died by 28 days after treatment. 

For comparison, the hospitalisation rate stood at 7 per cent for the patients given a placebo. There were also seven deaths in the placebo group.

Rates were similar for patients treated within five days of symptoms.

Antivirals need to be given as early as possible, before an infection takes hold, in order to be most effective. Merck tested its drug within five days of symptom onset.

‘We saw that we did have high efficacy, even if it was five days after a patient has been treated… people might wait a couple of days before getting a test or something, and this means that we have time to treat people and really provide a benefit from a public health perspective,’ Annaliesa Anderson, head of the Pfizer program, said.

The company did not detail side effects of the treatment, but said adverse events happened in about a fifth of both treatment and placebo patients.

‘These data suggest that our oral antiviral candidate, if approved by regulatory authorities, has the potential to save patients´ lives, reduce the severity of Covid infections, and eliminate up to nine out of ten hospitalizations,’ Pfizer’s chief executive Albert Bourla said.

Pfizer’s drug, part of a class known as protease inhibitors, is designed to block an enzyme the coronavirus needs in order to multiply.

Merck’s molnupiravir has a different mechanism of action designed to introduce errors into the genetic code of the virus. 

Merck has already sold millions of courses of the treatment, which was approved this week by UK regulators, to the US, Britain and others.

Britain said earlier this month it had secured 250,000 courses of Pfizer’s antiviral.

Pfizer is also studying whether its pill could be used by people without risk factors for serious Covid as well as to prevent coronavirus infection in people exposed to the virus.