A trial of Pfizer Inc’s experimental antiviral pill for COVID-19 was stopped early after the drug was shown to reduce the chances of hospitalization or death of adults at risk of developing a serious illness by 89%, the company said. Friday.
Full test data is not yet available from any of the companies.
Pfizer said it plans to send the results of the interim trial of its pill, which is given in combination with an older antiviral called ritonavir, to the US Food and Drug Administration as part of the emergency use application it opened. in October.
The combination treatment, which will be branded Paxlovid, consists of three pills administered twice a day.
The planned analysis of 1,219 patients in the Pfizer study looked at hospitalizations or deaths among people diagnosed with mild to moderate COVID-19 with at least one risk factor for developing a serious illness, such as obesity or old age.
It found that 0.8% of those who received the Pfizer drug within three days of symptom onset were hospitalized and none had died within 28 days of treatment. That compared to a 7% hospitalization rate for placebo patients. There were also seven deaths in the placebo group.
Rates were similar for patients treated within five days of symptoms: 1% of the treatment group was hospitalized, compared with 6.7% for the placebo group, which included 10 deaths.
Antivirals must be given as soon as possible, before an infection occurs, to be most effective. Merck tested their drug within five days of the onset of symptoms.
“We saw that we had high efficacy, even if it was five days after a patient was treated … people can wait a couple of days before getting tested or something like that, and this means we have time to treat people and they really provide a benefit from a public health perspective, “Annaliesa Anderson, director of the Pfizer program, told Reuters.
The company did not detail the side effects of the treatment, but said adverse events occurred in about 20% of the placebo and treated 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-19 infections, and eliminate up to nine out of ten hospitalizations,” said Albert Bourla, CEO of Pfizer. it said in a statement.
Pfizer said it currently expected to produce more than 180,000 packages by the end of 2021 and at least 50 million packages by the end of 2022, of which 21 million would be produced in the first half.
“We are currently adding additional capacity and increasing even more and we expect to update these numbers in the coming weeks,” the company said.
Infectious disease experts emphasize that preventing COVID-19 through widespread use of vaccines remains the best way to control the pandemic, but only 58% of Americans are fully vaccinated and access in many parts of the world is limited.
Pfizer’s drug, which is part of a class known as protease inhibitors, is designed to block an enzyme that the coronavirus needs 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 regulators in the UK, the US, the UK and others.
Britain said earlier this month it had obtained 250,000 treatments of the antiviral from Pfizer.
Pfizer is also studying whether its pill could be used by people without risk factors for severe COVID-19, as well as to prevent coronavirus infection in people exposed to the virus.