| 18 May 2024, Saturday |

Pfizer says antiviral pill cuts risk of severe COVID-19 by 89%

The company said on Friday that a trial of Pfizer Inc’s experimental COVID-19 antiviral pill was halted early after the medicine was demonstrated to reduce the risk of hospitalization or death in persons at risk of developing severe disease by 89 percent.

The findings appear to outperform those obtained with Merck & Co Inc’s molnupiravir tablet, which was proven last month to reduce the risk of death or hospitalization among COVID-19 patients who were also at high risk of serious illness.

Neither business has made the full study data accessible yet.

Pfizer’s stock jumped 13% to $49.47, while Merck’s stock dropped 6% to $84.69.

Pfizer said it plans to submit interim trial findings for its pill, which is used in conjunction with an earlier antiviral known as ritonavir, to the US Food and Drug Administration as part of an emergency use application it filed in October.

Paxlovid is the brand name for the combination treatment, which consists of three pills taken twice a day.

Pfizer’s study looked at hospitalizations and deaths among participants diagnosed with mild to moderate COVID-19 who had at least one risk factor for developing severe disease, such as obesity or advanced age.

It found that 0.8% of those given Pfizer’s drug within three days of symptom onset were hospitalized and none had died by 28 days after treatment. That compared with a hospitalization rate of 7% 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 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, told Reuters.

The company did not detail side effects of the treatment, but said adverse events happened in about 20% 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-19 infections, and eliminate up to nine out of ten hospitalizations,” Pfizer Chief Executive Albert Bourla said in a statement.

Pfizer said it was currently expecting to produce more than 180,000 packs by the end of 2021 and at least 50 million packs by the end of 2022, of which 21 million would be produced in the first half.

“We are currently bringing on additional capacity and ramping up further and we look forward to updating these numbers in the coming weeks,” the company said.

Infectious disease experts stress that preventing COVID-19 through wide 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, 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 U.K. regulators, to the United States, the U.K. 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-19 as well as to prevent coronavirus infection in people exposed to the virus.

  • Reuters