© Reuters. FILE PHOTO: A 3D-printed Pfizer logo is placed near drugs from the same manufacturer in this illustration taken September 29, 2021. REUTERS/Dado Ruvic
Written by Dina Beasley
(Reuters) – Trial Pfizer The company said Friday that Inc.’s (NYSE:) experimental antiviral pill for COVID-19 was discontinued early after the drug was shown to reduce 89% of the chances of hospitalization or death for adults at risk of serious illness.
The results appear to surpass those seen with Merck & Co’s birth control pill molnupiravir, which was shown last month to halve the likelihood of death or hospitalization for COVID-19 patients who are also at risk of serious illness.
Full trial data is not yet available from either company.
Pfizer said it plans to submit interim trial results of its pill, which is given in combination with an old antiviral called ritonavir, to the U.S. Food and Drug Administration as part of an emergency use application that it opened in October.
The combination therapy, which goes by the brand name Paxlovid, consists of three pills given twice daily.
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 severe disease, such as obesity or advanced age.
It found that 0.8% of those treated with Pfizer within three days of onset of symptoms were hospitalized and none died after 28 days of treatment. This compared to a 7% hospitalization rate for placebo patients. There were also seven deaths in the placebo group.
The rates were similar for patients treated within five days of onset of symptoms — 1% of the treatment group were hospitalized, compared to 6.7% for the placebo group, which included 10 deaths.
Antiviral medicines should be given as soon as possible, before the infection spreads, in order to be most effective. Merck tested its drug within five days of symptoms appearing.
“We’ve seen that we have high efficacy, even if it’s five days after a patient has been treated…People might wait two days before doing a test or something, and that means we have time to treat people and really provide the benefit of our A public health perspective.
The company did not detail the treatment’s side effects, but said that adverse events occurred in about 20% of patients treated with the placebo.
Albert Burla, CEO of Pfizer said in a statement.
Infectious disease experts assert that preventing COVID-19 through the widespread use of vaccines remains the best way to control the epidemic, but only 58% of Americans are fully vaccinated and access is limited in many parts of the world.
Pfizer’s drug, which is part of a class known as protease inhibitors, is designed to block an enzyme that the coronavirus needs in order to multiply.
Molnopiravir from Merck has a different mechanism of action designed to introduce errors into the virus’ genetic code. Merck has already sold millions of courses, which were approved this week by UK regulators, to the US, UK and other countries.
Britain said earlier this month that it had received 250,000 cycles of Pfizer’s antivirals.
Pfizer is also studying whether the contraceptive pill can be used by people who do not have risk factors for serious COVID-19 as well as to prevent coronavirus infection in people exposed to the virus.