The drug, known as PAXLOVID, was found in a scheduled interim analysis to reduce the risk of hospitalization or death from the CCP (Chinese Communist Party) virus by 89 percent if the patient receives the drug in time, according to a company press release published on Nov. 5.
Antivirals, just like Merck’s molnupiravir, need to be given to patients as early as possible to be most effective, best within days of the onset of symptoms.
The British medicines regulator has given a green light on Thursday to a similar oral COVID-19 treatment from Merck and has also filed an emergency use authorization application with the U.S. Food and Drug Administration (FDA).
U.S. advisers will meet this month to vote on whether Merck’s antiviral treatment should be authorized.
Pfizer said it plans to submit interim trial results for PAXLOVID, which is given in combination with an older antiviral called ritonavir, to the FDA as part of the emergency use application it opened in October.
Albert Bourla, Pfizer’s chief executive, said in a statement the results are “a real game-changer,” adding that the data collected shows that the companies’ oral antiviral, if approved by U.S. regulators, “has the potential to save patients’ lives, reduce the severity of COVID-19 infections, and eliminate up to nine out of ten hospitalizations.”
The company did not detail the side effects of the treatment but said adverse events happened in about 20 percent of both treatment and placebo patients, most of which were mild in intensity. Ritonavir’s possible side effects include nausea and diarrhea.
Full data from the clinical trial is not yet available from either Pfizer or Merck’s antiviral COVID-19 treatment.
Pfizer’s combination treatment consists of three pills given twice daily. The planned analysis of 1,219 patients in the company’s study looked at hospitalizations or deaths among people diagnosed with mild to moderate COVID-19 with at least one risk factor for developing severe disease, such as obesity or older age.
It found that 0.8 percent 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 percent for placebo patients. There were also seven deaths in the placebo group.
Rates were similar for patients treated within five days of symptoms—1 percent of the treatment group was hospitalized, compared with 6.7 percent for the placebo group, which included 10 deaths.
Pfizer is also studying whether PAXLOVID could be used by people without risk factors for serious COVID-19 as well as to prevent infection from the CCP virus in people exposed to the virus.
President Joe Biden said on Friday while he delivered remarks on the October jobs report that the United States has already secured millions of doses of the experimental antiviral pill.
“If authorized by the FDA we may soon have pills that treat the virus in those who become infected,” Biden said. “We’ve already secured millions of doses. The therapy would be another tool in our toolbox to protect people from the worst outcomes of COVID.”
Currently, the only COVID-19 antiviral treatment granted an emergency use authorization by the FDA is remdesivir, which is being sold under the brand name Veklury.
The treatment involves combining remdesivir with the anti-inflammatory oral drug baricitinib for patients 2 years of age or older who need supplemental oxygen, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO), according to the FDA.
Reuters contributed to this report.