To Pamela Cruz. Peninsula 360 Press [P360P]

Pharmaceutical company Pfizer on Tuesday requested emergency use authorization from the U.S. Food and Drug Administration (FDA) for its investigational oral antiviral candidate, “Paxlovid” ‒ritonavir‒, for the treatment of mild to moderate COVID-19 in patients at higher risk of hospitalization or death. 

If approved, Paxlovid would be the first oral antiviral of its kind, a 3CL protease inhibitor specifically designed to combat the SARS-CoV-2 virus.

The EUA submission includes clinical data from an interim analysis of the Phase 2/3 EPIC-HR study, which demonstrated an 89 percent reduction in the risk of COVID-19-related hospitalization or death compared to placebo in high-risk adults not hospitalized with COVID-19.

Applications have begun in several countries, including the United Kingdom, Australia, New Zealand and South Korea.

“With more than 5 million deaths and countless lives affected by this devastating disease worldwide, there is an urgent need for life-saving treatment options. The overwhelming efficacy achieved in our recent clinical study of PAXLOVID, and its potential to help save lives and keep people out of the hospital if approved, underscores the critical role that oral antiviral therapies could play in the battle against COVID-19,” said Albert Bourla, President and CEO of Pfizer. 

“We are moving as quickly as possible in our effort to get this potential treatment into the hands of patients, and we look forward to working with the U.S. FDA in reviewing our application, along with other regulatory agencies around the world,” he added.

Pfizer is seeking U.S. agency approval for Paxlovid based on positive results from an interim analysis of an Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients (EPIC-HR) trial, which included non-hospitalized adults 18 years of age or older with confirmed COVID-19 who are at increased risk of progressing to severe disease. 

The data demonstrated an 89 percent reduction in the risk of COVID-19-related hospitalization or death from any cause in patients treated with Paxlovid compared to placebo within three days of symptom onset, with no deaths in the treatment group. 

According to Pfizer, similar results were seen within five days of symptom onset. 

In a statement, the pharmaceutical company said that treatment-emergent adverse events were comparable between Paxlovid (19 percent) and placebo (21 percent), most of which were mild in intensity. 

On the recommendation of an independent Data Monitoring Committee and in consultation with the FDA, Pfizer stopped enrollment in the study due to the overwhelming demonstrated efficacy. 

Pfizer announced that it has begun and will continue to invest up to approximately $1 billion of its own funds to support the manufacturing and distribution of this investigational treatment candidate. 

In addition, the pharmaceutical company has signed a voluntary licensing agreement with the Medicines Patent Pool (MPP) to help expand access, pending regulatory approval or authorization, in 95 low- and middle-income countries representing approximately 53 percent of the world's population.

PAXLOVID is an investigational SARS-CoV-2 protease inhibitor antiviral therapy. It was specifically designed to be administered orally so that it can be prescribed at the first sign of infection or knowledge of an exposure, potentially helping patients avoid severe disease – which can lead to hospitalization and death – experience a decreased symptomatic period, or prevent disease development after exposure. 

If approved or licensed, the drug is given at a dose of 300 mg – two 150 mg tablets – with one 100 mg ritonavir tablet, twice daily for five days.

You may be interested in: COVID active antibodies present in milk maternal: study

COVID-19 infection and vaccination in pregnant women can result in significant antibodies in breast milk that exhibit different temporal patterns, but both neutralize the live SARS-CoV-2 virus, according to a study by researchers at the University of Rochester Medical Center and New York University.

The analysis published in the journal JAMA Pediatrics, reports that the study included a convenience sample of 47 lactating pregnant women who had been infected with the virus, in addition to another 30 who were vaccinated against COVID-19.

In the case of breast milk from those who were infected with COVID, the amount of antibodies was dominant and highly variable, while in those who were vaccinated, it was associated with a strong antibody response that began to decline 90 days after the second vaccine dose. 

However, milk from both groups showed neutralizing activity against the live SARS-CoV-2 virus, with slow antibody loading of IgA, which is found in the linings of the respiratory tract and digestive system, as well as in saliva, tears and breast milk, and IgG, which are the most abundant antibodies in the body.

“It’s one thing to measure antibody concentrations, but it’s another to say that the antibodies are functional and can neutralize the SARS-CoV-2 virus. One of the exciting findings of this work is that the breast milk of both mothers with COVID-19 infection and mothers who received the mRNA vaccine contained these active antibodies that were capable of neutralizing the virus,” said Dr. Bridget Young, one of the study’s lead authors.

"Our data suggest that both IgA and IgG contribute to the neutralizing capacity, implying a clinical benefit for infants receiving breast milk from mothers with COVID-19 infection or who are vaccinated," the document highlights.

This study has the longest follow-up of breast milk after vaccination compared to previously published studies. 

“Importantly, whether a dominant IgA or IgG response, both infection and vaccination generated human milk with neutralizing activity. Among other benefits, breast milk provides protection against morbidities, including respiratory and diarrheal diseases, due to specific and nonspecific immune factors, including antibodies,” the study states.

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