Pfizer announced that its investigational Covid-19 oral antiviral candidate, Paxlovid, has significantly reduced hospitalisation and death, in an interim analysis of the Phase 2/3 EPIC-HR study.
The primary analysis of the interim data set evaluated data from 1,219 adults in North and South America, Europe, Africa, and Asia who enrolled by 29 September 2021.
In the Phase 2/3 trial, Paxlovid reduced 89% risk of Covid-19-related hospitalisation or death compared to placebo, within three days from symptom onset, which is the primary endpoint, said Pfizer.
Paxlovid is a potential SARS-CoV-2 protease inhibitor antiviral therapy that blocks the SARS-CoV-2-3CL protease, an enzyme that is required by the virus to replicate.
The drug was specifically formulated for oral administration, facilitating it to be prescribed at the early sign of infection, to help prevent severe illness, hospitalisation and death.
Its co-administration with a low dose of ritonavir would slow the metabolism, allowing it to remain active in the body for a long time, to help fight the virus, said the company.
Pfizer chairman and chief executive officer Albert Bourla said: “Today’s news is a real game-changer in the global efforts to halt the devastation of this pandemic.
“These data suggest that our oral antiviral candidate, if approved or authorised 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 hospitalisations.
“Given the continued global impact of Covid-19, we have remained laser-focused on the science and fulfilling our responsibility to help healthcare systems and institutions around the world while ensuring equitable and broad access to people everywhere.”
Paxlovid showed comparable reduction in risk of Covid-19-related hospitalisation or death in patients treated within five days of symptom onset, with those treated within three days.
The drug showed high statistical significance, as only 1% of patients were hospitalised in 28 days, compared to 6.7% of patients who received a placebo.
Pfizer intends to submit the data to the US Food and Drug Administration (FDA) soon, as part of its ongoing rolling submission.
If authorised, Paxlovid will become the first oral antiviral that is specifically designed to inhibit the SARS-CoV-2-3CL protease enzyme to treat Covid-19 infection, said the company.
Upon completion of the EPIC programme and regulatory approval, Pfizer is planning for a wide roll-out of the drug as an at-home treatment against the Covid-19.
Pfizer worldwide research, development and medical president and chief scientific officer Mikael Dolsten said: “All of us at Pfizer are incredibly proud of our scientists, who designed and developed this molecule, working with the utmost urgency to help lessen the impact of this devastating disease on patients and their communities.
“We’re thankful to all of the patients, investigators, and sites around the world who participated in this clinical trial, all with the common goal of bringing forth a breakthrough oral therapy to help combat Covid-19.”