Under the agreement, Pfizer will supply 10 million courses of the investigational Covid-19 drug to the US government, from later this year, through 2022


Scientifically accurate atomic model of the external structure of the SARS-CoV-2. (Credit: Alexey Solodovnikov/Wikipedia.)

Pfizer has signed an agreement with the US government to supply 10 million courses of its investigational Covid-19 oral antiviral candidate Paxlovid (PF-07321332, ritonavir).

The US government’s procurement is subject to Paxlovid receiving regulatory authorisation from the US Food and Drug Administration (FDA).

Under the terms of the agreement, Pfizer will supply 10 million courses of the investigational Covid-19 drug to the US government, from later this year, through 2022.

The US drugmaker is eligible to receive $5.29bn from the US government.

According to Pfizer, Paxlovid becomes the first 3CL protease inhibitor specifically designed to be an oral antiviral to fight against SARS-CoV-2.

Also, the company said that it has reached advance purchase agreements with several other countries and has initiated bilateral outreach to around 100 countries around the world.

Pfizer chairman and CEO Albert Bourla said: “We were thrilled with the recent results of our Phase 2/3 interim analysis, which showed overwhelming efficacy of Paxlovid in reducing the risk of hospitalization among high-risk patients treated within three days of symptom onset by almost 90% and with no deaths, and are pleased the US government recognises this potential.

“It is encouraging to see a growing understanding of the valuable role that oral investigational therapies may play in combatting Covid-19, and we look forward to continuing discussions with governments around the world to help ensure broad access for people everywhere.”

Recently, the US drugmaker submitted an application to the US FDA, seeking emergency use authorisation (EUA) of Paxlovid.

The company has also started rolling submissions in several countries, and the company will continue working to submit applications to regulatory agencies around the world.

Paxlovid is an investigational Covid-19 oral antiviral candidate, comprising 3CL protease inhibitor PF-07321332, and HIV drug ritonavir.

PF-07321332 works by blocking the activity of the SARS-CoV-2-3CL protease enzyme, which is essential for viruses to replicate.

Its co-administration with a low dose of ritonavir is said to slow down its metabolism, to help it remain active in the body for longer periods at higher concentrations.

In July 2021, Pfizer commenced the Phase 2/3 EPIC-HR study in non-hospitalised adult patients with Covid-19, who are at high risk of progressing to severe disease.

In the study, Paxlovid reduced the 89% risk of Covid-19-related hospitalisation or death compared to placebo, within three days from symptom onset, which is the primary endpoint.

In a separate development, Pfizer has received the European Commission (EC) approval for Xeljanz (tofacitinib) to treat a type of active ankylosing spondylitis (AS).

The drug was indicated for the treatment of adults with active AS, who have responded inadequately to conventional therapy.

Xeljanz is the first and only oral Janus kinase (JAK) inhibitor approved for five indications in the European Union (EU).

The indications include rheumatoid arthritis (RA), adults with active psoriatic arthritis (PsA), active ulcerative colitis (UC), and polyarticular juvenile idiopathic arthritis (pcJIA) and juvenile psoriatic arthritis (PsA).