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Pfizer to Provide Canada with 1 Million Courses of Investigational Oral Antiviral Candidate for COVID-19


  • First orally administered investigational protease inhibitor specifically designed to combat COVID-19 being evaluated in clinical studies; currently undergoing Phase 2/3 safety and efficacy trials

  • Courses are expected to be delivered through 2022, subject to Health Canada authorization

Kirkland, QC, December 3, 2021 — Pfizer Canada today announced an agreement with the government of Canada to supply its investigational COVID-19 oral antiviral candidate, PF-07321332;ritonavir, subject to local regulatory authorization. PF-07321332 is the first orally administered investigational candidate evaluated in clinical trials that is specifically designed to combat COVID-19.

Under the terms of the agreement, the Government of Canada will acquire an initial quantity of one million treatment courses, to be delivered after regulatory authorization.

“We are honoured to work with the Government of Canada toward achieving our shared goal of addressing this public health crisis,” said Kevin Mohamed, Canada Lead of Pfizer’s Hospital Business Unit. “If successful, oral antiviral therapies such as protease inhibitors may help to reduce the severity or onset of illness in adults who contract, or have been exposed to, COVID-19. An oral treatment option may thus be an important tool to help address the ongoing global impact of the COVID-19 pandemic.”

PF-07321332 is designed to block the activity of the main SARS-CoV-2 protease, an enzyme essential for viral replication. Co-administration with a low dose of ritonavir is expected to help slow the metabolism, or breakdown, of PF-07321332 in order for it to remain active in the body for longer periods of time at higher concentrations to help combat the virus. Ritonavir has been used extensively in combination with other antivirals to help slow metabolism in a similar way.

The EPIC (Evaluation of Protease Inhibition for COVID-19) Phase 2/3 development program for PF-07321332 consists of multiple ongoing clinical trials: one in SARS-CoV-2 infected adults who are at high risk of severe illness (including hospitalization or death), a second in infected, symptomatic adults who are at standard risk (i.e., do not have risk factors for severe illness), and a third aimed at preventing development of SARS-CoV-2 infections in adult household contacts of symptomatic COVID-19 patients. 

About Pfizer Canada

Pfizer Canada ULC is the Canadian operation of Pfizer Inc., one of the world's leading biopharmaceutical companies. Our diversified healthcare portfolio includes some of the world's best known and most prescribed medicines and vaccines. We apply science and our global resources to improve the health and well-being of Canadians at every stage of life. Our commitment is reflected in everything we do, from our disease awareness initiatives to our community partnerships. To learn more about Pfizer Canada, visit or you can follow us on LinkedIn, Facebook, Twitter or YouTube.


For more information:

Pfizer Canada Corporate Affairs

1-866-9-PFIZER (1 866 973-4937)

[email protected]

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