TGA Approves Pfizer’s Novel COVID-19 Oral Treatment in Australia
• Therapeutic Goods Administration (TGA) approves PAXLOVID™ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) for supply to Australia.
• PAXLOVID is the first oral treatment of its kind; it includes nirmatrelvir, a 3CL (or main) protease inhibitor that was specifically designed to combat SARS-CoV-2.
• Pfizer Australia has entered an agreement with the Australian Government to supply 500,000 treatment courses over 2022.
SYDNEY, AUSTRALIA, 20 January 2021 – Pfizer announced today that Australia’s Therapeutic Goods Administration (TGA) has granted provisional approval for the supply and use in Australia of PAXLOVID™ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets. PAXLOVID has provisional approval for the treatment of coronavirus disease 2019 (COVID-19) in adults 18 years of age and older, who do not require initiation of supplemental oxygen due to COVID-19 and are at increased risk of progression to hospitalisation or death.
PAXLOVID is the first oral antiviral of its kind; it includes nirmatrelvir, a 3CL protease (also known as Main protease or Mpro) inhibitor that was specifically developed in Pfizer’s laboratories to combat SARS-CoV-2. Under this authorisation, PAXLOVID can be prescribed as an oral treatment to certain high-risk adults within the first 5 days of symptomatic infection, potentially helping patients avoid severe illness which can lead to hospitalisation or death.
“This milestone in Australia is an important moment in our continued fight against COVID-19, paving the way for use of PAXLOVID as cases continue to rise and we address the threat of a new variant of concern, Omicron,” said Anne Harris, Pfizer Australia and New Zealand Managing Director. “This at-oral therapy, developed to reduce hospitalisations and save lives, has the potential to transform COVID-19 treatment and help lessen the devastating impact of the virus that has now taken over 5 million lives globally”, Ms Harris said.
The TGA based its decision on positive results from the Phase 2/3 EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients) interim analysis, which enrolled non-hospitalised adults with confirmed COVID-19 who were at increased risk of progressing to severe illness. The data demonstrated an 89% reduction in risk of COVID-19-related hospitalisation or death from any cause in adults treated with PAXLOVID compared to placebo in those treated within three days of symptom onset, with no deaths in the treatment group. Similar results were seen in those treated within five days of symptom onset. Treatment-emergent adverse events were comparable between PAXLOVID (19%) and placebo (21%), most of which were mild in intensity. Pfizer recently announced that results from the final analysis of the primary endpoint from all patients enrolled in EPIC-HR were consistent with the interim analysis, confirming efficacy with a similar safety profile. Additional Phase 2/3 clinical trials are ongoing in adults at standard risk of progressing to severe illness, and in those who have been exposed to the virus through household contacts.
In October 2021, Pfizer announced an agreement with the Australian Government to supply 500,000 treatment courses of PAXLOVID over 2022. With the oral treatment now approved for supply and use by the TGA, Pfizer will begin delivering the first treatment courses from Q1 2022.
About PAXLOVID™ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets)
PAXLOVID is a SARS-CoV-2 protease inhibitor antiviral therapy. It was developed to be administered orally so that it can be prescribed at the first sign of infection – potentially helping patients avoid severe illness (which can lead to hospitalisation and death) – subject to the clinical success of the rest of the EPIC development program. Nirmatrelvir [PF-07321332], which originated in Pfizer’s laboratories, is designed to block the activity of the SARS-CoV-2-3CL (or main) protease, an enzyme that the coronavirus needs to replicate. Co-administration with a low dose of ritonavir helps slow the metabolism, or breakdown, of nirmatrelvir in order for it to remain active in the body for longer periods of time at higher concentrations to help combat the virus.
Nirmatrelvir is designed to inhibit viral replication at a stage known as proteolysis, which occurs before viral RNA replication. Nirmatrelvir has shown consistent activity against the SARS-CoV-2 viral 3CL protease in all variants of concern to date and this efficacy has been confirmed in in vitro antiviral testing. Additional in vitro antiviral studies assessing expected similar activity against the Omicron variant are also currently underway. PAXLOVID is authorised to be administered at a dose of 300 mg (two 150 mg tablets) of nirmatrelvir with one 100 mg tablet of ritonavir, given twice-daily for five days. One carton contains five blister packs of PAXLOVID, as co-packaged nirmatrelvir tablets with ritonavir tablets, providing all required doses for a full five-day treatment course.
Our Commitment to Equitable Access
Pfizer is committed to working toward equitable access to PAXLOVID for all people, aiming to deliver safe and effective antiviral therapeutics as soon as possible and at an affordable price. During the pandemic, Pfizer will offer its oral therapy, pending country approval, through a tiered pricing approach based on the income level of each country to promote equity of access across the globe. High and upper-middle income countries will pay more than lower income countries.
Pfizer will continue to invest to support the manufacturing and distribution of PAXLOVID, including exploring potential contract manufacturing options. It has entered into agreements with multiple countries and has initiated bilateral outreach to approximately 100 countries around the world. Additionally, Pfizer has signed a voluntary license agreement with the Medicines Patent Pool (MPP) for its oral treatment to help expand access, pending country regulatory authorisation or approval, in 95 low- and middle-income countries that account for approximately 53% of the world’s population.
About the EPIC Development Program
The EPIC (Evaluation of Protease Inhibition for COVID-19) Phase 2/3 development program for nirmatrelvir; ritonavir consists of three clinical trials spanning a broad spectrum of patients, including adults who have been exposed to the virus through household contacts, as well as adults at both standard risk and high risk of progressing to severe illness. In July 2021, Pfizer initiated the first of these trials, known as EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients), a randomised, double-blind study of non-hospitalised adult patients with COVID-19, who are at high risk of progressing to severe illness. At the recommendation of an independent Data Monitoring Committee and in consultation with the U.S. Food and Drug Administration (FDA), Pfizer ceased further enrollment into the study in early November 2021 due to the overwhelming efficacy demonstrated in results from an interim analysis. In August 2021, Pfizer began the Phase 2/3 EPIC-SR (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients), to evaluate efficacy and safety in patients with a confirmed diagnosis of SARS-CoV-2 infection who are at standard risk (i.e., low risk of hospitalisation or death). EPIC-SR includes a cohort of vaccinated adults who have an acute breakthrough symptomatic COVID-19 infection and who have risk factors for severe illness. Interim data from this study have been reported. In September, Pfizer initiated the Phase 2/3 EPIC-PEP (Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis) to evaluate efficacy and safety in adults exposed to SARS-CoV-2 by a household member. These trials are ongoing.