TGA provisionally approves Pfizer Australia Pty Ltd's COVID-19 treatment nirmatrelvir + ritonavir (PAXLOVID)

On 18 January 2022 the Therapeutic Goods Administration (TGA) granted provisional approval to Pfizer Australia Pty Ltd's oral COVID-19 treatment nirmatrelvir + ritonavir (PAXLOVID).

PAXLOVID has been granted 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 not intended to be used as a substitute for vaccination again COVID-19.

PAXLOVID should be administered as soon as possible after diagnosis of COVID-19 and within 5 days of the start of symptoms. The two active substances of the medicine, nirmatrelvir and ritonavir, which are given as separate tablets, must be taken together twice a day for 5 days.

PAXLOVID is a combination therapy, the nirmatrelvir component blocks the activity of a protease enzyme that the coronavirus needs in order to replicate. Nirmatrelvir is administered in combination with low-dose ritonavir to maintain plasma levels of nirmatrelvir for the duration of the treatment.

The use of PAXLOVID is not recommended in pregnancy or breastfeeding, and in women of childbearing potential. It is recommended that sexually active women of childbearing potential use contraception. PAXLOVID must also not be used with a number of other commonly used medicines, either because for some medicines this may lead to potentially harmful increases in their blood levels, or in the case of some other medicines they may reduce the activity of PAXLOVID. The list of medicines that must not be used with PAXLOVID is included in the Product Information (below). PAXLOVID must also not be used in patients with severely reduced kidney or liver function.

PAXLOVID has received conditional marketing authorisation from the UK Medicines and Healthcare products Regulatory Agency and emergency use authorization from the US Food and Drug Administration, it was also authorised by Health Canada earlier this week.

Provisional approval of this treatment in Australia is subject to certain strict conditions, such as the requirement for the sponsors to continue providing information to the TGA on longer-term efficacy and safety from ongoing clinical trials and post-market assessment.

Australians can be confident that the TGA's review process of PAXLOVID was rigorous. The decision to provisionally approve the treatment was also informed by expert advice from the Advisory Committee on Medicines (ACM), an independent committee with expertise in scientific, medical and clinical fields including consumer representation.

The Australian Government has secured access to 500,000 treatment courses of PAXLOVID for supply in 2022, with first deliveries anticipated in the coming weeks.

Supporting regulatory documents

The provisional approval pathway provides a formal and transparent mechanism for registration of promising new medicines with preliminary clinical data.

The following regulatory documents are made available as part of this process:

• Product information (PI)
• Consumer Medicine Information (CMI)
• PAXLOVID Decision Summary
  The decision summary provides a short overview of the TGA's evaluation process leading to the registration of a new prescription medicine on the ARTG.
• AusPAR for PAXLOVID
  An Australian Public Assessment Report (AusPAR) provides information about the evaluation of a prescription medicine and the considerations that led the TGA to approve or not approve a prescription medicine submission.
• Therapeutic Goods (Poisons Standard) (COVID-19 Treatment - Pfizer) (Nirmatrelvir and Ritonavir) Labelling Exemption 2022