Paxlovid: composition, when in France, price, effects

[Mise à jour le 10 janvier 2022 à 16h23] A new, more manageable and effective treatment against Covid variants, in particular Omicron, will be available in the first quarter of 2022 (mid-February 2022). It’s about Paxlovid, oral treatment specially designed by Pfizer to be administered orally at the first signs of Covid infection. L’European Medicines Agency (EMA) at started his exam “to help national authorities decide on its early use for Covid-19, for example in emergency situations, before the marketing authorization “, explains the agency in a statement. She is evaluating the benefits and risks of Paxlovid in a reduced time and could issue an opinion in a few weeks. To do this, the EMA’s Committee for Medicinal Products for Human Use (CHMP) is examining data from a study comparing the effect of Paxlovid with that of a dummy treatment (placebo) in non-hospitalized patients with mild Covid. who were at high risk of progressing to severe disease. Pfizer also requested on November 16, 2021 a emergency use authorization near Food and Drug Administration (FDA), the United States Food and Drug Administration. If the data concludes that the benefits outweigh its risks in treating Covid, the EMA will work closely with the European Commission to speed up the decision to grant a conditional marketing authorization in all EU member states. How does this pill work? Its effectiveness against Covid? Its side effects? Knowledge to date.

What is Paxlovid?

The American pharmaceutical laboratory Pfizer developed antiviral treatment, marketed under the name of Paxlovid. If it obtains the marketing authorizations, this pill, administered orally, could be taken at home in the first days after the appearance of symptoms in the event of infection with Covid-19. Paxlovid is a treatment similar to Molnupiravir, an antiviral drug developed by the American pharmaceutical company Merck. Already authorized since the beginning of November in the United Kingdom, this antiviral has been the subject of an emergency authorization request in the United States, which must be examined on November 30 by the FDA. The French government would have ordered 50,000 doses, indicated the Minister of Health Olivier Véran at the end of October, pending validation from the European Medicines Agency.

How effective is it against Covid and against Omicron?

Paxlovid would be able to reduce the risk of hospitalization or death by 89%

Paxlovid would be particularly effective against the variants of Covid – and therefore Delta and Omicron – because this treatment is directed against the protease of the virus which is little modified (protease inhibitor), explains the Scientific Council in a notice of December 16, 2021. In a double-blind randomized phase 2/3 interim analysis conducted on more than 1,800 patients not hospitalized in July 2021, all with at least one risk factor for developing a severe form of the disease, Pfizer has shown that Paxlovid was able to reduce 89% risk of hospitalization or death compared to the group that received a placebo, reports the laboratory in a press release dated November 5, 2021. Each patient received the treatment or a placebo orally every 12 hours during 5 days.

For patients who received Paxlovid treatment or placebo in the 3 days depending on the onset of symptoms:

• Hospitalizations: 0.8% (i.e. 3 of 389) of the patients who received Paxlovid were hospitalized until day 28 against 7% of the patients (27 out of 385) who received the placebo.
• Death : no deaths were reported in patients who received Paxlovid compared to 7 in patients who received placebo.

For patients who received Paxlovid treatment or placebo in the 5 days depending on the onset of symptoms:

• Hospitalizations: 1% (6 out of 607) of the patients who received Paxlovid were hospitalized until day 28 against 6.7% of the patients (41 out of 612) who received the placebo.
• Death : no deaths were reported in patients who received Paxlovid compared to 10 in patients who received placebo.

“These data suggest that our oral antiviral candidate, if approved or cleared by regulatory authorities, has the potential save patient lives, reduce the severity of COVID-19 infections and eliminate up to 9 out of 10 hospitalizations, said Albert Bourla, Chairman and CEO of Pfizer. Subject to approval or authorization, it could be prescribed more widely as home treatment to help reduce the severity of illness, hospitalizations and death, as well as the likelihood of infection. after exposure, in adults.“

When will it be available in France?

It will only be available in limited quantities from mid-February 2022

For now, Paxlovid is not marketed. He “will only be available in limited quantities from mid-February 2022“said the Scientific Council on December 16. But in front of”overwhelming efficiency“Highlighted in its clinical trials, Pfizer decided to end the trial earlier than planned and submitted an authorization file with the United States Drug Administration (FDA) for an emergency use authorization request (EUA) as soon as possible, the laboratory said in its November 5, 2021 press release. If the request is accepted, this pill could be administered in the United States and doses could be ordered by countries that wish, for example France. The company indicates have entered into advance purchase agreements with several countries and be in negotiation with several others. According to Washington post, the US government plans to purchase 10 million doses of it and invest up to $ 1 billion in the manufacture and distribution of Paxlovid. In addition, a voluntary license agreement, announced on November 16, with the Medicines Patent Pool (MPP), would have been voted. This patent sharing would thus allow generic manufacturers to produce the drug to supply them to 95 middle and lower income countries.

What is the composition of Paxlovid?

Paxlovid is made up of two molecules. The first one PF-07321332 is the active agent that prevents the virus protein from replicating. The second is ritonavir, a protease inhibitor, normally used for the treatment of HIV infections. “HIV is not related to coronaviruses and its genetic material replicates by a different mechanism. But it produces him too a poly-protein which must be cut 9 times by a protease to form the new viral particles“, Explain an article published in the scientific journal Médecine Science in June 2020.

Paxlovid is said to prevent the coronavirus protease from replicating.

A protease is an enzyme specific to a virus which acts on viral proteins to promote virus replication. To stop the replication of a virus, it is therefore necessary to reduce or prevent the protease from acting. Coronaviruses have two proteases, one of which is called SARS-CoV-2, 3CL. It is on this protease that the oral Paxlovid treatment works.

What are the side effects ?

Among the patients who participated in the study and who received Paxlovid, 1.7% experienced serious adverse events and had to stop treatment. The active substance in this medicine, ritonavir, can indeed cause side effects such as:

• diarrhea,
• nausea and vomiting
• abdominal pain
• throat irritation or cough
• headaches and dizziness
• rashes and itching
• disturbances in the metabolism of sugars and fats with an abnormal redistribution of fat observed after several months of treatment (called lipodystrophy)
• toxicity to the liver (increased transaminases) and the pancreas.

What is the price ?

The price of the Paxlovid pill is not yet known. Nevertheless, Pfizer announced in its press release tiered pricing based on the income level of each country in order to guarantee equitable access to all and an affordable price. In other words, high and upper middle income countries will pay more than low income countries.

Sources

– PFIZER’S NOVEL COVID-19 ORAL ANTIVIRAL TREATMENT CANDIDATE REDUCED RISK OF HOSPITALIZATION OR DEATH BY 89% IN INTERIM ANALYSIS OF PHASE 2/3 EPIC-HR STUDY, November 5, 2021.

– Targeting the major SARS-CoV-2 protease to manufacture an effective drug against this coronavirus, Medecine Science, June 2020.