Revolution on the treatment front? For the past few days, France has been on fire for Paxlovid, presented by Pfizer as a “miracle pill” to treat Covid-19. About 500,000 have been pre-ordered by France for 2022 and “the first deliveries, of a few thousand doses, should take place before the end of January”, reveals the
Ministry of Health.
This Friday, the High Authority for Health (HAS) should give its opinion on this treatment, which has obtained the European Agency for emergency use December 16. If its green light is probable, the HAS should specify the type of patients who will be able to benefit from it. 20 minutes explains to you why the arrival in France of this anti-Covid pill is good news… to be put into perspective.
Breaking the deadlock for the immunocompromised
This treatment is welcomed as the messiah because for immunocompromised patients (transplant patients, dialysis, chemotherapy, kidney failure, etc.), the Omicron wave is a dead end. Vaccination works very badly for them and the only treatments prescribed so far, monoclonal antibodies, are defeated by this same Omicron. “Today, we have a slightly less serious virus, a high level of vaccination, but populations at risk who do not respond to vaccination”, summarizes Bruno Lina, virologist at the Lyon University Hospital and member of the scientific council. This is why he believes that Paxlovid should be given as a priority to these people who are very at risk. Especially since this treatment has an advantage: it is oral. The patient takes three tablets twice a day for five days at home. Forgotten, therefore, infusions and trips to hospitals, perilous during a peak of contamination.
Above all, the Paxlovid seems extremely effective. According to a double-blind clinical trial unveiled by Pfizer on November 5, 2021, this treatment reduces the risk of hospitalization and death in the event of Covid-19 by 88%. But the test was carried out before the Omicron wave…
“The big advantage is that this treatment puts a spoke in the wheel of virus replication and targets an enzyme, common to many coronaviruses and which mutates little, reassures Sandrine Sarrazin, immunologist and researcher at Inserm. We can therefore imagine that it will work on the current variants and the following ones. » Efficacy against Omicron confirmed by three unpublished studies,
relayed on January 19 by the wall street journal. In Israel, where the treatment has been available since the end of December, a study by the Maccabi health fund reveals that 92% of coronavirus patients who received Paxlovid saw their condition improve in three days,
according to i24news.
Several elements that can worry
What would make the many researchers green with envy in the race for a miracle treatment? Several factors can dampen this enthusiasm. First, Paxlovid is only useful if taken within the first five days of infection, and ideally within the first three. It will therefore be necessary that at the slightest symptom, a patient can be tested and obtain it in time.
Second question, in connection: its availability. Unlike a repositioned drug, already produced and prescribed, Paxlovid is new, and therefore must be created from scratch. Will 500,000 stamps for one year be sufficient? “It’s very complicated to have the number of immunocompromised in France, warns Bruno Lina. It could be around 300,000 to 400,000 people. Furthermore, we know that 500,000 people over the age of 80 are still not vaccinated. “This antiviral treatment could be a ‘game changer’ in addition to vaccination, provided that they manage to produce it quickly in large quantities”, warns Sandrine Sarrazin. Regarding production in France, Pfizer announced last Monday that the active ingredient of Paxlovid would be manufactured by Novasep in Mourenx (Pyrénées-Atlantiques), but only in the third quarter of 2022.
Will the patients who expect it the most be able to take it?
If we now look further upstream, on the clinical trial, several specificities may call into question. Pfizer published an interim analysis of this trial involving 1,219 patients between the end of September and the beginning of November 2021. Why “intermediate”? “It happens that the
Data monitoring committee [un groupe indépendant d’experts chargé de surveiller les données d’un essai clinique] decides to lift part of the patients’ anonymity before the end of the clinical trial in the event of a serious side effect, for example. This time, this committee, in agreement with the manufacturer, considered that the results were so good that they had to be communicated as soon as possible. We were then faced with an abyssal therapeutic void…” But a month and a half is a bit short to assess the adverse effects.
The trial continues until April 2022. And real-life observations should provide answers for immunocompromised or very elderly people who will undoubtedly be the first to benefit. “We have no data that confirms that there is an interest in giving this treatment to these patients, recognizes Bruno Lina. We hope that the results will be equivalent. »
But it is a last aspect that worries some doctors more. Paxlovid is made up of two molecules: PF-07321332, which prevents the virus protein from replicating, and ritonavir, which extends the life of the treatment. Except that this antiretroviral has
a long list of contraindications : hepatic and renal insufficiency, pregnancy, breast-feeding, medicines based on St. John’s wort, anti-rejection medicines… Exit all transplant recipients? “There are brakes, but not insurmountable, relativizes Bruno Lina. As we are on a short treatment, it is possible that the consequences are not so important, but we do not have the proof. We will have to weigh the benefit/risk for each patient between their usual treatment and a severe form of Covid-19. »