The US FDA has urgently authorized Pfizer and MSD anti Novel COVID-19 oral drugs to go on the market
In December 22nd, novel coronavirus pneumonia Paxlovid was approved by the US Food and Drug Administration (FDA). The emergency use authorization of Pfizer was applied within 5 days after symptoms appeared. It was used to treat severe acute lung cancer patients aged 12 and above.
Meanwhile, novel coronavirus pneumonia was used by FDA to authorize the use of mercad Molnupiravir in December 23rd. It is the second newly approved oral medicine for patients with high risk and no other treatment options. The new adult patients with pneumonia will be given 5 days after the onset of symptoms.
Paxlovid consists of Pfizer’s nirmatrelvir and ritonavir twice a day for 5 days, with a total of 30 tablets. Clinical studies have shown that the use of drugs within 3 days after the onset of symptoms can reduce the risk of hospitalization or death by 89%, while the use within 5 days can reduce the risk of hospitalization or death by 88%. Previously, Pfizer has signed an agreement with the U.S. government on 10 million doses of treatment, which will be ready for delivery. In 2022, Pfizer’s production is expected to increase from 80 million dose courses to 120 million dose courses, and plans to submit new drug applications for full approval.
The recommended dose of molnupiravir is 4 tablets orally every 12 hours for 5 consecutive days, a total of 80 tablets. The interim analysis of the drug release showed that the drug could reduce the risk of hospitalization or death by 50%, while the risk of hospitalization or death in the final analysis was reduced by only 30%. By the end of next month, MSD will be able to provide about 3 million courses of molnupiravir.
At present, the United States is being attacked by COVID-19 variant Omicron. The new virus is more infectious than Delta. CDC data show that Omicron accounts for 73% of the number of new cases in a week. At the same time, the monoclonal antibodies currently used in the United States have significantly reduced or even ineffective effect on this new variant, and the early data of these two oral drugs show that they can fight Omicron.
Pfizer’s official website explained that Omicron’s spike protein had a large number of mutations, resulting in resistance to monoclonal antibodies targeting this protein. However, the target of Paxlovid is COVID-19 protease, which is less affected by mutation. The drug showed consistent antiviral activity in the previous tests of alpha, Delta, Mu and other variants, and the in vitro test also proved that the drug was effective against Omicron protease. Because the drug does not act on the viral RNA replication process, there is no clinical evidence of mutagenesis of human cell DNA, and the safety is good.
Paxlovid’s action mechanism is to inhibit the replication ability of the virus, while molnupiravir inserts the wrong fragment in the process of virus replication to prevent its transmission and has the ability to fight Omicron. However, when the latter changes the viral RNA, it is likely to lead to the emergence of new variants, and may also cause damage to human DNA. The FDA said it would prohibit the use of molnupiravir by children and pregnant women. Dr. Richard Murphy of the Department of Veterans Affairs of the FDA specifically pointed out that if a drug is more effective and safer than molnupiravir, the emergency use authorization of molnupiravir should be reconsidered.
Paxlovid and molnupiravir are authorized to provide new tools for fighting the epidemic and new treatment methods for fighting the Omicron epidemic. Although some studies say that the risk of hospitalization of this variant is small, it spreads very fast and may still cause a large number of patients to die, which is more likely to lead to the collapse of the medical system. In addition to these two drugs, relevant departments are also strengthening the supply and distribution of sotrovimab mAb of GSK, which also has therapeutic activity against Omicron.
Can the approval of two new drugs curb the current severe epidemic situation in the United States? Compared with monoclonal antibody therapy, oral drugs have relatively low cost and can be taken at home, which undoubtedly improves the accessibility of treatment. However, the drug can only be obtained through prescription. The best effect is to use it immediately after symptoms appear. Therefore, early diagnosis is also a difficulty in treatment. At present, Americans generally have to wait 1-3 days for detection and 1-2 days for diagnosis after symptoms.
With the increase of travel at the end of the year, it will be more and more difficult to detect appointments. In addition, taking drugs continuously for 5 days is also a difficulty for many people. With good medicine, how to improve the efficiency of disease diagnosis and seize the key window of treatment is also a difficult problem that the United States must solve.
It is reported that the expert group convened by the National Institutes of health is expected to release guidelines soon to introduce the limited two antiviral drugs and the use suggestions of monoclonal antibodies and remdesivir.
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