喜讯！日本厚生劳动省批准辉瑞新冠口服药Paxlovid

Introduction: Japan has approved Pfizer's oral COVID-19 drug Paxlovid for the treatment of mild to moderate COVID-19 patients aged 12 years and above, weighing at least 40 kilograms, and who are at high risk of developing severe symptoms that require hospitalization.

On February 10, 2022, Japan’s Ministry of Health, Labor and Welfare accelerated approval of Pfizer’s COVID-19 oral drug paxlovid, as the government hopes that the new treatment option can help reduce the burden on the health care system (driven by Omicron, Japan’s health care system is on the verge of collapse).

The drug is the second oral antiviral drug approved for the new coronavirus after Merck's molnupiravir.

Late-stage clinical trials conducted internationally, including in Japan, showed that adult patients who took the drug within 3 days of symptom onset reduced the risk of hospitalization or death by 89%; after taking the drug within 5 days of symptom onset, this risk was reduced by 88%. After 28 days of follow-up, there were no deaths in the treatment group compared with nine in the placebo group. Paxlovid and placebo produced similar side effects, most of which were mild.

Paxlovid consists of two different medicines, nirmatrelvir and ritonavir, taken by mouth twice a day for five days. The US FDA and the European Medicines Agency (EMA) granted emergency use authorization to Paxlovid in December 2021 and January 2022 respectively.

Although Japan does not yet have its own commercial COVID-19 vaccine, domestic pharmaceutical company Shionogi & Co is racing to develop an oral anti-COVID-19 drug that can be taken at home. Japanese Prime Minister Fumio Kishida said that Shionogi's drug can be approved in advance with conditions, because some medical institutions and pharmacies are facing supply shortages of Merck's oral drugs.

On February 7, 2022, Shionogi President Teshirogi said that the company plans to submit a conditional early approval application to the Japanese government next week or the week after.

Like Paxlovid, Shionogi's oral candidate targets an essential protein, 3CL protease, to inhibit viral replication and showed antiviral efficacy in a small subset of samples in its mid-stage clinical trial. By contrast, Monupivir, originally developed by Merck to treat influenza, fights various viruses by disrupting ribonucleic acid (RNA) polymerase, an enzyme that viruses use to replicate themselves.

Dr. Takeshi Urano, professor of pathochemistry at Shimane University School of Medicine, said that these oral drugs, which can be used to treat mild symptoms, will play a great role in the battle against the new coronavirus.

On December 22, 2021, the U.S. Food and Drug Administration approved Paxlovid for the treatment of adult patients with mild to moderate COVID-19 and pediatric patients 12 years and older weighing at least 40 kg who test positive on a direct SARS-CoV-2 viral test and are at high risk of progression to severe COVID-19, including hospitalization or death.

References:

https://www.japantimes.co.jp/news/2022/02/10/national/science-health/pfizer-drug-approval/