HONG KONG – Fujifilm Holdings Corp. stock (TYO:4901) jumped 8.8% to ¥5,890 (US$53.48) on Feb. 25, as Japan considers using Avigan (favipiravir), an anti-influenza medication developed by the company’s Toyama Chemical Co. Ltd., to treat COVID-19. The share price ended the day at ¥5,567, for a gain of 2.83%.
The medication attracted market attention when Minister of Health, Labor and Welfare Katsunobu Kato said on Feb. 22 that the country is planning to test Avigan against COVID-19. “We hear from foreign countries that some drugs among those that have been used against influenza may be useful,” Kato said.
As of Feb. 25, more than 850 cases have been confirmed in Japan.
Avigan is being used for observational research now. Kato said the ministry would test how effective flu medicines are at treating the disease and allow many medical institutions in Japan to use them for patients if needed.
“The National Center for Global Health and Medicine has formed a project team for research purposes and is preparing responses for patients of novel coronavirus at two medical centers,” Kana Matsumoto, of the corporate communications division of Fujifilm, told BioWorld. “On February 22, one of the medical centers started administration of the anti-influenza drug Avigan.”
The Japanese company said it is considering increasing production of Avigan. The medicine has a stockpile sufficient for 2 million patients, and the company will make a decision about additional production after monitoring the situation.
Avigan was developed as a flu medicine and also has been used for Ebola virus disease (EVD) treatment. EVD, which causes fatal hemorrhagic fever, resulted in more than 11,300 deaths in the West Africa region between 2014 and 2016. There is currently another outbreak in the Democratic Republic of Congo that has seen more than 2,000 fatalities to date.
In October 2014, a French nurse with Ebola virus who was treated with a combination of Avigan and other drugs recovered. Fujifilm said that information was relayed to the Tokyo-based company by the French National Agency for Medicines and Health Products Safety.
The French Institute of Health and Medical Research then carried out a clinical trial on Avigan’s efficacy as a treatment for EVD at four medical institutes in Guinea from December 2014 to May 2015. Based on the trial results, the Guinean government adopted Avigan tablet administration as part of a treatment regimen for EVD.
Broad range potential
Avigan functions as an antiviral drug against RNA viruses. Yousuke Furuta, a researcher at Toyama Chemical research laboratories, has said in a report that Avigan selectively inhibits the RNA-dependent RNA polymerase (RdRp) of RNA viruses. Avigan undergoes an intracellular phosphoribosylation to become an active form and then inhibits RNA polymerase activity.
As the catalytic domain of RdRp is conserved among various types of RNA viruses, that mechanism of action supports a wide spectrum of potential activity. Avigan works against a broad range of influenza virus types as well as West Nile virus, yellow fever, foot-and-mouth disease, and other flaviviruses, arenaviruses, bunyaviruses and alphaviruses, he noted.
Meanwhile, South Korea’s Ministry of Food and Drug Safety announced on Feb. 25 that it is considering a fast-track approval to import Avigan for the treatment of COVID-19. The drug has not been approved by the Korean government at this point.
As of Feb. 25 in Korea, the number of COVID-19 cases has rapidly soared to more than 1,000, of which most cases are from a church community. The number of cases is expected to rise as there is no established medication for the novel disease.