Favipiravir (Avigan) Shows Therapeutic Efficacy in Treating Coronavirus in Two Clinical Trials Conducted in China
Two recently conducted clinical trials in China involving 340 patients indicate that the Japanese-developed flu drug, Favipiravir, shows therapeutic efficacy in treating COVID-19 infection.
The Japanese Fujifilm Toyama Chemical Co. developed Avigan in 2014 and has licensed the patent for Favipiravir to the Chinese company Zhejiang Hisun Pharmaceutical.
Favipiravir (6-fluoro-3-hydroxy-2-pyrazinecarboxamide) is an antiviral drug that selectively inhibits the RNA-dependent RNA polymerase of influenza virus. This drug functions as a chain terminator at the site of incorporation of the viral RNA and reduces the viral load. It was also reported that the activity of this drug is particularly intense in the respiratory tract, decreasing the viral load to non-infectious levels.
In addition to influenza, Favipiravir has a broad spectrum of anti-RNA virus activities, and has been used for treatment of Ebola and Lassa viruses, rabies, and severe fever with thrombocytopenia syndrome.
Zhang Xinmin, China’s director of the National Center for Biotechnology Development said Favipiravir was found to reduce recovery time and improving lung condition in two clinical trials completed in Wuhan and Shenzhen involving 340 patients in total.
Zhang said the medicine worked for coronavirus-related symptoms including pneumonia and had no obvious side effects.
One of these clinical trials also found that X-rays confirmed improvements in lung conditions in 91% of patients treated with Favipiravir versus 62% in the placebo control group.
Of note, however, and as reported by The Guardian, a Japanese health ministry source suggested the drug was not as effective in people with more severe symptoms, quote: “We’ve given Avigan to 70 to 80 people, but it doesn’t seem to work that well when the virus has already multiplied”.
Importantly, and as reported by The Independent the Japanese officials also said that the drug could cause fetal deformities and should perhaps not be used by pregnant women or those trying to conceive.