History of Favipiravir in Timeline

Favipiravir, also known as Avigan, is an antiviral drug primarily used in Japan for influenza treatment. This pyrazinecarboxamide derivative is being researched for its potential in treating other viral infections, such as SARS-CoV-2, along with experimental antivirals T-1105 and T-1106.

2013: Mechanism of Action of Favipiravir

As of 2013, research suggested that favipiravir-RTP, a nucleoside analogue, mimics both guanosine and adenosine for the viral RdRP, potentially halting primer extension.

December 2014: Clinical Trial Investigating Favipiravir Against Ebola Begins

A clinical trial to study the use of favipiravir against Ebola virus disease was initiated in Guéckédou, Guinea, in December 2014.

2014: Favipiravir Approved for Medical Use in Japan

Favipiravir, developed and manufactured by Toyama Chemical (a subsidiary of Fujifilm), received approval for medical use in Japan in 2014.

2014: Favipiravir Approved for Stockpiling Against Influenza Pandemics in Japan

In 2014, Japan approved favipiravir for stockpiling to combat potential influenza pandemics.

2014: Japan Approves Favipiravir for Treating Influenza Strains

In 2014, Japan approved favipiravir for treating influenza strains that do not respond to existing antivirals.

2014: Favipiravir Shows Potential Efficacy Against Ebola in Mouse Models

Research conducted in 2014 suggested that favipiravir might be effective against Ebola based on studies using mouse models, although its efficacy in humans remained unknown.

2016: Fujifilm Licenses Favipiravir to Zhejiang Hisun Pharmaceutical Co.

In 2016, Fujifilm granted a license for favipiravir to Zhejiang Hisun Pharmaceutical Co.

2016: Preliminary Results of Favipiravir Trial for Ebola Presented at CROI

Preliminary findings from the favipiravir Ebola trial, presented at the Conference on Retroviruses and Opportunistic Infections (CROI) in 2016, revealed a reduction in mortality among patients with low to moderate viral loads. However, no significant effect was observed in patients with high viral loads.

2019: Favipiravir Becomes a Generic Drug

Favipiravir became available as a generic drug in 2019.

July 2020: Coronavir Approved for Hospital Use in Russia

In July 2020, Russia approved Coronavir, the brand name for favipiravir, for use in hospitals to treat COVID-19.

September 2020: Meta-Review Notes Clinical and Radiological Improvements with Favipiravir

A rapid meta-review in September 2020, analyzing four studies, indicated that favipiravir led to clinical and radiological improvements. However, it did not show a reduction in mortality or differences in oxygen-support needs.

September 2020: Coronavir Approved for Outpatient Use in Russia

In September 2020, Russia approved Coronavir for prescription sales, making it available for outpatient use.

2020: Favipiravir Approved to Treat Influenza in Japan

In 2020, Japan approved favipiravir for the treatment of novel influenza strains, showing low resistance development probability.

March 2021: Widespread Prescription of Favipiravir for COVID-19

Despite limited efficacy data, favipiravir was widely prescribed for outpatient treatment of mild to moderate COVID-19 in Egypt, Hungary, and Serbia as of March 2021.

May 2021: Large-Cohort Clinical Trials on Favipiravir Underway

As of May 2021, large-cohort clinical trials were being conducted to further evaluate the efficacy and safety of favipiravir.

Feb 2024: Cochrane Systematic Review Finds No Real Benefit of Favipiravir for COVID-19

A Cochrane Systematic Review published in February 2024, found that Favipiravir does not provide significant benefits in treating COVID-19, including mortality, mechanical ventilation, or hospitalization rates, and may not impact adverse effects.