On Antiviral Drug Avifavir, How is it Used to Treat COVID-19?

The Russian Direct Investment Fund (RDIF), Russia’s sovereign wealth fund, and drugmaker ChemRar Group announced Saturday the delivery of the first batch of Avifavir (favipiravir) to Russian hospitals.

With registration certificate from the Ministry of Health of the Russian Federation last week, Avifavir became the first favipiravir-based drug in the world approved for the treatment of COVID-19. On June 3, 2020, the Ministry of Health included Avifavir in the seventh edition of the guidelines for the prevention, diagnosis and treatment of the new coronavirus COVID-19.

Clinics and pharmaceutical organizations in the Moscow, Leningrad, Novgorod, Kirov and Nizhny Novgorod regions, as well as in the Republic of Tatarstan and Ekaterinburg have already received the first deliveries of the drug. 60,000 courses of Avifavir will be delivered to Russian hospitals in June. Production of Avifavir could be increased to two million courses per year if necessary.

Whats is Avifavir ?

Favipiravir is an oral antiviral approved for the treatment of influenza in Japan. It selectively inhibits RNA polymerase, which is necessary for viral replication.

How Does it Work ?

The mechanism of its actions is thought to be related to the selective inhibition of viral RNA-dependent RNA polymerase. Other research suggests that favipiravir induces lethal RNA transversion mutations, producing a nonviable viral phenotype.

Favipiravir is a prodrug that is metabolized to its active form, favipiravir-ribofuranosyl-5'-triphosphate (favipiravir-RTP), available in both oral and intravenous formulations.

Human hypoxanthine guanine phosphoribosyltransferase (HGPRT) is believed to play a key role in this activation process. Favipiravir does not inhibit RNA or DNA synthesis in mammalian cells and is not toxic to them

Effectiveness Against Covid-19:

In February 2020, favipiravir was being studied in China for experimental treatment of the emergent COVID-19. Trials are also being planned in Japan.

A study on 80 people in comparison to lopinavir/ritonavir found that it reduced viral clearance time, and that 91% of people had improved CT scans with few side effects. The limitation of this study was that it was not randomized double-blinded and placebo-controlled.

The drug has been approved for use in clinical trials of coronavirus disease 2019 in China. In March 2020, Italy approved the drug for experimental use against COVID-19 and has begun conducting trials in three regions most affected by the disease.

The Italian Pharmaceutical Agency, however, has reminded the public that the existing evidence in support of this drug is scant and preliminary. There are plans to study it in three hospitals in Massachusetts, USA as of April 20, 2020.As of early May 2020, a trial is starting in London, UK.

The drug was approved for the treatment of COVID-19 in the hospital settings in Russia on May 29, 2020, after an ongoing open-label randomized clinical trial had recruited 60 subjects on favipiravir.

According to the government clinical trial registry, this study COVID-FPR-01 is expected to recruit 390 subjects overall and finish by December 31, 2020.

On May 30, 2020, the Russian Health Ministry approved a generic version of favipiravir named Avifavir. RDIF backed the development of Avifavir and found it highly effective in the first phase of clinical trials.