Fujifilm Toyama Chemical has commenced a new Phase III clinical trial of its anti-influenza drug Avigan tablet (generic name: favipiravir) in Japan for treating Covid-19 patients.

In 2014, Avigan had received domestic manufacturing and marketing approval for treating new or re-emerging influenza viruses.

The drug works by selectively hindering RNA polymerase linked to influenza viral replication. The company expects that it could work against the novel coronavirus, which is also an RNA virus of the same kind as influenza viruses.

The double-blind, placebo-controlled clinical trial will analyse the efficacy and safety of the drug in patients with early-onset Covid-19 who are at the risk of progressing to severe symptoms.

It will enrol subjects aged 50 and above who are at risk of developing serious conditions, such as people with underlying diseases and obesity, within 72 hours of Covid-19 onset.

The ratio of patients who progress to severe disease in Avigan versus placebo groups will form the primary endpoint of the trial.

The design of the trial is based on the findings from a Phase III clinical study implemented last year, which showed that Avigan accelerated symptom improvement in early-onset Covid-19 patients.

In March last year, Fujifilm began a Phase III clinical trial of Avigan in Japan for treating Covid-19 patients with non-severe pneumonia.

The trial met the primary endpoint, with a statistically significant difference. The company filed an Application for Partial Changes for Avigan’s manufacturing and marketing approval.

Using 156 subjects as analysis targets, the median value of primary endpoints was 11.9 days for the Avigan group versus 14.7 days for the placebo group.

Fujifilm, in partnership with various strategic partners, is working on scaling up Avigan production for meeting the requests of the Japanese Government and other countries.