Fujifilm Toyama Chemical has announced plans to stop developing its anti-influenza drug, Avigan Tablet (favipiravir), for usage as a Covid-19 therapy.

Last year, the company commenced a Phase III clinical trial of the drug in Japan. 

The trial had a target subject enrolment of 316 participants to validate the efficacy of Avigan in averting Covid-19 progression to severe symptoms in patients who are unvaccinated. 

The ratio of patients whose symptoms became severe was the trial’s primary endpoint.

In March this year, enrolment in the trial was halted after enrolling 84 subjects. 

This move came after the circumstances changed including inoculation rate improvement and the spread of the Omicron variants of the SARS-CoV-2 virus which have reduced the rate of symptom severity compared to other strains. 

Clinical findings from these 84 participants were assessed subsequently and found to be not significant. 

Therefore, Fujifilm decided to stop further development assessing the efficacy of Avigan against Covid-19. 

The company will also withdraw its request to partially modify manufacturing and marketing approval for Avigan in the country to treat the disease.

In March 2014, Avigan received manufacturing and marketing approval to treat new or re-emerging influenza viruses in Japan. 

The government may consider giving this medication to patients if required following a new or re-emerging influenza virus outbreak, to which other anti-influenza therapies are not effective or have inadequate effects.

Phase II trial of Avigan was launched by the company in April 2020 to treat Covid-19 patients in the US.

This trial was intended to assess the safety and efficacy of the drug as a potential therapy for Covid-19.