A statistical analysis of multiple clinical trials that assessed Fujifilm’s antiviral Avigan (favipiravir) as a COVID-19 treatment has found that the drug showed limited efficacy in reducing mortality unless given early to infected patients.

In a meta-analysis of nine Avigan trials, a team of Iranian researchers concluded that the antiviral, which is approved in Japan for treating influenza but has not received any FDA approvals to date, appeared to provide no significant benefit overall against mortality in patients with mild-to-moderate COVID-19.

The analysis, published as a preprint in medRxiv, did find that the antiviral led to a significant clinical improvement vs. the control group seven days after patients were hospitalized, leading the researchers to consider that the drug may be a useful COVID-19 treatment if given early.

“We should consider that perhaps the use of antiviral once the patient has symptoms is too late and this would explain their low efficacy in the clinical setting,” the researchers said.

But they also noted limitations in the studies, such as different dosages and durations of intervention, and said they found it hard to determine the clinical improvement seen in patients given the antiviral, due to differing disease severity, ages and other medical conditions across the studies, which enrolled a total of 827 participants.

An application by Fujifilm for authorization of Avigan as a COVID-19 treatment in Japan was stalled in December when the country’s health ministry decided the available data were inconclusive.

Last month, Dr. Reddy’s Laboratories — which has exclusive rights to develop Avigan outside of Japan, China and Russia — called it quits on a phase 3 trial in Kuwait that was evaluating the drug in hospitalized patients with moderate-to-severe COVID-19. The company said that data from its initial interim analysis suggested the antiviral could be effective as an early treatment but did not support it as a late-stage hospital treatment for moderate and severe patients.

Dr. Reddy’s late-stage U.S. trial assessing the drug as an early coronavirus treatment is ongoing.

Read the full analysis here: bit.ly/3avSSH6. — James Miessler