Fujifilm Holdings Corp. is considering restarting a clinical trial in Japan for its anti-viral drug Avigan in treating COVID-19 patients, company sources said Sunday, after the government held off approval of the drug late last year.

Details, including when the trial would start, methods to be used and target patients have yet to be determined, the sources said. Approval of Avigan could expand treatment options in the country beyond the two currently available.

Supplied photo shows tablets of the anti-influenza drug Avigan. (Photo courtesy of Fujifilm)(Kyodo)

The Japanese government has approved the anti-viral drug remdesivir, developed by U.S. firm Gilead Sciences Inc., and the steroid dexamethasone for COVID-19 treatment.

The use of Avigan could be expanded if the government greenlights it as a COVID-19 therapeutic agent as well. Medical institutions currently offer Avigan to coronavirus patients who wish to have it administered to them as an "observational study."

In December, a health ministry panel judged that it is difficult to reach a conclusion on the effectiveness of Avigan based on the results of clinical testing. But a ministry official said the decision did not entirely rule out the effectiveness of the drug.

Drugmaker Fujifilm Toyama Chemical Co., a unit of Fujifilm, filed for COVID-19 approval in October.

Avigan, also known as favipiravir, has already received approval as an influenza drug. But some medical experts have opposed the use of Avigan for the treatment of coronavirus.

Possible side effects include decreased liver function, but Fujifilm said no new safety concerns were identified. Pregnant women cannot use the drug as some animal studies have pointed to possible fetal abnormalities.

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