The lead researcher in the coronavirus trial for flu drug Avigan says it’s too early to make a call on whether it works and shrugged off negative reports about the interim results, saying patients are still being enrolled.
The final results of the trial for the antiviral, made and sold by Fujifilm Holdings Corp., are expected around July, Dr. Yohei Doi said in an interview. Doi is leading the testing at Fujita Health University.
Doi’s comments came amid conflicting reports over the drug’s efficacy. Local media reports Wednesday said the off-patent drug was not effective against COVID-19 based on an interim analysis of Doi’s trial, but Prime Minister Shinzo Abe has said he expects the drug to be approved for use this month.
Doi said Abe's timeline seems tight, given the few days remaining this month.
Fujifilm shares fell as much as 4.9 percent in Tokyo trading Wednesday on the reports, which Doi said were misleading as they’re based on an interim analysis — an independent midpoint review of the results.
"Interim analysis is a routine procedure in these clinical trials,” Doi said, "and it was not meant to evaluate efficacy.”
Doi’s trial, sponsored by the health ministry, is not connected to two separate randomized control trials Fujifilm is running — one in Japan and one in the U.S. The Japan trial is in progress and is expected to be completed in June, a Fujifilm spokesman said. The U.S. trial is targeted for completion in December.
As the coronavirus continues to spread, upending economies and life around the world, drug companies have been racing to develop treatments and vaccines. Any early and nonconclusive news on these potential medicines has prompted knee-jerk reactions from investors, shifting trillions of dollars in value in the markets.
Shares of vaccine developer Moderna Inc. and drugmaker Gilead Sciences Inc., which manufactures another potential COVID-19 drug, remdesivir, have whipsawed in past weeks off similar types of news.
Chief Cabinet Secretary Yoshihide Suga confirmed at a news briefing Wednesday that Japan is targeting approval for Avigan this month if its safety and efficacy are proven. Fujifilm said the company has not filed an application to approve Avigan to treat COVID-19 with the government.
Avigan, also known as favipiravir, has been promoted heavily by the government despite the lack of conclusive evidence about its efficacy, and has been donated to over 80 countries in recent months. The drug, which has the potential to cause birth defects because of its mechanism for stopping RNA replication, is approved for use in Japan to treat influenza.
An early Chinese study of favipiravir, which was not randomized, showed it helped clear the coronavirus in patients earlier than an antiviral HIV medication did. The treatment was not added to the recommended COVID-19 regimen in China after an official said in March it was considering the matter.
As the principal researcher, Doi is prevented from seeing the interim results to maintain objectivity, but said he expects it was likely inconclusive as he is still continuing enrollment.
The interim analysis is done to check if the drug "is working way better than expected or if there’s unexpected adverse events. That doesn’t seem to be the case either way,” he said.