TOKYO (BLOOMBERG) - The lead researcher on a trial of the Japanese antiviral Avigan to treat Covid-19 said it's too early to make a call on whether the drug works or not, and patients are still being enrolled.
Final results of the trial for the drug, which is manufactured and sold by Fujifilm Holdings Corp, is expected around July, Dr Yohei Doi, who is leading the trial at Fujita Health University, said in an interview with Bloomberg News.
Dr Doi's comments came amid conflicting reports over the drug's efficacy. Japanese media reports on Wednesday (May 20) said the off-patent drug was not effective based on interim analysis of Dr Doi's trial, but Prime Minister Shinzo Abe has said he expected the treatment to be approved for use this month.
Dr Doi said that time line seemed tight given how few days remain this month.
Fujifilm Falls Fujifilm shares fell as much as 4.9 per cent in Tokyo trading Wednesday on the reports, which Dr Doi said were misleading as they're based on an interim analysis - an independent mid-point review of the results.
"Interim analysis is a routine procedure in these clinical trials," Dr Doi said, "and it was not meant to evaluate efficacy."
Dr Doi's trial, sponsored by Japan's Ministry of Health, is not connected to two separate randomised control trials Fujifilm is running - one in Japan and one in the US.
The Japan trial is in progress and is expected to be completed in June, a Fujifilm spokesman said. The US 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 non-conclusive 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 press briefing Wednesday that Japan is targeting an approval for Avigan this month if its safety and efficacy has been proved. Fujifilm said the company has not filed an application to approve Avigan to treat Covid-19 with the Japanese government.
Avigan, also known as favipiravir, has been promoted heavily by the Japanese 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 of stopping RNA replication, is approved for use in Japan to treat novel influenza.
An early Chinese study of favipiravir, which was not randomised, showed it helped clear the coronavirus in patients earlier than an antiviral HIV medication. 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, Dr Doi is prevented from seeing the interim results to maintain objectivity, but said he expects it was likely inconclusive as he is still continuing the 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.
