Rather surprisingly, the Japanese government shows reservations about the drug favipiravir, while the Chinese authorities are already recommending it.
"It is very safe and clearly effective," said Zhang Xinmin, director of the science ministry's China National Center for Biotechnology Development, in a news conference.
The best bet in treating COVID-19 would be if we could find an existing drug that also works for the existing virus. It typically takes years and years to develop a new drug, and even with the immense acceleration we've been seeing in the current situation, it will likely be at least a year before anything hits the market -- it takes a lot of time to check for effectiveness and potential side effects.
But an already-existing drug would have already faced those hurdles and is good to go.
It's also not as 'needle in the haystack' as it might seem. It's not uncommon for drugs to be effective in multiple situations. It's possible that this is also the case here.
With this in mind, several countries and companies are trialing existing, promising drugs. Japan, in particular, seems to be heavily invested in this research avenue, and the results are already paying off.
Fujifilm Toyama developed the drug favipiravir in 2014, selling it under the market name of Avigan. It has been administered to coronavirus patients in Japan since February.
Recently, clinical trials conducted on 200 patients at hospitals in Wuhan and Shenzen showed significant promise. Patients who received the drug had a marked reduction in pneumonia symptoms.
People taking the drug tested negative for coronavirus after a median of four days, compared to 11 days for the control group. Meanwhile, patients treated with favipiravir recovered from fever in 2.5 days on average, compared to the 4.2 days for other patients. Coughing was also reduced from 6.0 days to 4.6 days. Furthermore, only 8.2% of the patients taking favipiravir needed respiratory aids, compared to 17.1% of the patients in the control group were put on devices.
Results suggest that, while not a fail-proof cure, favipiravir has significant potential in reducing the symptoms associated with COVID-19 (including pneumonia-associated symptoms).
There is, however, an issue with favipiravir. Studies carried out in 2014 showed that in a minority of cases, it may cause fetal deaths or deformities, and can be transferred via semen. The Japanese government approved its usage only to fight new or re-emerging influenza viruses. There is clearly a reason to use it here, but Japanese officials are waiting for more clinical results before allowing the drug's commercialization. Similarly, South Korea has also declared its interest in the drug, but has said it will postpone imports until further tests.
However, Chinese authorities are already considering not only imports but mass-producing of the drug. Japan reportedly has a stockpile of 2 million pieces and can commence production immediately.
The HIV treatment drug Lopinavir/ritonavir (Kaletra) is also being tested. It has been administered to at least 54 patients, but appears to only be working when the virus has not severely multiplied in the body. An unnamed individual related to Japan's Ministry of Health Labor and Welfare has been quoted as saying:
"We've given Avigan to 70 to 80 people, but it doesn't seem to work that well when the virus has already multiplied. The same goes for Kaletra."
Also being tested is the drug Remdesivir, which was developed as a treatment for the Ebola virus, and it also shows promise. However, it has only been tested on nine people so far, and clinical results have not been published.
Hydroxychloroquine (Plaquenil), which was developed to treat malaria, is a similar sort of medicine. Of course, several trials with different drugs are also being carried out outside of Japan.
It is still early days, but there is some reason for hope that one such drug might prove effective against COVID-19 and its dreaded symptoms.