An expert panel advising the health ministry on measures to tackle the novel coronavirus decided on July 20 not to approve for now Shionogi & Co.'s oral COVID-19 pill under the ministry’s “urgent approval” system.

Instead, the panel will continue evaluating the pill.

Under the urgent approval system, medicine is rapidly approved for a limited period when an infectious disease is spreading, for example.

Most of the panel members agreed the available data on the pill collected through clinical trials are insufficient to presume its efficacy.

They agreed they should wait for the results of a larger clinical trial, which is in its final stage, to decide whether to grant approval to the pill.

The name of the pill is Xocova, and its generic name is ensitrelvir.

It is believed to be effective in preventing the virus from proliferating in people and is intended for COVID-19 patients with mild or moderate symptoms.

Patients will be advised to take one tablet a day for five days if the pill is approved. 

Shionogi requested at the end of February that the ministry grant the drug “conditional early approval,” which authorizes the use of the medicine even if all clinical trials have not been completed.

However, the conditional early approval is intended for medicine for diseases with few patients, such as intractable diseases or rare forms of cancer, for which it’s difficult to recruit participants for clinical trials.

The urgent approval system was created in May when the revised law on pharmaceuticals and medical devices was enacted in the Diet.

Following this, Shionogi changed its tactics and filed for the urgent approval of the pill.

Under the urgent approval system, a drug’s efficacy only needs to be “presumed” for the medicine to be approved.

This means medicine can be approved even if there is not much data on its efficacy available.

However, the safety of medicine needs to be confirmed under the urgent approval system just like under existing systems.

Shionogi only submitted data from clinical trials on around 400 people to the ministry in February, however. 

Pharmaceutical companies normally submit data on clinical trials conducted on several thousand or several tens of thousands of people when they seek approval for more general medicines from the ministry.

In addition, it wasn’t clear from Shionogi’s data whether the pill is comprehensively effective in alleviating 12 symptoms of COVID-19, such as fatigue or fever.

The data showed the pill is effective in reducing the level of the novel coronavirus in patients, though.

Members of the panel’s subcommittee were divided on its efficacy and postponed a decision at a meeting in June.

On July 20, members of the panel and the subcommittee jointly discussed the pill again.

Among the topics discussed were the efficacy of Xocova, its safety, whether there is other similar medicine and whether it is effective against the Omicron variant.

The experts present largely agreed that Xocova’s efficacy is not clear as data from participants of the clinical trials didn’t clearly show it can alleviate COVID-19 symptoms.

However, some members said it could be possible to presume its efficacy because the clinical trials found the pill can reduce the level of the virus in participants or shorten the period during which they show symptoms.

Other members said it would be helpful to have more treatments against COVID-19 available to prepare for the possibility of the virus spreading further or its mutation.

However, others noted that the pill’s efficacy in improving COVID-19 symptoms is unclear even if the focus is only on symptoms of Omicron patients.

Some members also pointed to the fact that pregnant women can’t take the pill because tests on animals and other sources showed it could cause birth defects in fetuses.

In addition, it could be difficult for doctors to prescribe the pill, some said, because it would be dangerous to take it along with other drugs. 

The same can be said about the oral COVID-19 pill manufactured by Pfizer, which has already been approved for use in Japan.

After the discussion, many members agreed they cannot “presume” the efficacy of the pill.

Another discussion on the pill’s approval is not expected until November, when results of the major clinical trial will be released.

(This article was written by Kai Ichino and Kenji Tamura, senior staff writer.)