Japanese pharmaceutical firm Shionogi & Co. said Monday it is looking to apply for approval of its oral COVID-19 drug as early as next week after mid-phase clinical trials showed it was effective in reducing the coronavirus in the body.

The results of "Phase 2a" clinical trials of the drug known as S-217622 are "extremely good," Shionogi President Isao Teshirogi said during a press conference. If approved, it would be the first such pill developed by a Japanese drugmaker.

The company said it intends to file for conditional early approval by the health ministry, aiming to start supplying between 400,000 and 500,000 doses in Japan by the end of February and 1 million doses by the end of March.

Shionogi & Co. President Isao Teshirogi (C) speaks at a press conference in Tokyo on Feb. 7, 2022. (Kyodo)

The drug was developed for mild-to-moderate coronavirus cases, regardless of whether patients are at risk of hospitalization. It is believed to prevent the virus from multiplying in the body.

The Osaka-based firm has confirmed the drug is also effective against the Omicron variant of the virus.

In an analysis of 47 patients with mild-to-moderate COVID-19 symptoms, Shionogi found that subjects who took the drug orally once daily for five days showed rapid reductions in viral load and a tendency toward improvement in symptoms compared with those who were given a placebo.

There were no cases of symptoms worsening in the group that received the drug, while two in the group which took the placebo developed severe symptoms.

The conditional early approval system allows drugmakers to skip the final stage of clinical trials once a certain level of efficacy and safety has been confirmed, according to the Health, Labor and Welfare Ministry.

The system applies in cases where effective treatments for a disease are scarce, and clinical trials may be protracted due to few subjects.

In May 2020, the health ministry gave special approval to remdesivir, an anti-viral drug developed by U.S. firm Gilead Sciences Inc., three days after the company filed the application.

The oral COVID-19 drug Molnupiravir was granted special approval in December 2021, around 20 days after U.S. pharmaceutical firm Merck & Co. filed the application.