TOKYO—Drugmaker Shionogi & Co. Ltd. has applied for approval to make and sell its oral COVID-19 treatment in Japan, the firm said on Friday. Known as S-217622, the drug would become the country’s third antiviral pill approved for coronavirus patients, following those developed by Pfizer Inc. and Merck & Co.. In a statement, Shionogi said it was seeking conditional early approval of the drug after completing the Phase IIb part of a Phase II/III clinical trial in Japan and South Korea. The study, involving 428 patients, reached its primary endpoint in reducing viral titres, but did not show a significant difference in reducing a measure of 12 COVID-19 symptoms. This month, Chief Executive Isao Teshirogi said Shionogi could deliver enough doses for a million people by the end of March.