Japan's Shionogi & Co. believes its COVID-19 pill will easily garner $2 billion in annual sales if it secures U.S. approval, which the company expects to receive in late 2024, its chief executive said.

Xocova, a protease inhibitor like the COVID-19 treatments developed by Pfizer and Merck & Co., was granted emergency approval by Japanese regulators in November, making it the nation's first domestically produced oral treatment for COVID-19.

CEO Isao Teshirogi said that the drug — seen as the biggest of heavy bets by Shionogi on pandemic-related treatments — could be approved in South Korea and China as early as next month.