(Yicai) Jan. 14 -- Swiss pharmaceutical giant Roche has denied rumors claiming its flu drug has lost effectiveness against some influenza strains.

Baloxavir Marboxil, which is sold under the brand name Xofluza, remains sensitive to influenza viruses worldwide, Roche said today, citing monitoring reports by the World Health Organization and the Chinese Center for Disease and Control Prevention.

The company had already addressed the rumors on Jan. 12, when it claimed no influenza strain had been found to be resistant to Xofluza in China.

China’s National Center for Infectious Disease and a team from Shanghai’s Huashan Hospital led by professor Zhang Wenhong are conducting further research on Xofluza’s drug resistance in China, Yicai learned.

Xofluza has recently been under public scrutiny because of its increased popularity in China after a massive seasonal flu outbreak swept the country, ramping up demand. According to public data, China has become Xofluza’s largest market.

Even though Xofluza is still in the patent protection period, some Chinese pharmaceutical companies have already begun working on imitations. For example, the Baloxavir Marboxil generic tablets developed by CSPC Pharmaceutical Group were approved in China in 2022, but they have not yet hit the market.

Editor: Futura Costaglione