Favipiravir(1) is a broad-spectrum antiviral drug used in the treatment of multiple diseases and is the first drug that has been approved by various countries as an emergency treatment for covid-19. Thailand's Department of Intellectual Property (DIP) has rejected a Thai patent application filed under the compulsory licence system for a specific formulation of Favipiravir in tablet form.

The patent for the original compound of Favipiravir was filed in 1998 by a Japanese pharmaceutical company, Toyama Chemical Co. The first patent application for Favipiravir(2) was filed in 2000 through the Patent Cooperation Treaty (PCT) and was designated in 27 countries, which did not include Thailand. Based on this original application, the patent protection of the original compound had already expired in 2020.

In 2010, applicants filed a patent application for the Favipiravir tablet via the PCT and designated 24 jurisdictions, including Japan, the United States, India and Thailand, and with the European Patent Office. With the exception of India, the corresponding applications in other designated countries have since been granted. The applications in Europe and Japan were considered inventive and were granted in 2013 and 2014, respectively, while in India, a generic version of Favipiravir has already been launched. The application in Thailand, despite having cited the same prior art documents as those in Japan and Europe, was not deemed inventive.

The DIP rejected the patent application for the Favipravir tablet on the ground that the invention lacked an inventive step. However, given the acceptance of the corresponding patent application in other jurisdictions based on the same prior art, it is suspected that the patent could have been rejected for a reason other than not having an inventive step – that is, to ensure the supply of the Favipravir tablet for covid-19 patients in Thailand. Early indication of this was seen at a press conference following the rejection of the application, wherein Vuttikrai Leewiraphan, the DIP's director general, stated: "All sectors are playing their part in coping with the spread of Covid-19, with the common goal to provide people with quick access to necessary drugs."

With the outbreak of covid-19, the demand for Favipiravir has risen significantly and there are now concerns that there may be a shortage of Favipiravir tablets in Thailand. The Government Pharmaceutical Organisation (GPO), the state enterprise that manufactures pharmaceutical products in Thailand, intends to set up a manufacturing centre for Favipiravir tablets to meet such growing demands. Previously, this was not possible due to the pending patent application for Favipiravir tablets. However, now that this patent application has been rejected in Thailand, Thailand is now proceeding to produce the drug for domestic use unencumbered by the patent application. The GPO is now working to establish the manufacture of Favipiravir tablets at the industrial level.

Compulsory licensing has previously been adopted in Thailand in other contexts; for instance, in order to pave the way for cheaper drugs to treat acquired immune deficiency syndrome. It is suggested that approving the drug for compulsory licensing would have been much better to maintain the integrity of the patent system. Such an approach would have served the interests of both the public and the patent system at large.

For further information on this topic please contact Ian Mirandah at Mirandah Asia by telephone (+60 322 788 686) or email ([email protected]). The Mirandah Asia website can be accessed at www.mirandah.com.


(1) T-705; 6-fluoro-3-hydroxy-2-pyrazinecarboxamide.

(2) WO2000/10569 A1.