Daiichi Sankyo loses six CNIPA administrative patent-linkage cases over mirogabalin formulation patents 

Context:

• China launched its pharmaceutical patent-linkage system in 2021, broadly similar in function to the U.S. Hatch-Waxman framework. Chemical generic applicants must make a declaration against each listed originator patent, as ip fray previously explained in the Nefecon case (August 17, 2026 ip fray article). Patent-linkage disputes can be filed either in the courts or through CNIPA’s administrative adjudication route (Article 76 of China’s Patent Law). A Category III declaration means the generic does not seek to launch before the patent expires, broadly like a U.S. Paragraph III certification. Category IV declarations challenge listed patents, but unlike U.S. Paragraph IV certifications, they do not separately include unenforceability as a ground. Category IV.1 is based on invalidity, while Category IV.2 asserts that the proposed generic falls outside the patent’s scope.
• Daiichi Sankyo’s mirogabalin portfolio has previously been tested under the Chinese patent-linkage system. The drug was added to China’s national reimbursement list effective January 1, 2025 (Daiichi Sankyo press release, November 2024). Later that year, Chengdu Easton Biopharmaceuticals secured three non-infringement decisions under formulation patent ZL201480001374.3 from the China National Intellectual Property Administration (CNIPA) (CNIPA administrative decisions on drug patent disputes No. 0011, No. 0012 and No. 0013).