Connecting The Dots: China’s Evolving Standard For Numerical Sub-Range Amendments

Managing global pharmaceutical or chemical portfolios requires navigating China’s notoriously rigid standards on the "same subject matter" requirement for priority and claim amendments. A recent invalidation decision (No. 588094) issued by the China National Intellectual Property Administration (CNIPA) concerning a pharmaceutical patent provides clarity on how numerical ranges and later added experimental data are evaluated in priority claims.¹ More specifically, how much literal support is needed for a claim directed towards a “new” numerical sub-range supported by later added working examples?

The Core Dispute: Priority Over specific Ratios and "Added" Data

The patent at issue protected a pharmaceutical composition comprising Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) and natural borneol (for treating cerebrovascular diseases), specifically claiming weight ratios from 4:1 to 1:1.² The challenged patent claimed priority to an earlier application that broadly disclosed weight