Thin Disclosure But "Bulletproof" Protection: How A Salt Form Patent Was Upheld In China Despite Minimal Data

In China, innovative drug companies typically rely on their initial composition of matter patents to block out competitors. Other "follow-on" IP, such as those directed towards formulations, polymorphs, and salt forms, are often regarded as less likely to survive invalidation challenges, especially in China where the standard of "person skilled in the art" is so high.

Having said that, we share below today a positive counter example case in which a salt form of a JAK inhibitor survived invalidation. This case is one of CNIPA's Top Ten Patent Re-examination and Invalidation Cases for 2024 (published in the 2025 list). These cases are meant to be guiding cases, showcasing exemplary real-world decisions that clarify certain aspects of the law.