Beijing Higher People's Court in a recent judgment holds that a Markush claim may include multiples technical solutions and thus may claim partial priority, i.e. some of the technical solutions may claim a priority while other solutions cannot. This holding is very welcome to owners of pharmaceutical patents.
The judgment was made out of an invalidation action against Gilead Sciences's patent No. 97197460.8 which relates to drug Tenofovir for treating hepatitis B.
This judgment is also a rare win for foreign pharmaceutical companies in defending their patents in China, by which Gilead has its patent upheld at least for now.
The court's detailed reasoning deserves a careful reading:
A Markush claim is different from generalization via a generic term,and is not a single monolithic technical solution.
Depending on the specific circumstance, a Markush claim may include a limited number of technical solutions that are clearly separable and thus are alternatives in parallel, in which case the claim can enjoy partial priority.
It is wrong to deny the whole priority claim merely on the grounds that the general formula in the subject claim is different from the general formula disclosed in the priority application. Instead, considerations should be given to the parallel alternatives that may be included in the claim.