Protection for dosage regimes in China
As in many countries, patent claims directed to methods of medical treatment are not allowable in China. Claims for inventions based on methods of treatment must currently be rewritten in the so-called “Swiss” format. This raises an issue when the invention involves only changes in the dosage regime or timing of administration.
In a recent Supreme Court decision in China, the patentability of a Swiss-type claim was considered where the distinguishing features were a lack of skeletal muscle toxicity, a treatment dose of 3-75mg/kg of daptomycin and the treatment dose being administered at a dose interval of 24 or 48 hours. Cubist Pharmaceuticals Inc appealed against the invalidation of the patent, but the Supreme Court ruled that Swiss-type claims are directed to the method of manufacturing a medicament only and features relating to administration and/or the effect after administration should be disregarded. The decision discussed the distinction between unit dose and an administration or treatment dose and confirmed that a treatment dose does not affect the manufacturing process of a medicament and therefore does not limit a Swiss-type claim.
It is possible that specifying that the dose is a unit dose or claiming the packaging as part of the manufacturing process where the packaging states the dosage regime could overcome this issue but this is yet to be tested.