Impact of patent-granting differences between Japan and the United States on patent protection for medical methods: insights from genome editing patents

Securing patents in multiple countries has become essential for the development of global medical products. However, differences in national patent systems result in varying patentability standards. Although global claim construction strategies have been applied in practice, these approaches have not yet been systematically organized.
This study examines how the patent scope for patent families of international applications related to genome editing technologies filed in 2013, differs between Japan, where medical method patents are prohibited, and the United States, where such patents are permitted.
For CRISPR-Cas system patents, claim structures varied significantly, even among the corresponding family patents. To navigate these differences, the following strategies were proposed for filing patents in countries that prohibit medical method patents such as Japan:

Convert medical method claims in the U.S. into composition claims that include product inventions, as this process ensures that such claims allow for the enforcement of rights against the suppliers of infringing products.
Clearly define the scope of the claimed use-inventions when specifying the characteristics of the product based on its effects.
Explicitly describe cells produced by a specific manufacturing method within the claimed rights.

Convert medical method claims in the U.S. into composition claims that include product inventions, as this process ensures that such claims allow for the enforcement of rights against the suppliers of infringing products.
Clearly define the scope of the claimed use-inventions when specifying the characteristics of the product based on its effects.
Explicitly describe cells produced by a specific manufacturing method within the claimed rights.