Considerations for Developing a Global Patent Term Extension Strategy

The length of PTE is generally linked to the period of patent term lost to the pre-marketing approval process of a regulated product. Maximum PTE is capped at 5 years in most jurisdictions. Canada, however, plans to set maximum PTE at 2 years. In some jurisdictions (e.g., Japan), PTE is only accumulated for that portion of the regulatory review during which the patent is already in force. Thus, in Japan, prosecution should be accelerated if possible to ensure that a patent is already granted before the regulatory review is initiated.

The type of claims that can support PTE significantly vary between jurisdictions. The Japanese system is perhaps the most permissive. Patents with a single composition, use or process claim covering the active compound may be eligible for PTE. There is no requirement that the active compound is recited in the claims. The requirement instead is that the patented invention could not be worked during pre-marketing regulatory review. Thus, in principle, claims directed to a drug delivery system may be eligible for PTE in Japan because it could not be worked without regulatory approval of the drug delivered. Furthermore, in Japan, the pharmaceutical product can be defined by its ingredients, quantity, dosage and administration—pharmaceutical composition for use claims. Thus, regulatory approval for a new dosage or use of an already approved active compound may trigger additional PTE. The Australian system, in contrast, is much less permissive. For a patent to be eligible for PTE, it must claim a new and inventive pharmaceutical substance per se and/or a pharmaceutical substance produced by a process that involves the use of recombinant DNA technology. Medical use claims, for example, directed to a new dosage, are not considered to be directed to the pharmaceutical substance per se and are thus not eligible for PTE. Similarly, claims to a pharmaceutical substance produced by a particular process are not eligible for PTE unless the process involves the use of recombinant DNA technology. Europe falls between these extremes. PTE may be awarded to a patent claiming the active ingredient(s) of an approved drug, a process for producing the active ingredient, or a medical use of the active ingredient.

The scope of protection provided during the extension period is generally reduced compared to the original rights in a patent. For example, in most countries except Australia that allow PTE, the extended patent confers protection on the approved use of the active ingredient(s) or composition and for any additional use that gains regulatory approval before expiry of the PTE.

Jurisdictions also differ in terms of the number of PTE applications that may be based on a single marketing approval, and the number of PTE grants that may be obtained for a single patent. Some jurisdictions are restrictive and allow PTE for a single patent based on a single regulatory approval (e.g., Taiwan) and allow only one PTE for a single patent even if it covers multiple active ingredients (e.g., Australia). Others, including Japan, allow PTE for multiple patents based on a single regulatory approval, and also allow the term of a patent to be extended more than once. Given that in Japan an extended patent’s scope is limited in respect of the active ingredient and its approved use, the scope of protection under a Japanese patent with multiple PTEs changes over time with the expiration of individual PTEs. In jurisdictions that allow PTE for a single patent, care must be taken when selecting the particular patent for which PTE is sought to maximize the amount of PTE and to ensure that the underlying patent will withstand any challenge to its validity. Additionally, if possible to achieve without risk of creating double patenting issues, claims directed to different active ingredients should be pursued in separate divisional applications to ensure that PTE can be obtained after the regulatory approval of each active ingredient.

In summary, patent term extension is available in a wide array of jurisdictions. While the concepts are similar, the particulars of PTE regulations are sufficiently varied across jurisdictions so that a country specific PTE strategy is needed to maximize the economic value of a patent family directed to a regulated composition.