Many jurisdictions provide for the extension of the term of the patents that cover a regulated product. Patent term extension (PTE) is particularly important in the bio/pharma industry given that development of an innovative drug can take more than a decade, biosimilar/generic competition is fierce, and the most profitable period for the patent owner tends to be at the end of the patent term. This article contains a brief discussion of the main considerations for developing a global PTE strategy.

Of the world's major economies, Australia, all European Union member states, Japan, Russia, South Korea, Taiwan, Israel, and the US provide PTE.[1] While Canada does not currently have PTE, it is in the process of establishing PTE regulations as part of implementing the Canada-EU Comprehensive Economic and Trade Agreement. Brazil, China, India, Indonesia, Mexico, Saudi Arabia, South Africa, and Turkey do not allow PTE. Most Central and Latin American countries also do not provide PTE. And in Southeast Asia, Singapore and Brunei are the only countries with established PTE regulations. It's worth noting that some of the jurisdictions without PTE, such as Brazil, China, and India, also place strict limitation on the patentability of biologics/pharmaceuticals. Getting meaningful patent protection in these jurisdictions for bio/pharma inventions is thus critical and requires careful planning.

While all PTE systems share the general idea that it is a compensation for regulatory delays, there are significant country specific differences in the products of which regulatory approval can support PTE, the length of PTE, patents eligible for PTE, and the scope of protection during the extension period. These differences need to be taken into account when developing a global prosecution strategy.

Products that in most countries require pre-marketing regulatory approval include pharmaceuticals, medical devices and agrochemicals. Of these, pharmaceutical compounds can generally support PTE, although some jurisdictions limit the type of active compounds eligible for PTE. For example, under the future Canadian system, new esters, salts, complexes, enantiomers, or post-translational modifications, inter alia, of a medicinal ingredient previously authorized for sale will not be able to support a new PTE award.[2] Medical devices and agrochemicals enjoy less broad protection. Medical devices can support PTE in Japan, but not in Australia, Canada or the EU member states.[3] Agrochemicals can support PTE in European member states and Japan, but not in Australia or Canada.

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.