Patent term extension: the US PTE, the EU SPC and the UK compared

Two mechanisms, one purpose

Both systems compensate for regulatory delay. The United States does it by extending the term of one patent; Europe does it with a new right, the supplementary protection certificate, that sits on top of the patent. The difference is not cosmetic: it changes what is protected, how long, and who can challenge it.

Side by side

	United States (PTE)	European Union (SPC)	United Kingdom (SPC)
Legal basis	35 U.S.C. § 156 (Hatch-Waxman, 1984)	Regulation (EC) 469/2009	Retained Regulation 469/2009, as amended
What is extended	The term of one chosen patent	A separate certificate on the authorised product	As EU
Term	Half the clinical testing period plus the FDA review period, less any delay by the applicant	First EU authorisation minus patent filing, less five years	First UK or EEA authorisation minus filing, less five years
Cap	Five years’ extension; no more than 14 years from FDA approval	Five years; in effect 15 years from first EU authorisation	As EU
Scope of protection	The approved product, and approved uses, under the extended patent’s claims	The active substance (or combination) covered by the basic patent, for any authorised use	As EU
How many	One patent per approved product, chosen by the holder	One SPC per product per patent holder per country	One per product in the UK
Granted by	USPTO, in consultation with the FDA	Each national patent office	UK IPO
Paediatric reward	Six months of exclusivity added to all patents and regulatory exclusivities (pediatric exclusivity)	Six months added to the SPC	As EU
Challenge	With the patent, in federal court or at the PTAB	Falls with the basic patent; own grounds too	As EU, in the UK courts

The practical differences

The US extends one patent; Europe protects the product. In the US, the holder chooses which patent to extend (usually the compound patent) and the others keep their normal terms. In Europe, the SPC protects the active substance as such: any product containing it infringes, under whichever patent was the basic patent. For a generic, a European SPC is a cleaner wall; a US PTE leaves the other patents to be dealt with separately, which is what Paragraph IV litigation is about.

The clocks start from different events. The US extension is computed from the clinical and review periods; the European term from the gap between filing and first EU authorisation. A product with a long pre-clinical phase and a quick review can have a short US extension and a full five-year SPC, or the reverse.

The 14-year cap in the US versus 15 in Europe. Both systems aim at roughly the same effective life, but they are measured from different approvals (FDA vs first EU) and the US cap is on total remaining life, so the resulting dates can differ by a year or more for the same molecule.

Paediatric rewards differ in kind. The US pediatric exclusivity attaches to every relevant patent and exclusivity; the European extension attaches only to the SPC. A US product can gain six months on a formulation patent; a European one cannot.

National versus federal. A US PTE is one decision for the whole country. European SPCs are granted office by office, with the differences in expiry dates and in grant that follow.

Why a US date is the wrong clock for Europe

Press coverage of “patent expiry” for a global product usually means the US date, because that is where the revenue and the litigation are. The European dates are set by different filings, different authorisations and different extensions, and are commonly later than the US for products approved first in the US and earlier for products approved first in Europe. Semaglutide is the current example: US and Canadian dates fill the headlines while the European SPCs run to the early 2030s.

For launch planning, sourcing and procurement in Europe, read the European registers and treat the US date as context only.

MPA Search covers the European and UK positions; it does not cover US patents.