UK Supreme Court Adopts Doctrine of Equivalents for Patent Infringement

On July 12, 2017, in Actavis UK Limited v Eli Lilly ([2017] UKSC 48) the UK Supreme Court adopted the doctrine of equivalents for patent infringement. This decision is very significant in that applying the doctrine of equivalents can capture variants that are outside of the claim language, even after applying a “purposive construction”.

The Supreme Court set out the following questions to determine infringement:

1. does the variant infringe any of the claims as a matter of normal interpretation; and if not; and

2. does the variant nonetheless infringe because it varies from the invention in a way that is immaterial; and if yes, infringement.

   Regarding question 2 above, the Supreme Court provided the following guidance:

1. Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, i.e. the inventive concept revealed by the patent?

2. Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?

3. Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?

In order to establish infringement in a case where there is no literal infringement, a patentee would have to establish that the answer to the first two questions was “yes” and that the answer to the third question was “no”.

The patent at issue in this case claims the use of pemetrexed disodium (Lilly’s ALIMTA®) in the manufacture of a medicament in combination with vitamin B12 for cancer treatment. Actavis’ products contain pemetrexed diacid, pemetrexed ditromethamine or pemetrexed dipotassium (Actavis Products). Although it found that the Actavis Products do not fall within the expression “pemetrexed disodium” in claim 1 under a normal interpretation, the Supreme Court still found infringement. In particular, it found that it was very unlikely that the notional addressee would have concluded that the patentee could have intended to exclude any pemetrexed salts other than pemetrexed disodium, or the free acid, from the scope of protection.

Summary By: Junyi Chen