IP Information & News

Mind the validity gap — the effect of the doctrine of equivalents in the UK

The United Kingdom Supreme Court's decision in Actavis v Lilly (12 July 2017) introduced a doctrine of equivalents concept in the United Kingdom for assessing infringement of a claim. Since the decision, there has been significant speculation on what the decision means in practice and how the doctrine will be applied. The question is how far does the doctrine of equivalents extend — does it apply when assessing novelty? In other words, can an equivalent disclosed in the prior art be used to attack the validity of a patent?

In Generics (Mylan) v Yeda and Teva, (26 October 2017) the UK High Court handed down its first substantive decision since Actavis v Lilly in which it considered whether the doctrine of equivalent1 extends to novelty. The patent in dispute related to a dosage form of glatiramer acetate (GA), an immunomodulatory drug marketed by Teva (the exclusive licensee) under the brand name Copaxone, for the treatment of multiple sclerosis (MS).

The court followed the legal tests set out in Actavis v Lilly (2017) to establish whether an equivalent dosage form disclosed in the prior art could be used to destroy novelty of the patent.

The court noted the reasoning in a previous case Synthon v SKB (20 October 2005) that in order to destroy novelty, the prior art must disclose subject matter which would necessarily result in an infringement of the patent claim. However, at the time of this decision, the question of anticipation by equivalents was not considered.

Nonetheless, the court proceeded to conclude that there is no anticipation by equivalents; the claim would only lack novelty if the prior art disclosed subject matter which fell within the claim on its ‘proper interpretation’. Thus, the court held that the doctrine of equivalents does not apply to validity and the prior art dosage form did not anticipate the patent claims.

This decision suggests that for cases where infringement is established on the basis of a doctrine of equivalents, there will be a difference in claim scope for purposes of infringement and purposes of validity — hence giving rise to a ‘validity gap’.

What does the validity gap mean in practice? Could a patentee choosing narrower claim language be less vulnerable to a novelty attack, but nevertheless enjoy broader protection under the doctrine of equivalents? The answer at present would appear to be yes. However, patentees should be aware that the present law on equivalents may change throughout the lifetime of a patent, depending on the type of cases reaching the Supreme Court.

In summary, the decision indicates that doctrine of equivalents is only relevant to the assessment of infringement of a claim, and cannot be extended to validity attacks.

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1 A legal rule that allows a court to hold a party liable for patent infringement even if the infringing product or process does not fall within the literal scope of a patent claim, but instead contains a feature equivalent to a claimed feature.

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