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Teva UK Ltd & Teva Pharmaceutical Industries Ltd v LEO Pharma A/s, England and Wales Court of Appeal (Sir Robin Jacob, Kitchin and King LJJ), London, UK, 28 July 2015, Neutral Citation Number: [2015] EWCA Civ 779

This is an appeal against Birss J’s finding that two LEO patents were invalid for lack of inventive step.  The key claims of the patents were for a combination of the active pharmaceutical ingredients calcipotriol and betamethasone, alongside the non-aqueous solvent Arlamol E.  The patents cover Leo’s Dovobet Ointment product, a dermal treatment for psoriasis.

The Court of Appeal held that Birss J had erred in his application of the law on the assessment of inventive step, thereby allowing the Court of Appeal to revisit the assessment de novo.  It is worth noting that in the absence of an error of principle, the English appellate Courts will be very cautious in differing from the first instance judge’s evaluation of the question of inventive step as it is considered a kind of jury question (see the House of Lords judgment in Biogen v Medeva at paragraph 54).  Sir Robin Jacob (with whom Kitchin and King LJJ agreed) returned to the bench for this appeal and delivered the leading judgment.


The Court of Appeal held that while it was established that the skilled person would know that it would be necessary to use a non-aqueous solvent in order to formulate the two active ingredients, there was not a sufficient expectation of success that the ultimately successful solvent – Arlamol E – would work.  Birss J had held that there was a sufficient prospect of a positive result in the tests with Arlamol E to make it worth testing.  However, the Court of Appeal considered that this amounted to the suggestion that just because a solvent was non-aqueous it would work even though in this case the evidence showed a real problem that had to be overcome.  Therefore Birss’ finding was in essence that the idea of including Arlamol E as part of a research project amounted to obviousness.  This finding was held to be contrary to the case law, which establishes that the “obvious to try” standard requires a higher expectation of success than mere possible inclusion in a research programme.   

A second point of principle on which Birss J was found to have erred was his failure to imbue the notional skilled person with the real practices and prejudices of someone working in the field.  That the skilled formulator would have had a strong preference to work with compounds with which he or she was familiar – of which Arlamol E was not one – was an important consideration that Birss J was wrong to overlook.

Having established these errors of principle, the Court of Appeal held that the use of Arlamol E did represent an inventive step, noting in its reasoning the existence of a long-felt want, the desired solution and no explanation of why that solution was not done before when it could have been.  In short, this was “the classic sort of case where the Courts have found invention over the years”.  The added matter and insufficiency allegations were quickly dismissed. 

The Court of Appeal’s decision accords with a recent decision of the EPO Opposition Division, which had upheld the patents, notwithstanding Birss J’s judgment to the contrary.

Read the decision here

Headnote:  Steven Willis, Bristows LLP