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Teva UK Ltd and Teva Pharmaceutical Industries Ltd v LEO Pharma A/S and LEO Laboratories Ltd (Third Party), Patents Court, 6 October 2014, [2014] EWHC 3096 (Pat), Birss J

The Patents Court held two Leo Pharma patents concerning a treatment for psoriasis invalid on the ground of obviousness.  The case is of interest not only for the unusual way in which the obviousness attack was structured but also due to the Court’s approach to regulatory considerations when assessing obviousness.

The two patents (EP 1,178,808 and EP 2,455,083) related to an ointment treatment for psoriasis comprising a combination of a corticosteroid and a vitamin D analogue with a particular solvent.  Leo Pharma has a successful product marketed in the UK as Dovobet Ointment, which is protected by both patents.  Its sales are substantial.  Teva wished to sell a generic version of that ointment.  Teva contended that Leo Pharma’s patents were invalid on three grounds: obviousness, insufficiency and added matter.  Leo Pharma applied to amend the claims of both patents and contended that the claims in their amended form were valid. Leo Pharma also contended that Teva’s proposed product would infringe the patents.


Teva’s obviousness case involved a single attack based on a combination of common general knowledge and a prior US patent (“Turi”).  It was unusual in the sense that it involved starting with the common general knowledge and adding information from a document (Turi) which was not part of the common general knowledge and which would not be found on a literature search.  Teva relied on the principle that any document forming part of the state of the art must be placed before the skilled person even if it did not lead the skilled person to the invention. Leo Pharma did not challenge the approach in principle and Birss J accepted the approach, but noted that it did not follow that it would always be legitimate to consider obviousness in this way.

Birss J found that on the basis of the common general knowledge alone it would be obvious to the skilled person to attempt to combine the two active agents (a corticosteroid such as betamethasone and a vitamin D analogue such as calcipotriol) in a non-aqueous ointment formulation: “The skilled team would expect a stable, bioavailable formulation to provide a compliance benefit and to be an effective treatment for psoriasis, better than monotherapy. They would be motivated to carry out a clinical study to confirm that expectation. The study would show that formulation was an effective treatment.” 

It would also be obvious to carry out compatibility tests on a number of possible solvents.  Regarding which solvents to test, the judge held that, presented with Turi, the skilled person would have no reason to disregard the teaching of Turi or doubt that the compound taught therein would work as a solvent in the topical preparations of corticosteroids. There was sufficient prospect of a positive result in the tests with this compound to make it worth testing. It was obvious to do so.  The judge concluded: “There is no reason to doubt that the skilled formulator would succeed in producing an ointment formulation consisting of betamethasone, calcipotriol and the compound…Accordingly all of the claims of the patent are obvious”.

Leo Pharma had also argued that the skilled person would not consider it obvious to use the solvent in question as it was not widely used as a pharmaceutical excipient and its use would add potential cost, time and uncertainty to the process of obtaining regulatory approval.  According to Birss J commercial considerations, including the one relied on, are capable of playing a role in the thinking of a notional skilled person as a matter of principle.  However, commercial factors would be unlikely to outweigh technical consideration in any but the strongest cases.  In this case, the regulatory factors were not sufficiently strong to have any material bearing on the decisions made by the skilled person.

The judge declined to deal with insufficiency and added matter arguments in light of his findings on lack of inventive step.  He noted that Teva’s product would plainly have infringed had the claims been valid.

While relatively short, this judgment provides a useful treatise on the approach to obviousness in relation to a pharmaceutical patent in a UK court (paras 50-101 in particular).

Read the judgment here.

Head note: Catriona MacLeod, Bristows