Teva UK Ltd & Anor v Leo Pharma A/s

In assessing obviousness, the court must consider the facts as a whole and ask whether the claimed differences would have been obvious to the skilled person, viewed without hindsight. A project may be obvious where common general knowledge supplies the motivation and a prior document supplies a candidate technical component. The skilled person is an empiricist: the prospect of success need not be certain, but must be sufficiently fair to make testing worthwhile. Commercial and regulatory considerations may be relevant, but ordinarily carry less weight than technical considerations. A step-by-step analysis is legitimate where it reflects the normal sequence of research and development rather than an artificial hindsight reconstruction.

Teva sought declarations that two Leo patents concerning non-aqueous topical compositions combining calcipotriol and betamethasone for treating psoriasis were invalid. Leo alleged that Teva’s proposed generic product would infringe, and applied to amend the claims. Teva’s principal challenge was lack of inventive step, based on common general knowledge concerning fixed combinations and a US patent, Turi, disclosing polyoxypropylene-15-stearyl ether as a solvent in topical corticosteroid preparations. The court also considered insufficiency, added matter and infringement, but the central issue was whether the claimed formulation was obvious.

1. Obviousness framework. The court applied the structured approach in Pozzoli v BDMO [2007] EWCA Civ 588: identify the skilled person and common general knowledge; identify the inventive concept; identify the differences from the state of the art; and ask whether those differences required invention. The ultimate question remained one of fact, as emphasised in Medimmune v Novartis [2012] EWCA Civ 1234.
2. The skilled team comprised a clinician and a formulator. A fixed combination of calcipotriol and betamethasone was an obvious clinical objective because it offered convenience and improved compliance. A non-aqueous ointment was an obvious formulation route because it reduced, without eliminating, problems caused by the different pH stability profiles of the active ingredients.
3. The court applied the guidance on “obvious to try” in LEO Pharma v Sandoz [2009] EWHC 996 (Pat) and Omnipharm v Merial [2011] EWHC 3393. The relevant question was whether success was sufficiently fairly expected to justify testing, not whether it was certain. On reading Turi, the skilled formulator had sufficient reason to include polyoxypropylene-15-stearyl ether in routine screening tests. Its unfamiliarity and regulatory history did not outweigh its disclosed properties and apparent suitability.
4. The court held that the claimed formulation would have been obvious. The claims of both patents were therefore invalid for lack of inventive step. Insufficiency did not arise, the added-matter issue was not decided, and Teva’s product would have infringed the relevant claims if valid.