UK – Sandoz and Hexal v. Searle and Janssen Sciences Ireland

Posted: May 16th, 2017


The UK Patents Court has recently handed down its decision in Sandoz v G.D. Searle.  Arnold J held that Searle’s SPC for darunavir (Prezista) is valid and refused to refer a question to the CJEU for a preliminary ruling regarding the application of Article 3(a) of the SPC Regulation to Markush formulae.

Searle’s SPC is based on EP (UK) 0 810 209 (the “Patent”) which the defendants contended protected darunavir within the meaning of Article 3(a).  The Patent claimed a class of compounds said to be useful as retroviral protease inhibitors and thus the treatment of retrovirus infections such as HIV.  It claimed the compounds, as is normal in the pharmaceutical field, using a Markush formula.

A Markush formula specifies a backbone chemical structure together with substituents usually donated as R1, R2, etc.  Potential substituents are then specified in the claims.  Markush formulae may cover a small number of compounds but normally patents with such claims will cover many hundreds of thousands.  The claimant’s unchallenged evidence was that claim 1 of the Patent was estimated to cover between 7 x 10^135 and 1 x 10^377 compounds.  It was not disputed that darunavir was one of the compounds falling within claim 1.

The validity of the Patent was not in dispute and the only attack on the SPC was based on Article 3(a).  The claimants’ case was that the test under Article 3(a) was unclear and that a preliminary ruling from the CJEU was required.   The defendants accepted that Article 3(a) was unclear (for example see Arnold J’s earlier decision for a preliminary ruling in Teva UK Ltd v Gilead Sciences Inc [2017] EWHC 13 (Pat)) but said that under any tenable interpretation of Article 3(a) darunavir was protected by the patent.

Arnold J first considered (at [62]) his previous commentary on the CJEU decisions of Medeva and its progeny where he had expressed the view that the “specified” or “identified” test was unclear.  Indeed, at that time he had said it was not clear whether it was “sufficient, say, for the claim to incorporate a Markush formula which covers a large number of compounds one of which is the product in respect of which an SPC is sought” (Novartis Pharmaceuticals UK Ltd v MedImmune Ltd [2012] EWHC 181 (Pat) at [53]).

At the time of Medeva, and the string of cases that followed, many commentators used the Markush formula example as one which potentially did not satisfy the “specified” or “identified” test.  The answer, according to Arnold J, was that the CJEU decision in Lilly (C-493/12 Eli Lilly & Co Ltd v Human Genome Sciences Inc) provided enough clarity for this case.  The court in Lilly said that it was sufficient for the active ingredient to be covered by a functional description provided that the claims “relate, implicitly but necessarily and specifically, to the active ingredient”.

Based on Lilly Arnold J said it was clear “that the identification of the active ingredient in the claim by means of a structural formula is permissible, but not essential; that it is not necessary for the claim individually to name or depict the active ingredient; and that it is not necessarily an objection that the claim in question covers a large number of other compounds in addition to the active ingredient in question” (at [63]).

Arnold J was still of the view that the test in Lilly was unclear and difficult to apply (hence the current reference in Teva).  However, in the circumstances of this case it was clear that danavir fell within the relevant test.  Arnold J formulated the test as “it is sufficient for the claim to specify the product by means of a Markush formula which covers it (at least without resort to equivalents)”.

Finally, Arnold J noted that he still preferred the inventive advance (or technical contribution) test that he had first suggested in Actavis v Sanofi ([2012] EWHC 2545 (Pat)) and which he has again suggested to the CJEU in Teva.  He held that darunavir also satisfied this test.

Arnold J noted that in effect the claimants’ contentions were based upon excessive claim breadth and related arguments.  This is relevant to the validity of the underlying Patent but, for reasons that were not explained in the judgment, the claimants had not put validity in issue.

A copy of the judgment can be found here.

Headnote: Ian Turner, Marks & Clerk Solicitors LLP

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