The Appellants in this action, Sandoz and Hexal, are appealing Arnold J’s decision to uphold SPC/GB07/038 on the basis that the Markush formulae in the basic patent are sufficient to satisfy the requirements of Article 3(a) of the SPC Regulation (Regulation (EC) No 469/2009). We have previously commented on the facts here and the first instance decision is available here. On 25 January 2018, the Court of Appeal handed down its judgment ([2018] EWCA Civ 49). Whilst provisionally agreeing with Arnold J’s conclusion, the CoA decided that it was necessary to refer a question to the CJEU on the level of specificity and how clearly recognisable a compound must be in a Markush claim to satisfy Art 3(a).

Court of Appeal

Floyd LJ reviewed the relevant case law of the CJEU, focusing on Medeva (Case C-322/10) (the identification test) and Lilly v HGS (Case C-493/12) (the Lilly requirement), including the requirement in Lilly v HGS that to satisfy Art 3(a) the claims must “relate, implicitly but necessarily and specifically” to the product in question.

The issues before the Court of Appeal included, first, whether the Lilly requirement would always be satisfied by a Markush claim which covers the active ingredient. The Court of Appeal considered that there is a “spectrum of specificity” and stated that Markush claims may not feature so low on the spectrum so as to not satisfy any requirement as to specificity at all.

The second issue before the Court regarded the Appellant’s submission that additionally Art 3(a) requires that the specific chosen substituents in question must be amongst those which the skilled person would be able to identify based on his common general knowledge at the priority date (the common general knowledge test). Floyd LJ held that such a requirement is at least arguable, in part due to the view expressed by the German Bundespatentgericht (the BPatG) in the Sitagliptin reference (available in English here) that the functional formula in that case and the Markush formula in this case are “absolutely comparable” for the purposes of Art 3(a). The result being that the BPatG may take the view that a Markush formula – at least in a case like the present – may fail to provide protection within Art 3(a).

In putting forward its own position, the CoA noted the “undesirable consequences” that could occur should the common general knowledge test be required (principally the difficulty the test would present to European patent offices when examining SPC applications) and expressed agreement with Arnold J that a “far better test” for Art 3(a) would be to ask whether the product embodies the “core inventive advance” of the basic patent. However, the Court also suggested that for Markush claims an additional question should be asked, namely “whether the skilled person, considering the claims of the patent on the one hand and the structure of the product in question on the other, would immediately recognise that the active ingredient in question is one of those specified by the formula”. On the assumption that this is the correct question to ask for Art 3(a) purposes, the CoA provisionally agreed with Arnold J that darunavir is protected by the Markush formulae in the basic patent.

Nevertheless, the Court still felt the need to refer the following question to the CJEU:

“Where the sole active ingredient the subject of a supplementary protection certificate issued under [the SPC Regulation] is a member of a class of compounds which fall within a Markush definition in a claim of the patent, all of which class members embody the core inventive technical advance of the patent, is it sufficient for the purposes of Article 3(a) of the SPC Regulation that the compound would, upon examination of its structure, immediately be recognised as one which falls within the class (and therefore would be protected by the patent as a matter of national patent law) or must the specific substituents necessary to form the active ingredient be amongst those which the skilled person could derive, based on their common general knowledge, from a reading of the patent claims?”


A win for the Appellants in this case could have far-reaching consequences. Of over 200 SPCs based on patents that relate to new chemical entities (NCEs) between 1994-2011, between 25 and 33 per cent (reasonably evenly distributed over the 17-year time-frame) are based on patents that do not contain a claim to the specific chemical compound that forms the medicinal product. These patents either contain claims that have Markush formulae covering the specific chemical compound, or they contain claims to a list of compounds that includes the chemical compound. Therefore, a win for the Appellants could open up a significant number of SPCs to invalidity challenges. (The results from A&O’s research into SPCs on the UKIPO’s register between 1994-2011 are discussed here and here).

One must also question whether a win for the Appellants would be consistent with the purpose underlying the SPC Regulation given that a Markush claim will often protect an innovative NCE i.e. it protects the result of significant R&D investment by the SPC holder. However, in the circumstances it is perhaps unsurprising that the Court of Appeal felt obliged to send a reference to the CJEU given the potential for diverging approaches in two of the EU’s most important patent jurisdictions.