On 3rd May 2017 Mr Justice Arnold handed down his judgment in Sandoz v Searle  EWHC 987 (Pat), the latest in a series of recent cases concerning supplementary protection certificates (SPCs). The product of the SPC in this case, darunavir, fell within the scope of a Markush claim in the basic patent, but the Claimants alleged that the SPC was invalid under Article 3(a) of the SPC Regulation because darunavir is not “specified” or “identified” by name or structure in any of the claims of the patent. Arnold J considered the earlier decisions of the Court of Justice of the European Union (CJEU) and found that darunavir was protected by the patent, so the SPC complied with Article 3(a).
Markush formulae are a type of chemical shorthand that allow large numbers of related chemical compounds to be represented as a single genus. Sandoz argued that merely falling within the scope of a Markush claim was not enough because of the “immense breadth” of the claims at issue, saying that “a Markush claim does not specify or identity a product unless the skilled person would consider the product to be part of the subject-matter of the patent based on their reading of the specification and their common general knowledge”.
Arnold J considered the successive CJEU decisions on Article 3(a), in particular Case C-322/10 Medeva and Case C-493/12 Eli Lilly v HGS, noting that a product must at least fall within the scope of the claims of the basic patent to fulfil Article 3(a). In Medeva, the CJEU held that the product must be “specified in the wording of the claims of the basic patent”, while in Eli Lilly v HGS it later clarified that it is not necessary for the active ingredient to be identified in the claim by means of a structural formula: it is 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”.
Arnold J points to the CJEU’s Eli Lilly v HGS decision as evidence that the number of other compounds covered by a structural formula cannot be a factor in the assessment of Article 3(a) – as if this were so, Eli Lilly v HGS (where the claims were to an antibody was functionally defined in terms of its target protein‑binding activity, potentially encompassing thousands of antibodies) would have had a straightforward and negative answer in his opinion. He concluded that, by falling within the scope of a Markush claim, darunavir is sufficiently protected by the basic patent under Article 3(a). The SPC was therefore held to be valid.