The Court of Appeal has referred questions to the CJEU in Sandoz v Searle on the meaning of Article 3(a) of the SPC Regulation which requires that a 'product is protected by a basic patent in force'. Interestingly, in doing so, it took a different approach to Mr Justice Arnold, who has made a series of referrals to the CJEU on the meaning of Article 3(a) but, in this case, had concluded no reference was necessary.
The SPC (SPC/GB07/038) relates to darunavir (sold under the mark Prezista) and concerns a Markush claim, i.e., where a class of compounds is represented by means of a structural formula, thereby allowing large classes of compounds to be defined without being listed out. As we discussed in the July 2017 edition, Arnold J decided that the product was specified or identified in the claims of the patent, even though it was not specifically identified by name or structure in the claims or anywhere in the specification, nor was there any teaching in the patent which pointed to darunavir and in particular its novel and unusual P1 group.
In reaching this conclusion, Arnold J referred to the CJEU's Lilly decision concerning functional claims which he said shed light on the Medeva test and suggested that it was sufficient for the claim to specify the product by means of a Markush formula which covers it - at least without resort to equivalents. On that basis, darunavir was 'protected' by the patent. However, he remained of the view (as he had expressed in Actavis v Sanofi and Teva v Gilead) that a better test would be one requiring that the product should embody the inventive advance (or technical contribution) of the claim. On the facts of this case, and applying that test to the Markush claim, it would mean that the inventive advance lay in the identification of the compounds covered by claim 1 as having utility (as HIV protease inhibitors), and darunavir embodied that inventive advance.
Sandoz argues that it is necessary to show that the skilled team would recognise the product as forming a part of the subject matter of the patent by reference to a careful reading of the patent based on the common general knowledge at the priority date. It argued this test was not satisfied here given the large number of compounds covered by the claim and the unusual nature of the P1 substituent on darunavir. It also argues that Arnold J's 'inventive advance' test is wrong in principle, at least when applied to a Markush claim.
Having reviewed the series of CJEU decisions on Article 3(a), as well as a recent German referral (Sitagliptin) on functional claims, Floyd LJ identified the core question as being: how specific must the claims be? He agreed with Searle's counsel that there is a spectrum of specificity: in some circumstances, a Markush claim could amount to a sufficiently precise claim. However, this did not mean that an active ingredient will be adequately identified by a Markush formula, however broadly it is framed, and however obscure the particular substituent required to form the active ingredient that is the subject of the SPC.
He concluded that it was arguable that the substituent must be one which the skilled person would be able to identify based on their common general knowledge at the priority date, albeit he recognised that such a test would be difficult for patent offices to apply. Ultimately, he agreed with Arnold J that the inventive advance test was a 'far better' one, disagreeing with Sandoz that it was inadequate in relation to Markush claims.
If he had thought he could reach a conclusion, Floyd LJ's provisional finding would have been that darunavir was protected by the claims of the patent: in the case of a product with a single active ingredient and a patent with a Markush claim, where all the compounds embody the core inventive technical advance, the test should be whether the skilled person considering the claims of the patent and the structure of the product, would immediately recognise that the active ingredient in question was one of those specified by the formula. That test was, he said, met here.
However, it was not clear that this was the correct approach in EU law, and so a reference to the CJEU was necessary. The Defendants argued that a reference would be futile given that the SPC will expire in February 2019 and it is very unlikely that the CJEU will be able to answer the reference and the UK court apply its answer before then.
In the meantime, the Grand Chamber of the CJEU heard argument in Teva v Gilead on 20 February. It remains to be seen how it will respond to Arnold J's invitation to revisit his inventive advance test.