Summary

At the end of June, the CJEU heard the joint referrals from the German Bundespatentgericht (case C-650/17) for Merck’s sitagliptin product and from the English Court of Appeal for Searle’s darunavir product (case C-114/18). The referrals sought clarification of the SPC requirements under Article 3(a) of the SPC Regulation, specifically that an SPC may be granted if the authorised active ingredient or combination of active ingredients is ‘protected’ by a basic patent. Following this, and the introduction of a new two-stage test to assist in this interpretation, the Opinion of Advocate General Hogan has now been published.

A summary of the Opinion is as follows:

  • the two-stage test from Teva v Gilead (C-121/17) applies to both combination and single active products;
  • Article 3(a) does not preclude the grant of an SPC for an active ingredient covered by a functional definition or Markush formula, so long as the Teva two-stage test is satisfied;
  • the two-stage test must be applied from the point of view of the person skilled in the art, on the basis of the prior art at the filing/priority date of the basic patent; and
  • the two-stage test requires that i) the product to which the claims of the basic patent relate is a specification required for the solution of the technical problem disclosed by that patent, and ii) the skilled person would have been able to derive the product in question on the basis of the prior art at the filing/priority date and in light of all the information in the patent in question.

Background to Sitagliptin (C-650/17: Royalty Pharma Collection Trust v Comptroller General of Patents)

This case concerns Royalty Pharma’s application for an SPC for sitagliptin, an active ingredient which, although falling within the functional definition of the claims of the basic patent (EP 1 084 705), was not individualised in the patent and was not developed until after the patent filing date.

The DPMA (the German Patent and Trader Marks Office) refused to grant an SPC on the grounds that the patent lacked any specific disclosure of sitagliptin, and thus did not meet the requirements of Article 3(a). At appeal, the Senate of the Federal Court stayed its decision pending a referral to the CJEU, in view of different approaches being taken by Member States on Article 3(a) and consequent contrasting case law.

Background to Darunavir (C-114/18: Sandoz Ltd, Hexal AG v G. D. Searle LLC, Janssen Sciences Ireland)

Until its expiry on 23 February 2019, Searle held an SPC for its product, darunavir (which was marketed exclusively by Janssen under the brand name Prezista). Sandoz sought to challenge the validity of the SPC in order to clear the way for the launch of its own generic version of darunavir on the basis that whilst the darunavir compound was represented by a Markush formula, it was not identified elsewhere in the patent and therefore it was not protected by a basic patent as required by Article 3(a). Similarly to Royalty Pharma, it was not until six years after the priority date of the patent that darunavir was specifically identified as having the desired effect as a protease inhibitor anti-viral medication used to treat HIV.

The CJEU’s test set out in Eli Lilly & Co Ltd v Human Genome Sciences Inc (Case C‑493/12) was applied. It was held in Lilly that a structural definition of the product is not necessary, so long as the claims relate ‘implicitly but necessarily and specifically to the active ingredient’. Kitchin LJ (leading) agreed with this approach in Sandoz (at paragraph 114), stating that:

In the case of a product with a single active ingredient and a patent with a claim which identifies a number of compounds by means of a Markush formula, all of which compounds embody the core inventive technical advance of the patent, the test should be 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.’

Therefore, in contrast to Royalty Pharma, and despite the lack of a specific reference to darunavir within the patent, the High Court and Court of Appeal agreed that darunavir was in fact specified and therefore a product protected by the patent’s claims. However, both Courts were unsure as to whether a correct interpretation of the Lilly test had been applied (how specifically must the claims focus on the active ingredient?) and so the referral to the CJEU made.

Further ‘clarity’ and a new two-stage test

Whilst the referrals pended, the CJEU handed down further clarification (and also further unanswered questions) of Article 3(a) last year in Teva v Gilead (C-121/17), following a request for a preliminary ruling from the English High Court. Teva sought to challenge the validity of Gilead’s SPC for an antiretroviral medicinal product indicated for the treatment of HIV (marketed under the brand name Truvada). Teva argued there was no evidence that at the priority date of the patent, emtricitabine (an active ingredient working in combination with another active ingredient, tenofovir disproxil. The latter was expressly stated in the SPC and was not in issue.) was an effective agent known to the skilled person and therefore was not protected by the patent in accordance with Article 3(a). Emtricitabine was not specified in the claims of the patent and Gilead instead argued that the expression ‘other therapeutic ingredients’ in the related SPC related ‘implicitly but necessarily’ to emtricitabine, in accordance with the approach taken in Lilly.

Here, the CJEU adopted the Lilly approach and confirmed that active ingredients do not need to be expressly mentioned in the claims to be ‘protected’ by a patent, providing those claims related necessarily and specifically to that combination. For that purpose the CJEU applied a new and more stringent two stage test, from the point of view of a person skilled in the art and on the basis of the prior art at the filing date or priority date of the basic patent:

  1. ‘the combination of those active ingredients must necessarily, in the light of the description and drawings of that patent, fall under the invention covered by that patent, and
  2. each of those active ingredients must be specifically identifiable, in the light of all the information disclosed by that patent.’

In Teva, the CJEU concluded that ‘it does not seem possible that a person skilled in the art, on the basis of the prior art at the filing date or priority date of that patent, would be able to understand how emtricitabine, in combination with tenofovir disproxil, necessarily falls under the invention covered by that patent.’ Back in the UK High Court Mr. Justice Arnold agreed with the CJEU’s conclusion and consequently found Gilead’s SPC for Truvada to be invalid.

However, the two stage test was not entirely satisfactory and it remained unclear (i) whether this could be applied to products consisting of a single active ingredient, (ii) whether the concept of ‘core inventive advance’ was still relevant, (iii) what the relevant date was for assessing whether a product is protected by a basic patent in force and (iv) how specifically the claims must focus on the active ingredient. Therefore the Sandoz and Royalty Pharma referrals continued on, and those were the key issues addressed by AG Hogan in his most recent opinion.

The Opinion of Advocate General Hogan

AG Hogan used the Teva judgment as a guide and considered that it laid down a ‘definitive test’ for the interpretation of Article 3(a) that must be applied by the national courts in ‘concrete cases’.

AG Hogan addressed each of the clarity concerns with Teva in turn. In his opinion, on the basis of Teva, the two-stage test is applicable to medicinal products composed of a single active ingredient, not just combination products. The concept of the ‘core inventive advance’ derived from Actavis v Sanofi (C-443/12) is not relevant in the context of Article 3(a), and Article 3(a) does not preclude an active ingredient which is covered by a functional or Markush formula, provided that the two-stage test is satisfied. Finally, this two-stage test must be applied on the basis of the prior art at the filing/priority date of the basic patent.

He then went in to a little more detail on the two-stage test itself.

For the first stage, he considered that a product which is the subject of the SPC that ‘necessarily falls under the invention covered by the patent’ does not require the product to embody the core inventive advance of the patent. Instead, this part of the test is satisfied if the product to which the claims of a patent relate is a specification required for the solution of the technical problem disclosed by a patent.

For the second stage, AG Hogan considered that for a product to be ‘specifically identifiable’, it must be established that a person skilled in the art would have been able, in light of all of the information contained in a patent, on the basis of the prior art at the filing/priority date, to derive the product in question.

Both cases will now be passed to the CJEU for final a decision.

Comments

AG Hogan’s Opinion gives Applicants some preliminary clarity for interpreting Article 3(a) – the Teva two-stage test is key, and it is necessary to consider whether a product is required for solving the technical problem of the invention and can be derivable from the patent as a whole, at its filing/priority date.

It remains to be seen how much weight the CJEU will give to this Opinion. We will continue to monitor the outcome of these referrals with interest!

The Opinion of Advocate General Hogan delivered on 11 September 2019 can be accessed here.