Third time’s not a charm

Welcome to the third and final part of the SPC drama miniseries on Patent my French, still courtesy of guest blogger Lionel Vial.

Spoiler alert: I would never have thought that the fate of an SPC application would be at least partly decided based on a number of bibliographic citations – and yet…

The Easter egg which was missing from the latest post has finally been found again.

The last of the three decisions we discuss today was rendered by the Paris Cour d’appel on February 9, 2021 following an appeal against a decision of the French patent office (INPI) to refuse SPC application No. FR16C1004.

The SPC application was filed by Wyeth and the General Hospital Corporation on the basis of European patent No. EP 1848414 filed on February 2, 2006 and of marketing authorization (MA) No. EU/1/16/1086 granted in 2016 to Astrazeneca for Tagrisso® (osimertinib mesylate).

Tagrisso® is indicated for the treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations (i.e. mutations of EGFR which cause cancer), and in particular for treating those patients who harbor a T790M mutation-positive EGFR (i.e. the amino acid threonine (T) in position 790 of the EGFR is substituted by a methionine (M)).

Osimertinib

Osimertinib is a Tyrosine Kinase Inhibitor (TKI) which irreversibly inhibits EGFRs harboring sensitizing-mutations (EGFRm) (i.e. mutations causing cancer) and the TKI-resistance mutation T790M.

Astrazeneca obtained an SPC for osimertinib on the basis of the MA and of European patent No. EP 2736895 filed on July, 25, 2012, which claims osimertinib as such.

The SPC application of Wyeth and the General Hospital Corporation was based on claim 23 of the basic patent which relates to a pharmaceutical composition for use in treating cancer in a subject with a cancer having a mutation in EGFR, wherein the mutation is a substitution of a methionine for a threonine at position 790; and wherein the pharmaceutical composition comprises an irreversible EGFR inhibitor.

Claim 24, which depends from claim 23, further gives a list of irreversible EGFR inhibitors: EKB-569, HKI-272 and HKI-357, which are structurally related to gefitinib, an EGFR inhibitor sensitive to the T790M mutation.

The SPC application was refused by the INPI on August 1, 2019 pursuant to Article 3(a) of Regulation (EC) No. 469/2009 (hereafter the “SPC regulation”). The INPI in particular considered that while the claims of the basic patent did implicitly and necessarily relate to osimertinib, they did not specifically relate to it, since osimertinib was neither mentioned in the specification of the patent nor identifiable as such.

The Cour d’appel essentially based its reasoning on the judgement handed by the CJEU on April 20, 2020 in case C‑650/17 (Royalty Pharma):

1. Article 3(a) of Regulation (EC) No. 469/2009 of the European Parliament and of the Council of 6 May 2009 concerning the supplementary protection certificate for medicinal products must be interpreted as meaning that a product is protected by a basic patent in force, within the meaning of that provision, if it corresponds to a general functional definition used by one of the claims of the basic patent and necessarily comes within the scope of the invention covered by that patent, but is not otherwise indicated in individualized form as a specific embodiment of the method of that patent, provided that it is specifically identifiable, in the light of all the information disclosed by that patent, by a person skilled in the art, based on that person’s general knowledge in the relevant field at the filing date or priority date of the basic patent and on the prior art at that date.

2. Article 3(a) of Regulation No. 469/2009 must be interpreted as meaning that a product is not protected by a basic patent in force, within the meaning of that provision, if, although it is covered by the functional definition given in the claims of that patent, it was developed after the filing date of the application for the basic patent, following an independent inventive step. (emphasis added by the Cour d’appel).

Regarding the first part of the Royalty Pharma test the Cour d’appel considered that:

To demonstrate that the person skilled in the art could specifically identify osimertinib as an irreversible inhibitor of the EGF receptor, the appellants only put forward allegations, arguing that the skilled person needed only perform standard enzymatic inhibition assays distinguishing EGFR irreversible inhibition from the reversible inhibition of EGFR, said assays being comprised in the basic knowledge of a biochemist […], without submitting any evidence, such as scientific publications or declarations from persons skilled in the art in support of their thesis.

Besides, the court observes that several years of research were necessary to precisely and specifically identify osimertinib as an active product, since osimertinib was only claimed in a patent on July 25, 2012 by Astrazeneca, which confirms that upon reading all the information contained in the [basic] patent in the light of its knowledge, this product was unknown to the person skilled in the art at the filing date in 2006. The skilled person could not directly and unequivocally infer [osimertinib] from said patent, its discovery being the result of several years of complex research.

Regarding the second part of the Royalty Pharma test the Cour d’appel considered that:

The appellants however argue, in the light of the Royalty Pharma judgement, that while osimertinib was developed after the filing date of the basic patent application, the inventive activity which led to the authorized product was not ‘independent’ since the inventors of the Astrazeneca patent relating to osimertinib based their work on the EP’414 basic patent and on scientific publications, in particular a KWAK publication of 2005 (Mr. Eunice KWAK being one of the inventors of the EP’414 basic patent), since an AVIZIENYTE publication of 2008, of which Mr. Richard WARD was a co-author (and also a co-inventor of Astrazeneca’s EP’895 patent in which osimertinib is identified) referred to the KWAK publication of 2005 […].

While these elements demonstrate that the EP’414 basic patent has undoubtedly enriched the state of the art and contributed to research relating to EGFR inhibitors, they do not establish that the active product osimertinib, which has led to the Tagrisso medicinal product, would not be the result of an independent inventive activity.

In this regard, the Cour finds that while Astrazeneca also filed two US patents US 8946235 and US 9732058 on July 25, 2012 and on December 19, 2014, relating to this active product, which mention the basic patent as prior art, fifteen other patents are also cited as prior art, which counterbalances the appellants’ allegations.

Similarly, it should be noted that if the AVIZIENYTE publication of 2008 mentioned the KWAK study of 2005, it also mentions thirty-one other bibliographic references.

Accordingly, the refusal of the SPC application was upheld by the Cour d’appel.

We must say that we are not entirely convinced by the simple quantitative approach adopted by the Cour d’appel for determining if the work underlying Astazeneca’s EP’895 patent is independent from the work which yielded the basic patent EP’414. Indeed, simply counting the total number of references cited by a patent or a scientific publication does not take into account the fact that not all cited references relate to the subject of interest, e.g. some of the cited references may only relate to minor experimental procedures, nor that not all cited references have the same scientific weight. In our opinion, it could be more relevant to establish the influence exerted by a publication/patent on following publications/patents, which can be estimated by counting the number of times the publication/patent has been cited by others, that is to say its impact factor. In this regard, it should be noted that the KWAK 2005 publication was cited more than 1000 times (Google Scholar count) which is a huge number. By comparison the AVIZIENYTE publication of 2008 was cited 93 times (Google Scholar count). We are not sure if this establishes whether the inventive activity leading to osimertinib depends from the work forming the subject-matter of the landmark KWAK 2005 publication and of the EP’414 patent, as the CJEU is rather elusive as to what constitutes an independent inventive activity, but in our opinion it is likely that this seminal work gave birth to a new field of research, i.e. searching for irreversible EGFR inhibitors useful to circumvent the T790M mutation, which eventually led to osimertinib.

With this decision we end our series of three recent decisions of the Paris Cour d’appel rendered on SPC refusals by the INPI. The final score is a spectacular hat trick (3 – 0) in favor of the INPI against SPC applicants.

Strikingly, if we perform a rapid statistical analysis of the decisions of the Paris Cour d’appel rendered on refusals of SPC applications by the INPI and discussed on this blog since 2016, we find that the Paris Cour d’appel upheld 100% (10/10) of the SPC refusals.

The odds of obtaining a reversal of a refusal decision are therefore clearly not in favor of SPC applicants. As such, if this trend were to continue, the best thing that could be expected from an appeal against a refusal of an SPC application by the INPI would be a reference for preliminary ruling by the CJEU, as e.g. in the Santen case (C-673/18). And indeed, all three decisions we discussed attempted to obtain a reference for a preliminary ruling, which the Cour d’appel however refused to pursue.

Thanks again Lionel for making my life easier reporting on this recent SPC case law – and for incidentally teaching me a sports-related idiom (definitely not my forte).

Is it fair to generally consider that, if a second patent filed after the publication of the basic patent gets granted and if it specifically claims an active ingredient which is generally covered by the basic patent, then there is almost no way the basic patent can be validly relied upon for an SPC application on that active ingredient?

Anyway, we will make sure to do something special on this blog next time an SPC refusal is overturned on appeal.


CASE REFERENCE: Cour d’appel de Paris, pôle 5 chambre 1, February 9, 2021, Wyeth LLC & The General Hospital Corporation v. Directeur général de l’INPI, RG No. 19/19410.

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