The team is joined by Guest Kats Rosie Burbidge, Stephen Jones, Mathilde Pavis, and Eibhlin Vardy, and by InternKats Verónica Rodríguez Arguijo, Hayleigh Bosher, Tian Lu and Cecilia Sbrolli.

Monday, 17 July 2017

An improved Improver? - Part 2

Here as promised is the second part of this GuestKat's commentary on Eli Lilly v Actavis UK [2017] UKSC 48, which promises to have much ink spilled and air of various temperatures emitted on its behalf in the coming weeks, months and years. As noted in the first post, the Supreme Court reformulated the Improver questions, originally posed by Lord Hoffmann when at first instance and subsequently further evaluated by him in the House of Lords in Kirin-Amgen, which thoroughly examined the UK approach to patent claims. This GuestKat has regarded Lord Hoffmann's judgment in that case as a definitive guide to interpretation and construction and it is a bit of a shock to see his analysis criticised as "wrong in principle" by the Supreme Court. More on that later. Now we should move on to the other aspects of the case, starting with the question of the role of the prosecution history in interpreting the scope of claims.

The file was not extensive ...
The starting point for the claims of the patent was a claim to "use of a methylmalonic acid lowering agent in the preparation of a medicament useful in lowering the mammalian toxicity associated with an antifolate, and the medicament is administered in combination with an antifolate". Here the "methylmalonic acid lowering agent" is something like vitamin B12 and the antifolate is the pemetrexed derivative. 

In a first attempt at amendment of the claims during prosecution, Lilly offered limitation of the antifolate to "pemetrexed" and of the methylmalonic acid lowering agent to vitamin B12, but the examiner objected that the amendments introduced subject matter beyond that originally filed, contrary to article 123(2) EPC. Reference to "pemetrexed" did not find any basis in the application documents, which referred only to pemetrexed disodium. That, according to the examiner, is a distinct compound from pemetrexed (the free acid). In response, Lilly filed claims limited to the use of pemetrexed disodium in combination with vitamin B12. This led the Supreme Court to the consideration of two important questions: when is it permissible to have recourse to the prosecution history of a patent when considering whether a variant infringes, and whether the prosecution history in this case should alter the provisional conclusion the court had reached on direct infringement.

After looking at the comments of Lord Hoffmann in Kirin-Amgen about the undesirable consequences of permitting reference to prosecution history, and at the approach of courts in other EPC states, the court concluded that it was appropriate to take "a sceptical, but not absolutist, attitude" to reference to the prosecution file "along substantially the same lines as the German and Dutch courts". The comments of the court on the practicalities of reference to the file are interesting. They thought it was tempting to exclude the file on the basis that anyone should be entitled to rely on the content of the patent itself, without reference to other material, "as a matter of both principle and practicality". However, given that the contents of the file are publicly available, there might be occasions when justice might require reference to the file. The court seems to have been influenced in that conclusion by having been told that the contents of the file "are unlikely to be extensive". However, the circumstances in which a court can rely on the prosecution history "must be limited". That meant where (i) the point at issue is truly unclear if one confines oneself to the specification and claims, and the contents of the file would unambiguously resolve the point, or (ii) it would be contrary to the public interest for the contents of the file to be ignored. An example of (ii) would be where the patentee had made it clear to the EPO that he was not seeking to contend that his patent, if granted, would extend to the sort of variant which he now claims infringes.

Applying that to the facts of the case, the court didn't think the prosecution file justified departing from its conclusion on direct infringement. The reason the examiner thought the claims should be limited to pemetrexed disodium was because the specification did not expressly extend to any other anti-folates (although the court seemed to think the examiner was wrong about that, without explaining why). But in the court's opinion, "the whole point of the doctrine [of equivalents] is that it entitles a patentee to contend that the scope of protection "extends beyond the ambit of its claims as construed according to normal principles of interpretation". 

This GuestKat has noted with interest comments which suggest that this case opens the way to a doctrine of "file wrapper estoppel" in the UK, but wonders whether the case really goes much further than existing UK case law which has admitted reference to the file in cases of "admissions against interest" - see for example Rohm & Haas v Collag [2002] F.S.R. 28 and Furr v Truline [1985] F.S.R. 553. The refusal of the court to admit reference to the file in this case is consistent with the court not regarding the limitation to the disodium salt during prosecution as determinative of whether the patentee could argue for scope of the claim to include other salts or the free acid after grant based on the reference to equivalents in Article 2 of the Protocol. Presumably the court took the view that Lilly had not "made it clear to the EPO that [it] was not seeking to contend" that the patent, if granted, would extend to other salts such as pemetrexed dipotassium. 

Such an approach might open the door to more difficulty in interpreting a claim from the point of view of infringement, if one cannot decide on the question of equivalents without recourse to external resources such as expert evidence. Note that the court itself says that answering its question (ii) "does the variant nonetheless infringe because it varies from the invention in away or ways which is or are immaterial?" raises questions "which would normally have to be answered by reference to the facts and expert evidence". This seems potentially to admit far more extraneous material into the process of claim construction than reference to the file, which at least is self contained, even it may sometimes be more "extensive" than the court had been led to believe. 

This GuestKat is impressed with the number of comments which the first post on this case has generated on the question of claim scope and interpretation, and thanks those who have contributed to an intelligent debate on the subject. The Supreme Court was clearly influenced in its decision by its study of the case law in other European countries, for example these quotations from the Bundesgerichtshof: that a variant will infringe if (i) “it solves the problem underlying the invention with modified but objectively equivalent means”, (ii) this would be recognised by the person skilled in the relevant art, and (iii) that person “focus[sing] on the essential meaning of the technical teaching protected in the patent” would regard the variant “as being equivalent to the solution” offered by the invention (Case No X ZR 168/00, 2002 GRUR 519 (Schneidmesser I). It seems to this GuestKat that in the context of the present case, this leads to a focus on the practical and technical solutions which an appropriately skilled person might regard as "equivalent" to the solution defined by the claim, with less regard to the actual words which the drafter has used to express that solution. It is not clear to this Kat whether this makes a patent attorney's job easier or more difficult, particularly if the object of clear wording in the claim might be to exclude embodiments which the drafter wants to exclude, for example if they fall within the prior art. It also surely means that the scope of a claim can't be definitively determined without recourse to material outside the patent specification, such as expert evidence (as considered above), which surely makes the job of advising on infringement more difficult. No doubt debate on the meaning and consequences of this decision will continue for some time to come. 

Taking another pause for breath at this point, the remaining aspects of this case will be explored in Part 3 of this series.


John said...

Now that we do have a doctrine of equivalents and a limited file wrapper estoppel doctrine the UK courts may want to also look to the US where the Festo decision quite nicely thought about the interaction between the two, i.e. where a claim has been amended it cannot have doctrine of equivalents.

Presumably doctrine of equivalents is also going to have to be responsive to 'equitable' considerations in judgements since it needs to take into account patentee behaviour and decisions, such as poor drafting or attempting to use the equivalent coverage where the normal coverage could not have been obtained based on inventive step, sufficiency or added matter considerations.

It seems we have 2 things to consider/decide:
- should equivalents coverage be obtained for good, honest behaviour leading to an unfair coverage being available if only the normal coverage is the only coverage
- should equivalents cover variants that the patentee could not have predicted (and so did not cover with normal coverage), but which they deserve to cover due to the nature of the contribution?

MaxDrei said...

This, I think, is a good case for debating whether the EPO's "Gold Standard" is fair. Does the disclosure of a document really amount to not one jot or tittle more than what the skilled reader derives from it "directly and unambiguously"? I think the answer is Yes, but I'm sure others will differ.

We look at the application as filed, which matured into the patent in suit. We look for disclosure of the key "intermediate generalization", the required intermediate layer of the onion, if you will, the one that limited the anti-folate to pemexetred (not the di-sodium class member but, rather, the pemetrexed "class" as such).

Basically, it is missing, isn't it? a bit unfortunate, that, what? So I categorize this as a case where the less than perfect drafting cost the patent owner a fortune in litigation costs, even if the owner came out OK in the end.

Applicant's diffidence, not pushing for the intermediate generalization, is very understandable. What else could he do?

The SC has displayed admirable humility and drive for international harmonization with the EPO White Book. Somehow I cannot imaging the TBA shifting from its Gold Standard any time soon. Not because of this case anyway.

But I'm not a chemist. What say other readers?

Rowan Freeland said...

The concern that assessment of infringement will require external resources is well expressed but nothing new. See for example Southco v Dzus No 1 [1989] R.P.C. 82, final paragraph:

"the guidance given in the Catnic case requires the court to conclude what would be the view of the skilled man in the art reading the specification. Even though construction is for the court, it is difficult for the court to come to a certain view as to what a skilled man would consider essential or nonessential without being educated as to the surrounding facts. This can seldom be done without evidence and cross-examination."

We now call the questions "equivalents" but we have lived with them under the guise of "purposive construction" for quite some time.

Observer said...

Dear Max Drei,

I strongly disagree that, especially this case, should be a pretext to open a discussion about the "golden standard" as defined by the TBA.

Opening Pandora's box would be fatal to the system. If national judges consider it necessary to go much further than what is actually disclosed directly and unambiguously in the original disclosure, let them do so, but such a position should not be generalised during prosecution. This is as well valid should the UPC open one day.

By this standard, multiple selection from one list and selection from two lists would be open to endless discussions in the absence of a pointer towards the chosen selection.

The same goes for intermediate generalisation. Unless the applicant/proprietor can show that at the filing date he made the corresponding invention, he should not be granted a monopoly which does not correspond to his contribution to the art.

All the proponents of such arrangements seem to forget one thing: added matter and novelty are the two faces of the same coin. What you lose out on adde matter you gain in novelty.

By the way the "White Book" is not a publication from the Boards of Appeal themselves, but from a department linked to the Boards, and the Boards do not check its content. Some interpretations do not necessarily correspond to the actual content of the decision. Before citing any part of the white book, it is advisable to check the decision itself, rather than its commentary.

Anonymous said...

This does not make any sense:

"Applicant's diffidence, not pushing for the intermediate generalization, is very understandable. What else could he do?"

Why try to import the meaning of the word "diffidence" into this situation?

MaxDrei said...

Sorry, but I have no idea why my use of the word "diffidence" is not apt. Can anybody enlighten me?

Proof of the pudding said...

As far as I can see, a determination of claim scope will now require lawyers to seek the opinion of a skilled person on two points.

Firstly, what does the skilled person understand to be covered by the wording of the claims? This is the "normal interpretation" mentioned by the SC (which, according to the House of Lords in Amgen v TKT was the only interpretation).

Secondly, the skilled person will also be asked to opine on whether an allegedly infringing embodiment represents an "immaterial variant" of the claimed invention.

The second point is an entirely new step that picks up where previously all analysis would have stopped.

If I am correct to characterise the SC's infringement test in this way, then this means that determining freedom to operate just got a whole lot more expensive (and uncertain). If you add in the HUGE unknowns (and possible flip-flopping / forum shopping) that will be introduced if and when the UPC gets up-and-running, then one could be forgiven for getting the impression that we can kiss goodbye to the concept of legal certainty for the foreseeable future.

MaxDrei said...

Observer, with me at least, you have no disagreement. In my earlier post, my own answer to my own question "Is the EPO Gold Standard fair?" was "Yes".

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