The Court of Appeal in Mexichem confirms the utility of ‘Arrow’ declarations is highly fact specific

The Court of Appeal in Mexichem confirms the utility of ‘Arrow’ declarations is highly fact specific


The recent Court of Appeal judgment in the case of Mexichem UK Limited v Honeywell International Inc ([2019] EWHC 3377 (Pat)) reveals how difficult it may be to strike out a claim for an ‘Arrow’ declaration. But, it does not provide much that is new in developing the principles that ultimately will be considered by the trial judge on whether or not to grant an ‘Arrow’ declaration. However, it may give a party who is concerned about a pending patent some encouragement to seek an ‘Arrow’ declaration, since such a claim is likely to bring pressure to bear on the patentee until trial.


Previously, in the case of Glaxo Group Limited v Vectura Limited ([2018] EWHC 375 (Pat)), HHJ Hacon (sitting as a High Court Judge) had struck out just such a claim on the basis that the claimant had not met the threshold for an ‘Arrow’ declaration by referring only to a pending divisional patent. This decision was reversed by the Court of Appeal ([2018] EWCA Civ 1496) which stated that there was no threshold requirement and, as a discretionary remedy, facts would need to be found and utility of the declaration should have been considered.


The decision in the Mexichem case, which was handed down remotely by email pursuant to the Covid-10 Protocol, confirmed that – on this occasion – HHJ Hacon was right to refuse to strike out (or give summary judgment on) the claim to an ‘Arrow’ declaration.


‘Arrow’ declarations are available in certain circumstances for claimants who wish to obtain a declaration that a certain product or process was obvious or not novel as at a certain date. The purpose of such declarations is to allow a claimant to have commercial certainty in the face of possible patents which are pending but not yet granted (and therefore not yet able to be revoked).


In this case, Honeywell sought to argue that the claim to an ‘Arrow’ declaration should be struck out on the basis that it was illegitimate to seek a declaration that a particular idea was obvious at a particular date without reference to a particular product of the claimant. It also said that the declaration sought was not sufficiently clear and that it was too broad to have utility.


The case concerned refrigerants in mobile air-conditioning systems (‘MACs’) for cars and, in particular, Mexichem sought a declaration that the mere idea of using refrigerant “ze” (R-1234ze)) or “yf” (R-1234yf) in a MAC was obvious at particular dates.


HHJ Hacon accepted that the declaration was not “directed at clearing a path for the marketing of a particular product or for the use of a particular process” and that it “aimed at providing a finding of obviousness which can serve as an unchallenged foundation for argument of the inventive step of inventions claimed in patents which may be granted to the defendant in the future.” Nevertheless, he refused to strike out the claim to the remedy.


The point was made by Honeywell to the Court of Appeal that, without reference to a particular product or process, the purpose of an ‘Arrow’ declaration to provide a Gillette defence would be frustrated. That is, there would still potentially need to be a trial about the obviousness of any difference between the idea which had been declared obvious and any additional feature in a patent and allegedly infringing product.


The Court of Appeal took the view that, even if a product were identified in a declaration, it would not be possible to be certain that there was no feature of that product (i.e. one not included within the wording of a declaration) which could not be validly protected by a subsequently granted patent. Although it would be obviously useful for a declaration to be made in relation to every aspect of a product or process, it said that: “what must be established at trial is that it would be useful for specified features of a product which a party wishes to sell to be declared old or obvious” (emphasis added).

That is, it is conceivably useful to make a declaration in respect of specified features and it need not be in relation to all or a multitude of definable features of a product or process. Ultimately, the question of whether such a declaration would be useful would be a matter for the trial judge.


Because the questions are for the trial judge, a party defending an application for strike out or summary judgment only needs to show there is a real prospect of it being able to establish the relevant matters (i.e. utility) at trial. Since utility in such cases will likely involve expert evidence (in this case as to the normal course of enquiry directed to testing a new refrigerant) it is not something that can easily be dismissed at a preliminary stage.


The trial judge will also be in the best position to determine if the declaration is pitched at a level which is commensurate with the patents against which it seeks protection. In this case, the Court of Appeal held that Mexichem had a real prospect of establishing at trial that a declaration in broad terms would be useful in fighting off patents with claims in equally broad terms.


In dismissing the appeal, the Court of Appeal was preserving the discretion of the ultimate trial judge based upon considerations about what could happen at trial. This is reflective of the fact that an ‘Arrow’ declaration is a discretionary remedy and will be influenced by many factors at trial. The Court of Appeal also recognised that a party seeking an ‘Arrow’ declaration does so in order to avoid certain issues being shielded from the scrutiny of the court by the patentee and, given the inherent uncertainty of the way such cases develop (particularly where a patentee de-designates or surrenders its patent), the procedural control afforded to a claimant seeking an ‘Arrow’ declaration should not be underestimated.


This case, therefore, highlights the difficulties in striking out such a claim and confirms that an ‘Arrow’ declaration is a useful tool for a party wishing to take the initiative in respect of as yet ungranted patents. We await the trial judgment (and any appeal) to see to what extent the principles referred to by the Court of Appeal may be determinative in the grant of a declaration.

Category: Latest Insights | Author: Daniel Byrne | Published: | Read more