The Itch That Couldn't Be Scratched: Merial lose appeal in Omnipharm "flea patent" dispute

The AmeriKat demonstrates what a cat would do
if they had an itch from a flea, not that she has any
experience of course....

Question: How valuable are "flea and tick killer" patents? Answer: Very valuable. Merial's best-selling Frontline products, for example, rake in $1 billion global sales per year. No surprise then that Merial owns patents on these formulations. Two of these patents - the '881 patent and the '564 patent (GB No. 2,317,564)- were subject to this morning's Court of Appeal decision in Omnipharm v Merial [2013] EWCA Civ 2. The '881 patent relates to "spot-on" formulations of the parasiticide fipronil for protecting small animals against ticks and fleas. The '564 patent related to spot-on formulations for the same purpose but comprising of fipronil and an insect growth regulator (IGR). "Spot-on" formulations are parasiticide formulations which are applied to the small area of the animal's back usually between the shoulder blades.

Unlike Merial, however, Omnipharm considered that these two patents weren't so valuable. In 2010, Omnipharm brought a revocation action claiming that the two patents were invalid on grounds of obviousness and insufficiency and, in case they were wrong on the revocation claim, requested that the court find that their own proposed products would be non-infringing. In response, Merial applied to amend the patents by limiting the scope of the claims. Mr Justice Floyd allowed the proposed amendments to the '881 patent and held the patent to be valid. He also granted Omnipharm a declaration that that three of the four of its proposed products did not infringe the '881 patent. The '564 patent did not fair as well. The judge found that although the formulation was inventive, it was insufficient and was thereby revoked.

Merial - represented by big guns Andrew Waugh QC and Tom Hinchliffe (3 New Square) - appealed arguing that Mr Justice Floyd errored in principle in finding that the '564 was invalid for insufficiency and in ordering Merial to pay 40% of Omnipharm's costs (excluding the costs of various interim applications). Omnipharm - represented by the dynamic duo that is Henry Carr QC (11 South Square) and Tom Mitcheson (3 New Square) - unsurprisingly said that the judge was correct on insufficiency. In applying the rule that if you are making a Court of Appeal outing anyway you might as well fire off some cross-appeals, Omnipharm filed two cross-appeals based on the insufficiency arguments. But because in the early days of the appeal the Court of Appeal quickly heard and decided that the '564 patent was invalid for insufficiency the cross-appeals died a quiet death.

The Skilled Addressee and Common General Knowledge

The AmeriKat hopes never to have
an appointment with Dr. Flea...

It was agreed that the skilled addressee was "an unimaginative team, comprising of a veterinary parasitologist and a formulation scientist, working in a veterinary healthcare company interested in the development of pesticides and their formulation."

Each party called two experts, but of particular interest to the AmeriKat was Merial's expert called Professor Michael Dryden from Kansas State University who has become widely known as "Dr. Flea". Purrrrrr…..

The judge also outlined the common general knowledge that the skilled team would be taken to possess including knowledge about fleas and their habits, the method and effectiveness of parasiticides and the variety of excipients available to them to assist in the delivery of any parasiticide formula. A special Katpat goes to Mr. Justice Floyd for providing us with the term "transdermal distribution" - also something forming the common general knowledge of the skilled team. Transdermal distribution refers to the way in which the formulations are transmitted into the bloodstream through the layers of skin. The skilled team would also know of the existence of some parasiticides which, following application on a single point on the animal's skin or along a line down the back of the animal, would lead to its distribution over the whole of the animal's body without the formulation ever entering the animal's bloodstream (dubbed "dermal non-systemic distribution"). Importantly, the team would not, however, understand why or how this happened.

The '564 Patent

'564 Patent - meet your nemesis

Claim 1 of the '564 patent entitled "Insecticidal combination effective against fleas on mammals, particularly cats and dogs" claimed the following

A composition which provides small mammals with long-lasting protection against fleas, which includes, on the one hand, [fipronil]

and, on the other hand, at least one ovicidal compound (B), of insect growth regulator (IGR) type,

in a fluid vehicle which is acceptable to the mammal and suitable for local application on the skin;

wherein the fluid vehicle and the concentration of the [fipronil] and (B) are adapted for point application to the skin by deposition of the "spot-on" type;

wherein in the composition:

[fipronil] is present in a proportion of from 5 to 15 % (percentage as a weight per unit volume W/V); and

(B) is present in a proportion of from 1 to 20 % (percentage as a weight per unit volume W/V).

The Insufficiency Appeal

Merial argued that the judge made four main errors of principle to his approach on sufficiency. These were as follows:

(1) The judge failed to take into account the whole of the teaching of the '564 patent: Merial argued that the judge only took into account the fact that the '564 patent taught a solvent, a co-solvent and anti-nucleating agent and ignored the active ingredients including fipronil and the insect growth restrictor, the disclosure of the nature of various classes of excipients (including the preferred excipients) and the instructions as to the amount and location of formulation to be applied. Merial also argued that the results of the successful testing of the formulations showed that they were efficacious. Overall this provided detailed guidance to the skilled team to work the invention and there was no evidence that any of the formulations of the invention would not be efficacious.

Lord Justice Kitchin, giving the judgment of the court, was unable to accept this argument. The trial judge did refer to and had in his mind the various components that Merial claimed he failed to consider. Further, the mere broad recital of various components, including those that were already commonly known, without specific concentrations (the ranges were to broad to be useful) or details as to why particular ingredients were preferred over others was not sufficient. Further, the test results did not contain any teaching other than details that there should be a crystallization inhibitor, an organic solvent and an organic co-solvent in the formulation. In short, the factors referred to above did not teach the skilled team how to formulate the product comprising of fipronil and an insect growth regulator.

Lord Justice Kitchin

(2) Omnipharm failed to adduce any evidence that the '564 patent could not be put into effect in any particular way and the judge ought to have found that it had failed to establish the patent is insufficient: The '564 patent did not include any exemplification of the formulation of a spot-on involving the two active ingredients - fipronil and IGR. This, the judge held, was fatal to sufficiency. Merial argued that this was wrong because the Patents Act 1977 does not require that the patent provide for specific examples. Further, Merial pointed out there was an example on page 16 of the patent which described five different pairs of active ingredients which were said to be formulated in a liquid medium comprising a crystallisation inhibitor, a solvent and co-solvent.

Lord Justice Kitchin rejected these submissions. The Court of Appeal held that Floyd J did not find that the lack of examples per se was fatal to the sufficiency of the '564 patent, more that the absence of a proper exemplification of a formulation of the invention in circumstances where the specification was "generally inadequate to guide the skilled person to success and provided no real practical assistance beyond the teaching of the prior art and the common general knowledge" was fatal to sufficiency. Further, Kitchin LJ stated:

"The specification contains no more than a very broad indication of the components of the formulation and, as the judge found, it is not a sufficient description to enable the skilled person to arrive at formulations across the breadth of the claims without undue effort."

As regards to the second point, the teaching on page 16 was held to be limited to the fact that a representative solvent, co-solvent and anti-nucleating agent should be chosen.

(3) The judge’s conclusion was inconsistent with the whole of the evidence: Merial argued that there was no evidence upon which the judge could have concluded that the '564 patent was insufficient. There was no evidence, for example, that anything falling within the scope of the claims did not work. The judge in assuming that there was such evidence effectively reversed the burden of proof.

Lord Justice Kitchin did accept that the burden of establishing that the patent was insufficient rested upon the shoulders of Omnipharm, but did not accept that the judge had no evidence to conclude that the '564 patent was insufficient (see below).

Fipronil

(4) The conclusion was contrary to all the evidence: The assessment of insufficiency involves a multi-factor evaluation by the judge of all the evidence against a statutory test which is expressed in simple terms. A finding of insufficiency must be treated with respect by an appellate court. An appellate court should, as Lord Hoffmann explained in Biogen v Medeva [1997] RPC 1, be very cautious in differing from a judge's evaluation unless it can be shown that the judge erred in principle or reached a perverse conclusion. Merial argued that the formulation experts of both parties - Professor Hadgraft and Dr. Walters - considered that implementing the formulation would be routine and that the judge had no evidence before him that the '564 patent would place undue burden on the skilled man.

Kitchin LJ again disagreed. After turning to the evidence of each of the experts, the he stated:

"So, in summary, the '564 patent provided the skilled team with a theory of dermal distribution and lists of solvents and excipients with which to set about the task of formulating the claimed combination of actives. But they would have had no understanding of that theory or which solvents and excipients should be employed to put it into practice, and no examples to assist them. As Professor Hadgraft himself said, it would be necessary to find a single set of conditions that provide adequate solubility, penetration, redistribution and stability for both actives at the same time. On the evidence before the judge, this was not a routine task and the '564 patent provides little by way of practical assistance. I am therefore satisfied that the judge had a proper evidential basis upon which to find the patent insufficient."

The Costs Appeal

The only time you should be happy
to see an arguement for "squeezing"
in a patent case...

Omnipharm had argued at first instance and on appeal that it was the winner. Its commercial objective was to clear a path so that it could bring the proposed formulations of fipronil onto the UK market without risk of being sued for patent infringement by Merial. In 2010, Omnipharm sent the formulations of their four proposed products to Merial requesting acknowledgements that they were non-infringing, but Merial did not respond so the revocation proceedings were brought. Before trial, three of the four products were acknowledged in Merial's filed defence to not infringe the '881 patent but because the broad claims of the '564 could have covered the four products the revocation case proceeded to the hearing. At first instance the obviousness attack failed, but the insufficiency attack succeeded so the '564 patent was revoked. Omnipharm thus achieved its key commercial objective in clearing the path and argued that it had won .

After recanting the rule on costs in patent actions, Mr Justice Floyd agreed that it was Omnipharm who was the overall winner. The judge in recognizing that the issues of obviousness and sufficiency were so "plainly interrelated" (i.e. there was a genuine "squeeze" arguement) Merial should be afforded a discount on Omnipharm's costs based on their success on obviousness. As such, the judge awarded Omnipharm 40 % of their costs.

At first instance, Merial contended that it was successful in relation to the '881 patent which survived the attack and which gave sufficient protection in respect of fipronil on its own or in combination with insect growth regulators (i.e. it covers the Frontline products). In other words, the '881 patent was the "jewel in Merial's crown". For this reason, Merial argued that it had won. On appeal, however, Merial argued that given that both parties were successful the judge should have concluded there was no overall winner and further and there was not a genuine squeeze argument .

After explaining that the appellate court had wide discretion as regards to costs and should only interfere with the lower court's exercise if it had "exceeded the generous ambit within which reasonable disagreement is possible" (Tanfern v Cameron-MacDonald [2000] 1 WLR 1311), the Court of Appeal held that judge was entitled to hold that Omnipharm was the overall winner, that Merial should pay 40% of Omnipharm's costs (i.e. receiving a 60% discount of Omnipharm's costs) and that there was a genuine squeeze argument.


All in all a successful day for Omnipharm and further indication from the Court of Appeal following the decision in Biogen that it will be reluctant to interfere with first instance decisions on sufficiency as they are, as stated by Merial in this case, "a kind of jury question which should be treated with appropriate respect by an appellate court". The same applies for costs orders. Unfortunately for Merial however, it seems that the points of principle at issue in this appeal was just one itch that could not be scratched by the Court of Appeal.