Omnipharm Ltd v Merial

JurisdictionEngland & Wales
Judgment Date21 December 2011
Neutral Citation[2011] EWHC 3393 (Pat)
Docket NumberCase No: HC10C01772
CourtChancery Division (Patents Court)
Date21 December 2011
Omnipharm Limited

[2011] EWHC 3393 (Pat)


The Hon Mr Justice Floyd

Case No: HC10C01772




Royal Courts of Justice

Strand, London, WC2A 2LL

Henry Carr QC and Thomas Mitcheson (instructed by Fasken Martineau LLP) for the Claimant

Andrew Waugh QC and Thomas Hinchliffe (instructed by Taylor Wessing) for the Defendant

Hearing dates: 10 th, 11 th, 14 th-16 th, 21 st and 22 nd November 2011

Approved Judgment

I direct that pursuant to CPR PD 39A para 6.1 no official shorthand note shall be taken of this Judgment and that copies of this version as handed down may be treated as authentic.


European Patent (UK) No. 0 881 881 and UK Patent No. 2 317 564 which are the subject of this action ("the patents", or "881" and "564" respectively) both relate to treatments for protecting pets or small mammals from fleas. By this action Omnipharm Limited seek revocation of the patents and certain declarations of non-infringement in respect of flea treatments which they claim that they plan to sell. Merial, the proprietors of the patents, have responded by making unconditional offers to amend.


Herman Melville wrote: "To produce a mighty book, you must choose a mighty theme. No great and enduring volume can ever be written on the flea, though many there be who have tried it." By raising multiple issues on each side, both parties have tried to induce me to make another attempt in the latter tradition, an inducement I will try to resist. Henry Carr QC and Thomas Mitcheson argued the case for Omnipharm; Andrew Waugh QC and Thomas Hinchliffe argued the case for Merial.


Both patents are attacked on the grounds of obviousness and insufficiency. Added matter objections arise in relation to certain of the amendments. The UKIPO has raised a possible objection, not pursued by Omnipharm, to one of the amendments. The substance of the non-infringement points is no longer in issue. There is an issue, which now only goes to costs, as to whether Omnipharm have the necessary standing to seek a statutory declaration of non-infringement.



Each side called two expert witnesses: one veterinarian/parasitologist and one formulator. In addition, Omnipharm called its solicitor, Mr Ralph Cox, and Mr Donnelly, its sole director and shareholder.


Omnipharm's veterinary/parasitologist expert was Mr Peter Watson. Mr Watson worked in a mixed (large and small) animal practice from 1975 to 1979, after which he joined Bayer Animal Health in the UK, where he worked until 2002. In that time he occupied the roles of Veterinary Advisor, Veterinary Technical Manager and Registration and Development Manager. Since 2002 he has operated his own consultancy company. Over the years his work involved him in various aspects of insecticides for both large and small animals.


Mr Waugh submitted that Mr Watson was unduly influenced by his experience at Bayer. Whilst it is true that his expert report did refer on occasions to unpublished work at Bayer, I am satisfied that this was done to show that Bayer's activities reflected views which would be possessed by an average person skilled in the art. Mr Watson did his best to put himself in the position of a veterinary parasitologist without any special knowledge internal to Bayer. If one is too critical of the fact that witnesses have a background in industry with one or more companies, we will be left with those with no industrial experience at all. That is undesirable in a field concerned essentially with industry.


Dr Ken Walters was called as Omnipharm's formulation expert. In 1974 he obtained a degree-equivalent qualification, membership of the Institute of Biology, whilst employed by ICI Limited. He obtained a PhD in 1979. From 1978 to 1980 he completed a postdoctoral fellowship at the University of Michigan where he gained experience in drug delivery into and through the skin and its appendages (such as hair follicles). From 1981 to 1986 he was employed by Fisons Pharmaceuticals Limited where he established a section concerned with skin drug delivery. From 1986 he worked for Kodak as a transdermal delivery scientist, and thereafter for Controlled Therapeutics Limited. In 1988 he formed Pharmaserve Limited, a contract research company, where he specialised in percutaneous absorption. Whilst at Pharmaserve he carried out some research for the predecessor of Merial, Rhone-Mérieux, to which I will come in due course. Thereafter, in 1992, he joined An- eX, a company specialising in the percutaneous absorption field. Professor Jonathan Hadgraft, Merial's formulation expert, is a joint owner with Dr Walters, of An- eX. Dr Walters has authored and edited a number of textbooks on percutaneous absorption including a 1993 textbook "Pharmaceutical Skin Penetration Enhancement" which he co-edited with Professor Hadgraft.


Dr Walters undoubtedly is and was a leading figure in the field of delivery of drugs through the skin. In a section of his closing argument directed at the various witnesses, Mr Waugh criticised Dr Walters for some of the evidence he gave about the theory of non-systemic distribution, and other matters. Whilst I shall have to analyse that evidence in due course, I do not doubt that the views which Dr Walters expressed were genuinely held. My task is to assess the extent to which those views represented those of the ordinary and unimaginative skilled formulator.


Merial called Professor Michael Dryden as its veterinary/parasitology expert. Professor Dryden is a Distinguished Professor of Veterinary Parasitology at Kansas State University. He qualified as a veterinarian in the United States in 1984 and was employed in private practice in Kansas from 1984 to 1986 which prompted him to pursue academic research into the study of the flea. This led to an MS in 1988 and a PhD in 1990. He has published widely on flea biology. Since 1990, in addition to his academic work, he has acted as a consultant to the pharmaceutical industry. He was involved in a technical capacity in the launch of Merial's Frontline products in Europe and the United States. He is such a leading figure in this field that he has become nicknamed, as he recognised, "Dr Flea". I consider that he was a frank and helpful expert witness: Mr Carr did not submit otherwise.


Professor Hadgraft is an Emeritus Professor of Biophysical Chemistry at the School of Pharmacy, University of London. His PhD from the University of Oxford involved the application of physical chemistry to an understanding of interfacial transfer and skin penetration. He has held a number of academic appointments, including a chair in Pharmaceutical Chemistry at the University of Cardiff from 1984. He has worked primarily in the field of delivery of drugs through the human skin. He too has acted as a consultant to a number of pharmaceutical companies.


Professor Hadgraft struck me, by and large, as a very rigorous scientist, who seeks out the evidential base for any given scientific proposition. Mr Carr said that he was not representative of the ordinary skilled person because he did not accept that a spot-on topical formulation could be delivered non-systemically. As I shall explain, I accept that Professor Hadgraft's view on this issue would not be held by the ordinary skilled formulator, but again I have no doubt that it was genuinely held. Mr Carr went on to say that Professor Hadgraft gave evidence which was inaccurate and lacked objectivity. There were occasions when Professor Hadgraft's answers were rather combative and inadequately thought out. He sought to explain the fact that companies advertised their products as "non-systemic" on the basis that it was suggesting that the compound was non-systemic with respect to the flea. This was certainly a peculiar suggestion. He also made assertions as to the similarity of human and animal skin which were shown not to be justified. I have treated his evidence with a degree of caution as a result, endeavouring to judge the extent to which his evidence is supported by documents.


Mr Cox was cross-examined about the notes he prepared of a conversation with Professor Hadgraft, with which I deal below. His evidence was careful and considered. Mr Waugh said he had not kept a note of every word that was said on the telephone. That is not a criticism of Mr Cox, nor could it be of anyone.


Mr Donnelly was called to deal with Omnipharm's standing to seek a declaration of non-infringement. He was a loquacious witness. His evidence at times was unsatisfactory, as for example when he answered a question put to him on Omnipharm's financial affairs by saying "I am happy to accept that whatever you say is correct". This was not an appropriate attitude to giving evidence on oath, or assisting the court. As a result I have treated his evidence with caution. That is not to say that I should reject the whole of his evidence.

Technical background



Fleas are classified as ectoparasites, as they inhabit the exterior of the host animal. For present purposes it is sufficient to focus on fleas.


Flea saliva is highly allergenic. Constant exposure to flea bites leads to flea allergic dermatitis or FAD. Fleas can also spread disease. Their safe elimination is therefore an important priority for animal owners and vets.


The life cycle of the adult flea starts with the adult female flea taking a blood meal from the host, mating and laying small, non-sticky eggs on the host. The eggs fall from the host into the environment, together with flea faeces which contain partially digested blood and which provide a food source for the hatching larvae. The larvae crawl into dark areas such as under furniture or in carpets and continue to feed on organic debris. After a period of...

To continue reading

Request your trial
8 cases

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT