Patent Baristas

In a case highlighting the importance of ensuring a correct chain of title when filing a patent application, the UK High Court addressed the issues of loss of priority due to an incomplete assignment, as well as the credibility of expert witnesses.  In particular, it is important to transfer rights to interests initially owned by consultant inventors as soon as possible — especially before the declaration in respect of the claim to priority needs to be made, i.e.,  within 12 months of the date of filing of the priority application.  See, Edwards Lifesciences AG v Cook Biotech Incorporated [2009] EWHC 1304 (Pat) (12 June 2009).

Edwards manufactures the SAPIEN artificial heart valve designed to be compressed onto a balloon catheter for percutaneous delivery via the femoral artery. It can also be delivered transapically through the side of the chest and into the apex (the bottom of the left ventricle) of the heart in patients with severe aortic stenosis. It is primarily used to replace the aortic valve but is also suitable for replacement of the pulmonary valve.

Cook alleged the SAPIEN infringes its patent and Edwards denied infringement and challenged the validity for lack of novelty, obviousness, insufficiency and added new matter. That is, Edwards said the matter disclosed in the specification of the European Patent as granted was extended beyond the original disclosure in the application for the patent as filed.

The international application which led to Cook’s European patent was filed on January 31, 2001, claiming priority from a US patent application filed on January 31, 2000. The claim to priority is disputed by Edwards, a matter of some importance because, if priority is lost, Pavcnik, published later in 2000, is relevant prior art.

The US application was filed in the names of Joe Obermiller, Francisco Osse and Patricia Thorpe, all as joint inventors. Mr Obermiller was an employee of Cook at the time the invention was made. Mr Osse and Ms Thorpe were not. The PCT application was filed in the name of Cook but at that time the only interest it had in the invention was via Mr Obermiller’s contract of employment. It is accepted that Mr Obermiller’s interest, such as it was, belonged to Cook. The interests of Mr Osse and Ms Thorpe were not assigned to Cook until September 2002, that is to say 21 months after Cook filed the PCT application but before the grant of the Patent.

Cook argued that the claim to priority is a good one because it had acquired all rights in the invention before the date of grant of the Patent and in any event always owned Mr Obermiller’s interest. Edwards says the claim is misconceived because the right of priority may only be enjoyed by the person who filed the priority application or his successor in title as at the date the right to priority is claimed, and on 31 January 2001 that was Mr Osse, Ms Thorpe and Cook, not Cook alone.

According to Article 4 of the Paris Convention, a person is to enjoy a right of priority if he has filed a relevant application for a patent or if he is the successor in title (in respect of the invention) to such a person. Furthermore any person wishing to take advantage of the right of priority is required to make an appropriate declaration. Article 4 is implemented by section 5 Patents Act 1977, which requires a declaration made by the applicant which complies with the relevant rules and specifies one or more earlier relevant applications made by the applicant or a predecessor in title.

The Court held that the priority claim was invalid because at the date of filing of the PCT application the right to claim priority belonged jointly to Cook and the two non-employee inventors, and not to Cook alone:

In my judgment the effect of Article 4 of the Paris Convention and section 5 of the Act is clear. A person who files a patent application for an invention is afforded the privilege of claiming priority only if he himself filed the earlier application from which priority is claimed or if he is the successor in title to the person who filed that earlier application. If he is neither the person who filed the earlier application nor his successor in title then he is denied the privilege. Moreover, his position is not improved if he subsequently acquires title to the invention. It remains the case that he was not entitled to the privilege when he filed the later application and made his claim. Any other interpretation would introduce uncertainty and the risk of unfairness to third parties. In reaching this conclusion I derive a measure of comfort from the fact that the Board of Appeal of the EPO has adopted the same approach to the interpretation of Article 87 EPC in two cases: J 0019/87 and T 0062/05.

Therefore, the acquisition by Cook of all rights in the invention in September 2002 did not permit it to claim priority from the US application. Since Cook’s patent was not entitled to its priority date, a document published between the priority and the filing dates was citable as prior art.  The Court held that several claims of the patent were obvious in light of this document.

A question was also raised regarding the credibility of an expert witness and specifically whether an expert changing his opinion undermined his value as an expert.  One expert witness appearing in the case had also appeared as an expert in an earlier decision of the UK High Court involving Edwards and another party.  It was noted that the opinions of the expert differed in material respects between the two cases.  However, the Court decided that opinions may change during the courts of a case, particularly after cross examination and further consideration as to the abilities of the ordinary skilled person.  The expert’s opinions were found to be “cogent and reasonable” rather than partisan.