Aga Medical Corporation v Occlutech (UK) Limited

Factual and Procedural Background

The case concerns European Patent (UK) No. 0,957,773 ("the Patent"), which relates to a medical device designed to occlude atrial septal defects ("ASDs") in the heart. The Plaintiff ("AGA"), an American company and the patentee, alleges that the Defendant ("Occlutech"), an English sales company linked to a German medical device manufacturer, infringes the Patent through several ASD occluders. Occlutech denies infringement and contends the Patent is invalid on multiple grounds, additionally counterclaiming for a declaration of non-infringement regarding a variant of the devices.

Parallel patent litigation between the parties is ongoing in multiple jurisdictions including the Netherlands, the European Patent Office (EPO), and Germany, with some proceedings stayed pending the EPO's decision. A previous litigation between the parties in this Court concerned an earlier patent related to the same technology, which was found not infringed by Occlutech's devices.

The Patent was granted on 8 June 2011 with a priority date of 14 May 1996. The infringement particulars concern several Occlutech devices, which are treated as materially identical for the issues in this case. During trial, the Plaintiff sought to reopen its case to call a key inventor as a witness, but this application was refused and subsequently dismissed on appeal.

Legal Issues Presented

1. Whether the Patent is invalid on grounds of anticipation due to prior disclosure during clinical trials at Bratislava Children's University Hospital.
2. Whether the Patent is invalid on grounds of obviousness over prior prototypes and presentations, particularly the Gu presentation of March 1996.
3. Whether the Patent is invalid for insufficiency related to the construction of claim 1, specifically integer (7) concerning "full engagement" of the disc perimeter.
4. Whether the Patent is invalid due to added matter extending beyond the original application as filed.
5. Whether the Defendant's devices infringe the Patent if it is found valid.
6. Whether the Defendant is entitled to a declaration of non-infringement regarding a variant device lacking fabric occluding fibers.

Arguments of the Parties

Plaintiff's Arguments

• The Patent is valid and infringed by the Defendant's devices.
• The prior clinical trial disclosures were confidential and did not anticipate the Patent.
• The "full engagement" claim term should not be interpreted as requiring perfect contact without any gaps.
• The added matter challenges fail as the Patent's claims and specification do not extend beyond the original application.
• The Defendant's counterclaim for non-infringement concerning devices without fabric fibers is unfounded.

Defendant's Arguments

• The Patent is invalid due to anticipation by clinical trials conducted in Bratislava in September 1995, where devices with cupped discs were used.
• The Patent is obvious in light of the Gu presentation and prior devices, lacking inventive step.
• The claim term "fully engage" is unclear and renders the Patent insufficient.
• Added matter arises from amendments in the Patent compared to the original application, including changes in claim language and generalisation of the cupped disc feature.
• The Defendant's devices do not infringe the Patent, particularly due to lack of "full engagement".
• The Defendant's variant occluders without fabric occluding fibers do not infringe and warrant a declaration of non-infringement.

Table of Precedents Cited

Court's Reasoning and Analysis

The court first examined whether the clinical trials conducted in Bratislava in September 1995, involving implantation of devices with at least one cupped disc, constituted prior disclosure amounting to anticipation. Evidence from witnesses, including doctors involved in the procedures and company executives, supported that at least some devices used then had cupped discs. The court considered whether the doctors were under an obligation of confidence regarding this information. Applying established English law principles, the court concluded there was no such obligation, as the doctors were not informed of confidentiality, did not sign confidentiality agreements, and publicly discussed the device thereafter. The court rejected the presumption that clinical trials are inherently confidential, finding that the disclosure was not confidential and thus formed part of the state of the art, anticipating the Patent.

Turning to obviousness, the court considered the Gu presentation of March 1996, which disclosed a flat-disc device tested on animals. The court accepted expert evidence that the skilled person would recognize the Gu device's potential but would seek modifications to improve stability and reduce embolism risk. The court found that curving or cupping at least one disc to increase contact pressure and aid endothelialisation was an obvious modification, supported by prior art devices and clinical considerations. The court rejected the Plaintiff's submission that previous devices were discredited and irrelevant, holding that the skilled person would consider their design concepts.

On insufficiency, the court construed the claim term "fully engage" as not requiring perfect, gapless contact but rather substantial and functional engagement, consistent with the Patent's teaching. This construction removed the alleged uncertainty, and the court found the Patent sufficiently disclosed for a skilled person to perform the invention.

Regarding added matter, the court applied the established three-step test comparing the original application and the granted Patent. It rejected challenges based on changes to securing the ends of the device, the terminology of "fully engage" versus "complete contact," the generalization of the cupped disc feature beyond specific embodiments, and the scope of the claim to cardiac septal defects generally. The court found no impermissible intermediate generalisation or extension beyond the original disclosure.

On infringement, the court accepted that if the Patent were valid, the Defendant's devices would infringe, rejecting the Defendant's arguments based on claim construction and sufficiency.

Finally, the court addressed the Defendant's counterclaim for non-infringement concerning devices lacking fabric occluding fibers. It found that claim 1 requires an occluding fiber retained within the woven fabric and that devices without such fibers do not infringe, warranting a declaration of non-infringement.

Holding and Implications

The court held the Patent INVALID on the grounds of anticipation or, alternatively, obviousness.

The court rejected challenges based on added matter and insufficiency. Had the Patent been found valid, the court would have found infringement by the Defendant's products and would have granted the Defendant's counterclaim for non-infringement in respect of the variant devices lacking fabric fibers, subject to appropriate wording.

This decision results in the Patent being revoked, affecting the Plaintiff's ability to enforce it against the Defendant. No new precedent was established, as the decision applied existing legal principles to the facts.