Corevalve Inc v Edwards Lifesciences AG & Anor

A patent specification need enable the skilled person to construct the claimed device, but need not provide a complete clinical manual for using it. A claim directed to a device “for” a stated purpose ordinarily requires suitability for that purpose, not proof of actual intended use. The experimental-use exception does not protect commercial supply merely because the supplier obtains useful clinical information. Where purposes are mixed, the court should consider the defendant’s preponderant purposes. A patent is sufficiently plausible where the claimed concept is not implausible in principle, even though clinical reliability and safety remain uncertain.

Edwards sought relief for alleged infringement of its European patent for a collapsible heart-valve prosthesis mounted on a collapsible and re-expandable stent. CoreValve sought revocation for anticipation, obviousness and insufficiency, denied infringement, and relied alternatively on the experimental-use exception in section 60(5)(b) of the Patents Act 1977.

The court considered the construction of claim 1, the characteristics of the accused device, the experimental-use defence, sufficiency, plausibility, anticipation by Ersek and Strecker, and obviousness over those disclosures.

1. Construction. The word “preferably” imposed no limitation, and “for” indicated practical suitability for implantation rather than actual intended use. “Elastical” required some springiness and capacity to flex and recover, at least under haemodynamic loading. “Cylindrical” referred to a generally cylindrical stent in its natural, free condition as manufactured. “Radially collapsible and re-expandable” was understood in the context of delivery and implantation by catheter. Catheterisation did not necessarily mean percutaneous delivery.
2. Infringement. The CoreValve product possessed the claimed attributes except the cylindrical support means and cylinder surface. Its bulbous end meant that it was not generally cylindrical, and the commissural points were mounted on the bulbous portion. The patent was therefore not infringed.
3. Experimental use. Section 60(5)(b) did not protect the alleged acts. The exception encourages scientific research while protecting the patentee’s legitimate interests. Regulatory field trials do not qualify merely because they generate useful information. The immediate purposes here included market confidence, substantial revenue and clinical information. The information-gathering purpose was not preponderant. The defence would also fail because the actual product was outside the claim.
4. Sufficiency. Section 72(1)(c) required disclosure sufficient for a skilled device manufacturer to construct a claimed device, using reasonable trial and error. It did not require directions teaching a cardiologist how to perform every difficult and hazardous clinical implantation procedure. The patent was therefore sufficient.
5. Plausibility and validity. The patent passed the plausibility threshold because the use of stents made the concept plausible in principle. The absence of clinical results did not establish insufficiency or obviousness. Ersek contained no clear and unmistakable directions to make a device having the claimed elastic and catheter-delivery properties. Strecker did not enable the claimed device. The proposed modifications over either disclosure depended on hindsight and were not obvious.
6. The patent was valid but not infringed. The claim and counterclaim were dismissed.

First-instance decision. No earlier appellate decision is stated in the judgment.