The UK High Court delivered its judgment earlier this week in AGA Medical Corporation v Occlutech UK Limited, declaring AGA’s patent to be invalid. The case concerned medical devices used to seal holes in the heart. AGA claimed that Occlutech’s devices infringed its patent (EP (UK) 957,773); Occlutech counterclaimed, successfully, for revocation of the patent. This was the second judgment in UK patent proceedings between these parties, Occlutech having defeated AGA’s claims for patent infringement on both occasions.

In Tuesday’s judgment, Mr Justice Roth held AGA’s patent to be invalid because the invention had been disclosed in clinical trials which took place before the priority date of the patent and because the invention was obvious over the prior art.

The High Court had previously (in July 2009) found an earlier AGA patent (EP (UK) 808 138) to be valid but not infringed by the previous generation of Occlutech devices. The Court of Appeal dismissed AGA’s appeal against the finding of non-infringement in June 2010.

In the latest decision, the Court found that AGA had disclosed the patented invention in pre-priority non-confidential clinical trials at a hospital in Bratislava. In determining the position on confidentiality, the Court distinguished principles of English law from the practice of the European Patent Office, which presumes that clinical trials are confidential unless shown to be otherwise.

The Court also found that the differences between a prototype of the patented device which was disclosed at a medical conference and the invention did not involve an inventive step. Accordingly, the invention failed to meet the criteria for patent protection and was held to be obvious.