Vector Corporation v Glatt Air Techniques Inc [2007] EWCA was an appeal by Vector Corporation, following proceedings in which Vector Corporation sought to revoke Glatt’s Patent EP (UK) 0 570 546. Glatt responded by seeking unconditional amendment but was opposed by Vector on several grounds including discretionary and allowability. The trial judge held the amendments allowable, but granted permission to appeal with regards the allowability of the proposed amendment to claim 13.

The technical field of the patent is fluidised beds and the main point in question was whether the proposed claim amendment would add matter. Jacob LJ believed that there was support for claim 13 as it stood, but Glatt further sought permission for deletion of a phrase within the new claim.

The Court refused. A court is allowed to exercise its discretion in allowing amendments, even if the new drafting itself is not objectionable. This is because allowing an amendment postgrant may have serious implications for others relying upon the content of the original application. In this case, Jacob LJ raised another serious consideration— that of endless litigation.

The validity of patents is, by their nature, dictated by their detailed drafting. Each amendment may result in objections raised on grounds of lack of novelty, inventiveness or support. A previous decision of the Court of Appeal in Nikken v Pioneer [2005] EWCA Civ 906 had laid down a general rule that, where there had already been a trial on the validity of patent claims, further applications to re-write claims should be refused because of the possibility of fresh trials being held.

Glatt said that this was an exceptional case with no need for a further trial. The trial at first instance had covered validity, albeit on a wider premise, but the new claim 13 would have been covered in the judge’s considerations.

Jacob LJ was not convinced by this argument but based his decision on Vector’s argument that there may be a new issue of “insufficiency”, if the patent failed to explain what structural device could be used to achieve the result in claim 13. This matter had not been brought before the judge at first instance. Jacob LJ was therefore of the opinion that there was the distinct possibility of a fresh trial. He noted, “If parties were allowed to change their position or add new points from time to time after trial, then there will never be an end of patent litigation.”

It is important that the courts get a firm grip on patent litigation as patents are detailed, technical documents requiring the gathering of extensive evidence. In addition, there is always the possibility of small amendments leading to large-scale commercial consequences. While Jacob LJ blamed delays in the European Patent Office procedures for a lack of control over amendments, this case does show the need for a robust Patent Office review of applications before patents get to trial.