Patents

Case Note: Inhale Therapeutic Systems Inc v Quadrant Healthcare Plc

Jane Lambert

Oct 2001
This case contains valuable practical guidance to advocates and litigators from Laddie J on anticipation and obviousness. A ground upon which a patent may be revoked is that it is not a patentable invention under s.72 (1) (a) of the Patents Act 1977. Two of the conditions of patentability are that the invention is new and that it involves an inventive step. An invention that is not new is said to have been anticipated and one that does not involve an inventive step is said to be obvious.
Anticipation
As Laddie J noted in his judgment in this case, a claim can be anticipated in two ways:

	the prior art may describe something within its scope; or
	the inevitable result of carrying out what is described in the prior art may be a product or process falling within the scope of the claim.

In General Tire & Rubber v. Firestone Tyre and Rubber [1972] RPC 457, Sachs LJ said at 485:

"... if carrying out the directions contained in the prior inventor’s publication will inevitably result in something being made or done which, if the patentee’s patent were valid, would constitute an infringement of the patentee’s claim, this circumstance demonstrates that the patentee’s claim has in fact been anticipated."

If a prior publication contains a direction that is capable of being carried out in a manner which would infringe but could also be carried out in a way which would not, the claim will not have been anticipated. Anticipation requires clear and unmistakable directions to do what the patentee claims to have invented. A signpost, however clear, upon the road to the patentee’s invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee.

In Evans Medical Ltd’s Patent [1998] RPC Laddie J had said that anticipation may be proved by an experiment "well within the general teaching" of the prior art that produces something within the scope of the claim under attack. In this judgment, he resiled from that remark: "showing that some types of implementation of a general teaching will produce a product within a subsequent claim may show that that subsequent claim is invalid for obviousness. By itself it does not prove anticipation."

Applying that principle, he held that although a process previously disclosed was in all material respects the same as the process contemplated in the patent, the presence of one variant defeated the case on anticipation.
Obviousness

Laddie J referred to Aldous J's dicta in Hallen v Brabantia [1989] RPC 307 explained that the public are entitled to manufacture that which has been made available to the public with obvious modifications. A skilled man should be assured that his actions will not be covered by a monopoly if he does what is already known with workshop or similar alterations. The test for obviousness is therefore whether such a skilled man with no knowledge of the invention would have viewed the differences between what was known and used and the alleged inventive concept as requiring something more than a workshop modification.

It is irrelevant that in real life a particular item of prior art might never come to the attention of the skilled addressee. On the other hand, the need to examine the question from the skilled addressee's perspective limits the scope of the prior art. The judge illustrated the point by the example of a notional skilled motor engineer who is assumed to have read and assimilated the contents of all published material including that on say baking. It may be that a document on baking discloses something that would produce a marked improvement in engine performance but the skilled addressee is not deemed to have read that document in that knowledge and may therefore dismiss it as irrelevant. The judge concluded that the more distant a document is from the field of technology covered by the patent, the greater the chance that an intelligent but uninventive person skilled in the art will fail to make the jump to the solution found by the patentee. The Court of Appeal expressly endorsed that approach in Amersham Pharmacia Biotech AB v Amicon Ltd. [2001] EWCA Civ 1042.
Comment
Much of the cost of patent infringement litigation lies in identifying and evaluating the prior art. It is in practice a lot harder for a defendant to get home on anticipation than novelty. It follows that in most cases the prior art should be selected with care primarily with a view to mounting an obviousness attack with the limitations of the addressee's practical interest in and understanding of its subject matter constantly in mind.

 

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