The case of Generics (UK) Ltd and others v H Lundbeck A/S [2007] involved a defendant who was a small research-based pharmaceutical company located in Denmark. He held a European patent (“the Patent”) in respect of an antidepressant drug, escitalopram. The patent had a priority date of June 1988.
The drug had been produced by resolving a racemate of an existing drug, citalopram, to obtain individual enantiomers of it. Thus, it comprised the pure (+) enantiomer, while citalopram comprised both the (+) and (-) enantiomers. The patent comprised seven claims. Claim 1 was a product claim directed to the (+)-enantiomer, claim 3 was related to a pharmaceutical composition containing the compound of claim 1 and claim 6 was related to a method of preparing that compound.
The plaintiffs initiated actions, requesting the revocation of the patent due to the state-of-the-art drug, citalopram. It would be for the court to determine whether:
§ Claims 1 and 3 of the Patent were not valid due to lack of novelty over the patents of the state of the art;
§ Claims 1, 3 and 6 were invalid as a matter of fact in light of those patents and common general knowledge; and
§ Claims 1 and 3 were invalid for insufficiency as citalopram had been an obvious target for settlement.
In relation to the obviousness, the plaintiffs maintained that in June 1988, it was common knowledge that the biological activity of the enantiomers was probably different from that of the racemate and that, for any racemate under development as a potential therapeutic agent, it was highly desirable to resolve the racemate to determine the properties of the enantiomers it contained.
The court ruled as follows:
If the claim in the Patent were simply about the product as such, then the monopoly would certainly cover that product wherever it is found. However, if the claim refers to the isolated product or to a pharmaceutical composition comprising that isolated product as an active ingredient, then the monopoly would not extend to that product, whatever form it takes. It would be unlikely that the patent holder intended to cover what he had expressly described as old. Therefore, in the circumstances of this case, claims 1 and 3 of the Patent were not invalid for lack of novelty. The citalopram racemate did not fall within the description of claim 1, and a pharmaceutical composition comprising the racemate as an active ingredient did not fall within the description of claim 3. The patent not only recognized citalopram, that is, the racemate , as old, but was also clearly directed to the isolation of its individual enantiomers.
In the court’s application of established authority to the facts of this case, it was held that statements 1, 3 and 6 were not invalid as a matter of obviousness. Investigation of citalopram enantiomers had been an obvious goal for the ordinary qualified medical chemist in 1988. The difference between the prior art patents and the Patent claims was that the former disclosed only the racemate and methods that would only produce racemic compounds. They did not describe any method to obtain individual enantiomers of citalopram. It would not have been obvious to solve for citalopram using the method adopted in 1988. The qualified analytical chemist would not have had practical experience with that method, and the qualified medical chemist would probably not have heard of it.
In the circumstances of this case, claims 1 and 3 of the Patent were invalid due to insufficiency. The defendant’s inventive step had not been to decide to separate the enantiomers of citalopram, but to find a way to do it. Patent claims 1 and 3 covered all ways of making the (+) enantiomer. The first person to find a way to achieve an obviously desirable goal was not allowed to monopolize all other ways of doing it. Therefore, claims 1 and 3 were too broad. The court held that they extended beyond any technical contribution made by the defendant.
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© RT COOPERS, 2007. This Information Note does not provide a comprehensive or complete statement of the law relating to the subjects discussed nor does it constitute legal advice. Its sole purpose is to highlight general issues. Specialist legal advice should always be sought in relation to particular circumstances.
