Lundbeck lose Cipralex protection

A recent decision from the High Court illustrates how it might be overambitious to claim patent rights over a new product when all you have done is show one way of making it.

In Generics (UK) Ltd & Ors v H Lundbeck A/S, decided last Friday by Mr Justice Kitchin at the High Court, Lundbeck's patent covering Cipralex (citalopram, right) was partially revoked on application by the claimants under section 72 for being insufficiently disclosed. The patent claimed not only a novel way of making the more active (+) enantiomer of citalopram, but effectively all ways of making it. Kitchin J stated (at paragraphs 265-267),

"I accept that if a patentee describes a new and non obvious compound which has a beneficial effect and describes a way by which it can be made then he is entitled to a patent for the compound. [...] In such a case the technical contribution lies in the provision of the new and useful compound. Others might find different ways of producing it. But this does not render the original patent insufficient because in each case they are making use of the technical contribution – the knowledge they are making the new and useful compound.

In my judgment this is not such a case. For the reasons I have set out at length earlier in this judgment I am satisfied that medicinal chemists working in the field of SSRIs at the priority date considered it obviously desirable to separate out and test the enantiomers of active racemates. True it is that in the case of citalopram no one knew the activity would lie in the (+) enantiomer. However it was entirely obvious that the activity might lie primarily in one enantiomer rather than the other. Further, once the enantiomers had been separated the tests which the inventors carried out to determine where the activity lay were routine and straightforward, as were the steps necessary to formulate the (+) enantiomer into a pharmaceutical composition. The inventive step taken by the inventors of the Patent was not deciding to separate the enantiomers of citalopram but finding a way it could be done. The technical contribution they made was the discovery that the diol intermediate could be resolved and then the enantiomers of the diol converted into the enantiomers of citalopram whilst preserving their stereochemistry.

Claims 1 and 3 of the Patent cover all ways of making the (+) enantiomer of citalopram. For example, they cover resolving citalopram on a preparative chiral HPLC column. Does this method of resolution owe anything to the teaching of the Patent or any principle it discloses? In my judgment it does not. By June 1988 the preparation of the individual enantiomers of citalopram was an obviously desirably goal and their testing was trivial. There is no teaching in the Patent as to how that goal is to be achieved other than by the use of the diol intermediate. Just as in Biogen, it not enough to say that the inventors showed that resolution could be done and that they found the activity lay in the (+) enantiomer. The first person to find a way of achieving an obviously desirable goal is not permitted to monopolise every other way of doing so. Claims 1 and 3 are too broad. They extend beyond any technical contribution made by Lundbeck".

The claims to the product itself, either in the form of (+) citalopram or a pharmaceutical composition comprising (+) citalopram, were therefore deemed to be invalid. This left Lundbek with only the particular method of making the enantiomer.

The IPKat thinks that this decision must be right. If the more active (+) enantiomer was obvious (i.e. ob via: lying in the way) once activity for the racemic mixture was known, a claim covering that enantiomer itself could not be inventive. A claim to a novel and inventive process for making the enantiomer would, however, be a different thing altogether.

He also wonders whether similar reasoning applied in the recent Monsanto case at the EPO (blogged here), where the patent in question claimed all GM soybeans, even though the specification disclosed only one particular way of making them.

Merpel says that one can't blame the patentees for trying it on, and at least they (in both cases) got 18 good and highly profitable years of protection before having it taken away from them.