Luck and the Law

Hsu Min Chung, Partner, Boult Wade Tennant

This article first appeared in the December 2009 / January 2010 issue of The Chemical Engineer. Click here to read this article in PDF format.

Suppose that you discover a new method of resolving a previously unresolved pharmaceutical compound. In testing the enantiomers, you find that one of them is significantly more active than the other. You apply for a patent to protect your work. Should you be entitled to a monopoly on the active enantiomer? After all, you were the first to isolate it and identify its beneficial properties. Such a monopoly, however, would provide you with patent protection for the enantiomer itself regardless of how it was manufactured. By finding just one way of producing your product, should you be entitled to a monopoly for other ways of making that product?

The UK Courts recently grappled with these questions when three generic pharmaceutical companies applied for the revocation of pharma company Lundbeck's patent for the (+) enantiomer of citalopram 1,2,3. When the patent was first filed in 1988, citalopram was known selective serotonin reuptake inhibitor (SSRI) and widely used as an anti-depressant. Although it was a known racemate, no one had resolved the compound into its constituent enantiomers. After an extensive period of research, Lundbeck successfully separated teh enantiomers and found that its anti-depressant effect was caused entirely by the (+) enantiomer. It was granted a patent with claims to the (+) enantiomer itself, which the company has since marketed under the brand name Cipralex.

In trying to revoke Lundbeck's patent, the generic companies argued that Lundbeck's patent claim to the (+) enantiomer was too broad. In their view, all Lundbeck had done was find a particular way of resolving citalopram. However, its patent claims covered the (+) enantiomer, however obtained. Lundbeck's technical contribution did not justify the breadth of its patent monopoly.

Broad claims
When the case was first heard in the High Court¹, the judge agreed with the generic companies' position. Although there was nothing in the statute to prevent patentees from securing broad claims for their inventions, the judge saw parallels between this case and an earlier case between Biogen and Medeva. In Biogen v Medeva⁴,  inventor Kenneth Murray had successfully developed a recombinant genetic method for producing a DNA molecule that could express the antigens of the hepatitis B virus in a host cell. To protect his research Murray obtained a patent to a DNA molecule defined in part by how it was made (by recombinant DNA technology) and what it did (express the antigens of the hepatitis B virus in a host cell). This claim covered a class of chemical compounds that could be produced by methods that owed nothing to Murray's method. The judge on that case held that Murray had not established a new principle which all his successors had to follow if they were to produce the same result. In finding Murray's claim too broad, the judge said that: "Care is needed not to stifle further research and healthy competition by allowing the first person who has found a way of achieving an obviously desirable goal to monopolise every other way of doing so."

The judge on the Lundbeck case saw no difference between Murray's invention and LUndbeck's. He took the view that medicinal chemists would have found it obviously desirable to separate out and test the enantiomers of racemates. While it was true that no one knew that the anti-depressant activity of citalopram would lie in its (+) enantiomer, it was entirely obvious that the activity might lie primarily in one enantiomer rather than the other. Once the enantiomers were separated, the tests required to determine where the activity lay were simple and routine. The inventive step taken by Lundbeck was not in deciding to separate the enantiomers of citalopram, but finding a way to do it. The judge took the view that LUndbeck's technical contribution was limited to the specific method it used to resolve the enantiomers. In claiming the (+) enantiomer per se, Lundebeck's monopoly extended beyond its technical contribution. Its claim therefore was too broad to be valid.

Appeal
At appeal², however, the Court of Appeal came to the opposite conclusion. In finding Lundbeck's claim to be valid, the judges drew a distinction between the technical contributions made by Murray and by Lundbeck. They explained that, when Murray produced his DNA molecule, he could not claim the relevant DNA molecule because it existed naturally in hepatitis B sufferers. Nor could he claim to have invented the molecule isolated from the human body because that had been done by purification of samples of the infective agent. There was no doubt that he was entitled to claim his process for making his DNA molecule. However, this would not give him much protection, as the science was developing rapidly and others would soon find other methods of achieving the same goal.

What Murray tried to do, therefore, was to claim the product was defined in part by how it was made (a kind of product-by-process claim). Effectively, his claim was to a product defined by a class of processes of manufacture. As Murray had only contributed to one of these processes, this did not justify a monopoply over the other, unrelated processes.

In the judges' view, Murray's claim was not the same as the ordinary product claim that was the subject of Lundbeck's patent. By claiming a single (+) enantiomer, Lundbeck was not claiming a monopoly over compounds defined by a class of methods of manufacture. On the contrary, LUndbeck had invented a specific compound that was not previously available to the public. Although it may have been an obviously-desirable compound, there was no known method of making it at the time that Lundbeck's patent was filed. Since Lundbeck was the first to make the (+) enantiomer in an inventive manner, it was entitled to claim the compound per se. In this connection, Lundbeck's technical contribution was not simply a specific process of manufacture, but the provision of the new compound itself - one that could not be provided before. Although the Court of Appeal acknowledged that the compound was obviously desirable, it took the view that this did not diminish its technical contribution. In fact, it made it all the more credible, as there was likely to have been more competition in trying to produce it.

More than you deserve
When the case was referred to the House of Lords³, the Lords upheld the Court of Appeal's decision. The House of Lords' decision confirms that, by finding one way of making a new product, a person can obtain a monopoly for that product. Although, in certain instances, this may give a patentee "more than he deserves"⁵, this alone does not mean that the patent is invalid. As one of the Law Lords put it: "The role of fortuity in patent law cannot be doubted: it is inevitable, as in almost any area of life."

Boult Wade Tennant

 Further reading

1. Generics v Lundbeck [2007] EWHC 1040 (Pat)
2. Generics v Lundbeck [2008] EWCACiv 311
3. Generics v Lundbeck [2009] UKHL 12
4. Biogen v Medeva [1997] RPC 1
5. see paragraph 57 of ref 2 above