The British Supreme court has overturned a ruling that found claims in H. Lundbeck A/S’ patent EP0347066 for its antidepressant drug Cipralex or Escitalopram (S-(+)-1-[3-(dimethylamino)propyl]-1-(p-fluorophenyl)-5-phthalancarbonitrileoxalate) insufficient, scoring a win for the innovator in an ongoing patent challenge brought by three generics makers Generics (UK) Ltd, Arrow Generics Ltd, and Teva.
Judgement
In a sweeping victory for Lundbeck, a three-judge panel in the Supreme Court of Judicature, Court of Appeal in England and Wales overturned part of the lower court’s ruling that deemed Lundbeck’s patent insufficient and obvious.
EP0347066 is entitled "New enantiomers and their isolation". Three claims were mainly at issue
Claim 1 which covers (+) -1-(3-dimenthylaminopropyl)-1-(4´-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile… and non-toxic addition salts thereof
Claim 3 which covers "pharmaceutical composition in unit dosage form comprising, an active ingredient, a compound as defined in claim 1."
Claim 6 which covers process for the preparation of a compound as defined in claim 1".
The high court judge Justice Kitchin held claim 1 and 3 invalid in his decision here That decision was based on the so-called ‘Biogen insufficiency’ principles, set down by Lord Hoffmann in Biogen v Medeva decision here. Judge Justice Kitchin reasoning was that claim 1, being a claim to the (+) enantiomer as a product, was a claim to a monopoly of that product however made: as per section 60(1)(a) of the 1977 Act. But Lundbeck's inventive idea was not to discover that the enantiomer existed and had a medicinal effect. Everyone knew that the two enantiomers existed and that one or other or both had a medicinal effect. What innovator Lundbeck discovered was one way of making it. But that did not entitle them to a monopoly of every way of making it.
Three judge panel LORD HOFFMANN, LADY JUSTICE SMITH and LORD JUSTICE JACOB reversed the Justice Kitchin judgement and held that patent can not be invalidated on insufficiency as per section 72(1)(c). Section 72(1)(c) explains revoking a patent [on the ground that] the specification of the patent does not disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art The judge Justice Kitchin founded his decision entirely upon the decision of the House of Lords in Biogen v Medeva. Supreme court panel held that decision in Biogen is limited to the form of claim which the House of Lords was there considering and cannot be extended to an ordinary product claim in which the product is not defined by a class of processes of manufacture. Supreme court panel further elaborated that Justice Kitchin in his judgement stick to “extent of the patent monopoly, as defined by the claims, should correspond to the technical contribution to the art in order for it to be supported or justified” notion. In holding claim 1 insufficient, Justice Kitchin was applying this principle. But then he treated the relevant "technical contribution to the art" as being the inventive step, namely a way of making the enantiomer, which was a wrong interpretation by Justice Kitchin. When a product claim satisfies the requirements of section 1 of the 1977 Act, the technical contribution to the art is the product and not the process by which it was made, even if that process was the only inventive step.
As for obviousness The panel held that generic companies argument was that the skilled man could have come by the invention by doing a short and simple experiment. But one could say that, with hindsight, of many an invention. It is not enough that an experiment revealing an invention would have been short and simple. There has to be a reason why the skilled man would have carried it out. Normally that would require at least an expectation that something might come out of it. Otherwise, short and simple though it would have been, doing the experiment would have been pointless. Court decision here
Escitalopram history
Escitalopram (Lexapro by Forest Laboratories in the United States and elsewhere by Lundbeck as Cipralex, Sipralexa and Seroplex) is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is approved for the treatment of major depressive disorder and generalized anxiety disorder; other indications include social anxiety disorder, panic disorder and obsessive-compulsive disorder. Escitalopram is the S-stereoisomer (enantiomer) of the earlier Lundbeck drug citalopram (Celexa), hence the name escitalopram. Escitalopram is noted for its high selectivity of serotonin reuptake inhibition and, as a result has fewer side effects not related to its serotonergic activity.
Escitalopram was developed in a close cooperation between Lundbeck and Forest Laboratories. Its development was initiated in the summer of 1997, and the resulting new drug application was submitted to the FDA in March 2001. The short time (3.5 years) it took to develop escitalopram can be attributed to the previous extensive experience of Lundbeck and Forest with citalopram, which has similar pharmacology. FDA issued the approval of escitalopram for major depression in August 2002 and for generalized anxiety disorder in December 2003. Escitalopram can be considered an example of "lifecycle management" - the strategy pharmaceutical companies use in order to extend the lifetime of a drug, in this case of the citalopram franchise. Escitalopram is an enantiomer of citalopram, used for the same indication, and for that reason it required less investment and less time to develop. Two years after escitalopram's launch, when the patent on citalopram expired, the escitalopram sales successfully made up for the loss. On May 23, 2006, the FDA approved a generic version of escitalopram by Teva.However, on July 14 of that year, the U.S. District Court of Delaware decided in favor of Lundbeck regarding the patent infringement dispute and ruled the patent on escitalopram valid.
