10 March 2011

What's prior disclosure of pharmaceutical compounds?

The recent decision in Albany Molecular Research Inc v Alphapharm Pty Ltd [2011] FCA 102 is a useful decision in determining how a court will deal with allegations of prior disclosure in relation to compounds where there is not sufficient information to enable the disclosed compound to be produced.

In summary, the Federal Court held that where a prior art document discloses a compound, even in the absence of an effective method to prepare it, that prior art document will anticipate a later claim to the compound.

Background

Albany Molecular Research, Inc (AMR) commenced proceedings against a number of generics, including Alphapharm, claiming that they had infringed Patent No 699799 by making, selling and otherwise dealing in various pharmaceutical products, the active ingredient in which was fexofenadine hydrochloride. Fexofenadine hydrochloride is marketed in Australia by sanofi-aventis under the trade name Telfast.

Alphapharm contended that the Patent was invalid for want of novelty, lack of an inventive step, inadequate description of the invention, failure to define the invention, lack of clarity and succinctness in the claims, lack of fair basis in the claims and false suggestion.

Alphapharm relied on two patents (the Carr Patents) which disclosed piperidine derivative compounds of the classes covered by the Patent, including fexofenadine.

Novelty

While the judgment deals with a number of grounds of invalidity, the finding in relation to novelty is of particular interest.

AMR conceded that the Carr Patents disclosed the claimed piperidine derivatives including fexofenadine. However, AMR argued that the Carr Patents were not novelty defeating disclosures as they did not provide sufficient information to enable the claimed compound to be produced or produced in a substantially pure form. Alternatively, AMR argued that anticipation could not arise unless a skilled person would have readily prepared the compound as a matter of routine.

Applying the Full Federal Court's decisions in H Lundbeck A/S v Alphapharm Pty Ltd [2009] FCAFC 60 and Apotex Pty Ltd v Sanofi-Aventis [2009] FCAFC 134, Justice Jessup rejected AMRI's arguments and held that exact naming of a compound in prior art is sufficient to constitute anticipation. Further, he went on to say that the question of enablement did not arise unless:

  • the prior art disclosed some but not all of the integers; or
  • the prior art disclosed a process that may or may not lead to the subsequently claimed invention.

In considering whether the Carr Patents in fact disclosed an effective means of preparing the compound, Justice Jessup found they did not. Consequently, he held that if he were wrong about the law as established in Lundbeck and Apotex, he "would hold that the invention, so far as claimed in the claims which are presently relevant, was not anticipated by [the Carr Patents]."

Conclusion

In light of this decision, it seems that a court will draw a distinction between cases in which there is a precise disclosure (such as in this case) and cases in which the prior art discloses:

  • some but not all of the integers; or
  • a process that may lead to the subsequent claimed invention.

In the former case the disclosure will be novelty-defeating and in the latter cases the question of enablement or sufficiently of the prior disclosure will arise.


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