Aktiebolaget Hässle v Alphapharm Pty Limited

Aktiebolaget Hässle and Astra Pharmaceuticals Pty Limited appealed against a decision that their patent was invalid for lack of an inventive step. The Court of Appeal held that the patent, which related to an oral formulation for the delivery of the drug omeprazole, was valid. The dispute centred on whether the claimed formulation involved an inventive step given the common general knowledge in the field of pharmacology at the relevant priority date. The Court found that while some aspects of the formulation were obvious, the use of a subcoating layer was not. This layer was soluble or rapidly disintegrating in water, or consisted of polymeric, water-soluble, film-forming compounds. The Court held that it was not obvious to use such a subcoating layer within the formulation described in the patent. The evidence indicated that it was not immediately apparent to those in the field that such a subcoating layer would be effective or necessary.

The Court of Appeal addressed the key legal issue of whether the claimed formulation involved an inventive step. The Court noted that for a patent to be valid, it must involve some degree of inventiveness, but this could be small. The Court applied the test of whether the invention would have been obvious to a non-inventive skilled worker in the field, equipped with the common general knowledge as at the priority date. The Court held that while the use of an enteric coating and the core material comprising omeprazole and an alkaline reacting compound or salt were obvious, the use of a subcoating layer was not. The Court found that the evidence showed that it was not obvious to those in the field that such a subcoating layer would be effective or necessary. The Court rejected the argument that the combination of the claimed elements was obvious from the outset.

The Court of Appeal held that the patent was valid as it involved an inventive step in the use of a subcoating layer within the formulation described in the patent. The Court held that the appeal should be dismissed and that the appellants should pay the costs of the respondent. The Court found that the claimed formulation did not involve an inventive step as a whole, but that the use of the subcoating layer was not obvious and thus contributed to the inventiveness of the formulation. The Court rejected the argument that the finding of the primary judge that the combination claimed in the patent was not obvious at the outset logically concluded the issue of obviousness in favour of the appellants.