Smith Kline & French Laboratories Ltd v Inter-Continental Pharmaceuticals (Australia) Pty Ltd

The parties to this appeal were Smith Kline & French Laboratories Ltd (the appellant) and Inter-Continental Pharmaceuticals (Australia) Pty Ltd (the respondent). The dispute concerned the respondent's alleged infringement of the appellant's patent for a pharmaceutical compound. The High Court of Australia was tasked with determining the validity of the appellant's patent and whether the respondent's product infringed it.

The central legal issues before the High Court were whether the patent was validly granted, particularly in light of prior art, and if so, whether the respondent's product, which contained a similar but not identical chemical structure, constituted an infringement of the patent claims. The court had to consider the scope of the patent claims and the principles of chemical patent infringement, including whether the respondent's product fell within the ambit of the patent's monopoly.

The High Court, in its judgment, affirmed the principles of patent law concerning novelty, inventive step, and sufficiency of disclosure. It examined the prior art relied upon by the respondent and concluded that the appellant's patent was valid. Furthermore, the court applied the doctrine of equivalents to determine infringement, finding that the respondent's product, despite minor structural differences, performed substantially the same function in substantially the same way to achieve the same result as the patented compound. This functional equivalence, coupled with the structural similarity, led the court to find that infringement had occurred. The appeal was allowed, and the respondent was found to have infringed the appellant's patent.