Inverness Medical Switzerland GmbH v MDS Diagnostics Pty Ltd

In the case of Inverness Medical Switzerland GmbH v MDS Diagnostics Pty Ltd, the primary dispute centred around the interpretation of patent claims related to immunoassays, specifically for the detection of the hormone human chorionic gonadotropin (hCG) in pregnancy tests. The litigation was heard in the Federal Court of Australia, where issues of patent validity, infringement, and cross-claims were examined. The central legal issues involved interpreting the term "specific binding reagent for an analyte" as used in the patent claims and determining whether the respondent's products infringed on the patents or if the patents were invalid due to lack of novelty. The court had to decide on the degree of specificity required for a reagent to be considered "specific" under the patent claims and whether this specificity meant exclusive binding to the analyte or a binding reaction that could also involve other related molecules.

The court evaluated the evidence provided by both parties' experts, Dr Sinosich and Ms Boscato, who offered differing interpretations of the term "specific binding reagent." Dr Sinosich argued that "specific" meant that the reagent should only bind to the analyte without any binding to other molecules, while Ms Boscato contended that "specific" referred to a reagent that engages in a specific binding reaction with the analyte, which could include binding to other related molecules. The court found that the specification and prior art literature supported Inverness's interpretation that "specific binding reagent for an analyte" could involve binding to other molecules as long as it engaged in a specific binding reaction with the analyte. This interpretation was consistent with the broader application of the invention described in the patent and the prior art. Consequently, the court ruled that the respondent's products infringed on the patents, and certain claims of the patents were found to be invalid due to lack of novelty.

Ultimately, the court ordered that certain claims of the patents were invalid, specific claims were infringed by the respondent's products, and directed the parties to submit proposed orders to give effect to these findings. The decision highlighted the importance of interpreting patent language in the context of the specification and prior art to determine the scope and validity of patent claims.