Mayne Pharma Pty Ltd & Anor v Debiopharm SA & Anor

For anticipation by inevitable result, it is insufficient that a prior disclosure merely enables the skilled person to perform a process within the claim. Following the disclosure must inevitably produce the claimed result.

Where a party serves notice of an experiment conducted for litigation purposes, privilege in workup experiments directly associated with that particular experiment may be waived. The extent of waiver is controlled by the issue for which the evidence is deployed and is ultimately a question of fact.

Experimental evidence has an objective character distinct from expert opinion. In an appropriate case, disclosure of the workup may be required so that the court and the opposing party can see the full evidential basis for the experiment.

The claimants sought revocation of four patents concerning oxaliplatin. The defendants applied for disclosure of documents relating to preliminary or workup experiments leading to an experiment described in the claimants’ notice of experiments.

The experiment was relied upon to establish that the process disclosed by the prior art inevitably produced a reaction mixture within specified pH ranges. The defendants argued that service of the notice waived privilege in the workup material.

The issues were whether the workup documents were privileged and, if so, whether privilege had been waived by deploying the particular experiment.

1. Inevitable result. Anticipation requires more than showing that the prior disclosure enables the skilled person to come within the claim. Following the prior disclosure must inevitably do so. This principle was identified from General Tire v Firestone [1972] RPC 457 and Synthon v SKB [2005] UKHL 59.
2. Nature of experimental evidence. Experimental evidence provides objective confirmation or corroboration of expert opinion and may provide a fixed point against which the experts can be assessed. It is therefore materially different from expert opinion. The court should, where possible, receive evidence showing how the experiment and any necessary workup were selected and conducted.
3. Workup experiments. The court approved the principle expressed by Jacob J in Honeywell Ltd v Appliance Components Ltd, namely that the opposing party should be told of experiments conducted but not relied upon, at least in the context of workup associated with the experiment deployed. The guidance in SKB v Apotex [2004] EWCA Civ 1568, [2005] FSR 23, against contrived repetitions of prior art was also material. Workup does not prevent an experiment from demonstrating anticipation by inevitable result.
4. Waiver. The rationale in Nea Karteria Maritime Co Ltd v Atlantic & Great Lake Steamship Corp [1981] Com L.R. 138 supports waiver where a party deploys privileged evidence but withholds material directly associated with or underlying it. Service of the notice waived privilege in documents relating to the workup of the particular experiment. The court expressed no view on whether the waiver extended further.
5. The application was granted to the extent of a declaration that privilege otherwise attaching to documents relating to the workup experiments for the notified experiment had been waived.