Pregabalin 2 – the invalidity appeal

In addition to clarifying infringement of method claims, the Full Court in Warner-Lambert (Pregabalin) also dismissed Apotex’ appeal against the findings that the Patent was fairly based and not invalidated by a false suggestion.

As you will recall, Warner-Lambert’s patent claimed methods for treating pain using pregabalin. The methods included claims 16 – 30 which were Swiss claims.

Apotex argued that the claims were not fairly based and had been obtained by false suggestion.

The main basis for these attacks stemmed from the parties’ acceptance that the point of the patent was the use of pregabalin to treat humans. However, the examples in the patent related to tests conducted on rats. Apotex argued that it was not certain that a compound shown to be efficacious in rats would necessarily work for humans or, if it did, what a “therapeutically effective amount” for humans would be without a considerable amount of testing and experiment. Apotex argued that the “prolonged research, inquiry or experiment” involved fell well short of what was required for a sufficient description of the invention. (This was the pre-Raising the Bar Act version of s 40(2)(a)). Accordingly, as laid down in Kimberly-Clark:

The question is, will the disclosure enable the addressee of the specification to produce something within each claim without new inventions or additions or prolonged study of matters presenting initial difficulty?

The Full Court accepted that it would be a complicated and expensive business to produce from the information in the Specification a medicament for the treatment of humans. After all, we are talking about a drug. However, the Full Court agreed with the trial judge that the work involved was nonetheless “routine” and did not require invention. For example, at [126] the Full Court accepted:

The need to produce “new inventions or additions” or to carry out “prolonged study of matters presenting initial difficulty” may mean that a description is insufficient. The need for time, cost and detailed work will not; at least where, as here, the work involved is of a routine and conventional kind.

“Routine” in this context was not merely simple and easy. The skilled addressees were scientists with Ph Ds and considerable experience.

An important consideration in reaching this conclusion was the nature of the claimed invention. According to the Full Court, the invention lay in the broad recognition that pregabalin, otherwise a known drug, could be used in the treatment of pain. It was not concerned with any particular dosing regime.

It also appears that (see [39] of the Full Court’s reasons) Apotex’ evidence did not identify any particular problems that would be encountered if one were to embark on formulating the drug for the relevant purpose.

In reaching this conclusion, the Full Court was also highly critical of Apotex’ attempt to characterise the work involved as imposing an “undue burden”. This formulation was derived from EPO and English cases in which the statutory test was close to the Raising the Bar Act formulation:[3]

(a) disclose the invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art; and

So it was irrelevant to the test under the pre-Raising the Bar Act form of s 40(2)(a) and, in any event, was an unhelpful gloss on the terms of the statute.

Bearing in mind the history of the terminology adopted in the Raising the Bar Act version of s 40 and the similarity of the wording to the EPC / UK Act, it is to be hoped that the High Court’s warnings in Lockwood v Doric not to get entangled in English cases post–1977 will fall away when a case arises under the new form of the provision.

Dr Summerfield addresses the invalidity issues of the appeal here.

Warner-Lambert Company LLC v Apotex Pty Ltd (No 2) [2018] FCAFC 26 (Jagot, Yates and Burley JJ)

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