Fosamax once weekly patent invalid on appeal in Australian Full Federal Court

Copyright Monday, June 19, 2006 Duncan Bucknell Company

On 15 June 2006, the Full Federal Court of Australia handed down its judgment in Merck & Co Inc v Arrow Pharmaceuticals Limited [2006] FCAFC 91.

Under Australian law, a patent specification which incorporates by reference the entire disclosure of one or more prior art documents is more likely to be invalidated for lacking a manner of new manufacture.

The classic test for the required degree of disclosure in a prior art reference was reiterated by the Full Court — would a skilled addressee have been able to at once perceive, understand, and be able practically to apply the discovery without the necessity of making further experiments?

Comment

The two grounds argued on appeal were whether the patent claimed a manner of new manufacture (s 18(1)(a)) and novelty (s 18(1)(b)(i)).

Manner of new manufacture

To invalidate a patent on this ground, it is necessary to demonstrate that there is no invention disclosed on the face of the specification.

Arrow argued that the patent was invalid on this ground since:

on comparing the description of the prior art in the patent to the claims, it merely claimed a known drug (alendronate) administered in a known way (oral alendronate) for a known indication (osteoporosis). The only difference being 70 mg once a week rather than 10 mg once a day.

on comparing the disclosure in the prior art documents which were incorporated by reference (Strein and Goodship), the claims of the patent merely added rest periods (Strein) and use of alendronate for the treatment of osteoporosis (Goodship). (Although Goodship assumed this in any event.)

In the words of the Judges of the Full Court:

“We see no invention in asserting that a patient is more likely to comply with a continuous weekly regime than with an intermittent regime involving periods of weekly administration and rest periods.”

“The Patent specification discloses no new substance, no new characteristic of a known substance, no new use and no new method. There is, therefore, no manner of new manufacture.”

Novelty

The two key issues argued in relation to novelty were whether the prior art ‘Lunar News’ articles had been adequately published and whether there was an anticipatory degree of disclosure in them.

The Full Court swiftly dealt with the first argument by the simple expedient of reminding Counsel of the wording of the Patents Act.

In relation to the degree of disclosure, Merck argued that the Lunar News articles merely disclosed a need for further testing rather than a full disclosure of the claimed invention. However, the Full Court reiterated the classic test, namely that all that is required is that a person of ordinary knowledge of the subject would at once perceive, understand, and be able practically to apply the discovery without the necessity of making further experiments.

Background

The patent in suit was AU 741818 for an invention entitled ‘Method for inhibiting bone resorption’. It basically claims a method of treating osteoporosis in a human comprising oral administration of alendronate (Fosamax) at a dosage interval of once per week.

Arrow had originally commenced revocation proceedings under s 138 of the Patents Act.Merck did not defend the claims of the Patent as granted but proposed and secured amendments to the claims so that only ten claims were finally pursued.Arrow asserted invalidity of seven of those claims, all of which were held invalid at first instance: Arrow Pharmaceuticals Limited v Merck & Co Inc [2004] FCA 1282.