Alza Corporation [2012] APO 70

In a recent decision the Australian Patent Office has considered under what circumstances a claim of a patent lacks novelty, based on inherent disclosure in a prior art document.

The decision provides useful guidance in relation to the information required in a prior art document in order for a claim to lack novelty based on inherent disclosure.

The patent in question

The decision arose following a request for re-examination of Australian Patent No. 774594, a patent for a device that is used for the transdermal delivery of nicotine.

The essential features of the device as claimed in the patent are as follows:

  • a backing layer;
  • a drug reservoir layer containing nicotine;
  • an adhesive layer;
  • an opacity index of less than 48.6%;
  • the natural colour of the skin is transmitted through the device;
  • nicotine in the device is substantially prevented from degradation by exposure of the device to light

When re-examination of the patent ultimately reached an impasse an oral hearing was held for the purposes of assessing novelty, having regard to a single prior art document.

Features disclosed in the prior art document

The Hearing Officer accepted that the prior art document explicitly discloses devices having a backing layer, a drug reservoir layer containing nicotine and an adhesive layer. As such, the question of novelty turned on whether the prior art device also has the following features:

  • an opacity index of less than 48.6%;
  • the natural colour of the skin is transmitted through the device;
  • nicotine in the device is substantially prevented from degradation by exposure of the device to light.

Because none of these features are explicitly disclosed in the prior art document the Hearing Officer considered whether the features are inherently disclosed.

What is the standard required for a claim to lack novelty based on inherency?

With reference to the Federal Court decision in the Danisco case1 which considered the issue of inherent disclosure, the Hearing Officer stated that in order for a claim to lack novelty based on inherency the prior art document must disclose something that would infringe the claim. In addition, the document must contain information that would enable a skilled person to understand that they would infringe the claim.

On this basis, for a lack of novelty to be established in the present case the Hearing Officer held that the devices of the prior art document must possess features 1 to 3 specified above, and that it must be apparent to a practical standard that the devices do possess those features. The Hearing Officer clarified that "A matter can be disclosed to a practical standard without being explicitly stated if it would have been apparent to the skilled reader, without difficulty, had they turned their mind to the issue".

With this approach in mind the Hearing Officer went on to consider whether the devices of the prior art document possess features 1 to 3, and whether such features are apparent to a practical standard.

Did the prior art document inherently disclose the additional features?

Expert evidence revealed that a device prepared in accordance with an example of the prior art document has an opacity index of 0% and that such a property is apparent to the naked eye, and hence apparent to a practical standard.

The natural colour of the skin being transmitted through the device was considered to be a restatement of the low opacity index feature and therefore also clearly apparent in the prior art document to a practical standard.

Based on examples and figures therein the Hearing Officer noted that it is apparent from the prior art document that nicotine is stable to the extent of at least 70% to 80%, and therefore substantially prevented from degradation.

It was therefore concluded that the prior art document possesses features 1 to 3 and that those features are apparent to a practical standard. As a result, a number of the claims of the patent were held to lack novelty.

Lessons arising from this case

Following on from the Danisco case, this decision provides useful guidance in relation to the information in a prior art document that is necessary for a claim to be found to lack novelty based on inherent disclosure.

The fact that a prior art document inherently discloses an invention is not sufficient to deprive a claim to that invention of novelty. It is also necessary that it be apparent to the skilled person without difficulty that the prior art document possesses all of the features of the claim.