It has for many years been the practice of the Australian Patent Office to grant patents for medical methods of treating humans, although there has never been a court decision expressly holding that such claims fall within the statutory definition of "invention" and the New Zealand Court of Appeal in construing a statute having substantially the same definition of "invention" has held that such claims do not fall within the statutory definition.

The Australian Patent Office approach was based on obiter dicta in the case of Joos v. Commissioner of Patents where the court, in finding that a cosmetic treatment of humans was patentable, had stated that it could see no basis for denying patents to any methods of treating humans. This situation may, however, be about to change.

In the case of Bristol-Myers Squibb Company v. F. H. Faulding & Co., Heerey J. in the Federal Court of Australia has questioned whether method of treatment claims comply with the statutory definition of "invention". His comments were not essential to his decision which was essentially that simply defining a particular dosage rate of a compound known to be useful for the specified purpose did not constitute an invention and so strictly speaking his comments were obiter dicta.

The Patent Office has indicated that at least for the time being it will not change its previous practice and will continue to allow claims to methods of human treatment. It has also issued a notice that it will no longer raise an objection to claims in the form "use of compound X to prepare a medicine for treatment of disease Y" where the novelty lies in disease Y, this being a form of claim adopted by the European Patent Office to circumvent difficulties in the definition of invention in the European Patent Convention (see our Information Letter N.S. 161).