In a landmark decision1 the High Court of Australia has affirmed that methods of medical treatment of humans constitute patentable subject matter and, more specifically, that methods of medical treatment of humans where a known pharmaceutical compound is used to treat a disease for which it was not previously known to be therapeutically effective, are also patentable subject matter. While it has been established practice in Australia that claims to methods of medical treatment of humans are patentable, this is the first decision from the High Court that affirms this practice.
The case before the High Court was an appeal by Apotex Pty Ltd (Apotex) against a decision of the Full Federal Court2 finding that by supply of leflunomide to treat psoriatic arthritis, Apotex contributorily infringed Australian Patent 670491 (the Patent) owned by Sanofi-Aventis Deutschland GmbH (Sanofi). Leflunomide was the subject of an earlier, expired Sanofi patent which included claims to leflunomide for treating diseases such as psoriatic arthritis. The Patent was a subsequent filing that included claims to a “new” medical use of leflunomide for treating psoriasis.
The Full Federal Court decided that the claims to a method of treating psoriasis with leflunomide were valid. The Full Federal Court construed such claims as directed to the intended purpose of the method, the intended purpose being the treatment of a new condition (i.e. psoriasis) for which leflunomide had not previously been known to be therapeutically useful. The Full Federal Court also decided that by supply of leflunomide for treating psoriatic arthritis, Apotex was a contributory infringer of claims to use of leflunomide for the “new” medical use of treating psoriasis. Apotex appealed this decision to the High Court on the grounds that (i) methods of medical treatment are not patentable subject matter; (ii) specifically, methods of medical treatment involving a “new” medical use of a known compound are not patentable; and (iii) that supply of leflunomide for treating psoriatic arthritis in not a contributory infringement under section 117 of the Patents Act 1990 (the Act).
In a 4-1 decision the High Court dismissed the Appeal by Apotex in relation to grounds (i) and (ii). In deciding that claims to methods of medical treatment are patentable subject matter, the High Court referred to the long-standing NRDC decision3 that an invention must be a manner of manufacture which constitutes an artificially created state of affairs relevant to a field of economic value. In NRDC, the High Court decided that a method of treating crops with a substance that resulted in the destruction of weeds was indeed a manner of manufacture and hence patentable subject matter. In the present decision, the High Court emphasised that claims to pharmaceutical substances have never been questioned as a manner of manufacture, even when the only economic use of the pharmaceutical compound is for treating a disease. The High Court found that it would be anomalous and arbitrary to distinguish between claims to a pharmaceutical compound and claims to a method of medical treatment using that compound to find that the former constitutes patentable subject matter and the latter not.
According to the High Court “It could not be said that a product claim which includes a therapeutic use has an economic utility which a method or process claim for a therapeutic use does not have”. On the specific question (ii) as to whether methods of medical treatment involving a “new” medical use of a known compound are patentable subject matter, in a direct reference to NRDC, the High Court reasoned that “It could not be contended that a patient free of psoriasis is of less value as a subject matter of inventive endeavour than a crop free of weeds”.
The High Court also noted that the legislature had chosen not to statutorily exclude methods of medical treatment either when the Act was adopted or during the recent “Raising the Bar” amendments to the Act. However, a cautionary note from the High Court was that medical treatments that do not involve administration of pharmaceutical compounds might not constitute patentable subject matter. The High Court did not elaborate in detail on the nature of such methods although references were made to “the activities or procedures of doctors (and other medical staff) when physically treating patients”. These comments, while not directly relevant to the final decision, seem to leave open the possibility that methods of medical treatment that do not involve administration of pharmaceutical compounds might be open to challenge in the future. Apotex was successful in regard to its third ground that supply of leflunomide for treating psoriatic arthritis is not a contributory infringement under section 117 of the Act.
While in one sense this High Court decision simply maintains the status quo in Australia, it is significant that this decision and the recent Myriad decision4 have both seen patent owners withstand challenges to patentable subject matter in the life sciences field. Australia therefore stands as a jurisdiction that clearly recognizes the need to provide patent protection for innovators in this economically important technological field.