The High Court has handed down its decision in the litigation between Sanofi-Aventis and Apotex. The case concerns Apotex's proposal to sell a generic version of Sanofi-Aventis' leflunomide drug, ARAVA®, for which Apotex obtained registration on the Australian Register of Therapeutic Goods (ARTG).

Sanofi-Aventis had a patent for the compound leflunomide, which expired in 2004. It also obtained a secondary patent that claims a method of preventing or treating psoriasis using leflunomide (Patent), and its infringement proceedings against Apotex relied on that Patent. Leflunomide is used in Australia to treat psoriatic arthritis and rheumatoid arthritis, but not psoriasis alone, and these were the indications for which Apotex's generic version was approved. However, psoriasis and psoriatic arthritis are now understood to be related disorders, and almost all patients with psoriatic arthritis will have, or are likely to develop, psoriasis. The administration of leflunomide will treat both disorders.

In the first instance proceeding, Apotex raised a number of invalidity challenges against the Patent in addition to asserting non-infringement. However, Apotex only asked the High Court to consider:

• whether the Patent was invalid on the basis that it was not a 'manner of manufacture' within the meaning of section 18(1) of the Patents Act 1990 (Cth), because it was a method of medical treatment; and
• if the Patent was valid, whether Apotex had infringed the Patent.

Manner of manufacture

A majority of the High Court held that the invention the subject of the Patent was a manner of manufacture, upholding the view of the Full Federal Court (the majority of which had regarded this position as 'representing orthodoxy in Australian patent law').

In separate judgments, Chief Justice French, and Justices Crennan and Kiefel, reviewed the history and earlier judicial interpretation of the 'manner of manufacture' requirement, and held that methods of medical treatment were patentable manners of manufacture. Chief Justice French found that, despite statements by some courts that methods of medical treatment were not patentable, the judicial authority evidenced no 'clear and consistent foundation' for their exclusion.

Justices Crennan and Kiefel (with whom Justice Gageler largely agreed) listed a number of reasons for their view, including, 'critically', the lack of a distinction on economic or ethical grounds between product claims and combined product/method claims (which are patentable), and method claims.

The majority of the Court applied the test that, in order to be a manner of manufacture, the invention not be 'essentially non-economic', and pointed to the economic interest in ensuring that individuals are fit and healthy. It was, however, noted by the Court that methods of medical treatment that are do not constitute use of a pharmaceutical product (for example, procedures used by medical staff in physically treating patients) may still fall outside the scope of what is patentable on the basis of this test.

In dissent, Justice Hayne held that a method of prevention or treatment of human disease is not a manner of manufacture, on the basis it does not have its own 'economic utility'. His Honour interpreted previous authority as requiring that, in order for a method to be patentable, the method itself must have economic utility (as distinct from the outcome of applying that method having economic utility). This sets a higher bar than the 'essentially non-economic' test applied by the rest of the Court. In Justice Hayne's view, the effect of using a medical treatment on an individual is personal to that individual, and can only indirectly be said to have an economic effect, by enabling that individual to make a more valuable contribution to economic activity.

Infringement

The Full Federal Court had held that Apotex had infringed the Patent under section 117 of the Patents Act, which deals with indirect infringement. Section 117 provides that the supply of a product to a person:

• for any use to which the supplier has reason to believe the person will put the product; or
• in accordance with any instructions for use of the product, or inducements to use the product included in advertising,

will also infringe a patent if that use of the product by the person would infringe the patent.

Apotex's product information document, as approved under the Therapeutic Goods Act 1989 (Cth), stated that its drug was to be used for the treatment of rheumatoid arthritis and psoriatic arthritis, and expressly stated that its use to treat 'psoriasis that is not associated with manifestations of arthritic disease' was not indicated. Despite this, the Full Federal Court held that Apotex's supply would be infringement under section 117 because it would treat any psoriasis that the patient had, even if it was not administered for that purpose, and almost every person who has psoriatic arthritis will also have or develop psoriasis. The Full Federal Court also found that Apotex had reason to believe that its generic leflunomide product would be used to treat psoriasis, even though this was not listed as an indication.

The High Court overturned this decision on infringement. It held that the Patent would not be infringed by a person who administered Apotex's leflunomide product for the purposes of treating a condition other than psoriasis, and section 117 could not render Apotex liable for contributory infringement where there was no primary infringement. The High Court also placed weight on the fact that Apotex's product was registered on the ARTG only for the indicated uses (namely, psoriatic and rheumatoid arthritis). In that context, it could not be said that Apotex was either instructing or inducing people to use its product in accordance with the patented method, or that it had reason to believe that they would do so.

This decision is valuable because it is the first High Court decision confirming that methods of medical treatment are patentable manners of manufacture, in the face of some lingering doubts from earlier case law. Even though the Patent was upheld, however, the two decisions of the lower courts finding infringement were overturned. The High Court gave Sanofi-Aventis' secondary patent a narrower scope of operation, meaning that generic pharmaceutical manufacturers may be able to circumvent method patents by drafting their product information documents to specifically exclude the patented use.