Are methods of medical treatment patentable?
The High Court affirmed that methods of medical treatment can be patented in Apotex Pty Ltd v Sanofi-Aventis Australia Pty Ltd  HCA 50.
Sanofi-Aventis Deutschland GmbH was the registered owner of a patent which claimed a method of preventing or treating psoriasis by using a compound called leflunomide.
Apotex Pty Ltd made a generic version of leflunomide to treat rheumatoid arthritis and psoriatic arthritis. However, most people with psoriatic arthritis will develop psoriasis. Moreover, dermatologists were not prescribing leflunomide for the treatment of non-arthritic psoriasis. They were proscribing it for psoriasis.
Sanofi-Aventis argued that its patent would be infringed by the actions of Apotex. Sanofi-Aventis relied on section 117(2)(c) of the Patents Act, which states:
(1) If the use of a product by a person would infringe a patent, the supply of that product by one person to another is an infringement of the patent by the supplier unless the supplier is the patentee or licensee of the patent.
(2) A reference in subsection (1) to the use of a product by a person is a reference to:
(c) the use of the product in accordance with any instructions for the use of the product, or any inducement to use the product, given to the person by the supplier or contained in an advertisement published by or with the authority of the supplier
Sanofi-Aventis also said that Apotex was breaching section 117(2)(b) of the Patents Act, which states: " if the product is not a staple commercial product—any use of the product, if the supplier had reason to believe that the person would put it to that use."
Apotex argued that it did not infringe the patent because it provided its product with instructions that it was to be used to treat rheumatoid arthritis and psoriatic arthritis (not psoriasis).
The majority judges found that:
"Apotex's approved product information document does not instruct recipients to use the unpatented pharmaceutical substance (which it proposes to supply) in accordance with the patented method, and therefore the product information document does not engage section 117(2)(c) of the 1990 Act."
The judges construed the claims of Sanofi-Aventis narrowly so that the claims only covered a method of treating of psoriasis.
They held that the evidence did not show that Apotex had reason to believe that its products would be used in accordance with the patented method.
The judges also held that the question of whether a generic company has reason to believe that a product it supplied would be put to an infringing use will depend on the facts of each case.
Apotex also argued that methods of medical treatment were not patentable subject matter. However, four of the five judges found a method of medical treatment are patentable.