High Court confirms patentability of methods of medical treatment

Consideration of what constitutes patentable subject matter has been a recurring theme in both Australian and US courts this year:

The US District Court also considered the patentability of diagnostic assays utilizing “principles of nature” (Ariosa Diagnostics Inc v Sequenom, Inc).

Judicial review of patentable subject matter in Australia continued on 4 December 2013 when the High Court of Australia confirmed by a four:one majority decision that methods of medical treatment of human beings, specifically the administration of therapeutic drugs, represent patent eligible subject matter.

Apotex Pty Ltd v Sanofi-Aventis Australia Pty Ltd [2013] HCA 50 (4 December 2013)

Australian Patent No 670491 (the Patent), owned by Sanofi-Aventis Deutschland GmbH, is directed to a method of using the known compound Leflunomide for the treatment of skin disorders and includes a single claim:

“A method of preventing or treating a skin disorder, wherein the skin disorder is psoriasis, which comprises administering to a recipient an effective amount of a pharmaceutical composition containing as an active ingredient a compound of the formula I or II”.

A compound of the formula I is Leflunomide.   Apotex obtained registration of generic versions of Leflunomide (Apo-Leflunomide) with the intention to supply the pharmaceutical products as treatments for psoriatic arthritis and rheumatoid arthritis.   Sanofi-Aventis initiated proceedings against Apotex in the Federal Court of Australia alleging that Apotex’s proposed supply of Apo-Leflunomide products for the treatment of psoriatic arthritis would infringe their patent.   Apotex cross-claimed for revocation of the Patent on a variety of grounds, none of which succeeded. Apotex appealed to the Full Court of the Federal Court. However, that appeal was dismissed.   On 14 December 2012, the High Court granted special leave to Apotex to appeal from the judgment of the Full Court in relation to the validity of the Patent. The single ground upon which special leave was granted was that the Full Court erred in finding that the claim defined a “manner of manufacture” within the meaning of s 18(1)(a) of the Patents Act 1990. Specifically, the question raised by Apotex was whether a method of medical treatment of human beings is capable of being a patentable invention.

The patentability of methods of medical treatment

Under Australian law, for an invention to be considered patent eligible subject matter it must satisfy the criteria of a “manner of manufacture within the meaning of section 6 of the Statute of Monopolies”. This patentability threshold was considered in the landmark High Court decision of National Research Development Corp v Commissioner of Patents (NRDC).   According to NRDC, if a process which does not produce a new substance but nevertheless results in “a new and useful effect” so that the new result is “an artificially created state of affairs” providing economic utility, it may be considered patent eligible.   However, the NRDC decision suggested in obiter that “processes for treating the human body may well lie outside the concept of a ‘manner of manufacture’ because the whole subject is conceived as essentially non-economic”. Thus, Apotex argued that methods of medical treatment of humans are “essentially non-economic”.

The majority of Justices rejected this argument. In particular, Crennan and Kiefel JJ, detailed seven reasons as to why the Apotex argument failed. The most “crucial” of these reasons stated that the subject matter of a claim for a new product suitable for therapeutic use, (a product claim) and the subject matter of a claim for an unknown method of treatment using a (known) product having prior therapeutic uses (a method claim), cannot be distinguished in terms of economics or ethics.   Gageler J and French CJ concurred with the findings of Crennan and Kiefel JJ. Notably, Chief Justice French distilled the majority decision by stating “the exclusion from patentability of methods of medical treatment represents an anomaly for which no clear and consistent foundation has been enunciated”.   In his lone dissenting judgment, Justice Hayne considered that although methods of medical treatment might have economic consequences for an individual, the result of a method of medical treatment “goes beyond the ambit of a ‘manner of manufacture’”.   Infringement In relation to the infringement issue, the question before the High Court was whether the supply of Apo-Leflunomide would constitute an infringement of an indirect or contributory nature.

The two relevant arms of the contributory infringement section of the Patents Act 1990 that the High Court considered included:

  1. whether Apotex had “reason to believe” that medical practitioners would use Apo-Leflunomide for the claimed purpose, namely the prevention and treatment of psoriasis; and
  2. whether there was any inducement included with the instructions which would result in Apo-Leflunomide being used for the claimed purpose.

Regarding, point (1) it was stated at paragraph [304] of the judgment, “it was not shown, nor could it be inferred, that Apotex had reason to believe that the unpatented pharmaceutical substance, which it proposes to supply, would be used by recipients in accordance with the patented method, contrary to the indications in Apotex’s approved product information document.”   In relation to point (2), Apotex’s approved product information states that Apo-Leflunomide is indicated for the treatment of active rheumatoid arthritis or active psoriatic arthritis. Apo-Leflunomide is not indicated for the treatment of psoriasis that is not associated with manifestations of arthritic disease.   On the basis of the above, the proposed supply of Apo-Leflunomide was found not be an infringement the Patent.

Conclusions

This decision is significant because it provides certainty in relation to the patentability of methods of medical treatment of humans, in particular methods involving the administration of therapeutic drugs.   The decision also provides guidance regarding contributory infringement of method of treatment claims by the supply of pharmaceutical compounds. The findings of the High Court suggest that contributory infringement may be avoided by registering pharmaceutical products for indications that are distinct to those defined in a method of treatment claim.