We have recently reported on the long-awaited decision of the United States Supreme Court in Bilski, which amongst other things, upheld the "machine or transformation" test as an "important tool" in determining patentable subject matter (see, http://www.shelstonip.com/news_story.asp?m=7&y=2010&nsid=151). The fallout has been swift – indeed, the very next day, the Supreme Court remanded the diagnostic methods case of Mayo v Prometheus Laboratories Inc. back to the Federal Circuit for further consideration in light of Bilski.

In its previous decision on Prometheus, the Federal Circuit applied the "machine or transformation" test as the sole criterion for determining patentable subject matter under the statute 35 USC 101. However, the decision in Bilski makes it clear that this is not to be the case, hence the remand.

During its initial term in the Federal Circuit, it was held in Prometheus that drug administration is not a natural phenomenon and is thereby "transformative" under the "machine or transformation" test. Moreover, determining metabolite levels not otherwise apparent from mere inspection also satisfies this criterion. Finally, it was held that such transformations were "central to the purpose of the claims" and thereby qualified as patentable subject matter.

The Federal Circuit characterised the "machine or transformation" test as an "either-or" investigation, following which two additional criteria need be satisfied. Specifically, in order to define patentable subject matter under 35 USC 101, a claimed process must be:

      (a)   tied to a particular machine or apparatus; or

      (b)   transform a particular article into a different state or thing.

If either criterion is met, the test further requires that "the use of a specific machine or transformation of an article must impose meaningful limits on the claim's scope"; and "the involvement of the machine or transformation in the claimed process must not merely be insignificant extra-solution activity". The Court was of the opinion in Prometheus that mere data-gathering steps could not be relied upon to show that a claimed process was indeed "transformative".

The patent at issue in Prometheus is US 6,355,623. Claim 1 was considered by the Court in determining whether the patent defined patentable subject matter under 35 USC 101:

      1.   A method of optimising therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:    

            (a)   administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and

            (b)   determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder, wherein the level of  6-thioguanine less than about 230 pmol per 8x108 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and wherein the level of 6-thioguanine greater than about 400 pmol per 8x108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.

The Court concluded that that steps (a) and (b) were each independently "transformative". The transformation being that "..of the human body following the administration of a drug and the various chemical and physical changes of the drug's metabolites that enable their concentrations to be determined" – and that "..claims to methods of treatment.. are always transformative when a defined group of drugs is administered to the body to ameliorate the effects of an undesired condition". The Court also endorsed the "determining" step (b) as defining a transformation "for those levels cannot be determined by mere inspection". Finally, the Court noted that the steps (a) and (b) were "central to the purpose of the claims" as the measurement allegedly enabled adjustment of the dosage by working a transformation on physical substances, and thereby sufficiently defined the monopoly claimed.

On one hand, it is not surprising that Prometheus has been remanded back to the Federal Circuit given that the Supreme Court has deemed the "machine or transformation" test no more than an "important tool" in determining patentable subject matter. However, on the other hand, the decision in Bilski appears consistent with the net result of Prometheus, despite being achieved via slightly different means. Accordingly, it remains to be seen whether the Federal Circuit merely now affirms its prior decision, or takes the Supreme Court's remand as a hint that they should develop a new test more specifically applicable to diagnostic methods. In the interim, those applying for US patents in the field of diagnostic technologies should carefully consider their filing and prosecution strategies. Such applicants may now wish to supplement or even replace their existing claims with revised claims that satisfy the "machine or transformation" test. As a guide, such claims should include: a) a step that comprises administering an agent or device (or taking a sample) in a manner that "transforms" a patient; and/or b) a step that comprises determining a measurable quantity that is not apparent from mere inspection; and c) clearly defining the purpose of the diagnostic method within the preamble of the claim.

Although the possibility remains that expanded criteria may be developed for diagnostic medical technologies, the Supreme Court's remand provides no guidance as to what such criteria may entail. Accordingly, ensuring that one's claims at least satisfy the "machine or transformation" test would seem a fair strategy in the interim.

In conjunction with our US Associates, the patent professionals of Shelston IP would be pleased to consider pending or even granted United States patent claims for compliance with the "machine or transformation" test.

For completeness, we note that the "machine or transformation" test has not been applied in either Australia or New Zealand. The closest either of these jurisdictions come to such a test is with respect to the Examination of business method patents, in which the famous State Street Bank case is quoted as but one of a series of guiding parameters for Australian Patent Examiners.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.