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Eligibility of Claims Previously Held Valid Under Machine-or-Transformation Test Reaffirmed

September 17, 2009

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Last Month at the Federal Circuit - October 2009

Judges: Rader, Lourie (author), Bryson

[Appealed from: On remand from S. Ct.]

In Prometheus Laboratories, Inc. v. Mayo Collaborative Services, No. 08-1403 (Fed. Cir. Dec. 17, 2010), on remand from the Supreme Court in light of Bilski v. Kappos, 561 U.S. -- (2010), the Federal Circuit reaffirmed its holding that Prometheus Laboratories, Inc.’s (“Prometheus”) asserted method claims are drawn to statutory subject matter, and again reversed the district court’s grant of SJ of invalidity under 35 U.S.C. § 101. 

Prometheus is the sole and exclusive licensee of U.S. Patent Nos. 6,355,623 (“the ’623 patent”) and 6,680,302 (“the ’302 patent”), which claim methods to optimize therapeutic efficacy and minimize toxic side effects of drugs used to treat autoimmune diseases.  These drugs include 6-mercaptopurine (“6-MP”) and azathiopurine (“AZA”), a pro-drug that upon administration converts to 6-MP.  6-MP is broken down by the body into various metabolites, including 6-methylmercaptopurine (“6-MMP”) and 6-thioguanine (“6-TG”) and their nucleotides. 

The claimed methods typically include two separately lettered steps: (a) “administering” a drug that provides 6-TG to a subject, and (b) “determining” the levels of the drug’s metabolites, 6-TG and/or 6-MMP, in the subject.  The measured metabolite levels are then compared to predetermined metabolite levels, “wherein” the measured metabolite levels “indicate a need” to increase or decrease the level of drug to be administered so as to minimize toxicity and maximize treatment efficacy. 

Mayo Collaborative Services and Mayo Clinic Rochester’s (collectively “Mayo”) test measured the same metabolites as Prometheus’s test, but used different levels to determine toxicity of 6-TG and 6-MMP.  Prometheus sued Mayo for infringement of the ’623 and ’302 patents.  On cross-motions for SJ, the district court held that Mayo’s test literally infringed claim 7 of the ’623 patent, but also granted Mayo’s motion for SJ of invalidity under § 101.  On appeal, the Court reversed and upheld the asserted claims’ validity under the machine-or-transformation test.  The Court held that both the “administering” and “determining” steps were transformative and not merely data-gathering steps under the second prong of the test, and as such, the claims did not wholly preempt the use of the recited correlations between metabolite levels and drug efficacy or toxicity.  Subsequently, the Supreme Court held in Bilski that the machine-or-transformation test was not the sole test for determining the patent eligibility of process claims.  Based on that decision, the Supreme Court vacated and remanded the Court’s prior decision in this case.

On remand, the Court noted that patent eligibility in this case turns on whether Prometheus’s asserted claims are drawn to a natural phenomenon or whether the claims are drawn only to a particular application of that phenomenon.  The Court stated that, prior to Bilski, it held not only that Prometheus’s asserted claims recite transformative “administering” and “determining” steps, but also that Prometheus’s claims are drawn not to a law of nature, but to a particular application of naturally occurring correlations.  Accordingly, the Court noted that the claims do not preempt all uses of the recited correlations between metabolite levels and drug efficacy or toxicity.  The Court further noted that the Bilski decision did not undermine its preemption analysis of Prometheus’s claims.  The Court elaborated that the machine-or-transformation test, as applied to the present claims, is a “useful and important clue, an investigative tool,” and leads to a clear and compelling conclusion that the present claims pass muster under § 101.

The Court explained that the inventive nature of the claimed methods stems not from preemption of all use of these natural processes, but from the application of a natural phenomenon in a series of steps comprising particular methods of treatment.  The Court rejected the district court’s view of the disputed claims as merely claiming natural correlations and data-gathering steps.  The Court explained that the asserted claims are in effect claims to methods of treatment, which are always transformative when one of a defined group of drugs is administered to the body to ameliorate the effects of an undesired condition.  The Court further explained that the administering step therefore is not merely data-gathering but a significant transformative element of Prometheus’s claimed methods of treatment that is “sufficiently definite to confine the patent monopoly within rather definite bounds.”  Slip op. at 18 (quoting Gottschalk v. Benson, 409 U.S. 63, 70 (1972)). 

The Court noted that not all of the asserted claims contain the administering step, but maintained that the determining step, which is present in each of the asserted claims, is also transformative and central to the claimed methods.  The Court described that some form of manipulation, such as a chromatography method, is necessary to extract the metabolites from a bodily sample and determine their concentration, and thus the determining step, by working a chemical and physical transformation on physical substances, sufficiently confines the patent monopoly, as required by the machine-or-transformation test.  The Court further explained that the administering and determining steps were central to the claims rather than merely insignificant extrasolution activity because the administering step provides thiopurine drugs for the purpose of treating disease, and the determining step measures the drugs’ metabolite levels for the purpose of assessing the drugs’ dosage during the course of treatment.  

The Court also discussed two earlier cases:  In re Grams, 888 F.2d 835 (Fed. Cir. 1989), which the Court called the “closest comparison,” and In re Abele, 684 F.2d 902 (C.C.P.A. 1982).  In Grams, the claims, which were found unpatentable, recited a process that involved (1) performing a clinical test on individuals and (2) based on the data from that test, determining if an abnormality existed and determining possible causes of any abnormality by using an algorithm.  The Court distinguished Grams by noting that the claims did not require the performing of clinical tests on individuals that were transformative, because the tests were just to “obtain data.”  Slip op. at 20.  In the instant case, the Court stated that the claimed methods are not merely data-gathering steps or insignificant extrasolution activity—they are part of treatment regimes for various diseases.  Moreover, while the Court agreed with the district court that the final “wherein” clauses were mental steps and thus not patent-eligible per se, the Court held that a subsequent mental step does not, by itself, negate the transformative nature of prior steps.   

In Abele, the method claim called for the use of X-ray attenuation data, which necessarily involved production, detection, and display with a CAT scan.  The method also recited the use of an algorithm.  In Abele, the Court found that the claim was patentable because the steps of a CAT scan were statutory subject matter whose patentability was not affected by the presence of an algorithm in the claimed method.  The Court reasoned in the instant case that the presence of mental steps similarly does not detract from the patentability of the administering and determining steps.  The Court discerned that viewing the treatment methods as a whole, Prometheus had claimed therapeutic methods that determine the optimal dosage level for a course of treatment. 

Accordingly, the Court reversed the judgment of the district court and remanded with instructions to deny Mayo’s motion for SJ that the asserted claims were invalid under § 101.


Summary authored by Sulay D. Jhaveri, Ph.D., student associate at Finnegan.