Administering Mayo to Patents in Medicine and Biotechnology: Appropriate Dosage or Risk of Toxic Side Effects?
| Citation | Vol. 64 No. 2 |
| Publication year | 2013 |
Administering Mayo to Patents in Medicine and Biotechnology: Appropriate Dosage or Risk of Toxic Side Effects?
Lauren Miller
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"That which distinguishes man from the brute is his power, in dealing with Nature, to milk her laws, and make them give forth their bounty."1
In Mayo Collaborative Services v. Prometheus Laboratories, Inc.,2 the United States Supreme Court considered whether it would uphold patents on the "bounty" arising from laws of nature, specifically, diagnostic tests based on natural laws that determined the efficacy and toxicity of certain thiopurine drugs.3 In a unanimous ruling, the Court invalidated the patents, which were held by respondent Prometheus Laboratories, Inc. (Prometheus).4 The Court ultimately concluded that the processes for which Prometheus claimed patents did not add "significantly more" to the underlying laws of nature, and thus did not
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warrant patent protection.5 The Mayo decision is likely to have a strong impact on the future of patent protection in the fields of biotechnology and personalized medicine, particularly in the emerging area of patenting human genes.6
Prometheus was the licensee of two patents on diagnostic tests that it had designed. The tests measured the physiological effects of thiopurine drugs, which are used to treat various autoimmune diseases. When a patient ingests a medication containing thiopurine, the body metabolizes the drug and produces metabolites in the blood as a result. However, because different patients metabolize the drug differently, physicians have encountered difficulty in determining whether a given dose of a thiopurine compound is too high, risking adverse side effects, or too low, rendering the compound ineffective.7
Prometheus designed the diagnostic tests as an attempt to alleviate these uncertainties about thiopurine dosages. At the time the discoveries underlying the patents were made, scientists already knew that the levels of particular metabolites in a patient's bloodstream could signal whether a given dosage of a thiopurine compound would be either harmful or ineffective. However, they did not know exact correlations between metabolite levels and the predicted effects of thiopurine. Prometheus's patent claims emerged from its discovery that blood metabolite levels within specified ranges indicated the likelihood that the drug dosage was either too high or too low. The claims established processes for maximizing the efficacy of the drug. The method consisted of administering the drug to the patient, determining the level of metabolites produced in the patient's bloodstream, and increasing or decreasing the dosage if the metabolite levels fell outside the predetermined safe and effective range.8
The petitioners, Mayo Clinic Rochester and Mayo Collaborative Services (Mayo), bought and used the diagnostic tests which relied on the processes described in Prometheus's patents. However, in 2004, Mayo stated that it intended to market a somewhat different diagnostic test, which would use higher metabolite levels to determine toxicity. Prometheus sued Mayo, alleging that Mayo's test infringed on its
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patents. The United States District Court for the Southern District of California found that Mayo's proposed test did infringe on the patents, but nevertheless granted summary judgment to Mayo, with the rationale that the patents essentially claimed natural laws that were not patentable.9 The United States Court of Appeals for the Federal Circuit reversed the district court's decision, holding that the processes were eligible for patent protection under that circuit's "machine or transformation test" because the processes covered by the patents "involve[d] the transformation of the human body or of blood taken from the body."10 Mayo then filed a petition for certiorari with the Supreme Court.11 The Supreme Court granted the petition, vacated the judgment, and remanded the case to the Federal Circuit in light of Bilski v. Kappos,12 which clarified that the "machine or transformation test" was not an exclusive test for determining patent eligibility.13 After the Federal Circuit affirmed its prior decision, Mayo filed another petition for certiorari, which the Court granted.14 The Court held that the patents attempted to claim laws of nature, and thus invalidated Prometheus's patents.15
Patentability is governed by section 101 of the Patent Act,16 which provides that "[w]hoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title."17 The Patent Act further specifies that an invention must be "novel"18 and "non-obvious"19 to receive patent protection. The Court has interpreted various portions of this statute in a number of patent cases.
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A. Gottschalk v. Benson: Overly Broad and Abstract Claims May Preempt Natural Laws
In 1972, the Supreme Court in Gottschalk v. Benson20 considered patent claims proposed by respondents, who sought to obtain patents for a process of converting binary-coded decimal (BCD) numbers into pure binary numerals.21 The patents were to cover any use of this method in any general-purpose digital computer. The question before the Court was whether this method was a "'process' within the meaning of the Patent Act."22 The Court held that the process being claimed for a patent was "abstract and sweeping," with an almost unlimited number of applications.23 According to the Court, to hold the patents valid would be equated with patenting an abstract idea, which is not permissible under the Patent Act.24 Moreover, the mathematical formula involved in the patent claims lacked any "substantial practical application except in connection with a digital computer."25 Thus, any patent issued would preempt the use of the mathematical formula, and essentially be a patent on the formula itself.26 Therefore, the Court overturned the respondent's patents.27
B. Parker v. Flook: Patent Claims Must Be Valid in Substance, Not Only in Form
Several years later, the Supreme Court in the 1978 case of Parker v. Flook28 invalidated patent claims for "alarm limits" used in the catalytic chemical conversion of hydrocarbons.29 When variables in the chemical conversion process, such as temperature or pressure, exceed a predetermined limit, an alarm can then signal an abnormal or dangerous condition. The respondent's patent claim employed an algorithm to calculate one such alarm limit value.30
The respondent argued that the existence of "post-solution activity"—adjusting alarm limits to match the number computed by the
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formula—should make the process patentable, but the Court disagreed.31 The Court indicated that almost anyone could draft around the patent requirements in this way, which would allow patentable subject matter to rely heavily on "the draftsman's art."32 The Court also held that there was no "inventive concept" in the respondent's process, and that the only added idea was the use of the algorithm.33 In fact, the only difference between the respondent's way of determining alarm limits and conventional methods was the use of the formula.34 The Court concluded with a word of warning: "[W]e must proceed cautiously when we are asked to extend patent rights into areas wholly unforeseen by Congress."35
C. Diamond v. Chakrabarty: Asserting the Court's Right to Interpret the Patent Statutes
In 1980, the Court in Diamond v. Chakrabarty36 considered a microbiologist's patent claims related to a genetically engineered bacterium.37 The bacterium, unlike any naturally-occurring bacteria, had the capability of breaking down crude oil, and thus could be useful for managing oil spills. The respondent's claims were for the bacterium itself, as well as the process of creating it.38 The question before the Court was whether Chakrabarty's bacterium comprised a "manufacture" or "composition of matter" as described in the Patent Act.39
The Court ruled that the respondent's man-made bacterium was clearly patent-eligible, as it had characteristics which were quite different from those found in naturally-occurring bacteria.40 It also addressed, but ultimately rejected, some of the petitioner's arguments against patent eligibility of the claims.41 The petitioner argued that microorganisms could not be patented until Congress explicitly allowed for such patent protection, and that Congress could not have predicted the genetic technology at issue in this case when it enacted the original Patent Act.42 However, the Court asserted its right to interpret the
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laws that Congress had enacted, and indicated that the statute at issue was not ambiguous.43 The majority entirely rejected the essence of the petitioner's argument, which was that "unanticipated inventions are without [patent] protection."44 The Court held that it would construe the language of the statute as it was unambiguously expressed, unless Congress acted to limit patentability in the areas at issue.45
D. Diamond v. Diehr: Adding Steps to a Natural Law Can Result in Patentability
In Diamond v. Diehr,46 the Court again considered the question of whether a structure or process that relied heavily on a mathematical formula warranted patent protection.47 The Court held that such a formula cannot itself be patented; however, when a patent claim containing a formula applies to a process which serves an overall function the patent laws are designed to protect, then the claim can be patented.48
In this case, the respondents filed a patent application for a process of turning uncured synthetic rubber into cured rubber products. They used a mathematical equation to determine the precise length of...
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