U.S. patent laws and rules of practice before the U.S. Patent & Trademark Office (USPTO) are complex and constantly changing. Nevertheless, what was considered to be patent eligible subject matter was seemingly clear and straightforward – that is, until the United States Supreme Court rendered its decisions in Bilski v. Kappos1 and Mayo v. Prometheus.2

Now, in our courts, there are raging wars over what subject matter is patent eligible.

Section 101 of the Patent Act defines patent eligible subject matter as “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.”3 Over the years, however, the United States Supreme Court has carved out certain exceptions and has held that laws of nature, natural phenomena and abstract ideas are not patent eligible,4 as they are the “basic tools of scientific and technological work.”5 The Court has precluded the patenting of mental processes6 and products of nature.7 In addition, under Section 33(a) of the Leahy-Smith America Invents Act, Congress has codified the long-standing exception that a “human organism” is not patentable.

However, the Court has recognized that interpreting these exceptions too broadly could ultimately “eviscerate patent law.”8 All inventions, at some level, embody a law of nature, natural phenomenon or abstract idea. Simply because an invention contains a natural law or algorithm does not mean the invention is ineligible for patent protection. Thus, the Court has held that applications of laws of nature, natural phenomena and abstract ideas that provide a new and useful end may be patent eligible if the claimed application has enough of an “inventive concept” to ensure that the patent amounts to significantly more than a patent upon the natural law itself.9

The Court has also allowed patents on compositions of matter that are man-made. The Court has held that manufactures or compositions of matter that are non-naturally occurring may be patent eligible. In Diamond v. Chakrabarty, the Court held that a man-made, living microorganism was patent eligible because it was not a product of nature and instead a product of human ingenuity “having a distinctive name, character [and] use.”10

In view of the precedents set forth by the Court, one would think the exceptions and rules of patent eligibility would be easy to apply. Unfortunately, the Court’s analysis and dicta in Mayo v. Prometheus11 have put the biotech industry and courts in a place of uncertainty, where subject matter once believed to be patentable might now be patent ineligible.


In Bilski v. Kappos, the Court held that the machine-or-transformation test is not the sole test for determining the patent eligibility of a process, but rather “a useful and important clue, an investigative tool” for determining whether some claimed inventions are patent eligible processes.12 The Court then held that the claimed method was not patentable subject matter as being directed to an abstract idea. In view of its opinion, the Court then granted judicial review, vacated and remanded two decisions, Classen Immunotherapies, Inc. v. Biogen Ide13 and May14, by the Court of Appeals for the Federal Circuit.

At issue in Classen were methods for optimizing childhood immunization. On remand, the Federal Circuit determined that method claims reciting an active physical step of immunization, despite the inclusion of a mental step, were patent eligible as the physical step was a specific tangible application.15 The court, however, held as patent ineligible other claims that were merely directed to an abstract principle that variation in immunization schedules may have consequences for certain diseases.16

The claims at issue in Mayo were directed to methods of giving a thiopurine drug to a patient, measuring metabolites of that thiopurine drug, and determining whether to increase or decrease the dosage of the thiopurine drug. The following claim17 is representative of the claims at issue:

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

Administering a drug providing 6-thioguanine to a subject...

Determining the level of 6-thioguanine in said subject... wherein the level of 6-thioguanine less than about 230 pmol per 8 x 108 red blood cells indicates a need to increase the amount of said drug ... and wherein the level of 6-thioguanine greater than about 400 pmol per 8 x 108 red blood cells indicates a need to decrease the amount of said drug... .

On remand, the Federal Circuit maintained its position that the claims were directed to patent eligible subject matter as the methods involved two transformative steps, i.e., administering the thiopurine drug and measuring the metabolites. Mayo appealed again and the Supreme Court reversed the Federal Circuit and held that the claims were not patent eligible.

The Court determined that the “administering” step simply refers to the relevant audience, e.g., doctors who treat patients with certain diseases with thiopurine drugs.18 The Court cited Bilski and stated that the “prohibition against patenting abstract ideas ‘cannot be circumvented by attempting to limit the use of the formula to a particular technological environment.”’19 The Court determined that the “wherein” clauses simply tell one about the relevant natural laws, and at most suggest that one should consider such when treating a patient.20 The Court indicated that the “determining” step tells the doctor to determine the level of the relevant metabolites in the blood and that such a step is simply pre-solution activity that is insufficient to transform an unpatentable law of nature into a patent eligible application of the law of nature.21

After holding the claims invalid for being patent ineligible, the Court then made several troubling statements in dicta, which include “[w]e need not, and do not, now decide whether were the steps at issue here less conventional, these features of the claims would prove sufficient to invalidate them” and “[w]e need not determine here whether, from a policy perspective, increased protection for discoveries of diagnostic laws of nature is desirable.”22


The Supreme Court then vacated and remanded Association for Molecular Pathology v. Myriad23 and required the Federal Circuit to reconsider the patent eligibility of claims to isolated DNA in view of Mayo. On remand, the Federal Circuit again held that Myriad’s claims to isolated DNA were patent eligible. The court emphasized the holding in Chakrabarty and determined that isolated DNA is not found in nature and is instead man-made and the product of human ingenuity. American Civil Liberties Union (the opponent to isolated DNA being patent eligible) appealed to the Supreme Court and the Court granted certiorari to determine whether human genes are patentable.

Those in favor of isolated DNA being patent eligible subject matter argue that isolated DNA is not naturally occurring in nature because it is “isolated” and, as such, it has utility in diagnostics and personalized medicine it would not otherwise have, and a significant amount of human ingenuity is involved in determining which isolated segments will have utility. Those who oppose the patent eligibility of isolated DNA essentially argue that isolated DNA is a product of nature because it is not “markedly different” from naturally occurring DNA since its informational content is the same, and patents on isolated DNA prevent access to personalized medicine.

Unfortunately, the misinformed incorrectly believe that patents on isolated DNA prevent access to personalized medicine. Personalized medicine is based on the principle that medical treatments can and should be tailored to an individual according to the individual’s biochemical and genetic makeup that is often different from the majority of those afflicted. This necessarily means researching and developing a variety of treatments for a plurality of small subsets of the population. No company is going to spend the millions of dollars required to conduct the research and development and obtain the necessary approval from the U.S. Food and Drug Administration if it is unlikely to recoup its investment. In fact, theMayo decision and upcoming review of the patent eligibility of isolated DNA by the Supreme Court is already having a destabilizing effect on the biotech and pharmaceutical industry.

The Supreme Court heard oral arguments in Myriad in April 2013, and its decision is expected in June 2013. Many believe the Court will hold isolated DNA, except for cDNA, to be patent ineligible and that such a decision will further destabilize the biotech and pharmaceutical industry.


The U.S. courts and the USPTO’s Patent Trial & Appeal Board (PTAB) are issuing numerous decisions that are adverse to patentees and patent applicants. Many courts have used Mayo to invalidate patents by reasoning that the claimed inventions do not add anything more than routine and conventional pre- and post-solution activity.

As an example, in PerkinElmer, Inc. v. Intema Ltd.24 (non-precedential), the Federal Circuit determined that claims to a prenatal diagnostic method for Down’s syndrome, which is not invasive and thereby avoids the risk of miscarriage, merely recite an ineligible mental step and natural law and that the remaining claim limitations are simply conventional pre- and post-solution activity. Thus, the court held the claims invalid for being directed to ineligible subject matter.

The PTAB used similar reasoning in Ex Parte Kovatchev25 to affirm an examiner’s rejection of claims directed to a method for evaluating the glycosylated hemoglobin of a patient based on blood glucose. The PTAB determined that the steps of converting blood glucose data into an estimate and electronically transforming the estimate into a visual depiction were merely abstract ideas under Bilski and that the steps of collecting the blood sample and assaying the blood glucose therein were well understood, routine, conventional activity that is preand post-solution activity that fails to convert the abstract ideas into patent eligible subject matter.

The ramifications of Mayo will undoubtedly have a destabilizing effect in other technology sectors, since all inventions at their most basic level are based upon or manipulate a law of nature, natural phenomenon or abstract idea. In fact, a divided en banc Federal Circuit recently held that claims directed to a system of devices for carrying out a software-implemented method were patent ineligible as the underlying principle of the claimed invention is to perform an abstract idea.26


The laws regarding patent eligibility can be complex and convoluted, especially in the biotech, pharmaceutical and medical device fields. Patent applicants should seek guidance from an experienced patent attorney with extensive expertise in these fields who will carefully consider how to obtain patent protection while minimizing the risk that the patent claims will be found to be patent ineligible.