How to succeed in the business of biotech patentability

The US Supreme Court has thrown down the gauntlet for patent eligibility in the biotechnology field. In spite of (or due to) their significant contributions to medicine, Mayo v Prometheus, Association for Molecular Pathology v Myriad Genetics, and Ariosa Diagnostics v Sequenom exemplify the harsh reality of recent changes in defining patent-eligible subject matter. These recent changes have left companies wondering how best to protect their products.

In the US, patent eligibility is defined under 35 USC §101, which states that “whoever 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”. Historically, patents have been issued for compounds purified from nature such as adrenaline, acetyl salicylic acid (aspirin), and the antibiotic streptomycin.

Furthermore, in Diamond v Chakrabarty the Supreme Court set the precedent that “anything under the sun that is made by the hand of man” is patent-eligible subject matter. Post Diamond, tens of thousands of biotech-based patents have been issued—most notably, patents directed to “purified” matter such as nucleic acid or amino acid. Roughly 30 years after Diamond, the courts have begun to severely restrict what is considered patentable subject matter in the biotech field.

Mayo

The first major change in the patent eligibility of biotech subject matter came in 2012 in Mayo. This decision focused on the patentability of a method of optimising the therapeutic efficacy of a drug based on the level of metabolites in the patient’s blood. The claims at issue were summarised as (1) administering the drug to a patient, (2) determining the drug or metabolite levels in the patient’s blood, and (3) adjusting the drug dosage based on the blood levels.

The court noted that “at the time the discoveries embodied in the patents were made, scientists already understood that the levels in a patient’s blood of certain metabolites ... were correlated with the likelihood that a particular dosage of thiopurine drug could cause harm or prove ineffective ... But those in the field did not know the precise correlations between metabolite levels and the likely harm or ineffectiveness”.

The Supreme Court determined that: “Prometheus’ patents set forth laws of nature—namely, relationships between concentrations of certain metabolites in the blood and the likelihood that a dosage of a thiopurine drug will prove ineffective or cause harm ... While it takes a human action (the administration of a thiopurine drug) to trigger a manifestation of this relation in particular a person, the relation itself exists in principle apart from any human action. The relation is a consequence of the ways in which thiopurine compounds are metabolised by the body—entirely natural processes. And so a patent that simply describes that relation sets forth a natural law.”

In explaining its decision, the court stated that “to transform an unpatentable law of nature into a patent-eligible application of such law, one must do more than simply state the law of nature while adding the words ‘apply it’”. It added: “Beyond picking out the relevant audience, namely those who administer doses of thiopurine drugs, the claim simply tells doctors to: (1) measure (somehow) the current level of the relevant metabolite, (2) use particular (unpatentable) laws of nature (which the claim sets forth) to calculate the current toxicity/inefficacy limits, and (3) reconsider the drug dosage in light of the law.

“These instructions add nothing specific to the laws of nature other than what is well-understood, routine, conventional activity, previously engaged by those in the field. And since they are steps that must be taken in order to apply the law in question, the effect is simply to tell doctors to apply the law somehow when treating their patients.”

To add to the confusion, the court acknowledged that the “administering”, “determining” and “wherein” steps “are not themselves natural laws but neither are they sufficient to transform the nature of the claim.” This leads to the question of what is sufficient to transform the nature of the claim? According to the court, the answer lies somewhere between Diamond v Diehr and Parker v Flook. The patents in Diehr were directed to the use of the Arrhenius equation to determine curing time in moulded rubber products. The patents in Flook were directed to the use of an algorithm to monitor the catalytic conversion of hydrocarbons. The claims in question for each case are shown in Table 1.

Table 1: Comparison of claims in the Diehr and Flook cases