Mayo Collaborative Services v. Prometheus Laboratories, Inc.

On March 20, 2012, the U.S. Supreme Court, by unanimous decision, handed down its opinion in Mayo Collaborative Services v. Prometheus Laboratories, Inc. (No. 10-1150), which addressed the issue of patent eligibility of certain types of medical diagnostic patent claims. The Prometheus decision concerned U.S. Patent Nos. 6,355,623 and 6,680,302, both of which relate to diagnostic tests for determining the appropriate dosages for a given patient of a thiopurine drug used to treat gastrointestinal autoimmune diseases such as Crohn’€™s disease and ulcerative colitis. In an opinion written by Justice Breyer, the Supreme Court reversed the Federal Circuit and held that the contested diagnostic process claims were not  patent eligible under 35 U.S.C. §101.

In brief, the Supreme Court found that the claims at issue recited “€œlaws of nature”€ that were not themselves patent-eligible. In order to meet the patent eligibility requirements of §101, the Supreme Court held that, in addition to reciting these laws of nature, the claims must also include “additional features that provide practical assurance that the process is more than a drafting effort designed to monopolize the law of nature itself.” The Court identified the laws of nature recited in the claims as being the relationships between concentrations of certain thiopurine metabolites (e.g., 6-thioguanine) in the blood and the likelihood that a thiopurine drug dosage will prove ineffective or cause harm. While the claims included an “administering”€ step, a “€œdetermining” step, and “€œwherein”€ clauses, the Court found that any additional features recited in the claims were “not sufficient to transform unpatentable natural correlations into patentable applications of those regularities.”

The “administering” step involved administering a drug providing 6-thioguanine to a subject having an immune-mediated gastrointestinal disorder. The Court found that this step simply referred to the relevant audience, namely, doctors who treat patients with thiopurine drugs. The Court also noted that treating these diseases with thiopurine drugs was already well known. The “€œdetermining” step involved determining the level of 6-thioguanine in the subject. The Court found that this feature merely told the doctor to determine the level of the relevant metabolites in the blood. Finally, the “wherein” clauses set forth the particular levels of 6-thioguanine in the blood that correlated to a need to either increase or decrease the drug to be subsequently administered to the subject. The Court determined that these clauses simply told a doctor about the relevant natural laws, and, at most, suggested that the doctor take those laws into account when treating his patient. In sum, the Court concluded that any additional steps contained in the claims at issue consisted of well-understood, routine, conventional activity already engaged in by the scientific community.

In the short time since its issuance, the Prometheus decision has generated a good deal of discussion among those in the biotechnology industry, particularly among innovators and practitioners in the areas of medical diagnostics and personalized medicine. Unfortunately, the Supreme Court did not provide explicit guidance on how the particular claims in Prometheus could have been amended to meet the requirements of §101; accordingly, at present, there is little consensus of how the Prometheus decision will impact and influence the continued growth, innovation, patent procurement, and commercialization of these promising medical technologies.

While many interested parties are concerned about the uncertainty created by the Prometheus decision, there are some practical considerations to be aware of with respect to medical diagnostic claims. It appears that, at the very least, diagnostic process claims similar in structure to those in Prometheus should require some post-solution activity. For example, in Prometheus, rather than merely suggesting an increase or decrease in the dosage of the thiopurine drug, the claim could have, at least, positively required the subsequent administration of the higher or lower dosage indicated by the metabolite levels found in the patient’€™s blood.

While the impact of the Prometheus decision is still to be determined, innovators of diagnostic processes and personalized medicine inventions should evaluate their diagnostic process patent claims pending before the U.S. Patent and Trademark Office and consider whether they need to be amended to bring them in line with the Prometheus decision. Similarly, those with issued patents containing diagnostic claims should immediately evaluate those claims to determine whether reissue is desirable and/or feasible. In particular, if you have a patent that issued less than two years ago, we urge you to contact us to discuss your options.

Note: On March 26, 2012, the Supreme Court granted certiorari review of the much-watched Myriad Genetics case. Without rendering an opinion, the Supreme Court vacated the Federal Circuit’€™s previous decision and remanded the case back to the Federal Circuit for further consideration in light of the Supreme Court’s decision in Prometheus.