Federal Circuit Reaffirms Patent Eligibility of Medical-Treatment Methods in Prometheus Laboratories

On December 17, 2010, the Federal Circuit issued its second decision in Prometheus Laboratories, Inc. v. Mayo Collaborative Services. The Federal Circuit had previously determined that Prometheus's patent claims to methods for calibrating the proper dosage of thiopurine drugs, which are used for treating autoimmune diseases, satisfied the patent eligibility requirement of 35 U.S.C. § 101. The Supreme Court vacated and remanded this earlier decision in view of its own decision in Bilski et al. v. Kappos. In Bilski, the Court rejected the Federal Circuit's determination that the so-called "machine-or-transformation" test is the exclusive test for assessing patent-eligibility of method claims under § 101, but still endorsed the test as a "useful and important clue" in assessing patent eligibility.

As expected, on remand, the Federal Circuit again concluded that Prometheus's method claims recite "a patent-eligible application of naturally occurring correlations between metabolite levels and efficacy or toxicity, and thus do not wholly preempt all uses of the recited correlations." As such, according to the court, the Prometheus claims "do not preempt all uses of the natural correlations," but instead "utilize them in a series of specific steps." The court further stated that Prometheus's claimed treatment methods "transform an article into a different state or thing" and that his transformation is "central to the purpose of the claimed process." Thus, the court re-affirmed that Prometheus's claimed methods satisfy the "transformation prong" of the machine-or-transformation test.

The latest Prometheus decision is not surprising as the court had previously determined that Prometheus's claims satisfied the machine-or-transformation test, and nothing in the Supreme Court's Bilski decision warranted a different result here. That is, Bilski merely rejected the notion that the machine-or-transformation test it is the exclusive test for §101 patent eligibility, but did not hold or suggest that a claimed method satisfying this test could still be ineligible for patent protection.

The Federal Circuit has yet to decide the case of Classen Immunotherapies, Inc. v. Biogen Idec, which like Prometheus, was remanded to the Federal Circuit by the Supreme Court in view of Bilski. In Classen, the Federal Circuit previously held that patent claims to "a method of determining whether an immunization schedule affects the incidence or severity of a chronic immune-mediated disorder in a treatment group of mammals" was not patent-eligible under § 101 solely on the basis that the claims did not satisfy the machine-or-transformation test. As this is no longer the sole test for patent eligibility under § 101, the Federal Circuit must now determine whether Classen's claims are an attempt to patent "laws of nature, physical phenomena, or abstract ideas" in view of Bilski.

Interestingly, in its supplemental briefs, the Classen defendants endorse the Federal Circuit's finding that Prometheus's claims are patentable subject matter. Specifically, the defendants argue that the "administering" and "determining" steps provide information about the particular patient treated, whereas the corresponding steps in Classen's claims more broadly apply a scientific concept to all patients. It is possible that the Federal Circuit will focus on this distinction and find that Classen's claims are not patentable as they preempt all uses of the natural correlation between an immunization schedule and the incidence of a disorder, and are thus improperly preempt "laws of nature, physical phenomena, or abstract ideas."