The patentability of subject matter that is facially within the classes set forth under 35 U.S.C. § 101 is most reliably resolved in accordance with the conditions of 35 U.S.C. §§ 102, 103, and 112.  Classen Immunotherapies, Inc. v. Biogen IDEC, 659 F.3d 1057 (Fed. Cir. Aug. 2011).  In Classen, the Federal Circuit reviewed the district court’s finding that Classen’s patent claims are ineligible subject matter under § 101 in light of the Supreme Court’s decision in Bilski v. Kappos, 130 S. Ct. 3218, 177 L. Ed. 2d 792, 95 U.S.P.Q.2d 1001 (2010), finding that § 101 should be used only as a threshold test, considering all of the specific facts of each individual case.

Classen’s patents are based on a theory that the schedule of infant immunization for infectious diseases can affect the later occurrence of certain chronic disorders, and that immunization should be conducted on the schedule that presents the lowest risk with respect to such disorders.  Two of Classen’s patents, U.S. Patent Nos. 6,420,139 (“the ’139 patent”) and 6,638,739 (“the ’739 patent”), claim a method of (1) screening and comparing information on immunization schedules and the occurrence of chronic disease to identify the lower risk schedule, and then (2) immunizing by administering the vaccine on that schedule.  The claims of a third patent, U.S. Patent No. 5,723,283 (“the ’283 patent”), do not include the later immunization step.

Section 101 states: “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 therefore, subject to the conditions and requirements of this title.”  Based upon its interpretation of § 101, the district court found all three Classen patents ineligible for patenting as directed to the “abstract idea” that there is a relationship between the infant immunization schedule for infectious diseases and the later occurrence of chronic disorders.

On appeal, the Classen court looked to the Supreme Court’s Bilski decision for guidance.  The Federal Circuit focused on Bilski’s reiteration of the concern for “barr[ing] at the threshold.”  The Federal Circuit noted that Bilski encouraged the preservation of the distinctions between the threshold inquiry of patent eligibility and the substantive conditions of patentability, recognizing that even if an invention meets the requirements of § 101, it still must satisfy the remaining conditions of Title 35 by being novel, nonobvious, and fully and particularly described.

Thus, the Classen court found that the presence of a mental step is not itself fatal to § 101 eligibility, and that the infinite variety of mental and physical activity negates application of a rigid rule of ineligibility.  Instead of applying a rigid rule, Classen found that each case must be determined on its own facts, considering all of the surrounding circumstances to determine if patent-eligible subject matter is present.  The Classen court held that even though it had serious doubts about the substantive patentability of the claims, the ’139 and ’739 patents contain patent eligible subject matter because they include the physical step of immunization on a determined schedule.  The Federal Circuit held this specific, tangible application sufficient to meet the § 101 bar, finding that questions of substantive patentability are most reliably resolved in accordance with the conditions of §§ 102, 103, and 112.

The Classen court, however, did draw a line on patent eligibility.  The Federal Circuit held that because the ’283 patent claim is limited to the idea of comparing known immunization results that are found in scientific literature, it does not qualify as patent eligible subject matter.  The claim does not apply any physical step, but merely claims the idea of collecting and comparing known information.  The Court found that merely disclosing an abstract idea is insufficient to cross the § 101 threshold.

Classen demonstrates the Federal Circuit’s continued struggle with the application of § 101, still avoiding the creation of a bright-line rule for patent drafters to follow.  In the absence of a bright-line rule, patent drafters should present for examination claims having a wide variety of scope, and keep in mind that even if a claim passes the § 101 threshold, it still must pass all of the other patentability requirements.