King Pharms., Inc. v. Eon Labs, Inc.: Informing a Patient of a Method’s Effect is Insufficient to Render the Method Patentable

King Pharms., Inc. v. Eon Labs, Inc., No. 2009-1437, -1438 (Fed. Cir. Aug. 2, 2010)

Slip Opinion

On August 2, 2010, the Federal Circuit affirmed the United States District Court for the Eastern District of New York's entry of summary judgment invalidating two patent claims held by King Pharmaceuticals, Inc. (“King”). In addition, the court vacated summary judgment against a third-party defendant for lack of subject matter jurisdiction.

King’s challenged patent claims pertained to the beneficial increase in bioavailability of a drug when the drug was ingested with food. Such claims were supported by two sources of novelty: the previously undiscovered result of increased bioavailability, and an “informing” limitation consisting of either instructing a patient to ingest metaxalone with food or applying printed labels bearing such instructions to packaging. In invalidating all of King’s claims in question, the Federal Circuit held that both alleged sources of novelty had been inherently anticipated by prior arts.

Patently-O provides an overview of the decision. Inventive Step provides a detailed summary of the court’s rationale in finding that the “informing” limitation was insufficient to impart patentability into an inherently anticipated claim.

King owned two patents that covered slightly different methods for increasing the bioavailability of metaxalone, a muscle relaxant. The first patent claimed as invention the unexpected finding that the bioavailability of metaxalone increased when a patient ingested a therapeutically effective amount of the drug with food. The second patent was similar to the first, except for an additional “informing” limitation that could either take the form of telling a patient the effect of taking metaxalone with food or using a container with such information. In 2004, Eon Labs, Inc. (“Eon”), a pharmaceutical company that planned to manufacture and sell generic brands of metaxalone, filed a patent certification pursuant to 21 U.S.C. § 355(j)(2)(A)(vii)(IV), arguing that all claims in King’s first patent were invalid. In response, King filed suit against Eon in the Eastern District of New York, claiming Eon had infringed upon both of its patents on the bioavailability of metaxalone. King appealed after the district court invalidated all of its patent claims on summary judgment.

The Federal Circuit found the main claim in King’s first patent was inherently anticipated by prior arts. Specifically, several reference guides for nurses, published decades before King’s filing of the patents, disclosed the method of providing metaxalone with food to reduce gastric discomfort. Although such prior arts did not expressly identify the increase in bioavailability, such increase was nonetheless a necessary result when the drug was administered as disclosed. The prior arts that suggested taking the drug with food therefore inherently anticipated the main claim in King’s first patent.

The court also invalidated the main claim in King’s second patent despite the additional “informing” limitation. Unlike the district court, however, the appeals court did not find the “informing” limitation non-transformative and therefore unpatentable under the “machine-or-transformation” test. See In re Bilski, 545 F.3d 943 (Fed. Cir. 2008); see also Bilski v. Kappos, 130 S. Ct. 3218 (2010). Instead, the court invalidated the claim again on grounds of inherent anticipation. The court found no “functional relationship” between the “informing” limitation and the increase in bioavailability, noting that the process of food increasing the bioavailability of metaxalone had no relationship to whether a patient was informed of the effect. Drawing analogy to precedents that established a known product is not patentable simply by the inclusion of “printed matter” describing the product, the court concluded that the “informing” limitation could not impart patentability to an otherwise unpatentable claim. Because the main claim in King’s second patent was essentially the same as that in King’s first patent with the addition of the “informing” limitation, the court similarly invalidated it for inherent anticipation.

As a separate matter, the court vacated the district court’s final judgment against Elan Pharmaceuticals, Inc., a third-party defendant on a counterclaim brought by Eon, for lack of subject matter jurisdiction.

In this decision, the Federal Circuit avoided an application of the post-Bilski “machine-or-transformation” test. The decision clarifies, however, that an unpatentable method cannot be saved by the simple inclusion of an information-providing limitation that is functionally unrelated to the method.

Harry Zhou is a 2L at the Harvard Law School.