High Court Again Agrees to Review Patent Eligibility of Diagnostic Tests

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Patent eligibility under Section 101 of the Patent Act is once again on the U.S. Supreme Court's agenda, as the high court granted a petition for writ of certiorari June 20 to review whether a patent claim that covers observed correlations between blood test results and patient health is statutory subject matter (Mayo Collaborative Services v. Prometheus Laboratories Inc., U.S., No. 10-1150, review granted 6/20/11).

At issue is the Dec. 17 holding by the U.S. Court of Appeals for the Federal Circuit that claimed methods for calibrating the proper dosage of a drug for treating autoimmune diseases are patent eligible. Prometheus Laboratories Inc. v. Mayo Collaborative Services, 628 F.3d 1347, 97 USPQ2d 1097 (Fed. Cir. 2010) (243 PTD, 12/21/10).

Petitioner Mayo Collaborative Services argued that the Supreme Court effectively has unfinished business, as it not only rejected the opportunity to comment on the instant case when it addressed Section 101 in Bilski, but it also left similar issues unresolved in Laboratory Corporation of America Holdings d/b/a/ LabCorp. v. Metabolite Laboratories Inc., in which the court first granted certiorari and then determined—with a vigorous three-justice dissent—that it was improvidently granted. 548 U.S. 124, 79 USPQ2d 1065 (2006) (121 PTD, 06/23/06).

Review was denied, however, in two other cases watched by the patent community. L-3 v. Honeywell involved a challenge to the invalidity evidence standard that the court resolved by a June 9 ruling in another case. Applera v. Enzo challenged a Federal Circuit opinion on biotechnology patent claim indefiniteness.

Patent for Measurement of Metabolite Levels

Prometheus Laboratories Inc. is the exclusive licensee of two patents (6,355,623 and 6,680,302) which involve measuring the level of certain metabolites in the blood of patients taking thiopurine drugs, including the anti-Crohn's disease drug azathioprine, for treatment of autoimmune diseases.

The patented test is claimed as methods providing a means to measure the level of two metabolites, whereby metabolite levels greater than certain threshold levels of either one provide a “warning” of toxicity or inefficacy and indicate to the treating physician that an adjustment in drug dosage may be required. The claims at issue do not include a step for further action by the physician.

Prometheus brought a patent infringement suit against Mayo, alleging that Mayo's tests measuring the same metabolites infringe the patents.

The Federal Circuit in a 2009 ruling overturned a lower court's finding of patent ineligibility. The court applied its then-definitive “machine-or-transformation” test, determining that the claims met the transformation prong of the test. The high court's Bilski decision, however, declared the machine-or-transformation test to be a valuable tool but not determinative. Bilski v. Kappos, 129 S.Ct. 2735, 95 USPQ2d 1001 (2010) (123 PTD, 6/29/10)

A day after Bilski, the Supreme Court granted certiorari in Prometheus, vacated the appellate court's panel decision, and remanded the case to the Federal Circuit for reconsideration in light of the Bilskidecision (124 PTD, 6/30/10).

Federal Circuit Finds Patent Eligibility Post-Bilski

On remand, a reconstituted Federal Circuit panel on Dec. 17 again upheld the patentability of the disputed claims. The court used the test as an investigative tool, as the high court had allowed in Bilski, and again held that the claims asserted passed the transformation prong of the test. The court did not end its analysis there, though, as it further concluded that the asserted claims did not preempt all uses of the correlations between the results of the diagnostic tests and the toxicity and efficacy of the drug dosage; that the testing steps were not mere data gathering; and that a final “warning” step requiring no physical action by a physician did not negate patent eligibility.

The question presented in Mayo's March 17 certiorari petition was: “Whether 35 U.S.C. §101 is satisfied by a patent claim that covers observed correlations between blood test results and patient health, so that the claim effectively preempts all uses of the naturally occurring correlations, simply because well-known methods used to administer prescription drugs and test blood may involve ‘transformations' of body chemistry.”

The Public Patent Foundation and the AARP Foundation filed an amicus brief April 20 supporting the petitioner, as did a collection of medical associations led by the American College of Medical Genetics.

Stephen M. Shapiro of Mayer Brown, Chicago, represents Mayo. Prometheus is represented by Richard P. Bress of Latham & Watkins, Washington, D.C.

Cert Denied in Two Other Cases

The court followed the suggestion of the solicitor general (103 PTD, 5/27/11)and denied cert in a Section 112 case on biotechnology patent claim indefiniteness (Applera Corp. v. Enzo Biochem Inc.,U.S., No. 10-426, review denied 6/20/11).

Petitioner Applera Corp. contended that, by rejecting patent validity challenges unless the claim language is “insolubly ambiguous,” the Federal Circuit has employed a “toothless standard” for weighing the indefiniteness of patent claims.

The SG responded that phrases like “insolubly ambiguous” are simply the court's shorthand expression for “principles that are well grounded in [the Supreme Court's] Section 112 jurisprudence.”

Applera further lambasted the appeals court for devising a standard different from that of the Patent and Trademark Office, but the SG rebutted by saying that the differing standards stem from “the distinct roles that the PTO and the courts play in the patent system.”

The high court also denied review in Honeywell International Inc.'s challenge to the standard for invalidating a patent for obviousness in light of the recent Microsoft v. i4i decision (L-3 Communications Corp. v. Honeywell International Inc., U.S., No. 10-491, review denied 6/20/11).

Honeywell appealed the Federal Circuit's 2-1 ruling overturning the judgment of Court of Federal Claims in its action against the military's use of a patent under the Invention Secrecy Act. Honeywell International Inc. v. United States, 596 F.3d 800, 93 USPQ2d 1740 (34 PTD, 2/23/10), withdrawn; 609 F.3d 1292, 95 USPQ2d 1193 (Fed. Cir. 2010). The petition asked the court to rule on whether a party seeking invalidation of a patent for obviousness must prove invalidity by clear and convincing evidence, or by the lower preponderance of the evidence standard.

The court upheld the clear and convincing standard June 9 in Microsoft Corp. v. i4i L.P.,No. 10-290, 98 USPQ2d 1857 (U.S. 2011) (112 PTD, 6/10/11).

By Tony Dutra