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The Federal Circuit’s only precedential patent opinion this week focuses on the written description requirement in the context of an anticipation analysis in the chemical arts.  Specifically, it concerns whether disclosures in asserted prior art were sufficient to disclose a claimed molecular structure.  At issue was Gilead’s flagship drug sofosbuvir, used to treat hepatitis C.

The University of Minnesota owns the ’830 patent, which discloses the following chemical compound:

The claim further specifies that R₂ is halo and R₃ is hydroxyl, and each of R₁, R₄, R₅, R₆, R₇, and X were provided in the form of menus of various possible chemical substituents.  For example, R₅ is “an amino acid,” and each of the chemical substituents of R₄, R₆, and R₇ could include (C₁-C-₆)alkyl, which could “optionally [be] substituted with one or more” of a laundry list of possible items that literally filled half a page of the Court’s opinion.

Gilead filed an IPR in relation to a number of claims, including independent claim 1, asserting that its own, 2010 patent application anticipated the claims by disclosing sofosbuvir.  Minnesota claimed priority to earlier patents in the family tree to attempt to get behind Gilead’s 2010 application.  The case turned on whether Minnesota’s earlier patent applications provided sufficient written description support showing it had possession of the claimed molecular compounds at the time of its claimed priority applications.  The Patent Office held that it did not, and the university appealed.

Written description of a genus of chemical compounds requires description not only of the outer limits of the genus, but also of either a representative number of members of the genus or structural features common to the members of the genus.  In this case, Minnesota did not assert that it disclosed a representative number of members of the genus, but rather asserted that it “literally described” the patented claim in its prior publications.

As the Court explained:

Claim 47 [of the asserted priority application, P1], like other claims set forth in P1, defines a potential subgenus of substituents for R7. P1 claim 47 recites:

47. The compound of any one of claims 1–46 wherein R₇ is hydrogen or (C₁-C₆)alkyl.

. . . .

Minnesota asserts that P1 claim 47, combined with P1 claim 45 (with its disclosure of R₆ substituents), P1 claim 33 (with its disclosure of R₅ substituents), P1 claim 21 (with its disclosure of the R₃ substituent), P1 claim 13 (with its disclosure of R₂ substituents), P1 claim 2 (with its disclosure of R₁ substituents), and P1 claim 1 (with its disclosure of R₄ substituents and of X), provides an ipsis verbis disclosure of the subgenus claimed in the ’830 patent.

The Board did not agree, and neither did the Court.  As the Court explained:

Following this maze-like path, each step providing multiple alternative paths, is not a written description of what might have been described if each of the optional steps had been set forth as the only option. This argument calls to mind what Yogi Berra, the Yankee catcher, was reported to have said: “when one comes to a fork in the road, take it.” That comment was notable because of its indeterminacy, its lack of direction. Similarly, here, all those optional choices do not define the intended result that is claim 1 of the ’830 patent.

In the alternative, Minnesota argued that the asserted priority application “provided sufficient blaze marks to provide written description support.”  Both the Board and the Court disagreed.  The Court held that “even if P1 claim 47 blazes a trail through the forest that runs close by the later-claimed tree, the priority applications do not direct one to the proposed tree in particular, and do not teach the point at which one should leave the trail to find it” (quoting Fujikawa v. Wattanasin, 93 F.3d 1559, 1571 (Fed. Cir. 1996) (cleaned up)).

The Court also disposed of Minnesota’s arguments that the Board violated the Administrative Procedures Act and that, as a state actor, it had sovereign immunity from IPRs.  Ultimately, the Court affirmed that the challenged claims were invalid as anticipated by Gilead’s prior patent application.

The opinion can be found here.

By Nika Aldrich