Eye Therapies, LLC v. Slayback Pharma LLC

141 F.4th 1264 (Fed. Cir. 2025) · United States Court of Appeals for the Federal Circuit · June 30, 2025 · No. 23-2173

Summary

The United States Court of Appeals for the Federal Circuit reviewed a Patent Trial and Appeal Board decision holding claims of U.S. Patent No. 8,293,742 unpatentable as obvious. The court reversed the Board's claim construction of the transitional phrase "consisting essentially of," determining that the patent prosecution history demonstrated the applicant intended to limit the claims to methods excluding active ingredients other than brimonidine. Accordingly, the court vacated the Board's obviousness ruling and remanded the case for further proceedings consistent with the corrected claim construction.

Court
United States Court of Appeals for the Federal Circuit
Writing for the Court
Scarsi, District Judge; Taranto, Circuit Judge; Stoll, Circuit Judge; Scarsi, District Judge, sitting by designation
Jurisdiction
United States Court of Appeals for the Federal Circuit
Decision date
June 30, 2025
Docket number
23-2173
Procedural posture
Appeal from the Patent Trial and Appeal Board's final written decision in an inter partes review determining all challenged claims of U.S. Patent No. 8,293,742 unpatentable.
Standard of review
Claim construction is reviewed de novo when based on intrinsic evidence, with subsidiary factual findings involving extrinsic evidence reviewed for substantial evidence. Obviousness is reviewed as a mixed question of law and fact: the ultimate determination is reviewed de novo and underlying factual findings for substantial evidence.
Precedential value
Published Federal Circuit opinion; precedential.
Parties
Eye Therapies, LLC v. Slayback Pharma LLC
Disposition
reversed_and_remanded

Topics

patent lawobviousnesspatent prosecutionintellectual property

Practice areas

patent lawpatent prosecutionobviousnessintellectual property

Questions Presented

  1. Whether the phrase "consisting essentially of" in claims 1 and 3 of the '742 patent excludes active ingredients other than brimonidine in light of the patent's prosecution history.
  2. Whether the Board's obviousness determination could stand after applying an erroneous construction of the "consisting essentially of" limitation.

Holdings

  1. As used in claims 1 and 3 of the '742 patent, the phrase "consisting essentially of" excludes the use of active ingredients other than brimonidine.
  2. The Board's obviousness determination could not stand because it materially relied on the erroneous construction of "consisting essentially of"; the determination was vacated and remanded for reconsideration under the correct construction.

Key quotations

We conclude the Board erred in its construction of the phrase “consisting essentially of” as allowing the coadministration of active ingredients other than brimonidine. (1266)
We read the transition phrase “consisting essentially of” as used in claims 1 and 3 of the ’742 patent to exclude use of active ingredients other than brimonidine. (1272)
For the foregoing reasons, we reverse the Board’s claim construction, vacate the Board’s final written decision, and remand the matter to the Board for further proceedings consistent with the construction provided above. (1273)

Factual background

Eye Therapies owns and licenses U.S. Patent No. 8,293,742, which claims methods of reducing eye redness using low-concentration brimonidine. During prosecution, the examiner rejected earlier claims using the open-ended term "comprising" based on Dean, which disclosed brimonidine administered with brinzolamide. Eye Therapies replaced "comprising" with "consisting essentially of" and represented that the claimed methods did not require other active ingredients; the examiner allowed the claims. In the inter partes review, the Board construed the phrase to permit additional active ingredients that did not materially affect the invention's basic and novel properties and found the claims obvious over combinations of prior art references.

Procedural history

The Board instituted inter partes review of claims 1–6 of the '742 patent and issued a final written decision finding all challenged claims unpatentable. Eye Therapies appealed, challenging the Board's construction of the phrase "consisting essentially of" and its obviousness determination. The Federal Circuit reversed the claim construction, vacated the final written decision, and remanded for further proceedings.

Remand instructions

The Board must conduct further proceedings consistent with the Federal Circuit's construction of "consisting essentially of" as excluding active ingredients other than brimonidine, including reconsideration of the obviousness analysis under that construction.

Court Document

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