Courts often will strive to construe ambiguous claim language to avoid indefiniteness under 35 U.S.C. § 112(b) (a patent's “specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention”).

In University of Massachusetts v. L'Oréal, S.A., No. 21-1969 (Fed. Cir. Jun. 13, 2022), the U.S. Court of Appeals for the Federal Circuit considered whether a patent claim directed to a topical skin care product applied to the skin was indefinite as to the “applied” concertation of adenosine. The Federal Circuit emphasized the following language from Claim 1 of U.S. Patent No. 6,423,327 (entitled “Treatment of Skin with Adenosine or Adenosine Analog”):

1. 1. A method for enhancing the condition of unbroken skin of a mammal by reducing one or more of wrinkling, roughness, dryness, or laxity of the skin, without increasing dermal cell proliferation, the method comprising topically applying to the skin a composition comprising a concentration of adenosine in an amount effective to enhance the condition of the skin without increasing dermal cell proliferation, wherein the adenosine concentration applied to the dermal cells is 10-4 M to 10-7 M.

Human skin includes a surface layer called the epidermis and a deeper layer called the dermis. The district court found that the wherein clause was directed to the adenosine concentration after entering the subsurface dermal cells—and not the adenosine concentration in the composition that is topically applied to the skin.

The “topically applying” clause and the “wherein” clause appeared to refer to different concentrations of adenosine, and the “topically applying” clause  claimed a concentration of adenosine “in an amount effective to enhance the condition of the skin.” The district court concluded that this was indefinite because the subjective determination of whether a person's skin is enhanced was “a paradigmatic example of indefiniteness.” Univ. of Mass. v. L'Oréal USA, Inc., 534 F. Supp. 3d 349, 355 (D. Del. 2021) (“Beauty, after all, is “in the eyes of the beholder'” ).

The Federal Circuit, construing the patent claim de novo, held that the “wherein” clause actually referred to the concentration of adenosine in the product applied to the skin, and not the resultant concentration in the dermis, which obviated the district court's indefiniteness determination.

The word “applied” is capable of covering both direct application (to the skin surface) and indirect application (to the sub-surface layer). . . . the fact that one phrase using a form of “apply” refers to the “skin” and the other to the “dermal cells” does not mean that different things are being applied: The same thing can be applied directly to one object and indirectly to the other.

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The wherein clause then speaks of a “concentration applied to the dermal cells.” This phrase naturally refers to a number of particles per unit of volume of the mixture of which the adenosine is a part before putting the mixture in contact with the dermal cells.

The Federal Circuit also found that the specification did not specify a measurement of adenosine concentration after seepage through the skin into the dermis.

Furthermore, the Federal Circuit found the prosecution history resolves the ambiguity surrounding the meaning of “the adenosine concentration applied to the dermal cells” in the wherein clause.

We hold that this prosecution history requires that the wherein clause's reference to the recited concentrations being “applied to the dermal cells” be read as referring to concentrations of the composition applied to the skin's surface. The amendments and comments clearly convey that UMass was continuing the pre-amendment reliance on the concentration in the composition before application to the skin, rather than introducing a materially different, unexplained notion of concentration, no longer assessed before contact with the object of application.

As a result of the new claim construction of the “wherein” clause about “the adenosine concentration applied to the dermal cells,” the Federal Circuit vacated the district court's indefiniteness ruling, and remanded the case back to the district court to determine whether a judgment of non-infringement should be entered in view of the new construction.

The patent attorneys at Thomas P. Howard, LLC prosecute and litigate patents nationwide including in Colorado.