Federal Circuit Emphasizes the Importance of Relative Claim Terms Such as “About”

Posted by Marc R. Labgold, Ph.D. | Dec 15, 2021 | 0 Comments

In Astrazeneca AB v. Mylan Phamaceuticals, Inc., (Docket No. 21-1729; decided Dec. 8, 2021) the Federal Circuit has once again emphasized how the inventor's statements in the patent specification and during prosecution impact upon the interpretation of patent claims.  Of particular interest, this case reminds practitioners of the importance of relative claim terms and, in this particular case, “about”.    

In this case, the parties agreed that the term “0.001%”, would ordinarily, as an abstract number on a page, encompass a range from 0.0005% to 0.0014%.  This “ordinary” meaning is premised upon the “standard scientific convention, and numbers falling within that range would typically be rounded up or down to 0.001%.”   Despite that understanding, the defendant argued the written description and the prosecution history required the term be construed in a much more narrow fashion. The district court, however, construed the term in accordance with its plain and ordinary meaning, allowing it to encompass the broader range from 0.0005% to 0.0014%.

The Federal Circuit, however, reversed based upon the statements made by the applicant in the specification and during prosecution.  Of particular note, the Court stated:

Over the course of the prosecution history, the inventors narrowed the claimed concentration of PVP to 0.001% w/w from a broader range without using the qualifier “about.”  The inventors did this not just once but multiple times, each time emphasizing to the Examiner that 0.001% w/w PVP—not concentrations slightly more or less than 0.001% w/w—was critical to stability of the claimed 2 mg/mL budesonide formulation. And, importantly, the prosecution history shows that the inventors knew how to claim ranges or describe numbers with approximation, e.g., by using the term “about” to qualify the amount of PVP claimed. Yet, in the asserted claims, the inventors chose to claim exactly 0.001% w/w PVP. Under our precedent, this provides further support for construing 0.001% narrowly. (Emphasis added).

Based on the intrinsic record, the Federal Circuit construed “0.001%” as “that precise number, with only minor variations i.e., 0.00095% to 0.00104%.”

About the Author

Marc R. Labgold, Ph.D.

Marc R. Labgold, PhD, is a registered U.S. patent attorney with nearly 30 years of experience specializing in patent litigation and international commercial arbitration.  He is an independent arbitrator listed on numerous distinguished panels ...


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