Sect. 112 Indefiniteness in Chemical and Biotech Patent Claims

Drafting and Prosecuting Patent Claims That Will Hold Up Under Any Definiteness Standard

Recording of a 90-minute premium CLE webinar with Q&A

Conducted on Tuesday, July 7, 2020

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Program Materials

This CLE webinar will guide patent counsel on how recent Federal Circuit and PTAB case law impact daily patent practice. The panel will offer best practices to navigate pre- and post-issuance scrutiny for compliance with 35 U.S.C. 112(b).


In Nautilus Inc. v. Biosig Instruments Inc., 134 S.Ct. 2120, the Supreme Court held unanimously that the Federal Circuit's "insolubly ambiguous standard for indefiniteness breed[s] lower court confusion." In re Packard, 751 F.3d 1307 (Fed. Cir. 2014) (per curiam) and Ex parte McAward, Appeal No. 2015-006416 (precedential), show that the USPTO applies a different (lower) standard; a difference that stems from the different claim construction standard used by the USPTO during prosecution than the courts for issued patents.

Where does that leave the chem/bio patent practitioner? Different standards for indefiniteness depending on whether the claim is pre-issuance in the PTO or post-issuance in the courts?

Post-Nautilus Federal Circuit case law continues to develop. The court upheld the claims in Eli Lilly and Co. v. Teva Parenteral Medicines Inc., (Fed.Cir. 2017), under the Nautilus standard ("a person of ordinary skill in the art would understand the scope of the claim term 'vitamin B12' with reasonable certainty.") In BASF Corp. v. Johnson Matthey Inc., (Fed. Cir. 2017), the Federal Circuit overturned a finding of indefiniteness of claims reciting a "composition ... effective to catalyze," holding that: "What is needed is a context-specific inquiry into whether particular functional language actually provides the required reasonable certainty."

In Nevro Corp. v. Boston Scientific (Fed. Cir. 2020), the Federal Circuit applied the "reasonable certainty" test and held, inter alia, that the claim limitation “paresthesia-free,” did not render the method, system or device claims indefinite. The court noted defining a term functionally does not inherently make it indefinite. “The test for indefiniteness is not whether infringement of the claim must be determined on a case-by-case basis. Instead, it is simply whether a claim “inform[s] those skilled in the art about the scope of the invention with reasonable cer-tainty.” Id. at *6.

MasterMine Software Inc. v. Microsoft Corp., 874 F.3d 1307, 1316 (Fed. Cir. 2017), reversed a district court holding of indefiniteness because "the claims merely use permissible functional language to describe the capabilities of the claimed system." In Presidio Components Inc. v. American Technical Ceramics Corp., (Fed.Cir. 2017), the court affirmed the holding of no indefiniteness because the claimed measurement required "was within the skill of a skilled artisan based on an established method."

In Nevro, the Federal Circuit also noted "that the ambiguity inherent in functional terms may be resolved where the patent “provides a general guideline and examples sufficient to enable a person of ordinary skill in the art to determine the scope of the claims.” Id. at *7.

Does functional claiming language then provide a path for life science claims struggling with Sec. 112 indefiniteness (and 101 subject matter eligibility)?

And what about PTAB proceedings? Section 112 arguments may arise as a ground of unpatentability in post-grant review (PGR), and in the context of priority date assertions in inter partes reviews (IPRs). Recently, in Galderma S.A. v. Medy-Tox, Inc., PGR2019-00062, Paper 14 (March 19, 2020), the PTAB agreed, at least for purposes of institution, with the Petitioner that "longer lasting effect" as recited in the claim were reasonably uncertain because multiple methods of measurement led to different results and there was no guidance as to which measurement to use.

Listen as our authoritative panel of patent attorneys discusses the impact of recent Federal Circuit and PTAB case law on your daily patent practice. The panel will offer best practices to navigate pre-and post-issuance scrutiny for compliance with 35 U.S.C. 112(b).



  1. Understanding 35 U.S.C. 112(b) ("indefiniteness")
  2. Post-Nautilus caselaw
  3. Post-Packard/McAward caselaw
  4. Best practices for drafting and prosecuting strong patent claims that will hold up in litigation and before PTAB under any of the definiteness standards


The panel will review these and other key issues:

  • How can practitioners navigate the difference between the USPTO's standard and the court's standard for indefiniteness?
  • What possibilities does functional claiming provide?
  • What steps can counsel take to increase the likelihood that patent claims will survive in litigation and under PTAB review?


Barker, M. Paul
M. Paul Barker

Finnegan Henderson Farabow Garrett & Dunner

Mr. Barker has a diverse practice, including interferences, post-grant proceedings, patent prosecution, arbitration,...  |  Read More

Burgy, Adriana
Adriana L. Burgy

Finnegan Henderson Farabow Garrett & Dunner

Ms. Burgy focuses on opinion work, client counseling, patent prosecution and management, and litigation in the...  |  Read More

Irving, Thomas
Thomas L. Irving

Finnegan Henderson Farabow Garrett & Dunner

Mr. Irving has 35 years of experience in the field of IP law. His practice includes due diligence, patent prosecution,...  |  Read More

Murphy, Amanda
Amanda K. Murphy, Ph.D.

Finnegan Henderson Farabow Garrett & Dunner

Dr. Murphy focuses her practice on client counseling and patent prosecution for a range of clients. She prepares new...  |  Read More

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