Sect. 112 Indefiniteness in Chemical and Biotech Patent Claims

Description

In January 2021, the USPTO issued binding guidance aligning the approach taken by the PTAB with the approach of the federal courts on indefiniteness.

Definiteness of claim language must be analyzed not in a vacuum, but in light of (1) the content of the particular application disclosure, (2) the teachings of the prior art, and (3) the claim interpretation that would be given by one possessing the ordinary level of skill in the pertinent art at the time the invention was made. Nautilus, Inc. v. Biosig Instruments, Inc., (U.S. 2014).

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 IBSA Institut Biochimique, S.A. v. Teva Pharms. USA, Inc. (Fed. Cir. 2020), the Federal Circuit, however, affirmed that the term "half-liquid" was indefinite; here, "the intrinsic and extrinsic evidence fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention." Practitioners should try to avoid claim language that could raise questions about “reasonable certainty” under 35 U.S.C. §112(b). Undefined terms that do not have well-established meanings in the art, such as “half-liquid” in this decision, are the types of claim language that could raise questions regarding indefiniteness.

In Nevro Corp. v. Boston Scientific (Fed. Cir. 2020), the Federal Circuit applied the "reasonable certainty" test, holding 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 make it indefinite. The Federal Circuit also noted "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." Does functional-claiming language then provide a path for life science claims struggling with Sec. 112 indefiniteness (and 101 subject matter eligibility)?

In the wake of Teva Pharms. v. Sandoz (U.S. 2015), multiple measurement methods without sufficient direction on how to determine infringement continue to trip up patent applicants. See, e.g., Pac. Coast Bldg. Prods. v. CertainTeed Gypsum, Inc. (Fed. Cir. 2020). Relative terms and ranges without end points also pose a challenge but should not block patentability if the Nautilus reasonable certainty test is met. This may require more effort into arguments as to what one of ordinary skill in the art would understand to try and show the scope of the invention is reasonably certain.

We will also discuss developments at the PTAB concerning indefiniteness and claim construction. Now, according to Samsung Elecs. Am., Inc. v. Prisua Eng'g Corp. (Fed. Cir. 2020), a prior art-based unpatentability analysis may be possible for an indefinite claim. Prior to Samsung, the PTAB decisions were inconsistent, sometimes deciding that the indefiniteness of a claim prevented reaching an anticipation and/or obviousness analysis.

Listen as our authoritative panel of patent attorneys discusses the impact of recent Federal Circuit and PTAB case law on your daily U.S. patent practice, whether you are preparing a patent application, prosecuting a patent application, litigating a U.S. patent, including before PTAB, conducting an FTO, or evaluating a third party’s U.S. patent as part of due diligence. The panel will offer best practices to navigate pre- and post-issuance scrutiny for compliance with 35 U.S.C. 112(b).