Means-Plus-Function Patent Claims Following Xencor: Preamble, Written Description, and More

Course Details
- smart_display Format
Live Online with Live Q&A
- signal_cellular_alt Difficulty Level
Intermediate
- work Practice Area
Patent
- event Date
Tuesday, June 17, 2025
- schedule Time
1:00 p.m. ET./10:00 a.m. PT
- timer Program Length
90 minutes
-
This 90-minute webinar is eligible in most states for 1.5 CLE credits.
This CLE webinar will guide patent counsel on means-plus-function (MPF) antibody claims in light of the Federal Circuit's decision in Xencor. The panel will discuss the potential outcomes and the best practice options flowing therefrom, including best practices to avoid an adverse decision in future antibody MPF claims.
Faculty

Ms. Burgy focuses on opinion work, client counseling, patent prosecution and management, and litigation in the chemical, pharmaceutical, and biotechnology arts. She counsels her clients on a diverse range of patent issues. She assists clients on single-patent issues as well as complex matters involving multiple patents and applications requiring ongoing advice on patent portfolio strategy and development, with an eye towards litigation. She has assisted clients in the early stages of development through due diligence and patent portfolio analysis.

Ms. Brougher is a patent attorney who focuses on all aspects of services related to patents in the areas of biotechnology, pharmaceuticals and medical devices, including patentability opinions, due diligence, patent drafting, domestic and foreign patent prosecution, development and management of patent portfolios, and general client counseling during all phases of a product’s lifecycle, from concept to commercialization.
Her patent experience covers a variety of complex and innovative inventions involving small molecule drugs, biologics, cell-based technologies, compositions, drug formulations and drug delivery systems, immunotherapeutics, medical devices, diagnostic tests, nanotechnology, and immunology, particularly vaccines and antibodies. Ms. Brougher also has experience counseling clients on the Hatch-Waxman Act and is monitoring developments involving biosimilars under the Biologics Price Competition and Innovation Act.

Ms. O’Brien has more than 20 years of experience representing domestic and foreign clients of all sizes in patent procurement, litigation, and client counseling, with a particular emphasis on chemical, biochemical, and pharmaceutical technologies. Exemplary areas of her technical expertise include polymer chemistry; ceramics; glass; food chemistry; cosmetics; paper products; adhesives; and pharmaceutical products, including new chemical entities and formulations and novel solid forms, including polymorphs, cocrystals, and amorphous forms of compounds.
Description
Nearly all technological fields use MPF claiming. MPF claims, often perceived as narrow, can provide more protection for patent applicants than other claims. Following the Xencor decision, MPF claiming lives to see another day. However, the decision gives guidance for steps to avoid the adverse decision.
In Xencor, the Federal Circuit upheld the Appeals Review Panel decision that the preamble of claim 9 is limiting. The court rejected Xencor's argument that only part of the preamble should be limiting, concluding that "treating a patient" and "administering an anti-C5 antibody" were connected and could not be split. Further, because the preamble in claim 9 was limiting, the claim did not have written description support as it was construed in view of the preamble to cover any patient and any disease.
Listen as our authoritative panel of patent attorneys examines MPF antibody claims in light of the Federal Circuit's decision. The panel will discuss alternatives to MPF and offer best practices for leveraging MPF claiming.
Outline
I. MPF antibody claims and the benefits of using them
II. Federal Circuit decision in Xencor
III. Written description in Section 112
IV. Definiteness of MPF antibody claims under Section 112(b)
V. Alternatives to MPF
VI. Best practices
Benefits
The panel will review these and other noteworthy issues:
- What are the benefits and limitations of using MPF patent claims for antibody patents?
- What are the potential implications of the Federal Circuit's decision in Xencor?
- What are the alternatives to MPF?
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