Improper Markush Rejection: The New Kid on the Patent Block

The U.S. Patent and Trademark Office (“USPTO”) quietly increased the examiners’ arsenal by slipping a new rejection into the latest revision of the Manual of Patent Examining Procedure (“MPEP”) released last month. One of the changes made in this revision is the addition of a new “improper Markush grouping” section, MPEP § 706.03(y), which authorizes patent examiners to reject a claim on the basis that it contains an improper listing of alternative elements. Patent applications in the life sciences, which frequently have claims in the “Markush” format, may soon face the new “improper Markush grouping” rejections.

A “Markush” claim format is often used as a straightforward way to capture various alternatives for a given element in a single claim. It is named after the patent applicant (Eugene A. Markush) who used this format in a court case that was decided in 1924. Markush claims contain a customized list of elements that are useful for the purposes of the claim. As an example, for the purposes of describing various alternative materials to coat an implant screw, a claim could contain a list such as “ceramic, glass, plastic, or metal.”

Prior to the recent MPEP revision, improper Markush grouping rejections had been uncommon because they were based on guidelines issued by the USPTO in 2011. However, now that the new section has been added to the MPEP, it is expected that rejections of patent applications based on improper Markush grouping will become much more frequent. The examiner can now make a rejection based on improper Markush grouping if the examiner determines that the members of a Markush group lack either a single structural similarity or a common use, or if the single structural similarity is a substantial structural feature of a chemical compound that is not essential to the common use. As to timing, the examiner should make a rejection based on an improper Markush grouping in the first action on the merits after presentation of the claim with the allegedly improper Markush grouping.

When making the improper Markush grouping rejection, the new MPEP section instructs the examiner to include suggestions for the applicant as to how to overcome the rejection, e.g., by suggesting a proper Markush grouping based on the specification as filed and/or by suggesting that applicant set forth each alternative (or grouping of patentably indistinct alternatives) within an allegedly improper Markush grouping in a series of independent or dependent claims. In doing so, the examiner cannot suggest any grouping that clearly would not meet the requirements of 35 U.S.C. § 112(a). For example, the examiner should not suggest a grouping that meets the requirements for a proper Markush grouping, but which would clearly lack adequate written description if presented in a separate claim.

The new MPEP section states that an improper Markush grouping rejection can be overcome by (1) amending the rejected claim such that the Markush grouping includes only members that share a single structural similarity and a common use; or (2) by presenting convincing arguments why the members of the Markush grouping share a single structural similarity and common use (i.e., are members of a physical, chemical, or art-recognized class that share a common use, or are chemical compounds that share a substantial structural feature that is essential to the common use).

In addition, even if the applicant does not take action sufficient to overcome the improper Markush grouping rejection, when all of the claims are otherwise in condition for allowance the examiner is instructed to reconsider the propriety of the improper Markush grouping rejection. If the examiner determines that in light of the prior art and the record as a whole the alternatives of the Markush grouping share a single structural similarity and a common use, then the rejection should be withdrawn. Note that no Markush claim can be allowed until any improper Markush grouping rejection has been overcome or withdrawn, and all other conditions of patentability have been satisfied.

The USPTO, by introducing section 706.03(y) into the MPEP, has taken the position that improper Markush grouping is a rejection on the merits and can be appealed to the PTAB. When drafting a Markush claim, patent practitioners should keep this new MPEP section in mind and recite members of the Markush grouping that share a single structural similarity and common use.

Jane Xia
Jane Xia's practice involves patent procurement, intellectual property due diligence, Patent Office appeals, intellectual property strategy counseling, and worldwide patent portfolio management. Jane represents clients in a wide range of technologies, including pharmaceuticals, nutraceuticals, semiconductor fabrication, battery technology, life sciences, polymer sciences, medical devices, diagnostic devices, cosmetic and personal care products. She has experience representing individual inventors, venture funded start-ups, university spin-offs, and publicly traded companies. She also represents a number of foreign clients in procuring U.S. patent protection in the Pharmaceutical and semiconductor technologies. Before attending law school, she worked as a research scientist in nanomaterials production and gained industry experience in developing quantum dots and nanomaterials in display technology. Jane worked as a summer associate at the firm in 2011 and joined the firm in 2012.
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Joseph Mallon
Joe's practice includes intellectual property due diligence, Patent Office appeals, preparation and prosecution of patent applications, and counseling on patent strategy, patent infringement and licensing issues. He represents clients in a wide range of technologies, including chemicals, polymers, pharmaceuticals, materials science, adhesives, coatings, composite materials, medical devices, semiconductor fabrication, and microelectromechanical system (MEMS) fabrication. Joe was recognized as one of the "World's Leading Patent Professionals" in the Intellectual Asset Management" IAM Patent 1000" publication from 2015 to 2017. He was also named a "Life Science Star" from 2013 to 2017 by LGM Life Sciences in recognition of the strength of his patent prosecution, strategy and portfolio management practice. He is recognized by both print and on-line news media for his experience relating to patent matters, and has been quoted numerous times, including by the San Diego Daily Transcript, Orange County Business Journal, Milwaukee Wisconsin Journal Sentinel, Law360, Healthline and InsideCounsel. He has presented numerous speeches to legal and technical organizations, including AIPLA and participants in the Biotechnology/Chemical/Pharmaceutical Partnership at the U.S. Patent Office. He has also provided technical training to U.S. Patent Examiners in the Patent Examiner Technical Training Program. After completing graduate school, Joe worked for seven years as a research scientist in the aerospace and chemical industries. His research resulted in numerous publications and patents and focused on chemical and polymer syntheses and manufacturing, liquid crystals, composite materials, rubbers, adhesives, coatings, biomedical polymers, and water soluble polymers. In 1995, Joe joined the Patent Law Department at Cytec Industries, Inc., as a patent agent and began attending law school in the evenings. He graduated from law school and a became Patent Counsel at Cytec in 1999. Joe joined the firm in 2000 and became partner in 2006.
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