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Mary B. Matterer

Partner T: 302.888.6960 F: 302.571.1750
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Mary B. Matterer has practiced patent litigation in the District Court of Delaware for more than 15 years. She frequently serves as Delaware counsel for law firms well known for their experience in patent and complex commercial litigation. 

Her practice consists of diverse forms of litigation, including intellectual property, commercial, and complex insurance coverage litigation. Mary primarily handles patent litigation across a wide range of industries, including pharmaceuticals, telecommunications, automotive, biomedical, electronics, and internet/software. She successfully defended the City of Wilmington against a claim of copyright infringement brought by a former employee. 

She has also represented insurance companies in multimillion dollar disputes involving demands for coverage with respect to environmental and products liability claims under general liability policies, and also demands for coverage under directors and officers policies. She has served as Liaison Counsel for insurers where numerous insurers were brought into the lawsuit. She represented an excess insurer regarding liability for defense costs incurred by Intel in defending against claims of anticompetitive activity. Summary judgment of no liability for such costs was granted in favor of this and other insurers.

Mary is praised by her clients, who appreciate her familiarity with the courts, as well as by judges who find her “confident, responsive, and flexible,” according to Chambers USA - America's Leading Lawyers for Business, 2008. She was again cited by Chambers USA in 2012 “as a source of confidence; clients particularly highlighting her coolness under pressure and ability to make progress in a tense environment."



  • Patent infringement claims
  • Complex insurance litigation 

American Law and Legal English Institute

Mary combines her background in linguistics and law by frequently lecturing at the University of Delaware on the topic of intellectual property as part of the American Law and Legal English Institute for foreign attorneys and judges.

Professional Affiliations

Delaware State Bar Association
American Bar Association, Intellectual Property and Litigation Sections
American Intellectual Property Law Association 

Community Affiliations

Returned Peace Corps Volunteers of Delaware Association, 2005-Present

Recent Matters

In re: Cyclobenzaprine Hydrochloride Extended-Release Capsule Patent Litigation
Patent– ANDA-Amrix/ Cyclobenzaprine Hydrochloride

Acura Pharmaceuticals, Inc. v. Par Pharmaceuticals and
Acura Pharmaceuticals, Inc. v. Sandoz
Patent– ANDA - Oxecta /oyxcodine hydrcloride

Pfizer, Inc. v. Impax Laboratories, Inc.
Patent– ANDA - Toviaz/fesoterodine

Pfizer, Inc., et al. v. Mylan Pharmaceuticals, Inc., et al.
Patent– ANDA - Lyrica/pregabalin

Bristol-Myers Squibb Co., et al. v. Mylan Pharmaceuticals, Inc., et al.
Patent– ANDA - Sustiva/efavirenz

Warner Chilcott Company LLC et al v. Mylan Pharmaceuticals Inc.
Patent– ANDA - Actonel/risedronate

Pfizer Inc. et al v. Zydus Pharmaceuticals USA Inc. et al.
Patent– ANDA - Pristiq/desvenlafaxine

Santarus Inc. et al v. Mylan Inc. et al.
Patent– ANDA - Fenoglide/fenofibrate

Alcon Research Ltd. v. Mylan Pharmaceuticals Inc. et al.
Patent– ANDA - TRAVATAN Z (treatment of glaucoma)

Roche Palo Alto LLC et al v. Mylan Pharmaceuticals Inc.
Patent– ANDA - VALCYTE/valganciclovir

Teijin Limited et al. v. Mylan Pharmaceuticals Inc.
Patent– ANDA - Uloric,/ febuxostat

In Re: Bendamustine Consolidated Cases
Patent– ANDA - TREANDA/bendamustine

Salix Pharmaceuticals Ltd. et al v. Mylan Pharmaceuticals Inc.
Patent– ANDA  - Giazo/balsalazide

Fresenius Kabi USA LLC v. Mylan Laboratories Limited et al
Patent– ANDA - Diprivan/propofol

Duchesnay Inc. et al v. Actavis Inc. et al.
Patent– ANDA - Diclegis/doxylamine

Cequel Communications LLC et al v. Rates Technology Inc.
Patent–telecommunications technology

Le v. City of Wilmington, et al.

Eisai Inc., et al v. Banner Pharmacaps Inc., et al.
Patent– ANDA -Targretin / bexarotene

Galderma Laboratories Inc. et al v. Amneal Pharmaceuticals LLC et al.
Patent– ANDA -Oracea/doxycycline

Kissei Pharmaceutical Co. Ltd. et al v. Hetero USA Inc., et al.
Patent– ANDA -RAPAFLO/silodosin

Flashpoint Technology, Inc. v. ZTE Corporation et al.
Patent–Computer Imaging Technology

Pragmatus Mobile LLC v. ZTE (USA) Inc.
Patent– Personal Security and Tracking System Technology

Helsinn Healthcare SA et al v. Cipla Ltd. et al.
Patent– ANDA- Aloxi/palonosetron

Pfizer Inc. et al v. Aurobindo Pharma Ltd. et al.
Patent– ANDA- TYGACIL/tigecycline

Orthophoenix LLC v. Ascendx Spine Inc. et al.
Patent– Medical technology

Orthophoenix LLC v. Osseon Therapeutics Inc. et al.
Patent– Medical technology

Orthophoenix LLC v. Sintea Plustek LLC et al.
Patent– Medical technology

Pragmatus Telecom LLC v. Aspect Software Inc.
Patent–Telecommunications Technology

Endeavor MeshTech Inc. v. Mueller Systems LLC and Endeavor MeshTech Inc. v Schneider Electric USA Inc.
Patent– Wireless Communications Technology

Forest Laboratories LLC et al v. Amneal Pharmaceuticals LLC et al. (Client Par Pharmaceutical)
Patent–ANDA- Namzaric/donepezil hydrochloride/memantine hydrochloride

News & Media Mentions

Mary was cited by Chambers USA an experienced IP litigator who handles patent disputes for a broad range of clients from the biomedical, electronics, telecommunications and automotive industries, among others. Sources describe her as "prompt, responsive and professional."

Practice areas


Delaware Today®, Top Lawyers, 2014-2016

Chambers USA - Recognized for Intellectual Property Law, 2008-2017

Best Lawyer®, 2009-2018

Corporate INTL Magazine®, "Attorney of the Year in Delaware," 2014

Delaware Journal of Corporate Law, Law Review


Ruby Vale Summer Clerkship, Delaware Superior Court

Clerk for The Honorable John E. Babiarz, Jr., Delaware Superior Court


Delaware, 1988

United States District Court, District of Delaware

U.S. Court of Appeals, Third Circuit

U.S. Court of Appeals, Federal Circuit 


Widener University School of Law, J.D., cum laude, 1988

Ohio University, M.A.,1979

University of Delaware, B.A.,1971