Partner
Yieyie Yang, Ph.D., focuses on complex patent litigation before U.S. district courts and inter partes review (IPR) proceedings in the chemical, pharmaceutical, and biotechnological fields. She has experience representing pharmaceutical patent holders in Hatch-Waxman litigations and has drafted numerous appellant and appellee briefs for pharmaceutical clients at the U.S. Court of Appeals for the Federal Circuit.Yieyie was named by Best Lawyers in its "Ones to Watch" list for excellence in patent law.
Yieyie has handled various aspects of trial preparation, including fact and expert discovery, depositions of key witnesses and experts, and motion practice, along with other pre-litigation due diligence and position analysis. She also has worked on multiple IPR cases on behalf of petitioners or patent owners and has been involved in all aspects of those cases, including developing key arguments, preparing and sitting in expert depositions, drafting expert declarations and key papers, and preparing for oral arguments. In addition, Yieyie has conducted a variety of due diligence analysis in the biotechnological field for licensing, acquisition, freedom-to-operate, and startup fundraising.
Yieyie's scientific background is in molecular and cancer biology. Her graduate research focused on identifying novel genes involved in axon guidance during the development of the nervous system, and her new findings were published in peer-reviewed scientific journals. During her post-doctoral research period at the Dana-Farber Cancer Institute, she studied epigenetic chromatin-remodeling complexes and identified tumor suppressor candidates that interact with oncogenes during cellular transformation and tumorigenesis.
While in law school, Yieyie also paid close attention to the development of Chinese intellectual property law. Her articles on Chinese patent law have been published by peer-reviewed law journals.
Grünenthal GmbH et al. v. Actavis Elizabeth LLC et al.
Member of team that represented Grünenthal GmbH in multiple Hatch-Waxman suits involving analgesic drugs Nucynta® and Nucynta® ER; the district court enjoined the defendants from marketing generic versions until patent expiry.
2:13-cv-04507, -06929, -07803; 2:14-cv-03941, -04617; 2:15-cv-06797, D.N.J., Judges Cecchi, Falk
Eli Lilly and Company v. Actavis Labs. UT Inc.
Member of team representing Eli Lilly in Hatch-Waxman action against several defendants relating to Cialis®.
1:16-cv-01119, E.D. Va., Judges Nachmanoff, Trenga
Eli Lilly and Company v. Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
Member of team representing Eli Lilly in an appeal from a Patent Trial and Appeal Board (PTAB) decision in an IPR case.
IPR2014-00693, -00752, PTAB, Judges Green, Prats, Snedden
16-1547, Fed. Cir., Judges Bryson, Moore, Newman
AstraZeneca LP v. SigmaPharm Laboratories
Member of team representing AstraZeneca in Hatch-Waxman litigations against several defendants involving the blood-thinning drug Brilinta®.
1:15-cv-01000, D. Del., Judge Andrews
Actelion Pharmaceuticals v. ICOS Corp.
Member of team representing ICOS in two IPRs defending their formulation patents.
IPR2015-00561, -00562, PTAB, Judges Mitchell, Snedden, Yang
Eli Lilly and Company v. Teva Pharmaceuticals International
Member of team representing Eli Lilly in multiple IPRs involving antibody patents.
IPR2018-01422; -01423; -01424; -01425; -01426; -01427; -01710, -01711, -01712, PTAB
Conference
10th IP Forefront Pharma Forum 10th IP Forefront Pharma Forum
September 17-19, 2025
Shanghai
Conference
9th IP Forefront Pharma Forum 2024 9th IP Forefront Pharma Forum 2024
October 16-18, 2024
Suzhou
Books
Biosimilars Litigation and Client Counseling Biosimilars Litigation and Client Counseling
June 17, 2024
American Bar AssociationConference
2024 @Philly Cell and Gene Therapy Annual Conference 2024 @Philly Cell and Gene Therapy Annual Conference
June 14-15, 2024
Philadelphia
Articles
Trending at the PTAB: Real Party in Interest and IPR Trending at the PTAB: Real Party in Interest and IPR
May 31, 2024
Law360Award/Ranking
Best Lawyers Recognizes 44 Finnegan Attorneys in its 2026 Edition of The Best Lawyers and Ones to Watch Best Lawyers Recognizes 44 Finnegan Attorneys in its 2026 Edition of The Best Lawyers and Ones to Watch
August 21, 2025
Best LawyersAward/Ranking
31 Finnegan Attorneys Recognized by Best Lawyers 31 Finnegan Attorneys Recognized by Best Lawyers
August 15, 2024
Best LawyersCommentary
Fed. Circ. OKs Boston Drug Developer's Patent Win Fed. Circ. OKs Boston Drug Developer's Patent Win
March 11, 2024
Law360Press Release
Finnegan Announces 2024 Partner Class Finnegan Announces 2024 Partner Class
January 2, 2024
Press Release
32 Finnegan Attorneys Recognized by Best Lawyers 32 Finnegan Attorneys Recognized by Best Lawyers
August 17, 2023
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