Betsy Flanagan is the office managing principal of the Minneapolis office of Fish & Richardson. She is an experienced intellectual property trial lawyer who represents some of the world’s largest pharmaceutical and biotech companies in patent trials and appeals in federal court, inter partes and post-grant reviews before the Patent Trial and Review Board, and Section 337 proceedings at the U.S. International Trade Commission.

Among notable engagements, she has represented Gilead Sciences in actions involving its revolutionary hepatitis C drugs Harvoni® and Sovaldi®; served on the legal team for Coherus BioSciences, which successfully invalidated three patents in the AbbVie blockbuster drug Humira® patent family; successfully defended a major diagnostic clinic against infringement claims by winning a high-profile ineligibility case; and successfully defeated institution of post-grant review for client Exela Pharma Sciences during co-pending Hatch-Waxman litigation.

Betsy focuses her practice on complex patent litigation with an emphasis on the life sciences, biotechnology, and the pharmaceutical industry. Drawing on her degree in chemistry and her experience as a scientist at Merck, Betsy brings deep and broad technical acumen to cases requiring knowledge of small molecules, new chemicals, biologics, formulations, antibodies, fusion proteins, and other compounds that form the basis of her clients’ products.

Known for her record of success in complex, multijurisdictional life sciences cases, Betsy also is recognized for her strategic thinking, novel legal arguments, impressive written advocacy, and ability to collaborate with and lead teams of outside and in-house counsel. She works closely with subject-matter experts to develop and communicate an effective case in clear terms that resonate with judges and juries.

Betsy advises clients in and handles all phases of litigation, including pre-filing due diligence, fact and expert discovery strategy, depositions, hearings, and settlement negotiations. She has led numerous briefings and arguments for claim construction and summary judgment, and routinely handles post-trial issues, including judgment as a matter of law motions. In addition to serving as lead and team counsel in bench and jury trials at the U.S. District Court level, Betsy has also played significant roles in a number of Federal Circuit appeals.

At the firm, Betsy serves as a mentor for early career attorneys, with a particular focus on advising women and individuals from diverse backgrounds who have traditionally been underrepresented in IP law. Among other activities, she led the summer associate program at Fish’s Delaware office for several years and mentored a University of Minnesota law student as part of Fish’s 1L Diversity Fellowship Program. As chairperson of Fish’s Minneapolis EMPOWER women’s initiative, Betsy helped launch programs that increased opportunities for female attorneys. She also maintains an active pro bono practice. On behalf of Immigration Equality, the nation’s leading LGBTQ+ immigrant rights organization, she has represented individuals who face persecution and fear for their lives if they are forced to return to their home countries.


Defended a major diagnostic clinic after a competitor accused our client of infringing a patent on a test for diagnosing a rare autoimmune disorder. The judge ruled that the claimed methods of testing relied on a law of nature, which cannot be patented. In arriving at the ruling, the judge cited the Supreme Court’s 2012 landmark ruling in Mayo v. Prometheus. On appeal, the Federal Circuit affirmed the ruling of the District Court and denied the opposing party’s petition for en banc review in a precedential order. The Fish team then successfully opposed its certiorari petition to the Supreme Court by noting that the Court had already provided adequate guidance in its 2012 Mayo ruling.

Exela Pharma Sciences LLC v. Eton Pharmaceuticals Inc., No. 1:20cv365 (D. Del.). Represents Exela Pharma Sciences in Hatch-Waxman litigation against Eton Pharmaceuticals, Inc., involving three patents related to Exela’s L-cysteine hydrochloride injection product ELCYS®. After Eton filed petitions for post-grant review of all three patents at the PTAB, the Fish team successfully obtained decisions of non-institution on all three petitions.

Gilead Sciences Inc. v. Merck & Co., No. 5:13cv4057 (N.D. Cal., June 6, 2016). Served as trial and appellate counsel on an all-women oral argument team for client Gilead Sciences. The matter was ultimately resolved in a unanimous Federal Circuit opinion that affirmed a June 2016 post-trial wipe-out of a $200 million jury verdict against Gilead. The Fish team mounted and proved, in a bench trial, an “unclean hands” defense against Merck. The Federal Circuit affirmed Judge Beth Labson Freeman’s finding of unclean hands, holding that the case involved clear misconduct by Merck in breaching commitments to a third party and clear misconduct in litigation, which “infected this entire case.”

Coherus BioSciences Inc. v. AbbVie Biotechnology Ltd., No. IPR 2016-00172 (PTAB, May 16, 2017). Served as a key member of the team that won three inter partes reviews (IPRs) for Coherus BioSciences, which invalidated three patents in the AbbVie Biotechnology blockbuster drug Humira® patent family. The PTAB found that the patents were obvious and unpatentable, and the result was upheld on appeal. These were the first-ever IPR decisions that invalidated patents for AbbVie’s biologic, which was the highest-selling drug in 2016 with $16 billion in global sales. The cases were among the most closely watched life sciences IPRs in 2017, given the broader implications for the biosimilar industry.

iCeutica Ltd. et al v. Lupin, Ltd., et al., No. 1:14cv1515 (D. Del. February 9, 2017). Represented iCeutica as trial team leader in Hatch-Waxman litigation over the pain medication ZORVOLEX®. The Fish team successfully resolved this litigation for branded pharmaceutical clients Iroko and iCeutica, which sued generic pharmaceutical company Lupin in December 2014 after it sought to bring generic versions of Iroko/iCeutica’s Zorvolex® drug to market. The case was settled amicably one week before trial.

Cephalon Inc. et al v. Mylan Pharmaceuticals Inc. et al. (D. Del.). Served as trial counsel for plaintiffs in Hatch-Waxman litigation involving the pain medication FENTORA®; won an injunction that was entered against the generic entry.

Immunex Corporation, et al. v. Samsung Bioepis Co. Ltd., Civil Action No. 19-11755 (D.N.J.). Representing Samsung Bioepis in Biologics Price Competition and Innovation Act (BPCIA) litigation concerning the SB4 biosimilar to Enbrel.


“I’m very impressed with her work….She can distill complicated concepts down to very simple concepts. She is also on her toes all the time and has very sage advice.” — Chambers and Partners, 2020

Professional associations

  • Law360 2021 Life Sciences Editorial Advisory Board