Daryl L. Wiesen

Daryl Wiesen is a nationally recognized patent litigator and a leading authority on intellectual property disputes for life sciences companies. As a partner at Goodwin and former co-chair of the firm’s IP Litigation practice, he brings more than 30 years of experience to client relationships, with specialized expertise in Hatch-Waxman litigation representing both plaintiffs and defendants. As lead trial counsel, Daryl has handled multiple matters across both branded and generic contexts. Fighting on behalf of Teva’s blockbuster multiple-sclerosis treatment Copaxone®, Daryl and his team prevailed on all nine asserted patents at the trial court and ultimately secured a U.S. Supreme Court victory that not only favored Teva but also produced one of the most consequential patent decisions in decades. Representing innovator company Cephalon against generic challengers, he secured a complete trial victory on validity and infringement, preserving exclusivity for a leading oncology therapy Treanda®. In separate litigation, he successfully proved non-opioid pain treatment Exparel® asserted patents invalid at trial, leading to a favorable settlement.

Daryl earned his JD from Yale Law School, serving as a senior editor of the Yale Law Journal. His tenure at Goodwin has been marked by long-term client relationships based on trust, precedent-setting wins, and industry honors. He has been recognized among the world’s leading patent practitioners by IAM Global Leaders 2026 guide, as an “IP Star” by Managing IP (2025), and a “Life Sciences Star” by LMG Life Sciences (2025) for his work in Hatch-Waxman and general patent litigation. He is a member of the Boston and Massachusetts Bar Associations and the recipient of Goodwin’s Robert B. Fraser Pro Bono Award for his substantial pro bono work, including helping to secure the freedom of a wrongfully convicted death row inmate in Ohio. He also serves on the Board of Directors of the ACLU of Massachusetts.

Daryl devotes a substantial amount of his practice to patent litigation. He has recently represented:

Pharmaceutical Clients

• Cephalon in patent litigation concerning its cancer treatment Treanda (Bendamustine). After a bench trial, the United States District Court for the District of Delaware found the asserted patents valid and infringed. (Lead Trial Counsel)
• Teva Pharmaceuticals and Fresenius Kabi USA, LLC in patent litigation concerning Eli Lilly’s antifolate cancer treatment pemetrexed (Alimta®). The case is currently under submission at the Federal Circuit. (Lead Trial Counsel)
• Teva Pharmaceuticals in patent litigation concerning the new dosing regimen of Teva’s blockbuster Copaxone®. The case is currently under submission to the United States District Court for the District of Delaware. (Trial Counsel)
• Fresenius Kabi USA, LLC in patent litigation concerning its branded parenteral anesthetic, Diprivan®. (Lead Trial Counsel)
• Epocal, Inc. in patent litigation against Abbott Point of Care, Inc. concerning point of care blood testing devices. Abbott brought two lawsuits against Epocal in the Northern District of Alabama. In the first, the jury rendered a verdict of non-infringement on all asserted claims. In the second, the District Court dismissed the complaint for lack of standing, and the Federal Circuit affirmed the dismissal. (Trial and Appellate Counsel)
• Teva Pharmaceuticals in patent litigation concerning its blockbuster innovative treatment for multiple sclerosis, Copaxone®. Teva prevailed on all nine patents asserted at the trial court in June 2012 and the Federal Circuit affirmed the judgment in 2013 as to four of the asserted patents. The case was subsequently appealed to the United States Supreme Court, resulting in a victory for Teva on the standard of review in claim construction in Teva v. Sandoz. (Trial and Appellate Counsel)

University Clients

• Massachusetts Institute of Technology in litigation with Alnylam, Inc. and the Max Planck Institute concerning ownership and prosecution of the Tuschl patent portfolio, seminal patents directed to technology related to the development of RNAi therapeutics. Alnylam and Max Planck filed suit in the District of Massachusetts in 2009. The case was settled on favorable terms. (Lead counsel)
• Massachusetts Institute of Technology and Children’s Medical Center (Boston) in patent litigation against Shire Regenerative Medicine concerning Shire’s Dermagraft product. Secured a favorable disposition at the district court and successfully defended the matter on appeal to the Federal Circuit. (Lead and Appellate Counsel)

Daryl is a member of the Boston and Massachusetts Bar Associations. He provides pro bono services for a variety of clients, including helping to obtain the freedom of a wrongfully convicted death row inmate in Ohio. He is a member of the Board of Directors for the Massachusetts Civil Liberties Union, the Massachusetts affiliate of the ACLU.

• In 2023, The Legal 500 US recognized Daryl for his work in Patent Litigation: Full Coverage
• Daryl has been recognized by The Best Lawyers in America Best Lawyers for his work in Litigation - Patent 2022 – 2023, 2026 and Litigation - Intellectual Property 2023
• Daryl has been recognized by Legal 500 for having “provided exceptional results. Both have extensive experience in all aspects of pre-trial and trial and have a unique understanding of the interplay between IP, regulatory, and business issues in the pharmaceutical sector”
• Daryl has been recognized by IAM Patent 1000 – The World’s Leading Patent Professionals as a leading patent litigator, touted as a lawyer who is “really creative and tenacious” and “well balanced in terms of his technical, legal and business understanding”
• “Outstanding IP Litigator Massachusetts” for 2016 by Managing IP
• “Life Sciences Star” for IP by LMG Life Sciences
• Recognized by Managing IP as an “IP Star”
• Recognized by Best Lawyers in their “Best Lawyers in America” publication

While in law school, Daryl was a senior editor of the Yale Law Journal and author of “Following the Lead of Defamation: A Definitional Balancing Approach to Religious Torts.”

• Speaker, “Hikma v. Amarin: Breaking Down the Supreme Court Argument on Skinny Labels and Induced Infringement,” Goodwin Webinar, April 2026
• Contributor, “Guide to Biosimilars Litigation and Regulation in the U.S., 2023-2024 ed.,” published by Thomson Reuters, January 2024
• Contributor, “Guide to Biosimilars Litigation and Regulation in the U.S., 2022-2023 ed.,” published by Thomson Reuters, December 2022
• Co-Author, “Pharma Pipelines Need ‘Whole Company’ Approach to Patent Lawsuits,” Bloomberg Law, May 2021
• Contributor, “Guide to Biosimilars Litigation and Regulation in the U.S., 2019-2020 ed.,” published by Thomson Reuters, November 2019