For more than four decades, Fenwick & West LLP has helped some of the world’s most recognized companies become, and remain, market leaders. From emerging enterprises to large public corporations, our clients are leaders in the technology, life sciences and cleantech sectors and are fundamentally changing the world through rapid innovation.  MORE >

Fenwick & West was founded in 1972 in the heart of Silicon Valley—before “Silicon Valley” existed—by four visionary lawyers who left a top-tier New York law firm to pursue their shared belief that technology would revolutionize the business world and to pioneer the legal work for those technological innovations. In order to be most effective, they decided they needed to move to a location close to primary research and technology development. These four attorneys opened their first office in downtown Palo Alto, and Fenwick became one of the first technology law firms in the world.  MORE >

From our founding in 1972, Fenwick has been committed to promoting diversity and inclusion both within our firm and throughout the legal profession. For almost four decades, the firm has actively promoted an open and inclusive work environment and committed significant resources towards improving our diversity efforts at every level.  MORE >

At Fenwick, we are proud of our commitment to the community and to our culture of making a difference in the lives of individuals and organizations in the communities where we live and work. We recognize that providing legal services is not only an essential part of our professional responsibility, but also an excellent opportunity for our attorneys to gain valuable practical experience, learn new areas of the law and contribute to the community.  MORE >

Year after year, Fenwick & West is honored for excellence in the legal profession. Many of our attorneys are recognized as leaders in their respective fields, and our Corporate, Tax, Litigation and Intellectual Property Practice Groups consistently receive top national and international rankings, including:

  • Named Technology Group of the Year by Law360
  • Ranked the #1 firm worldwide for technology deals through Q3 2015
  • Nearly 20 percent of Fenwick partners are ranked by Chambers
  • Consistently ranked among the top 10 law firms in the U.S. for diversity
  • Recognized as having top mentoring and pro bono programs by Euromoney


We take sustainability very seriously at Fenwick. Like many of our clients, we are adopting policies that reduce consumption and waste, and improve efficiency. By using technologies developed by a number of our cleantech clients, we are at the forefront of implementing sustainable policies and practices that minimize environmental impact. In fact, Fenwick has earned recognition in several areas as one of the top US law firms for implementing sustainable business practices.  MORE >

At Fenwick, we have a passion for excellence and innovation that mirrors our client base. Our firm is making revolutionary changes to the practice of law through substantial investments in proprietary technology tools and processes—allowing us to deliver best-in-class legal services more effectively.   MORE >

Mountain View Office
Silicon Valley Center
801 California Street
Mountain View, CA 94041

San Francisco Office
555 California Street
12th Floor
San Francisco, CA 94104

Seattle Office
1191 Second Avenue
10th Floor
Seattle, WA 98101

Shanghai Office
Unit 908, 9/F, Kerry Parkside Office
No. 1155 Fang Dian Road
Pudong New Area, Shanghai 201204
P.R. China
+86 21 8017 1200

David Tellekson

Partner, Litigation

icon partner 206.389.4560  

Office: Seattle


David Tellekson focuses his practice on litigating patent cases for clients in the areas of biotechnology, pharmaceuticals, polymer chemistry and medical devices. In addition to his trial work, he also consults on patent strategy, opinions and due diligence.

David is a frequent writer and lecturer in areas of patent law and patent litigation. He has been selected as a Washington "Super Lawyer" in the area of Intellectual Property Litigation each year since 2008. He has also been recognized as one of the top Intellectual Property Litigation lawyers in Washington by Chambers USA. From 2012-2014, Intellectual Asset Management magazine named David to the IAM Patent 1000: The World’s Leading Patent Practitioners. He is also included in the list of IP Stars by Managing Intellectual Property ​for 2014 and 2015. Prior to joining Fenwick & West, he was the managing principal at Darby & Darby P.C. in Seattle.

Representative Engagements

  • Novozymes v. Danisco: Lead trial counsel representing Novozymes in a successful action against rival Danisco for infringement of Novozymes’ patent for an improved alpha-amylase useful for fuel ethanol production, among other industrial applications. A jury found that Danisco willfully infringed Novozymes’ patent and awarded over $18.2 million in damages.
  • Sigma-Aldrich and Oxford Biomedica (UK) Ltd. v. Open Biosystems: Represented patent owner Oxford Biomedica as lead trial counsel in patent infringement action involving HIV vectors useful for drug delivery. Markman victory led to favorable settlement.
  • Novozymes v. Genencor: Represented Novozymes as lead trial counsel asserting patent on genetically modified alpha-amylases. Genencor was found to willfully infringe and ordered to pay double damages and attorneys’ fees.
  • Cardiac Science v. Philips Electronics: Represented plaintiff as lead trial counsel in case involving 21 patents. Damages asserted by each side combined in excess of $200 million. Key victories by Cardiac Science at Markman and summary judgment led to favorable settlement hours before seven-week jury trial set to begin.
  • 3M v. Seibu Polymer Chemical Co., Ltd. (ITC): Co-trial counsel at patent infringement trial protecting retroreflective sheeting market valued at more than $1 billion per year.


  • David Tellekson and Elizabeth B. Hagan, Ph.D., Federal Circuit Expands Liability for Divided Patent Infringement, IP Strategist, September 2015
  • David Tellekson and Ewa M. Davison, Ph.D., Riddle Me This: The Federal Circuit Provides a Measure of Clarity to the Enigmatic Biosimilar Approval Pathway, Fenwick & West LLP, August 2015
  • ​David Tellekson and Phillip K. Decker, Litigation Alert: A Good­Faith Belief of Patent Invalidity Is Not a Defense to Inducement of Infringement, Fenwick & West LLP, June 2015
  • David K. Tellekson and John LaBarre, The Intersection of Antitrust and Intellectual Property: A Review of Recent Case Law and Trends, BNA's Patent, Trademark & Copyright Journal, August 11, 2006.
  • David K. Tellekson, Sandra S. Lee and Elizabeth A. Richardson, Strategies for Attacking and Defending Pharmaceuticals Patents; A Modern Take on 'The Art of War,' Intellectual Property & Technology Law, December 2005.
  • David K. Tellekson and Elizabeth Bernard, Have Patent, Will Travel: Can One Infringe a U.S. Patent by Making, Using, and Selling a Product Solely Outside the United States?, Intellectual Property Today, July 2004.


  • The Decline of Process Patents: Enforceability of process claims and the controversy around divided infringement, BIO IP Counsels Committee Conference, April 2012.




About David