David J. Tsai is an associate in Townsend's San Francisco office and a member of the Litigation Practice Group. Mr. Tsai’s practice focuses on trade secret and patent litigation, with an emphasis on pharmaceuticals (Hatch-Waxman Act/ANDA), biotechnologies, the Internet, software, semiconductors, and medical devices. His legal experience also includes litigating in the areas of copyrights and trademarks, preparing and prosecuting U.S. electrical engineering patent applications, drafting patentability, freedom-to-operate and non-infringement opinions, as well as dealing with patent interference in the area of biotechnology. Mr. Tsai has written on Hatch-Waxman related issues and Internet software applications.
Prior to joining Townsend, Mr. Tsai served as an extern to the Honorable Howard R. Lloyd of the United States District Court for the Northern District of California and a law clerk for the Law Foundation of Silicon Valley (AIDS Legal Services). In addition to his time at Townsend, Mr. Tsai was also a summer associate at a large international law firm during part of his two law school summers.
Prior to his legal career, Mr. Tsai worked in product management at Internet/software startups Zaplet, Inc., and TimeDance.com funded by Kleiner Perkins and the Mayfield Fund, respectively. He focused on developing platforms for collaborative communications.
Mr. Tsai has authored numerous articles for scientific publications (Proceedings of the National Academy of Sciences, The Journal of Comparative Neurology, Experimental Neurology, and Society of Neuroscience Abstracts) related to his undergraduate honors thesis and graduate research at Harvard Medical School and Stanford University on stem cell and viral gene therapy tools for the treatment of neurological diseases and cancer.
Mr. Tsai currently serves on six boards, including the Board of Directors of Bar Association of San Francisco and the Silicon Valley Intellectual Property Law Association, and was named a “Rising Star” in intellectual property litigation by Super Lawyers in 2009 and 2010.
Mr. Tsai is a member of Townsend’s Diversity Committee and is committed to serving pro bono clients on behalf of the firm. He has represented pro bono clients at settlement conferences through the Northern District Court Assisted Settlement Conference Program. Mr. Tsai has also worked on civil rights and immigration pro bono matters with the Lawyers Committee for Civil Rights and the Asian Law Caucus. He is the recipient of the Minority Bar Coalition’s Rising Star Award and the ABA Section of Litigation’s Outstanding Subcommittee Chair Award.
Mr. Tsai is fluent in spoken Taiwanese and Mandarin Chinese and a member of Townsend’s Asia Practice Group, focusing on representation of clients based in Taiwan.
Representative Cases
- Bayer Schering Pharma AG, et al. v. Watson Pharmaceuticals, Inc., et al., District of Nevada: Counsel for Watson in Hatch-Waxman ANDA litigation regarding competing branded oral contraceptive, YAZ®.
- Duramed Pharmaceuticals, Inc. v. Watson Laboratories, Inc., District of Nevada: Counsel for Watson in Hatch-Waxman ANDA litigation regarding competing branded oral contraceptive, SEASONIQUE®.
- PDL BioPharma, Inc. v. Sun Pharmaceutical Indus. Ltd., District of New Jersey and Eastern District of Michigan: Counsel for PDL in Hatch-Waxman ANDA patent infringement action arising out of Sun’s submission of an ANDA referencing PDL’s branded product CARDENE® I.V., an intravenous calcium channel blocker for treatment of hypertension. PDL's motion to stay case in the Eastern District of Michigan was granted. Plaintiff’s cross motion for summary judgment of infringement was granted in the District of New Jersey. Case dismissed after the expiration of the patent-at-issue.
- TronTech Licensing Incorporated v. Epson America Inc. et al., Eastern District of Texas: Counsel for Epson America in patent infringement action involving a patent related to printer/copier technology.
- Infinity Computer Products, Inc. v. Brother International Corporation et al., Eastern District of Pennsylvania: Counsel for Epson America in patent infringement action involving patents related to facsimile machine technology.
- Infineon Technologies AG, et al v. Fairchild Semiconductor International Inc. et al., District of Delaware: Counsel for Fairchild in patent infringement action involving fifteen patents related to the design and fabrication of power semiconductor devices.
- Trade secrets case involving high technology silicon materials: Successfully second-chaired two-week arbitration in defense of an ex-employee.
- Avocet Sports Technology, Inc., et al v. Amer Sports Corporation, et al., Northern District of California: Counsel for Amer Sports in patent infringement case regarding altimeter technology.
- Tofasco of America, Inc. v. Atico International, U.S.A., Inc., et al., Central District of California: Defense counsel for Williams-Sonoma, Inc., in patent infringement suit involving folding chair hinge technology. The case settled favorably.
- Zappos.com v. Charles E. Hill & Assoc., Inc., Southern District of Indiana and Eastern District of Texas: Counsel for Zappos.com in declaratory judgment and patent infringement actions involving technology related to electronic catalog systems. Successfully opposed Charles E. Hill's attempt to transfer the case to the Eastern District of Texas. The case then settled favorably.
- MicroUnity Systems Engineering, Inc. v. Advanced Micro Devices, Inc., Eastern District of Texas: Counsel for MicroUnity in patent infringement suit involving twelve MicroUnity patents related to processor technology. The case settled favorably.
- Rambus Inc. v. Hynix Semiconductor Int’l et al. and related cases, Northern District of California: Represented Hynix in patent infringement and unfair competition case related to computer memory (DRAM) technology.
- Strauss, et al. v. Horton, et al. (2009): Pro bono counsel for clergy and their congregations. Filed an amicus brief before the California Supreme Court in support of the petitioners against Proposition 8.
- Pro bono asylum case (2007): Successfully represented HIV+ transgender Mexican woman in removal proceedings before the San Francisco Immigration Court.