Eric Zylstra, Ph.D., is an associate whose practice focuses on patent prosecution and counseling, including opinion writing, due diligence, and patent portfolio strategy, working primarily in the chemical and pharmaceutical sciences. His technology experience includes small molecules, pharmaceutical and agricultural formulations, dyes, and fuel cells. Before joining the firm as a student associate, he worked as a technical advisor, patent agent, and student associate at Townsend and Townsend and Crew.

Dr. Zylstra’s technical experience includes total synthesis of natural products, organic methodology, solid-and solution-phase parallel synthesis and polymer chemistry. He was a senior scientist at Discovery Partners International (previously known as ChemRx and Axys Advanced Technologies) where his area of research was synthetic and medicinal chemistry for early-stage drug discovery. He was also a postdoctoral research scientist for the Pharmaceutical Science Department at the University of Tokyo, where his area of research was total synthesis of natural products.


Represented Prometheus Laboratories, Inc. owner of an Orange Book listed branded drug, Lotronex (alosetron hydrochloride), indicated for women with severe Irritable Bowel Syndrome. Prometheus Labs bought the franchise from GSK several years ago, however US Patent No. 6,284,770 drawn to a method for treatment was not listed in the Orange Book. A reexamination strategy was devised to ensure patentability of the claims that covered the indication. After an initial PTO action denying the reexamination request, a petition was filed citing further relevant facts. Thereafter, the petition was granted. After successful prosecution of amended claims, a reexamination certificate issued providing valid patent coverage for Lotronex. The reexamined patent is now listed in the Orange Book.


University of San Francisco School of Law, J.D. magna cum laude, Certificate in Intellectual Property with Honors

University of California, Berkeley, Ph.D., Synthetic Chemistry

Massachusetts Institute of Technology, S.B. Double Major in Chemistry and Literature


California (2013)

Illinois (2018)

Court Admissions

U.S. Patent and Trademark Office (2007)

Professional & Community Activities

American Chemical Society, Member (1992-Present)

American Association of Intellectual Property Law, Member (2009-Present)

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