About William J. Mostyn
William J. Mostyn IV combined science and law early in his career. He earned a B.A. in biochemistry and pre-medicine from Ohio Wesleyan University in 1999, followed by an M.A. in medical sciences from Boston University in 2004. He completed his J.D. at Northeastern University School of Law in 2010. Those academic choices set a clear path toward intellectual property work in the life sciences.
Before law school he worked in laboratories and clinical research. He was a chemist at Cytosol Laboratories in 2003 and later served as a clinical research coordinator at Boston Medical Center in 2005. That hands-on laboratory and clinical experience informed his later patent practice. It also provided technical grounding for counseling scientists and companies on intellectual property matters.
Mostyn’s legal career began after law school. He opened a solo practice, the Law Office of William J. Mostyn, in 2010 and soon took on contract work for industry, including a patent role at Genzyme Corporation in 2011. Later that year he joined Cesari and McKenna LLP as an associate. Those early years combined private practice and in-house contract work, giving him experience on both client-facing matters and larger corporate projects.
In 2016 he founded Mostyn IP, LLC, the firm he runs today. He is registered to practice before the United States Patent and Trademark Office and maintains membership in the Massachusetts bar. He is also active in local professional groups, holding membership in the Boston Patent Law Association since 2011 and the Boston Bar Association since 2010. Those affiliations reflect steady engagement with the local patent and legal communities.
Mostyn’s practice draws directly on his scientific background. He handles patent prosecution and prepares patent applications for inventions in biotechnology and related fields. His work includes drafting claims, responding to office actions, and advising clients on patentability questions. He represents individuals, start-ups and companies that develop medical and biochemical innovations.
Colleagues and clients describe him as methodical and practical in approach. He tends to emphasize technical clarity in filings and aims for precise claim language. He balances the procedural demands of patent prosecution against the technical realities of laboratory work.
Today he leads Mostyn IP, LLC from his office in Massachusetts, continuing to represent inventors and companies before the USPTO and state authorities. He concentrates on patent prosecution and IP counseling for life sciences and biotech clients.
