Eileen McMahon > Torys > Toronto, Canada > Lawyer Profile


Work Department

Intellectual Property


Eileen’s market-leading experience, practical advice and industry insight in intellectual property and regulatory law make her a go-to advisor for clients in Canada and the United States.

Chair of Torys’ Intellectual Property and Food and Drug Regulatory practices, Eileen is one of a handful of Canadian lawyers who advise on regulatory clearance and intellectual property protection of products. Across sectors—including life sciences, agribusiness, regenerative medicine and stem cells, cannabis and more—Eileen helps clients identify IP and regulatory assets, obtain and maintain market exclusivity, exploit IP assets and enforce their IP rights.

Eileen is a registered patent and trademark agent in the United States and Canada and is adroit at navigating the issues at play in cross-border matters. She is also a Certified Licensing Professional of the Licensing Executive Society (LES) (2011-2014), United States and Canada. This certification is issued only to persons who have met the requirements for licensing professionals, established by CLP, Inc., under the guidance of the LES. Fewer than 1% of all attorneys have this certification, making Eileen a specialized resource for clients.


Ontario Bar, 1987


Eileen is a co-leader of a healthcare licensing course accredited by the Canadian Healthcare Licensing Association and endorsed by the Toronto Biotechnology Initiative on licensing and strategic alliances in the healthcare industry.

As one of Canada’s Top 100 Most Powerful Women (Women’s Executive Network), Eileen participates in the Wisdom II Mentoring Program, which matches Canada’s Top 100 award winners with young women from across Canada for mentoring.

Lawyer Rankings

Canada > Cannabis

Torys draws on 16 years of experience working with the cannabis industry, providing advice to banks, pension funds and blue-chip companies, as well as advising licensed producers. It offers significant M&A and capital markets expertise, advising on multiple consolidating acquisitions, IPOs and follow-on offerings. Much of this is thanks to the firm’s full-service New York office, which offers high-end cross-border advice. It also has a key focus on medical cannabis, where it covers both regulatory and transactional matters. Eileen McMahon and Cheryl Reicin jointly lead the team from Toronto, focusing on transactional and cannabis-related pharmaceutical issues, respectively. Teresa Reguly is also noteworthy for her IP, advertising and marketing work on behalf of cannabis growers, and Frazer House is known for his corporate law work.

Canada > Intellectual property

(Leading individuals)

Eileen McMahonTorys

The Toronto-based IP team at Torys concentrates on lifecycle management for its clients products, providing guidance on potential loss of market exclusivity and responding to IP disputes. One standout recent matter saw IP group chair Eileen McMahon and head of IP litigation Andrew Shaughnessy acting for Horizon Therapeutics in proceedings before the Patented Medicine Prices Review Board concerning allegations of excessive pricing. Andrew Bernstein has extensive litigation experience across all facets of IP, while on the transactional side, coordinator of the group, Edward Fan, is the key contact, honing his focus on the acquisition, exploitation and enforcement of IP. Teresa Reguly is particularly formidable in the biotechnology and medical device industries, and from a strong all-women pool of junior lawyers, counsels Nicole Mantini and Yolande Dufresne are particularly integral to the practice; the former due to her prominent reputation among North American and international pharmaceutical companies and the latter owing to her risk management and regulatory capabilities..