Partner, Patent Attorney Southampton
Profile of Garreth Duncan

I have 25 years' experience in the patent profession, joining D Young & Co in 2007 and becoming a partner in 2011. Before I arrived at the firm, I worked in private practice as well as an in-house attorney at Pfizer – my experience taking in both their European and US patent departments.

My area of expertise embraces all chemical subject-matter including pharmaceuticals, agricultural chemistry, food chemistry, and petrochemicals, as well as chemical synthesis and processes. I have particular experience in pharmaceutical patenting, encompassing new active substances, formulations, combination therapies, new medical indications, and manufacturing processes. My work embraces drafting new applications as well as UK, EPO and worldwide prosecution, EPO oppositions and appeals, and validity and freedom to operate opinions.

I have specialist experience in obtaining supplementary protection certificates (SPCs) and other forms of patent term extension, advising clients on SPC strategies and filing and prosecuting SPC portfolios throughout Europe on a number of important marketed pharmaceutical and plant protection products. I also have experience advising on regulatory-based protection for pharmaceuticals.

I act for a broad spectrum of clients, from multinationals and up-and-coming life sciences companies through to universities, spin-out and start-up companies.

I have spoken at a variety of conferences on life sciences IP, and in particular on SPCs. I am vice-chair of the Intellectual Property Owners Association (IPO) Pharmaceuticals & Biotechnology Issues committee.


Managing IP IPSTAR 2022.


  • MChem in Chemistry, St Anne’s College, University of Oxford.
  • Research project on free-radical routes to novel alkaloids.
  • Certificate in Intellectual Property Law, Queen Mary, University of London
  • European Patent Attorney 2002.
  • Chartered Patent Attorney 2005.
  • Chartered Chemist.


  • Chartered Institute of Patent Attorneys (CIPA).
  • European Patent Institute (epi).
  • Intellectual Property Owners Association (IPO).
  • Royal Society of Chemistry (RSC).
Garreth Duncan specialises in life sciences and is notably strong in obtaining supplementary protection certificates.
Legal 500
Managing IP IPSTAR 2020
IP Stars (Managing IP)
Experienced European patent attorney.
IP Stars (Managing IP)
Garreth Duncan provides “dynamic and pragmatic advice”, especially concerning SPCs and other patent term extensions; his in-house stint at Pfizer demonstrates his outstanding industry connections.
IP Stars (Managing IP)
Garreth Duncan has an assured command of the food chemistry, petrochemicals and polymer chemistry fields; obtaining SPCs is a speciality.
IAM Patent 1000
Recommended senior patent attorney.
IP Stars (Managing IP)
Key player on the biotechnology, chemistry and pharmaceuticals side.
Legal 500.
Duncan has broad horizons, having previously worked in Pfizer’s European and US patent departments, and a knack for obtaining SPCs.
IAM Patent 1000
They [Aylsa Williams and Garreth Duncan] make an invaluable team and provide a wonderful experience for rights holders. They’re collaborative and bring a lot to the table – it’s clear how committed they are. Clients feel like they have 24/7 access to them, with regular in-person meetings and video conferencing.
IAM Patent 1000
Garreth Duncan matches incisive SPC knowledge with "attention to detail, advocacy for clients' positions, thoughtfulness and a willingness to embrace creative solutions".
IAM Patent 1000
A trusted partner who can be relied upon for his technical expertise.
IAM Patent 1000
Exceptionally knowledgeable.
IAM Patent 1000
Those seeking counsel on SPCs need look no further than Kirk Gallagher and Garreth Duncan.
IAM Patent 1000
Recommended by Legal 500 2020
Legal 500
Garreth Duncan's stint at Pfizer has endowed him with first-hand insight into the pharmaceutical sector – and in particular the commercial importance of SPCs and how best to obtain them.
IAM Patent 1000
IP Star 2019/20: recognising top practitioners in private practice who have performed exceptionally for their clients and firms in the past year.
IP Stars (Managing IP)
Really adds value to cases and is a pleasure to work with.
IAM Patent 1000
Patrons marvel at the quality and cost effectiveness of the services provided by the eminently qualified Duncan.
IAM Patent 1000