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Tom is a Partner in our Life Sciences and Chemistry group specialising in biotechnology, therapeutics and diagnostics. Described by clients as an “antibody expert” (IAM Patent 1000, 2020 edition) who is “at the top of his game in terms of both technical ability and client service, providing fantastic strategic advice for almost any project” (IAM Patent 1000, 2021 edition), Tom’s experience also includes machine learning and digital health, chemotherapy, biomarkers and infectious diseases. His practice is also strong in the areas of vaccines, liquid biopsies, next generation sequencing and new uses for known compounds.
Freedom-to-operate opinions and due diligence form a significant part of Tom’s practice, and he is experienced in helping business maximise the value of their IP when seeking to collaborate, to develop products or to sell their portfolio. With a reputation for getting difficult patents granted, Tom is accomplished at representing his clients at oral proceedings and he relishes the opportunity to represent his clients in EPO oppositions and appeals. Tom is cited by a client in the 2017 edition of Managing IP, IP Stars Handbook, as “one of the best advocates I have worked with in my 20 years of practice,” who adds, “[his] logical and concise arguments are perfectly tailored to what [IP offices] need to see to make proper decisions”. 
Many of Tom’s clients are UK start-ups, for whom Tom devises and implements an IP strategy to maximise the company’s value in the early stages of development. Several of his clients have been purchased for hundreds of millions of dollars, with Tom guiding them through not only the patent drafting and filing process, but also the freedom-to-operate and due diligence exercises required to complete these deals.

His legal expertise has seen him lecture for the AIPLA, the Centre for Commercial Law Studies and at various conferences, and he also leads tutorials on European patent law to students studying for the European Qualifying Examinations. Tom is also happy to provide comments to journalists on the latest legal developments.

As part of the industry’s IP Inclusive initiative, Tom is co-chair of IP Out, the support and networking group for LGBT people working in IP.

Tom attended Christ's College, University of Cambridge, where in 2004 he graduated with a BA honours degree in Natural Sciences (Pharmacology). He also undertook an additional part II in Management Studies, which included a management consultancy project at Cambridge Antibody Technology (as it was then), and a master’s in Musical Theatre, which somehow he stills finds time for through his involvement in Sedos, London’s premier amateur theatre company.

'Notable Practitioner' for Patents - Managing IP, IP Stars, 2024

Tom Leonard is a tremendous patent attorney who completely engages his audience at opposition and appeals proceedings at the EPO.” He presents his arguments clearly and persuasively, and has an excellent track record of success. Recently Leonard has been representing long-term patron Zogenix in two opposition proceedings filed by Teva, and has secured favourable results in each. - IAM Patent 1000, 2024

"Tom is a superb attorney and his attention to detail is second to none. He is always available day and night and is a technical expert. Tom is first-class in the biopharm space, extremely diligent and very hardworking. He is also friendly, emotionally intelligent and highly considerate of others." - IAM Patent 1000, 2023

"Leonard is an antibody expert with a fast-growing practice, which sees him advise on extremely high-value products in an increasingly relevant area." - IAM Patent 1000, 2022 

'Recommended' in IAM Patent 1000 2021 edition.

Antibody specialist Tom Leonard “picks matters up very quickly and will always go out of his way to assist, even at very short notice”. - IAM Patent 1000, 2020

“One of the best advocates I have worked with in my 20 years of practice” – Managing IP, IP Stars Handbook 2017


European Patent Attorney (2010)
Chartered UK Patent Attorney (2010)
​Representative before the Unified Patent Court (UPC) (2023)
IP Litigator - Patent
Design Attorney (2010)
Foreign Legal Consultant (FLC) – State Bar of California
Queen Mary Certificate in IP (2008)
MA Musical Theatre Performance, Mountview Academy of Performing Arts (2006)
BA Natural Sciences (Pharmacology), University of Cambridge (2004) with an additional Part II in Management Studies (2005)


​Chartered Institute of Patent Attorneys (CIPA)
The Institute of Professional Representatives before the European Patent Office (EPI)

“Antibody Patents: How to maximise value in Europe and beyond”, online seminar presenter (August 2020)

EPO Enlarged Board of Appeal Decision G 3/19 and the patentability of plant and animal products in Europe, Kilburn & Strode, (2020) 

Second medical uses at the EPO, Kilburn & Strode, (2020) 

Regeneron v Kymab and the effect of claim scope on the requirement of sufficiency of disclosure, Kilburn & Strode (2020) 

The worldwide pharma response to coronavirus – Part 2: Promising leads, Kilburn & Strode, (2020) 

Too big to pay – has Shanks v Unilever changed the way the courts interpret ‘outstanding benefit’?
Kilburn & Strode, (2019)

Why LGBTQAI+ pride is important, Kilburn & Strode, (2019)

The SPC manufacturing waiver enters into force, Kilburn & Strode (2019) 

SPC manufacturing waiver adopted by European Parliament, Kilburn & Strode (2019) 

Protecting the protector: The intersection of IP and Immuno-Oncology, Kilburn & Strode (2019) 

‘Antibody workshop’, Speaker at C5 Life Sciences IP Summit (October 2016)

‘Biotech patenting workshop’, Speaker at C5 Life Sciences IP Summit (October 2015)

‘Freedom-to-operate workshop’, Speaker at C5 Life Sciences IP Summit (October 2014)

‘A ray of hope for embryonic stem cell patents in Europe; and the 4 things you need to know’, Patently-O (August 2014) 

‘G3/14: In Pursuit of Clarity’, CIPA Journal, Vol. 43, No. 7, pp 393-394 (July 2014)

‘European Patent Law at 19th Annual AIPLA PCT Seminar’, Speaker, Denver, CO & Arlington (July 2014)

‘What is central limitation and why is it useful?’, Kilburn & Strode Publication (June 2014)

‘Refunds on search fees by the EPO’, Kilburn & Strode Publication (May 2014)

‘Filing divisional applications at the EPO – FAQs’, Kilburn & Strode Publication (April 2014) 

‘Patent exhaustion – at what level should this be assessed?’, Kilburn & Strode Publication, (2014)

‘Divisional deadline practice at the EPO to be reversed’, Kilburn & Strode Publication, (2013),

‘Virgin v. Zodiac: the end of the Unilin principle’, Kilburn & Strode Publication, (2013),

‘European Patent Law’, 18th Annual AIPLA PCT Seminar, Speaker, Minneapolis, MN & Alexandria, VA (2013)

"Supreme Court follows EPO Technical Board of Appeal: a sign of things to come?", Human Genome Science Inc v Eli Lilly and Company [2011] UKSC 51, United Kingdom Supreme Court, 2 November 2011 (on appeal from [2010] EWCA Civ 33), Journal of Intellectual Property Law & Practice, 2012, Vol. 7, No. 3, pp 150-151