Cameron Marshall

Cameron focuses exclusively on the biotechnology and pharmaceutical fields, with an extensive EPO opposition practice (including many cases defending against multiple opponents) that runs alongside a large prosecution practice. These two areas often overlap, so strategic prosecution and parent/divisional strategies are a regular part of his workload. He is often engaged to advise clients at an early stage, in situations where future patent fights with competitors are inevitable.

Cameron acts for biotech companies including Guardant Health and Mammoth Biosciences, but most of his time is spent acting for blue-chip pharmaceutical companies, including Novartis, Merck, Gilead, and Lilly. This work includes defending patents covering blockbuster products which have attracted numerous EPO oppositions, whether from traditional generics companies or from biosimilars. He often acts as lead counsel at the EPO, but also collaborates with other firms to provide a second pair of eyes, and frequently plays a support role for national litigations. His expertise means that he has also been in demand as a UPC representative, acting for Novartis and Curio in two high profile UPC disputes.

Cameron has over 25 years of experience of inter partes proceedings at the EPO, both defending and attacking, and he is one of only a handful of attorneys to have represented a patentee in an EPO opposition (and subsequent appeal) involving more than 15 opponents. This experience means that he is often engaged to defend patents which provide crucial protection and exclusivity for blockbuster pharmaceuticals and biologics, including patents on new medical uses, dosing regimens, and formulations. In addition to that work, though, he also handles biotech innovations and has recently been defending Guardant’s groundbreaking work on liquid biopsy against several opponents. His biotech work goes back a long way, and he defended the “Southern” patents on DNA microarrays and spent two decades working on the inventions underpinning lifesaving meningococcal vaccines.

Cited as “an exceptional attorney” (Chambers UK, 2025), the main independent guides to the legal profession regularly rank Cameron at the top of his field. Sources say, “Cameron provides well-reasoned strategic advice and has an outstanding ability to argue cases”…”[He] works on critical cases and he is especially impressive in oppositions”…and “consistently delivers solid results.” Chambers UK, 2025.

He is recognised as a “highly experienced litigator” (JUVE 2023) with “great business acumen and a strategic mind” (Chambers & Partners).

As well as advising on patent matters, he was a tutor for several years on the JDD residential course preparing candidates for the EQE opposition paper, and was an advisor to the IP monitoring group of the UK Government’s Human Genetics Commission.

Cameron graduated from the University of Oxford where his work on the folding thermodynamics of fibronectin type III modules was awarded the university research prize and contributed to his first class degree.