Katherine Green

Katherine specialises in EPO oppositions and appeals and particularly enjoys working in teams to defend patents in complex cases involving very large numbers of opponents.  

Katherine advises on European prosecution strategies for strategically important patent families, particularly divisional strategies for opposed patents. Katherine advised on securing grant in Europe for the very high-profile family of patent cases protecting the CRISPR/Cas platform technology invented by Jennifer Doudna and Emmanuelle Charpentier. 

Areas of Expertise

• CRISPR/Cas
• Gene therapy, AAV
• Purification and formulation techniques for biological therapeutics, particularly recombinant antibodies
• Recombinant antibody engineering
• Therapeutic use claims at the EPO – modes of administration, dosage regimens

Opposition Highlights

Katherine regularly leads teams and represents clients at large scale, high profile and complex opposition hearings at the EPO, for example: 

• EP3570884 - Roche vs four opponents - Defence of a patent for the ground-breaking product Phesgo® in which all four oppositions were rejected by the Opposition Division and the patent maintained as granted.
• EP2188302 - Genentech vs eleven opponents - Defence of a bioprocessing patent before the Opposition Division in one of the longest ever EPO hearings, taking 8 days, at the end of which the patent was maintained as requested by Genentech.
• EP1324776, T99/13 - Genentech and Novartis vs eleven opponents - Defence of formulation patent for Xolair®, the Board of Appeal decision for which is now cited in both the EPO book of case law and the EPO Guidelines for Examination on the issue of added matter (issue decided in favour of Genentech and Novartis).

Other cases include defending and opposing patents in diverse technical fields including:

• Bioprocessing;

  • Chromatography (EP3257564, T900/21; EP2480561, T314/19)

  • Viral filtration (EP2462158, T1108/22)

  • Cell culture (EP3227454,  T1136/23)

• AAV gene therapy (EP2678435)
• Respiratory disease therapy (EP2970468)
• Cancer therapy (EP1383532, T975/14; EP2238172, T358/22)
• Ophthalmology;

  • Retinal prosthesis (EP1061996, T794/08)

  • Treatment for the inherited retinal degeneration choroideremia (EP2678435)

• Bispecific antibodies (EP1940881, T1875/19; EP2155783, T2589/16)
• Subcutaneous administration of known therapeutics (EP3570884; EP3177645)
• Bacterial transformation methods for preparing mutant libraries (EP1309677)

Background

Katherine has a degree in Biochemistry and Molecular Biology from the University of Cambridge and graduated with the top mark that year.

Katherine also completed a PhD at the University of Cambridge, based in the Medical Research Council’s Mitochondrial Biology Unit.  Her doctoral project was on the efficiency of mitochondrial ATP synthesis – which is implicated in phenomena as diverse as aging, obesity, pancreatic glucose sensitivity, and thermogenesis in baby penguins.

Katherine joined Mewburn Ellis in 2006, became a Chartered Patent Attorney and European Patent Attorney in 2010, and joined the partnership in 2014.

Recommendations

Katherine’s work advising UC Berkeley, California on their European and UK applications for CRISPR/Cas gene editing technology was noted in Legal 500 2018. She was also recognised as a 'Key Lawyer' in Legal 500 2021 and 2022.

"Katherine Green is very dedicated to deliver the best possible position for her clients. She can dig into every detail but keeps the big picture at the same time – very impressive!" - The Legal 500, 2022

Katherine is a Recommended Individual in IAM 1000 2025

Katherine is also a Recommended Individual in Juve Patent 2025