David Lethem

David Lethem has worked in the patent attorney profession for 40 years. He joined HOFFMANN EITLE in 1987 when he helped found our London Office as its first chemist. A year later he became a dual qualified Chartered Patent Attorney and European Patent Attorney.

David was a partner from 1994 to 2020 during which period HOFFMANN EITLE underwent a major expansion in terms of its size and number of Offices. He was responsible for the supervision of all paralegal work in the London Office and coordinated its GB tax affairs. He retired from the partnership in 2021 and now works as a consultant.

David is proud of having trained 5 technical assistants through to full qualification and, in this way, contributed to the firm’s growth and that of the patent profession generally. His approach to training is, together with the trainee, to subject a file to fine-tooth comb analysis to inculcate the critical attorney skill of identifying, in a morass of facts and information, the key point or points on which the case can be successfully argued. It is only with experience and after handling many, many files that this becomes second nature.

As lead advocate in many hundreds of successful inter partes Oral Hearings before the Opposition Divisions and Appeal Boards of the EPO, he believes in over-preparation and under-pleading. The former means that no one in the Hearing room should be more familiar with the critical case facts than the advocate. The latter means that the advocate’s pleadings should focus on the strengths of his/her case and the weaknesses of the adversary’s case to the exclusion of everything else. He has witnessed numerous times adversary advocates lose perfectly winnable cases because either they were unable to appropriately marshal the key facts or presented unfocussed pleadings discussing both strong and weak points with equal vigour.

Now with some spare time, David enjoys long rambles in the Chilterns with his schnauzer, Monty, and dipping into his cellar of Burgundy wines.