Experts and skilled addressee come to the fore in UK Patents Court Eloxatin decision
Mayne Pharma v Debiopharm SA & Sanofi-Synthélabo [2006] EWHC 1123 (Pat)
Copyright Monday, May 22, 2006 Duncan Bucknell Company
On 19 May 2006, Mr Justice Pumfrey of the UK High Court (Patents Court) handed down his decision in Mayne Pharma v Debiopharm SA & Sanofi-Synthélabo [2006] EWHC 1123 (Pat).
Take home
Mayne Pharma had sought revocation and declarations of non-infringement in relation to EP0943331 and EP1308454 owned by Sanofi and Debiopharm respectively. Both patents were held not-infringed and revoked. An important aspect of the case was the nature of the skilled addressee of the patents and the testimony given by expert witnesses for each side.
Comment
As is always the case, the nature of the skilled addressee was largely driven by the associated common general knowledge that they would bring to the construction and validity of the relevant patents.
Naturally, Sanofi argued that the skilled addressee was a general organometallic chemist, while Mayne argued that the addressee had at least knowledge of other platinum-based anti-cancer compounds.
Mr Justice Pumfrey commented:
‘…this is one of those cases where it is important to bear in mind that those primarily interested in the invention will be employees of pharmaceutical companies interested in improving, or making for the first time, pharmaceutical compositions containing oxaliplatin…’
“…It is not sensible not to attribute to the skilled person the common general knowledge of those presently engaged in the manufacture and formulation of platinum-based pharmaceuticals.”
As a result, Mr Justice Pumfrey held that Mayne’s characterization of the skilled addressee was correct and proceeded on the basis that Mayne’s expert was well qualified to give evidence on the perspective of such a person. In contrast, Mr Justice Pumfrey appears to have been unimpressed by the testimony of Sanofi’s leading expert and stated in relation to one contention about the obviousness of EP ’454 — ‘I remain surprised and unconvinced by the contention he advanced,…’
Mr Justice Pumfrey repeated several sizeable sections of the expert’s cross-examination transcript in the judgment to explain his conclusions.
Background
The patent dispute relates to Sanofi-Aventis’ leading oncology drug - Eloxatin® (Oxaliplatin).
Mayne had originally sought revocation and declarations of non-infringement of ten patents. By the time that evidence was exchanged, the scope of the dispute had narrowed to four patents, and in respect of two of those Sanofi declined to file any evidence. Consequently, the issues of infringement and validity were to be decided by Mr Justice Pumfrey in respect of EP(UK) 0943331 (“’331”) and EP(UK) 1308454 (“’454”).
It became apparent during the trial that it would be difficult for Sanofi to maintain the allegation of infringement in relation to the ‘331 patent and it was formally withdrawn. Accordingly, the judgment deals with the validity of ’331 and with both infringement and validity of ’454.
